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Tuesday, 30 June 2015

Ardeola June 2015 : Volume 62 Issue 1 - Abstracts

Ardeola

Published by: Spanish Society of Ornithology / BirdLife



Table of Contents
June 2015 : Volume 62 Issue 1

LINK

ARTICLES 

Long-Term Changes in Mountain Passerine Bird Communities in the Sierra Nevada (Southern Spain): A 30-Year Case Study
Regino Zamora and José Miguel Barea-Azcón

Abstract
Shifts in composition and abundance of bird communities were studied along an elevational gradient in the Sierra Nevada (S. Spain), comparing censuses made at the same locations in the 1980s and during 2008–2012. Censuses were made in three representative ecosystems: 1) Pyrenean oak woodland, 2) high-mountain juniper scrubland, 3) high-mountain summits. In a global change context, avian-community dynamics are related mainly to changes in two of the following drivers: climate change and land-use change occurring over the past 30 years. Our results show a continuous turnover of the bird community, with an overall 27% change in species composition, in an ecological setting that has changed little, especially in the high-mountain scrubland and summit areas. We detected an increase in species diversity relative to the 1980s, mostly in the Pyrenean oak woodland. Moreover, our results also show a sharp decrease in bird density during the 30-year study period, chiefly affecting the dominant species of the 1980s in the Pyrenean oak forest and in the high-mountain scrubland. In the high-summit ecosystems, the decline of alpine species has paralleled the uphill expansion of some mediterranean ones. The outcome of these processes is a community in continuous flux, both in composition and abundance, where interannual variability is similar to interdecadal variability. We conclude that the bird communities of Sierra Nevada are showing strong spatial and temporal dynamics that are now accelerating, perhaps because of global warming.


Moult and Morphometrics of the Pallid Swift Apus pallidus in Northwestern Italy
Giovanni Boano, Irene Pellegrino and Marco Cucco

Abstract
We examined moult patterns and body morphometry of pallid swifts at two locations in NW Italy, by sampling 352 birds at their nests from July through October over a 20-year period. Birds were sexed by behaviour at the nest. We found no sexual dimorphism in 8th primary length, tail length, depth of the tail fork, rectrices T5–T4 tip delta length or body mass. We found a significant difference between the sexes in wing length (females mean: 174.7 mm, range 169–184; males: 177.0 mm, range 169–191), but because of extensive overlap it cannot be used to determine the sex of most individuals. Measurements of birds recaptured in following years did not differ with increasing age. Birds began the moult in July. Moult was estimated to last about five months, from July until November–December, and was not completed on our study sites. Females and males did not differ in the timing and progression of the moult during the season. About one-third of individuals did not replace the 9th or 10th (outermost) primary, with a complex pattern of retention and substitution in sequence year after year. The overlap of breeding season and moult in this population appears to be higher than that reported for two other Italian swifts and is similar to that found in tropical swift species.


Influence of Landscape and Field-Level Agricultural Management on a Mediterranean Farmland Winter Bird Community
Manuel B. Morales, Juan J. Oñate, Irene Guerrero and Leandro Meléndez

Abstract
We studied the response to agricultural management factors of birds wintering in an unirrigated cereal farmland area of central Spain, examining the influence on species richness, abundance and community composition of different field-level and landscape-level agricultural management variables related to intensification. Our initial hypothesis was that landscape-level management factors exert a stronger effect on wintering bird species richness, total abundance and community composition than field-level ones. The particular responses of the most frequent species (skylark Alauda arvensis, corn bunting Emberiza calandra and meadow pipit Anthus pratensis) were also examined. Richer assemblages were found in more substrate-diverse plots with natural vegetation patches or in plots with higher yield crops, while the more abundant ones, dominated by the skylark, occupied more homogeneous areas dominated by cereals and arable land. As expected, landscape-level management factors explained a much greater proportion of variance in community composition compared to field-level factors (71% vs 29%, respectively). Species richness per se was favoured by substratediverse plots containing patches of natural vegetation, but also by plots where cereal crops were more productive in the previous harvest, declining in more homogeneous plots dominated by cereal crops and arable land in general. Conversely, skylark abundance and total abundance increased as landscapes became more homogeneous and dominated by cereals and arable land, although the relationship for total abundance only approached significance. Results suggest that the current landscape structure and levels of agricultural production of cereal farmland in central Spain can host relatively abundant winter populations of seed-eating and open landscape specialists like the skylark, although certain levels of habitat diversity need to be guaranteed to ensure the maintenance of rich wintering bird communities.


The Incidence of Clutch Replacements in the Pied Flycatcher Ficedula hypoleuca is Related to Nest-Box Availability: Evidence of Female-Female Competition?
Juan Moreno

Abstract
Clutch destruction and replacement are sometimes observed during studies of cavitynesting birds. This could be due to abandonment by the first female to lay, with subsequent replacement by another female, or to male infanticide. Clutch replacement is accompanied in some cases by evidence of aggressive competition between females and of destruction of eggs/hatchlings immediately prior to a new clutch being laid. This may indicate that clutch replacements are in fact nest take-overs by females after eviction of incumbent females. In the course of long-term studies of pied flycatchers Ficedula hypoleuca iberiae in central Spain, I have found evidence of clutch destruction through egg burial and ejection and replacement during laying or incubation, as well as of female-female aggression. No male involvement has been detected. Clutch replacements occur with a frequency that depends on the density of available nest-boxes and is positively associated with the rate of nest-box occupation by the same or other species. Moreover, clutch replacements can be accompanied by female wounds or death and involve clutch destruction in all cases. Putative replacers within the area of highest occupation frequently display the white forehead patch that is more typical of males, which may thus be associated with social dominance in females in Iberian populations. Clutch replacements in cavity-nesters should be studied in detail to confirm whether they represent cases of nest take-overs by competing females.


Ecological Modelling of the Distribution of the Lanner Falcon Falco biarmicus feldeggii in Sicily at Two Spatial Scales
Massimiliano Di Vittorio, Andrea Ciaccio, Salvatore Grenci and Luca Luiselli

Abstract
The presence of the lanner falcon Falco biarmicus feldeggi in Sicily was modelled by generalized linear models using climatic, topographic, ecological and land-use variables at both the landscape (UTM cells of 10 × 10 km) and the home range (12.56 km2) spatial scales. At the landscape scale, a significant spatial autocorrelation of the lanner population, corresponding to the longitudinal distribution of sites, was found, with the species occurring within the most xeric UTM cells. There was also a negative relationship between falcon presence and potential evapo-transpiration values, either in the coldest months or throughout the year. The same negative relationship was also seen with the surfaces of CORINE artificial areas, thus showing that the species has a low tolerance to any anthropogenic landscape. At home range scale, our predictive models revealed a preference for territories with steep slopes surrounded by natural grassland, sclerophyll vegetation, arable land and agricultural land. The lack of spatial correlation and the identification of specific preferred land use classes, suggests that the home range scale is more appropriate than the landscape scale for predicting the occurrence of lanner falcons. The maintenance of a stable lanner falcon population in Sicily should be addressed at both small and large scales.


Migration Patterns of Iberian Little Bustards Tetrax tetrax
Eladio L. García de Lamorena, Manuel B. Morales, Gerard Bota, Joao Paulo Silva, Anna Ponjoan, Francisco Suárez, Santiago Mañosa and Eduardo De Juana

Abstract
The term “migratory” refers to animals performing yearly round-trips between breeding grounds and post-breeding areas, whereas the term “sedentary” refers to those remaining the whole year in their breeding grounds. However, migration is a complex and varying phenomenon governed by genetic and environmental factors, particularly in species with wide distribution ranges. Here we describe and classify the seasonal movement patterns of 71 little bustards Tetrax tetrax, an endangered Palearctic steppe bird, radio- and satellite-tracked in the Iberian Peninsula. Four major movement patterns were identified, with 89% of little bustards behaving as migrants, among which 75% (summer migrants and summer-winter migrants) performed their first movement after breeding during the summer (mainly between May and July), whereas 14% (winter migrants) left their breeding sites in autumn (mainly between September and November). The remaining 11% were strictly sedentary. On average, summer migration started on June 14th, and winter migration on October 3rd, while pre-breeding migration started on March 23rd. Summer migration occurred in most Iberian regions, although it was mainly found in semiarid Mesomediterranean areas. Winter migration occurred only in the northern half of the Peninsula, being the only pattern found in Subatlantic and highland areas. All winter migrants wintered in Thermomediterranean localities of southern Iberia. The sedentary pattern was found only in the Semiarid Mesomediterranean and Thermomediterranean sectors. This is a good example of complex intraspecific variation in the migratory behaviour of a species that occupies a diverse range of environments. The variability of movement patterns of Iberian little bustards is much greater than previously thought and should be taken into account in conservation programmes for the species.


Nest-Site Selection and Reproductive Success of the Little Grebe Tachybaptus ruficollis in Northeast Algeria
Mohammed Athamnia, Farrah Samraoui, Bilal Kelailia, Ahlem Rouabah, Ahmed H. Alfarhan and Boudjéma Samraoui

Abstract
We studied the phenology, habitat selection, and interannual and seasonal changes in breeding performance of the little grebe Tachybaptus ruficollis in relation to the spatial structure of a shallow lake during three breeding seasons (2010–2012). Nests were mostly located in shallow waters, close to the shore (98.3 ± 37.9 cm), in vegetation dominated by Scirpus lacustris. The egg-laying period started at the end of March and extended for four months until the end of July. Overall, the mean clutch size was 4.7 ± 1.1 (N = 154) with a modal clutch of 5. There was a seasonal decline in both egg volume and clutch size. The overall nesting success was 60% and the chief causes of nest failure were predation (52%) and adverse weather (20%). Breeding outcome was influenced by water depth, nest size and year of breeding. Predation and nest flooding markedly varied between years. Larger nests had a higher nesting success than smaller ones. Likewise, nests located at greater water depth (further from the shore) succeeded better than ones located in shallower water. As the little grebe forages preferentially in shallow waters, these results suggest that optimal nesting locations may be the result of a trade-off between conflicting selection pressures such as foraging efficiency (better in shallow waters) and nest predation risk (greater in shallow waters).


