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Wednesday, 23 March 2016

Journal of Ornithology: Volume 157, Issue 2, April 2016

Journal of Ornithology

Volume 157, Issue 2, April 2016

Original Article

From eggs to fledging: negative impact of urban habitat on reproduction in two tit species
Juliette Bailly , Renaud Scheifler, Sarah Berthe, Valérie-Anne Clément-Demange, Matthieu Leblond, Baptiste Pasteur, Bruno Faivre

The exploration of the effects of urbanization on bird demography has attracted much attention, and several studies found lower reproductive success in towns, which suggested strong environmental constraints. Here, we conducted a 3-year study to explore the consequences of urbanization on the breeding success of two species that originated in forests, the Blue Tit Cyanistes caeruleus and the Great Tit Parus major. In two replicates of urban and forest habitats, we studied the components of reproductive success. In one replicate of each habitat, we quantified nestling growth over the three breeding seasons, and we collected data on egg quality during one breeding season. The general picture that emerges from our finding is that in urban sites breeding success was lower with smaller clutch sizes, higher clutch, higher brood failure rates and lower survival rates. Our results also showed reduced growth in urban habitats, at the embryonic and nestling stages, with potential adverse consequences on fitness. Crucial ecological factors could explain the observed contrasts between the habitats, and food limitation is among the most likely. Overall, we demonstrated the negative effects of urbanization on the reproductive success of forest birds, and our results were consistent between species and geographic areas for these negative effects. Our results suggest a mismatch between urban environments and the habitat exploitation abilities that birds have evolved in their native forest ecosystems.

Nest-site selection and consequences for nest survival among three sympatric songbirds in an alpine environment
Elizabeth C. MacDonald , Alaine F. Camfield, Michaela Martin, Scott Wilson, Kathy Martin

We examined timing of breeding, nest site selection and nest survival of Horned Larks (Eremophila alpestris), Savannah Sparrows (Passerculus sandwichensis) and American Pipits (Anthus rubescens) in an alpine habitat on Hudson Bay Mountain, BC, Canada in 2003–2007. These species partitioned their nesting niches temporally and spatially. We compared nest site characteristics among species using one-way ANOVA and logistic regression. Horned Larks (n = 103 nests) initiated breeding 2 weeks earlier (mean = 1 June) than Savannah Sparrows (n = 52, mean = 14 June) and American Pipits (n = 38, mean = 11 June). Horned Larks and American Pipits nested at similar elevations (means = 1714 and 1719 m, respectively); however, lark nests were more exposed (greater bare ground, rock and lichen/moss cover), with minimal nest concealment, while pipit nests, built into banks and soil mounds, had high concealment. Savannah Sparrows nested at lower elevation (mean = 1649 m) with greater dead vegetative cover. We assessed intraspecific habitat preferences for Horned Larks and Savannah Sparrows using logistic regression; both species chose nest sites with greater availability of their preferred habitat characteristics. We used model selection to evaluate effects of nest site characteristics, nest age, season and year on daily nest survival (DNS). Horned Larks displayed the lowest DNS of 0.954 ± 0.009 (n = 189 nests), which varied with year, season and nest age, but was not influenced by site characteristics. In contrast, DNS was highest for Savannah Sparrows (0.961 ± 0.014, n = 89) with strong responses to nest concealment, year and nest age. American Pipits exhibited an intermediate DNS (0.959 ± 0.009, n = 38), which varied with overhead concealment and elevation. Despite the simple structure of the alpine habitat, there was significant niche differentiation in nest site choices among these species. Preferences for nest concealment were positively related to nest survival in Savannah Sparrows and American Pipits but not Horned Larks, indicating how a common environment can differentially influence behavior and demography.

Populations on the limits: survival of Svalbard rock ptarmigan
Sigmund Unander , Åshild Ø. Pedersen  , Eeva M. Soininen, Sebastien Descamps, Maria Hörnell-Willebrand, Eva Fuglei