Influence of Nesting Location on Movements and Survival of Juvenile Saker Falcons Falco cherrug During the Post-Fledging Dependence Period 
Md Lutfor Rahman, Nyambayar Batbayar, Gankhuyag Purev-Ochir, Mark Etheridge and Andrew Dixon

Abstract
We used patagial tags, VHF radio transmitters, and satellite-received transmitters to investigate the movements and survival of juvenile saker falcons fledged from artificial nests in open landscapes and natural nest sites in hilly areas in Mongolia. During the post-fledging dependence period (PFDP) juveniles progressively moved farther from their nest until dispersal from the natal area. Natal home ranges were larger for juveniles fledged at artificial than natural sites and the distance moved by juveniles during PFDP was positively related to fledging date and brood size. Duration of the PFDP was estimated as 40 days (range: 31–52 days). Over the PFDP, the best-fitting model to explain juvenile survival incorporated fledging date and nest site type, with juvenile survival being higher in early fledged broods from natural sites. Predation was identified as a major cause of mortality, especially in open landscapes where artificial nests were located. However, because artificial nests produced more fledglings, we found that overall productivity of juveniles to dispersal at artificial and natural nests sites did not differ significantly.


Effect of Age, Colony of Origin and Year on Survival of Yellow-Legged Gulls Larus michahellis in the Bay of Biscay
Leire Juez, Asier Aldalur, Alfredo Herrero, Aitor Galarza and Juan Arizaga

Abstract
We studied sources of variation in apparent local survival of yellow-legged gulls ringed as chicks in a number of colonies with different size trends. Specifically, our aim was to test whether individuals hatched in colonies with decreasing population trends had lower survival rates than those from stable or increasing colonies. From 2006 to 2013, 3,024 chicks were colour-ringed in four colonies along the coast of the Basque Country (from east to west): Ulia, Santa Clara, Guetaria and Izaro. Sighting data of these gulls were compiled from August 2006 to June 2013. Cormack-Jolly-Seber models with mixtures were used to estimate apparent survival (hereafter, survival). Overall, survival differed between two age classes (first-year birds < older birds), colony of origin and in relation to year. The Izaro colony, one of the decreasing colonies, showed the lowest survival rate. However, survival was observed to be reasonably high in another declining colony. Hence we did not find a general link between survival and colony trends. Survival did not seem to be affected by colony size and we did not find evidence supporting a decrease in survival across the study period. More research is needed to disentangle factors explaining variation in local survival in yellow-legged gulls.

FEATURED ARTICLES

Sparrow Plagues in Extremadura (Western Spain) Over Four Centuries (1501–1900): A Spatio-Temporal Analysis of Records From Historical Archives
Luis M. Torres-Vila, Juan J. Ferrero-García, Daniel Martín-Vertedor, Francisco J. Moral-García, Pedro P. Bueno, Juan Morillo-Barragán, Álvaro Sánchez-González and F. Javier Mendiola

Abstract
Some bird species can cause crop damage but the historical variation in the incidence of such events is poorly documented. We analyse the spatio-temporal variation of damage attributed to sparrows (Passer domesticus, P. hispaniolensis and/or P. montanus) at a regional scale in Extremadura (western Spain) over four centuries (1501–1900). Textual data were extracted from historical documentary sources using over 12,000 Books of Accords (Libros de Acuerdos) belonging to 203 municipal archives. Sparrow agricultural damages were estimated from reported actions to control sparrow populations and two simple indices were constructed to analyse the spatial (PIM) and temporal (PIY) variation in sparrow plagues. We used these indices to fit geostatistical models and analyse time curves. We found 251 accords reporting sparrow plagues, distributed across 236 years and involving 47 municipalities. Most of these reports (97.2%) were mandatory impositions (repartimientos) on residents to deliver a certain number of dead sparrows within a fixed period, under penalty of a fine or imprisonment. Results show a significant spatio-temporal variation in sparrow plagues, which we tentatively relate to dynamic environmental and agroecological factors. The spatial index showed high values (PIM > 4) in certain cereal-producing areas, among which La Raya zone located in western Badajoz province was the best example. The temporal index reached maximum values (PIY = 7.3) in the mid 18th century (1741–1770), probably because this was a milder period (within the so-called Little Ice Age) coinciding with increased food availability for birds. In addition, we also examine some sociopolitical, economic and historical features that could have shaped the plague indices. We particularly discuss the normative and legislative developments (e.g. mandatory impositions), the municipal activity itself (affected by wars and other historical events) and the bird conservation interest (which flourished during the final quarter of the 19th century). We conclude that textual data-based indices provide a suitable historical perspective of the agricultural impact of sparrows in Extremadura and of human perceptions of them.

SHORT COMMUNICATIONS

Key Factors Controlling the Metapopulation Dynamics of the Little Grebe Tachybaptus ruficollis in an Artificial Habitat Network of Irrigation Ponds
Esther Sebastián-González, Karen Luisa Alexander, José Antonio Sánchez-Zapata and Francisco Botella

Abstract
Most applied metapopulation studies have focused on habitat structures that are the result of landscape fragmentation but few have studied the dynamics in newly created patches. In artificial habitats, factors determining habitat quality can become especially relevant. Here, we studied the dynamics of linked populations of the little grebe Tachybaptus ruficollis inhabiting a group of irrigation ponds, sited and designed purely for agricultural purposes. We used five years of detection/nondetection data to parametrise incidence function models, in order to analyse the metapopulation dynamics of the species. We aimed to detect the role of pond size, isolation and intrinsic pond characteristics related to the habitat quality (i.e. pond construction design) in determining pond colonisation, extinction and turnover rates. We also used repeated surveys during one year to calculate detection probability of the species in the system. The incidence function model used accurately predicted the proportion of irrigation ponds occupied and detection probability was high (0.88). Little grebes inhabiting the irrigation ponds performed as a metapopulation with extinction events related to pond size and colonisation events related to pond construction design but unaffected by isolation factors. Our simulations highlight the importance of pond construction design in the persistence of the metapopulation and show a simple method for studying the dynamics of a population using detection/non-detection data.


Fledgling Productivity in Relation to Diet Composition of Tengmalm's Owl Aegolius funereus in Central Europe
Markéta Zárybnická, Bohuslav Kloubec, Ján Obuch and Jan Riegert

Abstract
Based on 52 nesting attempts of Tengmalm's owl Aegolius funereus in the Šumava Mountains (South Bohemia, Czech Republic), in habitats comprised mainly of Norway spruce forests, we investigated the relationships between diet composition and fledgling productivity of this owl. We found that (i) owls feed mainly on Sorex shrews (39%), Microtus voles (19%), Apodemus mice (15%), bank voles Myodes glareolus (14%) and birds (6%), (ii) the percentage of Apodemus mice, as well as the percentage of Myodes glareolus, negatively correlated to the percentage of Sorex shrews and birds in the owls' diet, and (iii) the fledgling productivity of the owls positively correlated to the percentage of Apodemus mice in the diet. Finally, (iv) the percentage of Microtus voles, the second most common prey, exhibited no close relationships with other prey groups or fledgling productivity of the owls. These results suggest that Apodemus mice were an important prey in the diet of the Tengmalm's owl in our study area, and support the theory that, compared to their northern counterparts, nocturnal raptors in Central Europe may be less dependent on Microtus voles due to the increased diversity of available prey species.


Phenological Parameters of a Bluethroat Luscinia svecica azuricollis Population Breeding at High Altitude in Spain
Juan Arizaga and Daniel Alonso

Abstract
Bluethroats Luscinia svecica azuricollis breeding in Spain belong to a poorly known endemic subspecies that is restricted to a relatively small distribution range. We aimed to present information on some basic life-history parameters from a population breeding at high altitude in central Spain. In particular, we wanted to answer the following questions: (1) When do these birds reach their breeding area, and when do they depart? (2) When do chicks appear in the population? (3) Do adult birds reach their breeding area with extra fuel? Do they depart from their breeding areas with fuel? (4) Do they moult within their breeding area? To answer these questions we used ringing data of birds captured during 2011 at La Covatilla, Salamanca province. Adults were caught mostly from May to July (no captures in August, 2.4% of adults in September). First-year bluethroats, however, appeared in June and remained in the zone up to September. Moulting adults (66% of 12 birds in total) were caught only in July. Moulting first-year birds were caught from July to September. The percentage of moulting firstyear birds in relation to all captures in August and September was comparatively low (10% in both months) relative to July (40%), indicating that most birds underwent their post-juvenile moult shortly after fledging. Body condition (residual body mass) did not differ between age classes and months. We detected no evidence suggesting fuel accumulation before the autumn migration. Thus, if the population needs to gain fuel for this migration, this must happen elsewhere.


Isolation and Characterisation of Eight Microsatellite Markers of the Thorn-Tailed Rayadito Aphrastura spinicauda
Diego I. Yáñez, Verónica Quirici, Gabriel J. Castaño-Villa, Elie Poulin and Rodrigo A. Vásquez

Abstract
Eight novel microsatellites were isolated and characterised in the thorn-tailed rayadito Aphrastura spinicauda in order to evaluate genetic diversity in three contrasting populations, two of them at the boundaries of the geographic range of the species. All loci were found to be polymorphic and 3–15 alleles were found per locus. Expected and observed heterozygosity ranged from 0.26 to 0.89 and from 0.27 to 0.87, respectively. Global and pairwise Weir and Cockerham's Fst showed that genetic differentiation was greater between the northern population and the ones in central and southern Chile. The eight markers developed will be useful to study the genetic diversity of the thorn-tailed rayadito across its distribution.

Tuesday, 23 June 2015

Oecologia - July 2015 Abstracts

Oecologia

Volume 178, Issue 3, July 2015

LINK














Selected Avian Research Articles

Survival and local recruitment are driven by environmental carry-over effects from the wintering area in a migratory seabird
K. Lesley Szostek 1   and Peter H. Becker 1
(1)Institute of Avian Research, Vogelwarte Helgoland, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany

Abstract

We estimated annual apparent survival rates, as well as local recruitment rates in different age groups and for different breeding status in the common tern Sterna hirundo using mark–recapture analysis on a long-term individual-based dataset from a breeding colony in Germany. Strong inter-annual variability in survival rates became apparent, especially in prospectors. Local recruitment also varied strongly between years and age groups. To explain these fluctuations, we linked survival and recruitment estimates to several environmental covariates expected to be limiting during the wintering period and migration, including the global climate indices of North Atlantic Oscillation and Southern Oscillation, fish abundance indices, and marine primary productivity in the West African wintering area. Contrary to expectations, global indices did not seem to be linked strongly to vital rates. Results showed that primary productivity had the strongest effect on annual survival, especially in young and inexperienced individuals. Primary productivity in the wintering area was also strongly associated with the probability of recruitment in the following breeding season, indicating that conditions during winter can have carry-over effects on the life cycle of individuals.


Changes in the apparent survival of a tropical bird in response to the El Niño Southern Oscillation in mature and young forest in Costa Rica
Jared D. Wolfe 1, 2   , C. John Ralph 1, 2  and Pablo Elizondo 3
(1)USDA Forest Service, Pacific Southwest Research Station, Arcata, USA
(2)Klamath Bird Observatory, Ashland, OR, USA
(3)Costa Rica Bird Observatories, Instituto Nacional de Biodiversidad (INBio), Santo Domingo de Heredia, Costa Rica

Abstract
The effects of habitat alteration and climatic instability have resulted in the loss of bird populations throughout the globe. Tropical birds in particular may be sensitive to climate and habitat change because of their niche specialization, often sedentary nature, and unique life-cycle phenologies. Despite the potential influence of habitat and climatic interactions on tropical birds, we lack comparisons of avian demographics from variably aged forests subject to different climatic phenomena. Here, we measured relationships between forest type and climatic perturbations on White-collared Manakin (Manacus candei), a frugivorous tropical bird, by using 12 years of capture data in young and mature forests in northeastern Costa Rica. We used Cormack–Jolly–Seber models and an analysis of deviance to contrast the influence of the El Niño Southern Oscillation (ENSO) on manakin survival. We found that ENSO had little effect on manakin survival in mature forests. Conversely, in young forests, ENSO explained 79 % of the variation where dry El Niño events negatively influenced manikin survival. We believe mature forest mitigated negative effects of dry El Niño periods and can serve as refugia for some species by buffering birds from climatic instability. Our results represent the first published documentation that ENSO influences the survival of a resident Neotropic landbird.


Experimental evidence that ptarmigan regulate willow bud production to their own advantage
Katie S. Christie 1   and R. W. Ruess 1
(1)The Institute of Arctic Biology, University of Alaska Fairbanks, 902 N. Koyukuk Dr., Fairbanks, AK, USA

Abstract

In some ecosystems, vertebrate herbivores increase the nutritional quality and biomass of their food source through repeated grazing, thereby manipulating their environment to support higher densities of animals. We tested whether ptarmigan (Lagopus lagopus and L. muta) are capable of regulating the nutritional quality, abundance, and availability of feltleaf willow (Salix alaxensis) buds using a simulated browsing experiment and a feeding preference study with wild birds. Simulated ptarmigan browsing resulted in smaller buds, but greater numbers of buds per shoot. Furthermore, browsing altered the morphology of willow branches such that buds were at higher densities and closer to snow level compared to unbrowsed controls. Browsing increased the number of willows with accessible buds (buds within 50 cm of snow level) from 55 to 89 %, and increased total accessible bud biomass from 113 ± 30 to 129 ± 50 mg/ramet. Browsing did not affect bud nitrogen or carbon concentration and slightly reduced protein precipitation capacity (tannins) in buds the following winter, indicating that ptarmigan browsing does not induce a defensive response in this species. When branches of broomed (previously browsed) and unbroomed willows were placed in the snow at equal heights, ptarmigan showed no preference for either type; however, they obtained more buds from broomed willows. Increased accessibility and density of willow buds caused by browsing has the potential to increase habitat carrying capacity, thereby supporting higher densities of ptarmigan.
  

Nectar robbery by a hermit hummingbird: association to floral phenotype and its influence on flowers and network structure
Pietro Kiyoshi Maruyama 1, 2  , Jeferson Vizentin-Bugoni 1, 2, Bo Dalsgaard 2, Ivan Sazima 3, 4 and Marlies Sazima 5
(1)Programa de Pós-Graduação em Ecologia, Universidade Estadual de Campinas (Unicamp), Cx. Postal 6109, Campinas, SP, 13083-970, Brazil
(2)Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen Ø, Denmark
(3)Museu de Zoologia, Universidade Estadual de Campinas (Unicamp), Campinas, SP, 13083-970, Brazil
(4)Projeto Dacnis, Estrada do Rio Escuro 4754, Sertão das Cotias, Ubatuba, SP, 11680-000, Brazil
(5)Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas (Unicamp), Cx. Postal 6109, Campinas, SP, 13083-970, Brazil

Abstract

Interactions between flowers and their visitors span the spectrum from mutualism to antagonism. The literature is rich in studies focusing on mutualism, but nectar robbery has mostly been investigated using phytocentric approaches focused on only a few plant species. To fill this gap, we studied the interactions between a nectar-robbing hermit hummingbird, Phaethornis ruber, and the array of flowers it visits. First, based on a literature review of the interactions involving  P. ruber, we characterized the association of floral larceny to floral phenotype. We then experimentally examined the effects of nectar robbing on nectar standing crop and number of visits of the pollinators to the flowers of Canna paniculata. Finally, we asked whether the incorporation of illegitimate interactions into the analysis affects plant–hummingbird network structure. We identified 97 plant species visited by P. ruber and found that P. ruber engaged in floral larceny in almost 30 % of these species. Nectar robbery was especially common in flowers with longer corolla. In terms of the effect on C. paniculata, the depletion of nectar due to robbery by P. ruber was associated with decreased visitation rates of legitimate pollinators. At the community level, the inclusion of the illegitimate visits of P. ruber resulted in modifications of how modules within the network were organized, notably giving rise to a new module consisting of P. ruber and mostly robbed flowers. However, although illegitimate visits constituted approximately 9 % of all interactions in the network, changes in nestedness, modularity, and network-level specialization were minor. Our results indicate that although a flower robber may have a strong effect on the pollination of a particular plant species, the inclusion of its illegitimate interactions has limited capacity to change overall network structure.


Urbanized birds have superior establishment success in novel environments
Anders Pape Møller 1  , Mario Díaz 2, Einar Flensted-Jensen 3, Tomas Grim 4, Juan Diego Ibáñez-Álamo 5, Jukka Jokimäki 6, Raivo Mänd 7, Gábor Markó 8, 9, 10 and Piotr Tryjanowski 11
(1)Laboratoire d’Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-Sud, Bâtiment 362, 91405 Orsay Cedex, France
(2)Department of Biogeography and Global Change, Museo Nacional de Ciencias Naturales (BGC-MNCN-CSIC), 28006 Madrid, Spain
(3)Cypresvej 1, 9700 Brønderslev, Denmark
(4)Laboratory of Ornithology and Department of Zoology, Palacky University, 77146 Olomouc, Czech Republic
(5)Departamento de Zoología, Facultad de Ciencias, Campus Universitario de Fuentenueva s/n, Universidad de Granada, 18071 Granada, Spain
(6)Nature Inventory and EIA-services, Arctic Centre, University of Lapland, P. O. Box 122, 96101 Rovaniemi, Finland
(7)Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, 51014 Tartu, Estonia
(8)Ecology Research Group, MTA-ELTE-MTM, Pázmány Péter sétány 1/c, 1117 Budapest, Hungary
(9)Department of Plant Pathology, Corvinus University of Budapest, Ménesi Út 44, 1118 Budapest, Hungary
(10)Behavioral Ecology Group, Department of Systematics, Zoology and Ecology, Eötvös Loránd University, Pázmány Péter sétány 1/c, 1117 Budapest, Hungary
(11)Institute of Zoology, Poznan University of Life Sciences, Wojska Polskiego 71C, 60-625 Poznan, Poland

Abstract

Many animals have adapted to the proximity of humans and thereby gained an advantage in a world increasingly affected by human activity. Numerous organisms have invaded novel areas and thereby increased their range. Here, we hypothesize that an ability to thrive in urban habitats is a key innovation that facilitates successful establishment and invasion. We test this hypothesis by relating the probability of establishment by birds on oceanic islands to the difference in breeding population density between urban and nearby rural habitats as a measure of urbanization in the ancestral range. This measure was the single-most important predictor of establishment success and the only statistically significant one, with additional effects of sexual dichromatism, number of releases and release effort, showing that the ability to cope with human proximity is a central component of successful establishment. Because most invasions occur as a consequence of human-assisted establishment, the ability to cope with human proximity will often be of central importance for successful establishment.