Predictable variation in demographic patterns among populations inhabiting extreme environments can be used to direct common management actions. Ptarmigan and other grouse are ecologically important herbivores in Arctic and alpine areas, but survival estimates are lacking for many harvested populations. This hampers more detailed assessment of how this key determinant of population growth rate is related to environmental variability and whether there is predictable between–population variation. In this article, we estimated apparent survival by age and sex of the endemic high-Arctic Svalbard rock ptarmigan (Lagopus muta hyperborea) using a 6-year mark–recapture dataset from the west coast of Spitsbergen (1980–1986). Second, we tested whether seasonal climatic variability explained temporal variation in adult survival rates. Within the Svalbard rock ptarmigan population, annual adult survival did not differ between the sexes, but varied among locations. Temporal variation in adult survival was limited and could not be explained by climatic variability. A review of inter-population comparisons of vital rates (survival and reproduction) of rock ptarmigan populations suggested that the high-Arctic, low-elevation Svalbard rock ptarmigan populations resemble their low-Arctic counterparts, and settles at the ‘low survival–high reproduction’ end of the ‘slow–fast continuum’. The demographic traits of high-Arctic ptarmigan contrast with the ‘high survival–low reproduction’ of rock ptarmigan populations at low latitudes and high elevations. Our study demonstrated that spatial variation in survival rates exists both within and between Svalbard rock ptarmigan populations. We suggest that further studies focus on ecological gradients underlying the spatial variation of life history and thus shape the population dynamics and long-term resilience.

Extracting historical population trends using archival ringing data—an example: the globally threatened Aquatic Warbler
Martins Briedis, Oskars Keišs 

Understanding how animal population size changes over time is one of the key means to identify threats and facilitate the successful implementation of conservation measures. The globally endangered Aquatic Warbler has undergone a major decline throughout its range. While in the first half of the 20th century, it was still an abundant species across major parts of Central and Western Europe, over the last century the size of its European population is considered to have declined by more than 90 %. However, little is known of the historical changes in its population size. Here we model the past population size of the Aquatic Warbler using historical ringing records of European ringing schemes and population monitoring software (TRends for Indices and Monitoring). We found that during the short 30-year period between 1950 and 1980 the European Aquatic Warbler population underwent a dramatic 95 % decline. According to this model, the population has recently been stable, no further decline was observed between 1980 and the late 1990s.

Survival of Sooty Falcons (Falco concolor) breeding in Oman
M. J. McGrady , W. A. Al Fazari, M. H. Al Jahdhami, J. E. Hines, M. K. Oli

Although the Middle East supports a high level of avian biodiversity, the ecology of relatively few species that use the region has been studied in detail. Despite its restricted breeding distribution in the Middle East, and apparent unfavorable conservation status, little is known about the population ecology of the Sooty Falcon (Falco concolor), one of only two falcon species that breeds in the boreal summer. We applied multi-state models to capture–mark–recapture data collected during 2007–2014 in the Sultanate of Oman to estimate, for the first time, the probabilities of capture, age-specific breeding probabilities, and state-specific apparent survival for Sooty Falcon. Capture probability for breeding adults (±1SE) was 0.443 ± 0.088. Annual apparent survival probability for pre-breeders and for breeding adults was 0.570 ± 0.048 and 0.656 ± 0.069, respectively. The probability that 2-, 3-, and 4-year-old falcons returned as breeders was 0.065 ± 0.036, 0.159 ± 0.069, and 0.339 ± 0.211, respectively. In 2013, we radio-tagged five fledgling falcons, and monitored their fates using satellite-based tracking. All initiated their first migration and survived for 48 days following radio-tagging, but four of the five birds died by 70 days post-tagging; only one survived >100 days. Our results suggest that only about 12 % of fledglings survive to the average age of first breeding (~3.8 years), and that most of first-year mortality occurs during their first migration or soon after they reach their destination. Low apparent survival of pre-breeders could result in low recruitment to the breeding population, and population declines. A comprehensive population-level assessment is urgently needed to accurately determine the status of Sooty Falcons, and to devise flyway-scale conservation plans.

Shared space, individually used: spatial behaviour of non-breeding ravens (Corvus corax) close to a permanent anthropogenic food source
Matthias-Claudio Loretto , Sabrina Reimann, Richard Schuster, Dana Marie Graulich, Thomas Bugnyar

Natal dispersal is a well-studied phenomenon that can be divided into three stages: (1) starting from an area, (2) wandering to another area and (3) either settling in that area to breed or merely temporarily stopping there before continuing to wander. During the third phase, we can distinguish breeders from non-breeders, which may show similar or different patterns of space use. Breeding Common Ravens are territorial year-round; non-breeders are highly vagrant but may gather at food sources and night roosts for varying lengths of time. In contrast to the wandering phase, little is known about the space use of ravens at such “stop” sites. Here, we used radio telemetry to investigate the space use of 21 non-breeding ravens in the Austrian Alps during a stop stage at an anthropogenic food source. The tagged ravens were present in 69.2 % of the relocation attempts. They used only 27.0 ha (range 6.7–59.7 ha, 95 % utilisation distribution) of the study area, and their activity ranges strongly overlapped with each other. However, within this shared space, sub/adult non-breeders could be found at individually distinct locations, while juveniles showed similar spatial distributions. These results, combined with reported long-distance movements, underline the high behavioural flexibility of non-breeding ravens, which may be a reason for their success in very different habitats throughout the Northern Hemisphere.

Variation in parental care in the spectacled tyrant Hymenops perspicillatus is associated with increased nest predation in grassland fragments
Matías G. Pretelli , Juan P. Isacch, Daniel A. Cardoni

Predation risk on birds is often an important source of natural selection that shapes parental care and may promote behavioral changes. Parents can often estimate certain risks and adjust their behavior to reduce the likelihood of nest predation. The fragmentation of habitats is one of the main consequences of loss of habitats, and in general, for birds breeding in smaller patches, their daily nest-survival rate is lower due to increased nest predation. Since nest survival is an estimate of predation risk in the environment, we evaluated the daily survival rate (DSR) for nests of spectacled tyrants (Hymenops perspicillatus) and parental care behavior on fragmented and unfragmented grasslands. We conducted nest searching and monitoring during the 2012–2013 breeding season in small patches and in a continuous patch of grassland. In addition, parental activity was recorded using video monitoring. We found a lower DSR for the spectacled tyrant in fragmented grasslands, associated with increased nest predation risk; females showed a variation in parental care. This variation was evidenced by larger incubation bouts and lower visitation rate during the incubation period, and by a lower food delivery rate to nestlings, compensated by larger prey sizes. The results show that fragmentation not only reduces the fitness of individuals and impacts adversely on population, but individuals are also subjected to a strong selection pressure, and their reproductive success may depend to some extent on the ability of parents to estimate at least certain predation risk and adjust their behavior in this regard.

Common Cuckoo home ranges are larger in the breeding season than in the non-breeding season and in regions of sparse forest cover
Heather M. Williams , Mikkel Willemoes, Raymond H. G. Klaassen, Roine Strandberg, Kasper Thorup

Knowledge of species’ habitat requirements can be gained from studying individual variation in home range size, under the assumption that larger home ranges reflect increased resource needs or decreased habitat quality. We used satellite telemetry to delineate home ranges of South Scandinavian Common Cuckoos (Cuculus canorus) throughout their annual cycle. Annual stage (breeding or non-breeding period) and percentage of forest cover were good predictors of home range size. Average breeding season home ranges were ten times as large as those of non-breeding home ranges, suggesting strong temporal variation in the birds’ resource needs, and perhaps lower habitat quality in the breeding range compared to the African part of their annual range. Furthermore, although the Cuckoos rarely chose a home range with complete forest cover, we found a significant negative relationship between forest cover and home range area. This suggests that heterogeneous landscapes which include some dense forest cover constitute important habitat for Cuckoos, and that the continuing trend of forest loss in tropical Africa could reduce habitat quality for the Cuckoo in the non-breeding season.

Habitat fragmentation effects and variations in repertoire size and degree of song sharing among close Dupont’s Lark Chersophilus duponti populations
Cristian Pérez-Granados , Tomasz Osiejuk, Germán Manuel López-Iborra

We describe the song type repertoire variation and degree of song sharing in three isolated and declining Dupont’s Lark (Chersophilus duponti) populations located close to each other in eastern Spain, studied over two years. We found no differences between sites either in song rate or individual repertoire size. We detected great differences in song type diversity at the population level, ranging from five to 18 song types. We used, for the first time, the SIMPROF test, a method that objectively discriminates significant groups resulting from agglomerative clustering methods, to study geographic variation in bird song. We found four microdialects in the study area with a low degree of song sharing among populations, which may be related to the influence of habitat fragmentation and the song learning process and ecology of the species. We detected different patterns of song sharing among sites. All males of two populations shared about 80–100 % of their song types throughout the habitat patch. At the other site, we found two microdialects within the same habitat patch, where song types were only shared among neighbouring males. The high degree of song sharing found can be explained by the reduced dispersal movements of the species. We also detected a high consistency in the song types between years. The creation of corridors and habitat management in potential habitat patches surrounding Dupont’s Lark populations could act as stepping-stones, improving the connection between populations and thereby song transmission between patches.