Monday, 22 June 2015

Journal of Ornithology - Volume 156, Issue 3, July 2015

Journal of Ornithology

Volume 156, Issue 3, July 2015














LINK

Effects of breeding habitat and field margins on the reproductive performance of Skylarks (Alauda arvensis) on intensive farmland
M. W. Kuiper 1  , H. J. Ottens 2, 3, J. van Ruijven 1, B. J. Koks 2, G. R. de Snoo 4 and F. Berendse 1
(1)Nature Conservation and Plant Ecology Group, Wageningen University, PO Box 47, 6700 AA Wageningen, The Netherlands
(2)Dutch Montagu’s Harrier Foundation, PO Box 46, 9679 ZG Scheemda, The Netherlands
(3)SOVON Dutch Centre for Field Ornithology, PO Box 6521, 6503 GA Nijmegen, The Netherlands
(4)Institute of Environmental Sciences, Leiden University, PO Box 9518, 2300 RA Leiden, The Netherlands

Abstract
Field margin management is a common measure employed in Europe to support farmland bird populations. In this study we found and analysed 237 nests of the Skylark Alauda arvensis in the Netherlands over a period of 6 years to determine the effects of arable field margins and breeding crop on nest-level reproductive success. Additionally, the effect of field margins on predation was investigated and food availability in crops and field margins was compared. Neither clutch size, nest survival nor nestling body weight were improved by field margin availability, irrespective of the breeding crop used. However, the choice of breeding crop had important effects. Nestling weight was significantly lower in cereals than in grassland and lucerne, corresponding with the low prey densities present in cereals. Nest survival was lowest in grassland due to frequent silage cutting. Predation rates were highest in cereals but were not affected by field margin proximity. The highest reproductive success was achieved in lucerne, which was mown twice a year and retained a suitable height for breeding throughout the breeding season. We conclude that field margins are not sufficient to maintain a Skylark population in this intensively farmed area. The presumably more subtle effects of increased food availability cannot compensate for the high nest failure rates resulting from agricultural operations and predation. In this and similar areas, the provisioning of safe nesting habitat throughout the breeding season is essential to improve breeding performance. Our research suggests that this can be achieved by reducing the frequency of silage cutting on grassland and by increasing the surface area of lucerne.


Vegetation structure and inter-individual distance affect intake rate and foraging efficiency in a granivorous forager, the Eurasian Skylark Alauda arvensis
Thibaut Powolny 1, 2  , Cyril Eraud 1, Jean-Daniel Masson 2, and Vincent Bretagnolle 2
(1)Office National de la Chasse et de la Faune Sauvage (ONCFS), Carrefour de la Canauderie, 79360 Villiers en Bois, France
(2)Centre d’Etudes Biologiques de Chizé, Centre National de le Recherche Scientifique (CNRS), 79360 Villiers en Bois, France

Abstract

Animals gain benefits from group living through increased probability of predator detection, dilution of individual risk and confusion of predators during attack. A further benefit involves larger groups in which individuals may further decrease the amount of time spent being vigilant, while maintaining the probability of predator detection by allocation of this extra time to foraging activities. Living in groups or flocks, however, also incurs costs, e.g., by increasing inter-group competition, with negative impacts on intake rates. Our aim was to investigate the trade-offs between the costs of competition and the benefits of group living in contrasted habitats. For prey species that rely on sight for detecting predators, vegetation structure may influence the perceived predation risk. Hence, we experimentally examined the combined effects of vegetation height and inter-individual distance on foraging time, intake rate and foraging efficiency in a granivorous species, the Eurasian Skylark (Alauda arvensis). Our experimental results based on temporally captive birds indicate that time devoted to foraging decreased with increasing inter-individual distance, but was unrelated to cover height. Conversely, increasing both vegetation height and distance with other group members did translate into a foraging disadvantage, i.e. reduced intake rate as well as foraging efficiency. Overall, our results show that both vegetation structure and inter-individual distances modify patch profitability, and therefore provide another example of how flock dynamics can influence the trade-off between vigilance and foraging.


Habitat management varying in space and time: the effects of grazing and fire management on marshland birds
Thomas Oliver Mérő 1  , László Lontay 2   and Szabolcs Lengye l, 3  
(1)Nature Protection and Study Society - NATURA, Milana Rakića 20, 25000 Sombor, Serbia
(2)Aggtelek National Park Directorate, Tengerszem oldal 1, Jósvafő, 3758, Hungary
(3)Department of Tisza River Research, Centre for Ecological Research, Danube Research Institute, Hungarian Academy of Sciences, Bem tér 18/c, Debrecen, 4026, Hungary

Abstract

Freshwater wetlands and marshes with extensive reed beds are important hotspots of biological diversity, but in the absence of proper management, they are subject to biotic homogenisation. We assessed the impact of spatiotemporally variable management by cattle grazing (for 4 years) and late-summer burning (1 or 3 years before the study) on both songbirds and non-passerines in a previously homogeneous reed bed. We surveyed birds using a combination of line transects and point counts in a quasi-experimental design comprising six treatment levels. Management increased both the diversity of marsh habitats and the diversity of bird species. The species richness and abundance of non-passerines (ducks and geese, wading birds, gulls and terns, rails, coots and grebes) was higher in recently burned than in unburned or old-burned patches. Species richness of farmland songbirds was higher in grazed than in non-grazed patches, and the richness and abundance of reed songbirds was higher in unburned, old-burned, and grazed patches than in recently burned patches. Total Shannon diversity and evenness of birds was lowest in areas with the most intensive treatment (patches grazed and twice-burned), whereas Simpson diversity was highest in these areas. Non-managed patches had fewer species and individuals of all groups except reed songbirds. The proportion of old reed was low in recently burned and grazed patches, and was similarly high in all other treatment areas. No other property of reed stands was influenced by management, and both the allocation and the effect of management were independent of water level. Spatiotemporally variable management by cattle grazing and late-summer burning may thus simultaneously benefit several groups of birds. The effect of burning alone disappeared in 3 years, even in the presence of grazing; thus it must be repeated every 2–3 years. We conclude that both management actions are necessary to establish and maintain highly diverse habitats for marshland bird communities.


Bluethroats Luscinia svecica namnetum offset landscape constraints by expanding their home range
Laurent Godet 1  , Matthieu Marquet 2, Marie-Christine Eybert 3, Elisa Grégoire 1, 2, Sarah Monnet 1, 2 and Jérôme Fournier 4, 5
(1) Le laboratoire LETG-Nantes-Géolittomer (CNRS-UMR 6554), Nantes University, BP 81227, 44312 Nantes Cedex 03, France
(2)Parc Naturel Régional de Brière, 214, Rue du chef de l’île, Ile de Fédrun, 44720 St-Joachim, France
(3)Joint Research Unit ECOBIO (CNRS-UMR 6553), University of Rennes 1, Campus de Beaulieu, Bât. 25, Avenue du Général Leclerc, 35042 Rennes Cedex, France
(4)Le Laboratoire de BOREA (CNRS-UMR 7208), French National Museum of Natural History, 75231 Paris Cedex 05, France
(5)CRBPO (Research Center for the Bird Banding Populations), French National Museum of Natural History, 75005 Paris, France

Abstract

The highly fragmented landscape structures of coastal salinas are known to result in decreased terrestrial bird abundance, species richness and diversity but to promote original assemblages dominated by specialist species, such as the Bluethroat Luscinia svecica namnetum. This species is mainly found at the core of these salinas, where the landscape characteristics are a priori the most hostile for terrestrial birds. The aim of this study was to test whether individuals of a specialized species like the Bluethroat may offset such landscape constraints by expanding their home ranges. We therefore radio-tracked 21 males in 2013 and 2014 in the salinas of the Marais du Mès (Parc Naturel Régional de Brière, Western France). The data of the 18 best-monitored males were used to carry out a hierarchical partitioning of variance to test the relative influence of landscape characteristics, individual characteristics and distance to other males on their home-range sizes. We found that landscape characteristics were the factors that best explained home range sizes. Home-range sizes were significantly smaller in diversified landscapes composed of tidal creeks and salt-marsh patches and tended to be larger in landscapes dominated by the aquatic matrix consisting of water ponds. The results of this study demonstrate that although a few bird species are able to select a priori hostile landscapes, they can offset such constraints by expanding their home-range size.


Factors affecting growth parameters of White Stork nestlings in eastern Algeria
Naouel Benharzallah 1, Abdelkrim Si Bachir 2, Fayçal Taleb 1 and Christophe Barbraud 3  
(1)Department of Natural and Life Sciences, Faculty of Exact Sciences and Natural and Life Sciences, University Mohamed Khider of Biskra, 07000 Biskra, Algeria
(2)Department of Natural and Life Sciences, Faculty of Sciences, University of El Hadj Lakhdar, 05000 Batna, Algeria
(3)Centre d’Etudes Biologiques de Chizé, UMR7372 CNRS/Univ. La Rochelle, 79360 Villiers-En-Bois, France

Abstract

Survival and reproduction of young can be affected by growth parameters. It is thus important to estimate intraspecific growth rate variability and environmental factors affecting growth to better understand the dynamics of populations and the potential impacts of environmental changes. Growth parameters of White Stork (Ciconia ciconia) nestlings were estimated in eastern Algeria, in the southern part of the species’ range. A total of 2,756 measurements of 65 nestlings from 18 nests were taken for body mass, and tarsus, wing and bill lengths. Individual growth data were used to investigate the effects of nest occupation date, laying and hatching dates, clutch size, number of hatchlings, productivity, hatching order, and brood reduction on nestling growth patterns. Body mass and bill length growth rates were lower in the studied population than in a more northerly White Stork population. This supports the hypothesis of a geographic variation in intraspecific growth parameters. Chicks from nests occupied early reached higher asymptotic body mass but tended to grow more slowly. However, chicks from late arriving birds compensated for the difference in body mass and wing length by higher growth rates. Wing length was significantly affected by asynchrony and hatching order. Last hatched chicks had larger asymptotic wing lengths, lower wing growth rates and longer growth periods. Wings of nestlings from highly asynchronous broods grew faster but took more time to attain the inflection point. Brood reduction had a negative effect on nestling bill length at hatching. Chicks from nests with little brood reduction had a longer bill at hatching than nestlings from nests with high brood reduction.