Population genomics of Sociable Weavers Philetairus socius reveals considerable admixture among colonies
Gavin M. Leighton , Sebastian Echeverri

The evolution of sociality often leads to genetic structuring among groups and alters the evolutionary forces that the groups experience. Describing the genetic structuring of social species is, therefore, necessary to understand the selective forces that act on a species. While recent work has used genomic methods to investigate population structure in eusocial insects, relatively little genomic work has examined population structure in the largest non-human mammal and avian clades. We delimited population genetic structuring in Sociable Weavers (Philetairus socius), a passerine that lives in large, stable, perennial colonies, using the genotyping-by-sequencing approach to generate a dataset of several thousand SNPs. We used the SNPs to estimate genetic structuring within and among eight nests. While we document relatively low levels of genetic structuring among nests, the structuring was not explained by distance between nests. We also found significantly higher structuring among male Sociable Weavers compared to female weavers, suggesting that female Sociable Weavers are more prone to dispersal in this species. Not all nests represent distinct genetic groups according to Bayesian clustering analysis, which is unsurprising given the low differentiation among nests, especially compared to other social species. In almost all colonies there was less heterozygosity than expected, possibly due to reproductive skew within each colony.

Molecular cloning and 3D structure prediction of myoglobin and cytoglobin in Eurasian Tree Sparrow Passer montanus
Lina Wu, Yanfeng Sun, Mo Li, Yaqing Li, Yao Yao, Xuelu Liu, Yinchao Hao, Dongming Li , Yuefeng Wu 

In vertebrates, myoglobin (Mb) and cytoglobin (Cygb) are closest relatives in the family of globins, which are heme-containing proteins that can bind gaseous molecules. Mb acts not only as an O2 transporter but also a nitric oxide (NO) scavenger in cardiac and striated muscle. Cygb has been suggested to play important functions in lipid-based signaling processes, defense against reactive oxygen species (ROS), and nitric oxide (NO) metabolism, and it is present in a variety of cell types. However, little information about the structures and functions of Mb and Cygb is known in birds. Here, we cloned the full-length open reading frames (ORFs) of the two globins in Eurasian Tree Sparrow (Passer montanus). The Mb ORF cDNA contains 465 base pairs (bp) encoding 154 amino acids (aa), and the Cygb ORF cDNA contains 540 bp encoding 179 aa. Our results show that the amino acid sequences and three-dimensional (3D) structures of Mb and Cygb are highly conserved in vertebrate species. Interestingly, two specific substitutions were detected in Cygb compared with other vertebrates, which resulted in slight variation of the 3D conformation (e.g., distance between Tyr H16 and Lys G8, the strength of hydrogen bonds, and angles between the G–H helices). Our results may contribute to further understanding the structures, properties, and functions of Mb and Cygb as well as the potential mechanisms of oxygen utilization pathways in vertebrates.

Complete mitochondrial genomes render the Night Heron genus Gorsachius non-monophyletic
Xiaoping Zhou, Chengte Yao, Qingxian Lin, Wenzhen Fang , Xiaolin Chen 

In the present study, the complete mitochondrial genomes of three Night Herons from the genus Gorsachius were sequenced. All the complete mitochondrial genomes in this genus exhibit duplications in the region between cytochrome b and 12S ribosomal RNA. In Gorsachius magnificus, the duplicated regions span from the last 108 base pairs of cytochrome b to the control region, which are nearly identical to each other in nucleotide sequences, suggesting they are evolving in concert. In G. goisagi and G. melanolophus, the duplicated control regions were nearly identical in majority portions within each individual, while the first tRNA Pro -ND6-tRNA Glu and the second Cytb-tRNA Thr regions have degenerated into non-coding regions. Phylogenetic analyses with Bayesian inference and maximum likelihood based on the nucleotide sequences of two ribosomal RNA genes and 12 protein coding genes indicate that G. magnificus is not monophyletic with the other two Gorsachius species. These new results provide the fundamental basis for further studies to elucidate their phylogenetic positions and relationships with other genera within the subfamily Ardeinae.