Natural nest-sites of Great Tits (Parus major) in a primeval temperate forest (Białowieża National Park, Poland)
Marta Maziarz 1  , Tomasz Wesołowski 1, Grzegorz Hebda 2 and Marta Cholewa 1
(1)Laboratory of Forest Biology, Wrocław University, Sienkiewicza 21, 50 335 Wrocław, Poland
(2)Department of Biosystematics, Opole University, Oleska 22, 45 052 Opole, Poland

Abstract

Knowledge of the breeding ecology of the Great Tit Parus major is vast, but almost exclusively concerns birds using nest-boxes. Information on birds nesting in natural conditions is scant. Here, we present the results of the first thorough study on natural nest-sites of the Great Tit. The data, including descriptions of nest-cavity location and dimensions, were collected during 39 breeding seasons in the primeval forest of Białowieża National Park (BNP), Poland. With an excess of available tree-cavities providing a diverse choice of nesting options, Great Tits nested mainly in non-excavated, very deep and spacious cavities with elongated, narrow openings, placed at intermediate heights in living tree trunks. Different sets of tree species were used in different habitats. The pattern of nest-site utilisation by Great Tits in BNP overlapped with that recorded in other areas, but showed niche separation from other non-excavating hole-breeders in BNP. This indicates that Great Tits have core nest-site preferences, which have probably evolved in response to selective forces such as, e.g., risk of predation, flooding, sufficient nest illumination and/or efficient air ventilation.


Flexibility in foraging strategies of Brown Skuas in response to local and seasonal dietary constraints
Ana P. B. Carneiro 1, 2  , Andrea Manica 1, Wayne Z. Trivelpiece 3 and Richard A. Phillips 2
(1)Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK
(2)British Antarctic Survey, Natural Environment Research Council, Madingley Road, High Cross, Cambridge, CB3 0ET, UK
(3)Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration, La Jolla, CA 92037, USA

Abstract

The Brown Skua Stercorarius antarcticus lonnbergi is an opportunistic species that displays a high degree of flexibility in foraging tactics. We deployed global positioning system (GPS) and immersion (activity) loggers on breeding Brown Skuas of known sex, body size and condition at Admiralty Bay, King George Island with the aim to examine the impacts of spatial and seasonal fluctuations in prey availability on movement and foraging behavior. We also investigated whether reversed sexual size dimorphism (females larger than males) in this species leads to differences between sexes in foraging behavior and whether this or other factors contribute to variation in breeding success. Analysis of the GPS data highlighted the high degree of plasticity in foraging behavior among individuals. Although most Brown Skuas were flexible in their feeding tactics, this was not enough to ensure a successful breeding season, as few pairs fledged chicks. During early chick rearing, Brown Skuas spent most of their time on land, feeding almost exclusively on penguin chicks. By late chick rearing, when the availability of penguins had diminished, Brown Skuas supplemented the food obtained on land by traveling to the ocean. All foraging trips to sea occurred during daylight, mostly during the early morning. Despite marked sexual size dimorphism, we failed to find any difference in foraging tactics between males and females. Furthermore, although laying date affected the number of chicks hatched (earlier pairs were more successful), no relationship was found between breeding success and male or female body size, condition or degree of dimorphism within pairs.


Analyses of Black Grouse (Tetrao tetrix) faeces with infrared spectroscopic methods
Sebastian Url 1, Manfred Schwanninger 2 and Ursula Nopp-Mayr 1  
(1)Department of Integrative Biology and Biodiversity Research, Institute of Wildlife Biology and Game Management, University of Natural Resources and Life Sciences, Vienna, Gregor Mendel Straße 33, A 1180, Vienna, Austria
(2)Department of Chemistry, Institute of Wood Science and Technology, University of Natural Resources and Life Sciences, Vienna, Muthgasse 18 A 1190, Vienna, Austria

Abstract
In recent years, the Fourier transform infrared spectroscopy (FT-IR) was used to assess the diet, digestibility or nutritional values of food items of ruminants. However, it has never been used to analyse the diet of grouse species. Commonly used methods have so far been direct observations of birds and microscopical analyses of droppings. The sample preparation and comparison of microscopical analyses is a highly time-consuming procedure. The comparison is based on morphological structures of epidermal cells, like the shape of cells, stomata or trichomes. In contrast, the sample preparation for the FT-IR and the subsequent measuring is simple and quickly done. We investigated the diet of Black Grouse (Tetrao tetrix L.) in two study areas with infrared spectroscopic methods comparing summer and winter droppings’ content with plant reference material. The study areas are located in the provinces of Salzburg and Upper Austria, Austria. In our study, samples were measured in the mid- and near-infrared range. We tried to determine the dominating content of faecal samples at species, genera or family level or at least to assign samples to one of four main plants groups (i.e. woody plants, heathers, herbs and grasses). Our results showed a dominance of Larix decidua within the group of woody plants in both areas and, within the group of heathers, a dominance of Calluna vulgaris and Rhododendron hirsutum in one study area. Partially, our results are in marked contrast to other studies conducted in the Alps, as Vaccinium myrtillus was not detected in the samples. For further methodological studies, faecal sampling over larger areas, larger samples of plant reference material (including seeds and other parts of plants at different seasons), taking more samples per dropping and synchronous comparisons of microscopic analyses as well as FT-IR spectroscopy, are recommended.


Disentangling the drivers of change in Common Teal migration phenology over 50 years: land use vs. climate change effects
Matthieu Guillemain 1  , Claire A. Pernollet 1, 2, Grégoire Massez 3, François Cavallo 1, Géraldine Simon 2 and Jocelyn Champagnon 2, 4
(1)Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, La Tour du Valat, Le Sambuc, 13200 Arles, France
(2)Centre de Recherche de la Tour du Valat, 13200 Arles, France
(3)Les Marais du Vigueirat, Mas Thibert, 13200 Arles, France
(4)Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, A.P. 70-275, 04510 México D.F., Mexico

Abstract

A large body of research has accumulated on the impact of climate change on wildlife movements and distributions, especially for migratory birds. We used large ringing datasets for the Common Teal (Anas crecca) from the Camargue, southern France, to compare historic (from 1956–1975) spatiotemporal patterns of teal recovery with those seen in modern (2002–2012) years and assess whether the migration phenology of these ringed birds and their use of the Camargue as winter quarters has changed. Because teal are short-distance migrants (i.e., they breed in northern Europe and winter north of the Sahara), they would be predicted to delay their autumn migration in response to climate change. Conversely, ring recoveries showed that teal are now arriving much earlier: a stable 80 % of the recoveries were made locally in the Camargue each week between mid-November and late January in the modern dataset, whereas this percentage was only 53 % on average in the older data, and the proportion of recoveries made locally in the Camargue gradually increased through the autumn and winter until late January. This suggests that Camargue habitats have changed markedly and become more attractive to teal compared to other potential wintering areas, consistent with known changes in local habitat management practices and improvements in the body condition of the birds. Despite the fact that global climate change will likely be one of the main drivers of wildlife distribution over the long term and at large spatial scales, local habitat management should not be overlooked, as it can increase habitat attractivity to migratory birds.


Migration distance and breeding latitude correlate with the scheduling of pre-alternate body moult: a comparison among migratory waders
Pedro M. Lourenço 1, 2   and Theunis Piersma 2, 3
(1)Centro de Estudos do Ambiente e do Mar (CESAM)/Museu Nacional de História Natural e da Ciência, Universidade de Lisboa, Rua da Escola Politécnica 58, 1250-102 Lisbon, Portugal
(2)Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, PO Box 11103, 9700 CC Groningen, The Netherlands
(3)Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands

Abstract
Moult is an important maintenance activity that should be carefully timed within the annual cycle. Many birds perform a pre-alternate moult of body feathers some time prior to the breeding season. In migrants, the timing of the pre-alternate moult coincides with the migration from wintering to breeding areas. In this study, we used visual plumage scores collected on the Continental Black-tailed Godwit Limosa limosa limosa in Portugal and The Netherlands to establish that the pre-alternate body moult of these birds during the northward migration between West Africa and The Netherlands takes place only in staging areas in the Iberian peninsula from late January to late February. A comparison of the moult strategy of these godwits with that of 20 other migratory wader populations (13 species) revealed that the former had a rather uncommon moult schedule which was more characteristic of populations with rather short migrations that breed at lower latitudes. We argue that this unusual moult schedule can be explained by a combination of ecological opportunity and proximate and ultimate trade-offs (hormonal incompatibly and maximization of plumage quality vs. time spent on migration, respectively).


Evaluation of aerodynamic parameters from infrared laser tracking of free-gliding white storks
Heinrich Eder 1  , Wolfgang Fiedler 1, 2   and Markus Neuhäuser 3  
(1)Max Planck Institute for Ornithology, Am Obstberg 1, 78315 Radolfzell, Germany
(2)University of Konstanz, Universitaetsstrasse 10, 78457 Konstanz, Germany
(3)Fachbereich Mathematik und Technik, RheinAhrCampus der Hochschule Koblenz, Joseph-Rovan-Allee 2, 53424 Remagen, Germany

Abstract
Free-flight paths of White Storks (Ciconia ciconia L. 1758) were tracked using a modified laser rangefinder system (Vector IV) based on a 1550-nm diode laser. Field measurements were taken of two flocks comprising approximately 100 adult storks in all. Tracking data allowed mathematical reconstruction of their spatial trajectories using a ground-mounted GPS-based system. Atmospheric influences were accounted for by performing regular observations of ground wind speed and temperature and evaluating recorded trajectories with respect to local disturbances. A model was created by splitting the speed polar into three subspeed polars based on typical wing configurations: “soaring” (V = 7.5–10 m/s), “gliding” (V = 10–14 m/s), and “fast flight” (V = 14–19 m/s). Subspeed polars for a reference stork were derived from 60 measured data couples of sinking speed and forward speed. Multiple regression analysis was used to determine both the induced and noninduced proportionality coefficients. Morphometric data, such as wing span, wing area, and aspect ratio, were collected from 58 photogrammetric examinations. PC-connected outdoor scales provided the body masses of 36 storks from the investigated flocks. Wing loading and aspect ratio vs. forward speed were evaluated to estimate the induced drag factor k. For lift coefficients (C L) of 1.2–1.6, characterizing the range for a fully open primary cascade, k lies between 0.70 and 0.96 at a confidence level of 95 %. Our findings show agreement with the theoretically predicted k values for cascaded wing tips.


How to hatch from the Common Cuckoo (Cuculus canorus) egg: implications of strong eggshells for the hatching muscle (musculus complexus)
Marcel Honza 1  , Kateřina Feikusová 1, Petr Procházka 1   and Jaroslav Picman 2
(1)Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Květná 8, 60365 Brno, Czech Republic
(2)Department of Biology, University of Ottawa, Ottawa, ON, Canada

Abstract

One of the most obvious adaptations to the brood parasitic mode of reproduction is the formation of eggs with unusually strong shells, which apparently reduce chances of egg breakage during laying and puncture ejection attempts of parasitic eggs by the hosts. We tested a hypothesis that strong eggshells of the Common Cuckoo, Cuculus canorus, may have also led to a stronger hatching muscle, musculus complexus. First, the Cuckoo hatching muscle had a higher density of fibers than that of the similarly sized Great Reed Warbler Acrocephalus arundinaceus chicks; and second, the cross-sectional area of fibers of the hatching muscle was smaller in the Cuckoo than in the Great Reed Warbler. We propose that the increased density of muscle fibers in the Cuckoo facilitates hatching out of structurally strong eggshells because chicks possessing this trait should be able to exert greater pressure on the shell during the hatching process. Our results are consistent with the hypothesis that the higher density of fibers in the musculus complexus represents another adaptation facilitating hatching from unusually strong parasitic eggs that has presumably evolved during coevolution involving the Cuckoo and its hosts.


Roles of phenotypic and genetic characteristics in the social mating pattern of Silver-throated Tits (Aegithalos glaucogularis)
Jianqiang Li 1, 2, 3  , Lei Lv 2, Pengcheng Wang 2, Zhengwang Zhang 2 and Yong Wang 2, 3
(1)College of Nature Conservation, Beijing Forestry University, Beijing, 100083, China
(2)Ministry of Education Key Laboratory for Biodiversity Sciences and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
(3)Department of Biological and Environmental Sciences, College of Agriculture, Life, and Natural Sciences, Alabama A&M University, Normal, AL 35762, USA

Abstract

Choice of mating partners may affect fitness. Both phenotypic and genetic traits have been shown to play roles in the mating processes of animals. We investigated the roles of phenotypic and genetic characteristics in the patterns of social mating in the Silver-throated Tit (Aegithalos glaucogularis), a sexually monochromatic species that exhibits sexual size dimorphism, rarely sings, does not occupy territories, and has a relative low level of extrapair paternity. To explore the role of phenotype traits, we tested for assortative mating based on the sizes of seven morphological traits. To explore the role of genetic traits, we tested for assortative mating with respect to genetic heterozygosity (the heterozygous mate hypothesis) and whether birds mated with genetically dissimilar individuals (the compatible mate hypothesis). We found significant correlations between paired individuals for bill length and body length, indicating possible assortative mating based on these two traits. In contrast, genetic heterozygosity was not correlated between paired individuals, and the mean relatedness of the mates was not significantly different from that of randomly mated individuals, which do not support the idea that Silver-throated Tits assortatively mate with heterozygous individuals or choose genetically dissimilar mates. Also, individual heterozygosity was not reflected in the measured morphological traits, as no correlation was detected. Neither the individual heterozygosity nor the relatedness between mates was correlated with reproductive performance measures, including clutch size, brood size, and number of fledglings. However, we found that clutch size increased with female body length, which could explain the benefit to males of mating with larger females. Taken together, while our current data failed to provide evidence for an effect of genetic characteristics on the social mating pattern of Silver-throated Tits, the results suggest that phenotypic traits are likely associated with their mating pattern.


Intra-specific plasticity in parental investment in a long-lived single-prey loader
Eric W. M. Stienen1  , Allix Brenninkmeijer2   and Wouter Courtens1
(1)Research Institute for Nature and Forest, Kliniekstraat 25, 1070 Brussels, Belgium
(2)Altenburg and Wymenga bv, Suderwei 2, 9269TZ Feanwâlden, The Netherlands

Abstract

Seabirds exhibit considerable behavioural flexibility in foraging investment in order to meet the nutritional needs of their chicks during variable environmental conditions. Although regulation of offspring provisioning is generally thought to be related to species-specific constraints imposed by central place foraging, some studies suggest different responses within the same species linked to local differences in foraging conditions. Under adverse conditions, seabirds are expected to be less flexible because they must secure their own survival chances first before investing in current reproduction. Short-ranging single-prey loaders are expected to show large intra-specific variation in time spent on foraging because their mode of foraging is energetically expensive, and because they face restricted possibilities to increase the numerical prey input to the colony compared to multiple prey loaders. In this study, we examined if and how the single-prey loading Sandwich Tern Thalasseus sandvicensis varies colony attendance based on the nutritional status of their chick as well as parental body condition in two study colonies. The proportion of time that a chick was left unattended at the colony negatively correlated with chick body condition, suggesting that the parents tried to counterbalance poor feeding conditions by investing more time in foraging. Energy transport rates to the chicks (corrected for time spent away from the colony) and body condition of the chicks were similar in both colonies. However, at Zeebrugge, where adults were in poor body condition, parental non-attendance was much lower than on Griend, even when chicks were in poor condition. Still, our results suggest that parental nest non-attendance in Sandwich Terns is merely a corrective response to food loss to kleptoparasitic gulls in order to meet the nutritional status of the chick, although an effect of adult body condition could not be excluded.


To fledge or not to fledge: factors influencing the number of eggs and the eggs-to-fledglings rate in White Storks Ciconia ciconia in an agricultural environment
Ute Eggers 1, 2  , Michael Arens 3, Mario Firla 4 and Dieter Wallschläger 1
(1)Eco-Ethology, University of Potsdam, Maulbeerallee 2a, 14469 Potsdam, Germany
(2)Plant Ecology and Nature Conservation, University of Potsdam, Maulbeerallee 2, 14469 Potsdam, Germany
(3)White Stork Carer, Rural District Salzwedel (Saxony-Anhalt), Vienau, Germany
(4)White Stork Carer, Rural District Genthin (Saxony-Anhalt), Ferchland, Germany

Abstract

Numerous studies have explored the relationship between environmental factors and White Stork Ciconia ciconia reproduction, mainly expressing breeding success as the number of fledglings. Nonetheless, one of the most critical life-history stages in birds falls between egg-laying and fledging, and identifying the factors causing offspring mortality during this period provides valuable knowledge. We quantified the number of laid White Stork eggs and the proportion of eggs that turned into fledglings in an agriculture-dominated region in Eastern Germany. Moreover, we identified the factors among land cover, weather and arrival dates, which influenced these two reproductive measures the most, and analysed the monitored mortality causes. On average, four eggs were laid per nest, and 57.8 % of the eggs turned into fledglings. The number of eggs laid was best explained by the negative effect of the arrival date of the second stork, while the percentage of eggs that turned into fledglings was more dependent on weather: most important parameters were mean temperature in the fifth and seventh weeks after the assumed breeding start (i.e. around the assumed hatching date), and the number of consecutive days with precipitation when nestlings are assumed to be approximately 3 weeks old. In an agricultural environment, weather effects that potentially disturb food availability might be more important than effects directly affecting the survival of White Stork offspring. The most frequent observed mortality cause, nest fights, furthermore revealed the relevance of intraspecific competition in the study population.


The influence of phenology on double-brooding and polygyny incidence in the Sedge Warbler Acrocephalus schoenobaenus
Tadeusz Zając 1  , Wojciech Bielański 1, Adam Ćmiel 1 and Wojciech Solarz 1
(1)Institute of Nature Conservation, Polish Academy of Sciences, al. Mickiewicza 33, 31-120 Kraków, Poland

Abstract

There is growing evidence that the fitness of birds in temperate zones depends strongly on the match between the timing of breeding and local phenology. We have analysed data collected from a 15-year study on a Sedge Warbler (Acrocephalus schoenobaenus) population in its natural habitat. The highly skewed distribution of arrival dates of males indicated that they competed intensely to be the earliest arrivals. The distribution of mating dates, unlike arrival dates, was not skewed, rather it formed a bell-shaped distribution. Because females arrived much later, they could not base their mating choices on the arrival dates of males. Females, however, could use male song repertoire, a trait we found to be correlated with male arrival date. Double-brooded females mated early in the season, exactly within the peak of mating date distribution. Polygynous females, on the other hand, mated later in the season, choosing high-quality older males which had arrived significantly earlier. Male territory quality did not differ between double-brooded and polygynous females, nor did the quality of the territories occupied by an individual female change during her lifetime. Although longer lifespan and double-brooding influenced a female’s fitness over the course of her lifetime, polygyny had no significant effect. We conclude that Sedge Warbler females do not compete for territorial resources, but they do prefer to mate with high-quality early-arriving males. Polygyny is an effective strategy used by females to compensate for their late arrival and breeding onset, since they pair with high-quality males.


Frequent within-pair copulations during incubation in Northern Lapwings Vanellus vanellus are consistent with the sperm competition hypothesis
Miroslav Šálek 1  
(1)Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 16521 Praha 6, Czech Republic

Abstract

Social partners of some bird species copulate during the incubation period; explanations for this include strengthening social bonds and/or reducing the risk of extra-pair paternity in consecutive clutches within the same season. According to current opinion, Northern Lapwings Vanellus vanellus exhibit this behavior, uncommon in shorebirds, in order to strengthen social bonds. Based upon field observations at 36 nests, I found that mating frequency increased after cessation of male incubation bouts, i.e., after the male had been unable to guard the female and prevent opportunities for extra-pair mating. This pattern is consistent with the sperm competition hypothesis: increased rates of copulation may be a way of devaluing the sperm of possible competitors and a strategy to secure paternity in subsequent clutches, which Northern Lapwings frequently lay throughout the breeding season. This explanation extends the previous interpretation of the frequent mating of Northern Lapwings during the incubation period.


Interspecific competition and nest survival of the threatened Red-headed Woodpecker
Barbara Frei 1  , Joseph J. Nocera 2 and James W. Fyles 1
(1)Department of Natural Resource Sciences, McGill University, Macdonald Campus, Sainte-Anne-de-Bellevue, QC, H9X 3V9, Canada
(2)Ontario Ministry of Natural Resources, Trent University, Peterborough, ON, K9J 7B8, Canada

Abstract
The cavity-nesting Red-headed Woodpecker (Melanerpes erythrocephalus) is a once common, but now threatened, species across most of its range. Although several drivers for the species’ decline have been suggested, few have been quantitatively tested and still little is known of the Red-headed Woodpecker’s breeding ecology. From 2010 to 2011, we monitored 60 Red-headed Woodpecker nests across a variety of habitats in southern Ontario to estimate the species’ nest survival near the northern edge of their range where populations are rapidly declining. We investigated the relevance of a suite of meteorological, biotic, temporal, and habitat-based drivers on woodpecker nesting success. The frequency of European Starlings (Sturnus vulgaris) sightings near active woodpecker nest sites was the strongest factor influencing Red-headed Woodpecker nest survival. Logistic-exposure nest success assuming constant survival (68 %) dropped significantly (to 13 %) when the frequency of Starling sightings was considered. More than a third of nest failures were suspected to be the result of aggressive cavity takeovers by Starlings, and nests with Starlings present were almost four times more likely to fail than nests without. Red-headed Woodpecker nest survival early in the breeding season appeared depressed, perhaps as a result of interference competition with Starlings. Nesting success increased with the availability of snags and dead branches, which may increase foraging opportunities and parental attentiveness at the nest, leading to more effective nest defense. This research is contrary to previous reports that Starlings do not negatively affect North American primary cavity nesters, and demonstrates the importance of considering multiple ecological, temporal, and spatial factors when determining threats for species-at-risk.


Is income breeding an appropriate construct for waterfowl?
Adam K. Janke 1  , Michael J. Anteau 2, Nicholas Markl 1, 4 and Joshua D. Stafford 3
(1)Department of Natural Resource Management, South Dakota State University, Brookings, SD 57007, USA
(2)US Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND 58401, USA
(3)US Geological Survey, South Dakota Cooperative Fish and Wildlife Research Unit, Department of Natural Resource Management, South Dakota State University, Brookings, SD 57007, USA
(4)South Dakota Department of Game, Fish and Parks, Webster, SD 57274, USA

Abstract

Breeding birds use a range of nutrient accumulation and allocation strategies to meet the nutritional demands of clutch formation and incubation. On one end of the spectrum, capital breeders use stored nutrients acquired prior to clutch formation and incubation to sustain metabolism during reproduction, while on the opposite end, income breeders derive nutrients solely from exogenous sources on the breeding grounds. Blue-winged Teal (Anas discors) are an ideal candidate to test for adoption of an income strategy among migratory waterfowl because of their small body size, temperate breeding range, and timing of reproduction relative to pulses in nutrient availability within breeding habitats. We collected migrating and pre-breeding Blue-winged Teal (n = 110) during the warmest spring in over a century in the southern edge of the species’ breeding range, which produced ideal conditions to test for adoption of an income breeding strategy among migratory waterfowl. Regression analyses revealed that females accumulated protein and fat reserves early in follicle development and appeared to mobilize at least some reserves coincident with the onset of clutch formation. Accumulation and subsequent mobilization of nutrient reserves was inconsistent with adherence to an income breeding strategy and suggested breeding Blue-winged Teal used capital (albeit locally acquired) for reproduction. Our results add to existing knowledge on the ubiquity of endogenous nutrient reserve accumulation prior to and during reproduction by waterfowl, perhaps suggesting endogenous nutrient reserves are universally used for clutch formation or incubation to some degree. If indeed Blue-winged Teal and other waterfowl universally use capital for breeding, research and conservation efforts should shift from evaluating whether an income breeding strategy is used and focus on when and where necessary capital is acquired prior to clutch formation.


Geographic variation in White-throated Sparrow song may arise through cultural drift
Scott M. Ramsay 1   and Ken A. Otter 2
(1)Department of Biology, Wilfrid Laurier University, Waterloo, ON, N2L 3C5, Canada
(2)Ecosystem Science and Management Program, University of Northern British Columbia, Prince George, BC, Canada

Abstract
Geographic variation in song may arise to facilitate assortative mating among locally adapted individuals or to increase ability to communicate within local neighbourhoods. Alternatively, geographic song variation may be functionally neutral, emerging as a by-product of idiosyncrasies of founder effects and song learning in peripheral populations. We studied differences in the terminal notes of songs in White-throated Sparrows (Zonotrichia albicollis) in a peripheral population found west of the Rocky Mountains. Unlike the common triplet of notes found in terminal strophes of the main distribution of this species in eastern North America, birds in Prince George, British Columbia, Canada, had terminal notes composed of doublets. We mapped song variation on an east–west transect through central Alberta, Canada, but were unable to find a sharp division between areas where the terminal notes shift; instead, we found evidence of a cline of increasing frequency of doublet endings from east to west. We performed playback experiments of local versus foreign song types in populations where doublet terminal strophes (Prince George, BC) versus triplet terminal strophes (Algonquin Park, ON) predominate. We found a significant difference between the populations, with the western birds responding more strongly overall than the eastern birds, and males in both populations responding more strongly to the doublet-ending song type. Our results do not support the origination of regional variation to discriminate among local populations, but are consistent with neutral cultural shifts.


The influence of social dominance on calling rate in the Large-billed Crow (Corvus macrorhynchos)
Noriko Kondo 1, 2   and Mariko Hiraiwa-Hasegawa 1
(1)Department of Evolutionary Studies of Biosystems, The Graduate University for Advanced Studies, Shonan Village, Hayama Kanagawa, 240-0193, Japan
(2)Japan Society for Promotion of Science, Sumitomo-Ichibancho FS Bldg., 8 Ichibancho, Chiyoda-ku, Tokyo 102-8472, Japan

Abstract

Individual animals of social species that form dominance hierarchies use status signals to advertise their dominance status to conspecifics. Bird species often have a visual status signal known as a “badge of status.” However, the hierarchies of some social species are fluid, and dominance status may change depending on the composition of the group. In such situations, vocal signals are more suitable as a status signal because they are readily modifiable by the signaler. In this study, we investigated the relationship between social dominance rank and calling rate in the Large-billed Crow (Corvus macrorhynchos) by observing a captive flock of Large-billed Crows and determining the dominance rank of each individual. The number of vocalizations each individual produced during the study period were also recorded. Our results revealed that there was a clear linear dominance hierarchy within the flock and that more dominant crows produced sequential-note calls more frequently than their subordinate counterparts. Contact call rate, however, was not affected by dominance status. These results suggest that sequential-note calls function as status signals in groups of Large-billed Crows.


Age-related change in carotenoid-based plumage of the American Redstart (Setophaga ruticilla)
Kristen L. D. Marini 1, Ann E. McKellar 2, Laurene M. Ratcliffe 3, Peter P. Marra 4 and Matthew W. Reudink 1  
(1)Department of Biological Sciences, Thompson Rivers University, Kamloops, BC, Canada
(2)Environment Canada, 115 Perimeter Road, Saskatoon, SK, Canada
(3)Department of Biology, Queen’s University, Kingston, ON, Canada
(4)Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA

Abstract

Plumage colouration serves a variety of functions for birds, including conspecific signalling, crypsis, and predator–prey interactions. Though much research has been conducted on colour changes in species with delayed plumage maturation, where birds do not exhibit definitive adult plumage until their second breeding season or later, relatively few studies have examined how plumage colour changes once definitive adult plumage has been attained. In this study on male and female American Redstarts (Setophaga ruticilla), which exhibit male delayed plumage maturation, we used reflectance spectrometry to evaluate carotenoid-based tail colour changes over 11 breeding seasons, examining both within-individual and population-level changes. At a population level, males in their first breeding season in definitive adult plumage had a feather hue that was more orange-shifted than birds in their second year in adult plumage, and marginally, but not significantly, more orange-shifted than birds in their third year in adult plumage. Within-individual analysis of males recaptured in subsequent seasons also revealed a shift away from orange towards a more yellow feather hue as individuals aged. Within individuals, red chroma was highest for males in their second year in adult plumage, but it showed no population-level effects. At the population level, female redstarts in their first breeding season displayed plumage with a higher red chroma and a lower brightness than birds in their second breeding season, potentially as a result of differences in the timing and conditions of moult (first-year bird tail feathers were grown in the nest). For adult males and females, there was no difference in plumage colouration between birds that returned to the study site compared to those that failed to return. Together, our results suggest that within-individual change rather than differential survival best explains our findings. We suggest that studies examining age-related colour changes are critical for understanding the evolution of complex signalling systems, such as that of American Redstarts.
 

Experimentally reduced male ornamentation increased paternal care in the Barn Swallow
Masaru Hasegawa 1   and Emi Arai 2
(1)Department of Evolutionary Studies of Biosystems, The Graduate University for Advanced Studies, 1560-35 Kamiyamaguchi, Hayama-machi, Miura-gun 240-0115, Kanagawa, Japan
(2)Division of Ecology and Evolutionary Biology, Graduate School of Life Sciences, Tohoku University, Sendai, Japan

Abstract
It has recently been demonstrated that male ornaments feedback on their physiological state and this is expected to be followed by behavioral alterations in paternal care. However, only a few studies have shown the effects of experimental manipulation of ornamentation on paternal care behavior. The present study investigated the effects of experimental manipulation of the size of a male ornament, the red throat patch, on the feeding rates of nestlings by male and female Barn Swallows (Hirundo rustica gutturalis). First, we observed a dynamic change in male throat patch height during the breeding season, indicating that behavioral alterations in response to changes in throat patch height may be beneficial for male Swallows. Second, males with an experimentally reduced throat patch, but not their mates, fed their nestlings significantly more often compared with control individuals. In addition, we found a significant interaction between treatment and male body size: i.e., the effects of a reduced throat patch height varied depending on male body size. Among males with a reduced throat patch, male feeding rate increased with body size, but this was not the case in control males. This interaction is consistent with the idea that small males have low behavioral flexibility, and might contribute on positive correlation between throat ornamentation and male body size, given that behavioral flexibility is adaptive. The current finding indicates that males can increase paternal care in response to a seasonal decrease in ornamentation and this differential behavioral flexibility among males may facilitate the honesty of ornamentation.


Effects of immune supplementation and immune challenge on bacterial assemblages in the avian cloaca
Kevin D. Matson 1, 2  , Maaike A. Versteegh 1, Marco van der Velde 1 and B. Irene Tieleman 1
(1)Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands
(2)Resource Ecology Group, Department of Environmental Sciences, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands

Abstract

Relationships between avian physiology and bacterial assemblages in the cloaca are poorly understood. We used molecular techniques to analyze cloacal swabs from pigeons that were subjected to two immunological manipulations: lysozyme supplementation and endotoxin challenge. From the swabs, we derived ecological indices of evenness, richness, and diversity of bacterial assemblages. Challenge led to changes in evenness that depended on supplementation. When analyzing these changes, we neutralized the effects of a possible statistical artifact by including the starting values as a covariate. Repeatability calculations suggested that swabbing reliably captured the evenness but not the richness or diversity of bacterial assemblages in the cloaca.


Patterns of year-to-year variation in haemoglobin and glucose concentrations in the blood of nestling Pied Flycatchers Ficedula hypoleuca
Michał Glądalski 1  , Joanna Skwarska 1, Adam Kaliński 3, Mirosława Bańbura 2, Marcin Markowski 1, Jarosław Wawrzyniak 1, Piotr Zieliński 4 and Jerzy Bańbura 1
(1)Department of Experimental Zoology and Evolutionary Biology, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 12/16, 90-237 Lodz, Poland
(2)Museum of Natural History, Faculty of Biology and Environmental Protection, University of Łódź, Kilińskiego 101, 90-011 Lodz, Poland
(3)Department of Teacher Training and Biological Diversity Studies, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237 Lodz, Poland
(4)Department of Ecology and Vertebrate Zoology, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 12/16, 90-237 Lodz, Poland

Abstract

Physiological tools can be used to identify the sources and consequences of stressors on animals. Understanding the influences of variation in habitat quality and anthropogenic disturbance on organism condition and health may improve future management and conservation. We present results concerning variation in haemoglobin and glucose concentrations in the blood of about 14-day-old nestling Pied Flycatchers Ficedula hypoleuca in central Poland over a 4-year period, 2011–2014, in a deciduous forest. The most important findings of the study are: (1) the concentration of haemoglobin and glucose of the nestlings from the same brood tended to be consistently similar, with much variation occurring among broods; (2) repeatability of haemoglobin concentration was higher than repeatability of glucose concentration; (3) mean levels of haemoglobin and glucose varied among years; (4) haemoglobin and glucose concentrations were negatively correlated; and (5) there was a positive relationship between haemoglobin levels and breeding success.


A hybrid snipe Gallinago gallinago × G. media found in the wild
Jacob Höglund 1  , Stein Are Sæther 1, 2, Peder Fiske 2, David Wheatcroft 1 and John Atle Kålås 2
(1)Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden
(2)Norwegian Institute for Nature Research (NINA), P.O. Box 5685, Sluppen, 7485 Trondheim, Norway

Abstract
A hybrid snipe male was observed and caught in 2009 in the Norwegian mountains. We report behaviour, vocalizations, morphology, and genetic data for this bird. Mitochondrial and nuclear DNA sequences revealed that the hybrid had a great snipe mother and a common snipe father. The hybrid was intermediate in most measured morphometric traits and showed some intermediate plumage characteristics. The behaviour was similar to that of a great snipe—it displayed and vocalised at a great snipe lek for more than a week. The song was somewhat reminiscent of a great snipe's, but lacked the frequency-modulated whistles that are part of the great snipe song, consisting of more rapid click notes of a narrower frequency spectrum. This is the only putative hybrid that we have found among the more than 4,400 adult individuals we have examined between 1986 and 2014 at great snipe leks in Norway, Sweden, Poland, and Estonia. Common snipes invariably occur near these sites. Reports on putative hybrids among snipe species are very rare, and we question the validity of previous claims. This is the first where the parental origins—and, indeed, the hybrid status—have been unequivocally determined. We speculate on how a great snipe female, known for being extremely choosy about mating, came to mate with a common snipe male. We also note that, although perhaps behaviourally more likely, physical constraints on chick development (caused by the smaller egg size of the common snipe and larger body size of the great snipe) might prevent any successful male great snipe × female common snipe hybridisation—a possible example of an unidirectional post-zygotic barrier.


Intergeneric hybridization between Common Redstart Phoenicurus phoenicurus and Whinchat Saxicola rubetra revealed by molecular analyses
Silje Hogner 1  , Albert Burgas Riera 2, Margrethe Wold 2, Jan T. Lifjeld1 and Arild Johnsen 1
(1)Natural History Museum, University of Oslo, Blindern, P.O. Box 1172, 0318 Oslo, Norway
(2)Lista Bird Observatory, Fyrveien 6, 4563 Borhaug, Norway

Abstract

Hybridization between members of different genera is relatively rare in nature. Here, we present the first molecular evidence of an intergeneric hybrid within the avian Muscicapidae family. The suspected hybrid was captured at Lista Bird Observatory, Norway, in September 2013. Molecular analysis of the mitochondrial COI gene showed that the mother of the hybrid was a Whinchat, while two intronic sequences revealed that the father was a Common Redstart. Molecular sexing showed that the hybrid was a male. A detailed phenotypic description of the hybrid is presented together with the parental species. Documenting hybridization is increasingly feasible using molecular methods and provides important information to studies of species borders, reproductive barriers and the process of speciation. We emphasize the importance of securing solid documentation (photos and morphometrics) and DNA samples (from feathers or blood) whenever suspected hybrids are captured in the wild.


A primitive heron (Aves: Ardeidae) from the Miocene of Central Asia
Andrzej Elzanowski 1   and Nikita V. Zelenkov 2  
(1)Museum and Institute of Zoology, Polish Academy of Sciences, 64 Wilcza Street, 00-679 Warsaw, Poland
(2)Borissiak Paleontological Institute, Russian Academy of Sciences, Profsoyuznaya ul. 123, Moscow, 117997, Russia

Abstract

A robust quadrate from the Middle Miocene of Mongolia represents a new genus of Ardeidae that combines the similarities to Nycticorax and Tigrisoma, both of which have been recovered in basal positions in recent phylogenies of the Ardeidae, and to cf. Pikaihao from the Middle Miocene of Africa. The confluence of mandibular facets on the medial condyle and pterygoid condyle in the new genus, Nycticorax, and cf. Pikaihao is likely to be symplesiomorphic, as it is shared with nearly all other waterbirds (except for the Ciconiidae), including the immediate outgroup (Threskiornithidae). However, the medial supraorbital crest is a likely synapomorphy of the new genus and cf. Pikaihao. The similarities to Trigrisoma support its basal position, as recovered from molecular sequences and proposed by a pre-cladistic morphological analysis. Since both the night herons and Tigrisoma have heads that are proportionally much larger than those of the large day herons, it appears that the Ardeidae started their evolution with relatively heavy heads, which may have contributed to the origins of the family-specific head retraction in flight.


Mercury concentrations in primary feathers reflect pollutant exposure in discrete non-breeding grounds used by Short-tailed Shearwaters
Yutaka Watanuki 1  , Takashi Yamamoto 1, 2, Ai Yamashita 1, Chihiro Ishii 3, Yoshinori Ikenaka 3, Shouta M. M. Nakayama 3, Mayumi Ishizuka 3, Yuya Suzuki 1, Yasuaki Niizuma 4, C. E. Meathrel 5 and R. A. Phillips 6
(1)Graduate School of Fisheries Sciences, Hokkaido University, Minato-cho 3-1-1, Hakodate 041-8611, Japan
(2)Arctic Environment Research Center, National Institute of Polar Research, Midori-cho 10-3, Tachikawa 190-8518, Japan
(3)Graduate School of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Sapporo 060-0818, Japan
(4)Faculty of Agriculture, Meijyo University, Shiogamaguchi 1-501, Tenpaku-ku, Nagoya 468-8502, Japan
(5)LaTrobe University, Wodonga, VIC, 3086, Australia
(6)British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK

Abstract

We measured mercury concentrations ([Hg]) and nitrogen stable isotope ratios (δ15N) in the primary feathers of Short-tailed Shearwaters (Puffinus tenuirostris) that were tracked year-round. The [Hg] were highest in 14 birds that used the Okhotsk and northern Japan Seas during the non-breeding period (2.5 ± 1.4 μg/g), lowest in nine birds that used the eastern Bering Sea (0.8 ± 0.2 μg/g), and intermediate in five birds that used both regions (1.0 ± 0.5 μg/g), with no effects of δ15N. The results illustrate that samples from seabirds can provide a useful means of monitoring pollution at a large spatial scale.