Measuring difference in edge avoidance in grassland birds: the Corncrake is less sensitive to hedgerow proximity than passerines
Aurélien G. Besnard , Yoan Fourcade  , Jean Secondi

Edge avoidance is an important feature of habitat selection in grassland birds, as their density is usually reduced close to habitat boundaries. In many extensively managed European grasslands, fragmentation is caused by the presence of wooded hedgerows dividing meadows. Comparing the magnitude of hedgerow avoidance by co-occurring species is essential for the management of grassland areas and the implementation of efficient conservation schemes. We quantified hedgerow avoidance by the Corncrake and four grassland passerines in western France. As expected, all species avoided hedgerows, but the effect was less pronounced for the Corncrake. We hypothesize that this may reflect a lower predation risk towards the larger and most inconspicuous species. Alternatively, social communication in Corncrakes may be less impeded by wooded vegetation than in passerines. However, the mechanisms responsible for the observed pattern remain uncertain. Nevertheless, our study provides a general technique that can be applied to measure boundary avoidance. This information is important for policymakers in their efforts to improve management guidelines, which often do not take edge effects into account.

High prevalence of Leucocytozoon parasites in fresh water breeding gulls
Magdalena Zagalska-Neubauer , Staffan Bensch

Seabirds are regarded as a group of species with relatively low levels or even complete lack of blood parasites. We used PCR to amplify a DNA fragment from the cytochrome b gene of the parasites to search for infections of the genera Plasmodium, Haemoproteus and Leucocytozoon in individuals of two sympatrically breeding gull species, the Herring Gull Larus argentatus, the Caspian Gull Larus cachinnans and their hybrids. Out of 56 analysed individuals, 53 (95 %) were identified as infected with Leucocytozoon, whereas three individuals carried double and triple infections with at least one Leucocytozoon and one Plasmodium lineages. No Haemoproteus lineage was detected. The most common lineage (LARCAC02), for the first time reported here, was found in 51 (96 %) of all infected birds, and 14 gulls carried two Leucocytozoon lineages. We analysed the evolutionary relationship of Leucocytozoon lineages from the Herring and Caspian Gull and other bird species. Our results show that (1) the two identified Leucocytozoon lineages are not closely related as they belong to two distinctly different clusters. Moreover, (2) seabirds breeding inland could be highly infected with blood parasites and (3) this high prevalence is probably associated with areas where parasite vectors are abundant. Further studies should explore the importance of environmental factors affecting parasite prevalence, in particular within species comparisons under different environment conditions, including vector monitoring and sampling.

Avian haemosporidian prevalence and its relationship to host life histories in eastern Tennessee
Alix E. Matthews, Vincenzo A. Ellis, Alison A. Hanson, Jackson R. Roberts, Robert E. Ricklefs, Michael D. Collins 

Haemosporidian parasites (genera Plasmodium and Haemoproteus) are common blood parasites of birds transmitted by dipteran insect vectors. We analyzed blood samples from 329 individuals of 43 bird species in eastern Tennessee to better understand the relationship between the local community of birds and their blood parasites, including the distribution of parasites across hosts and the underlying ecological factors and life -history traits that influence parasite prevalence across host species. Using molecular methods, we found 144 individuals of 25 species to be infected with haemosporidian parasites (overall prevalence of 44 %). We distinguished 22 genetic lineages, including 11 in the genus Haemoproteus and 11 in Plasmodium. Fourteen percent of infected individuals harbored more than one parasite lineage. Across species, total prevalence increased with local abundance and decreased with incubation period, but did not vary with nesting or foraging height, average annual survival of host species, migratory or flocking behavior, sexual dimorphism, average species mass, or among sites. The prevalence of Haemoproteus was higher in species that nest 1–5 m above ground than in species that nest below 1 m or above 5 m, and the prevalence of Plasmodium was marginally higher in species with open-cup nests. Infection status did not vary with age, sex, or body condition. Our research reveals substantial variation in prevalence and richness of haemosporidian parasites, some of which is related to specific avian life history traits.

First molecular study of prevalence and diversity of avian haemosporidia in a Central California songbird community
Erika L. Walther , Jenny S. Carlson, Anthony Cornel, Brett K. Morris, Ravinder N. M. Sehgal

We studied avian haemosporidian parasites of the genera Plasmodium, Haemoproteus and Leucocytozoon in a riparian songbird community in Central California, USA, over a period of 2 years. We sequenced a well-characterized region of the mitochondrial cytochrome b gene to identify the prevalence and diversity of these parasites from 399 birds. Of the 39.8 % of birds infected with haemosporidian parasites, most (30.8 %) were infected with Plasmodium. We identified 35 lineages, including 13 from the Plasmodium genus, 12 from Haemoproteus, and 10 from Leucocytozoon, 14 of which were novel lineages. In addition, we provide the first report of haemosporidian infections in 13 host species. Plasmodium prevalence ranged widely among host species from 0.0 to 68.6 %. We identified 2 Plasmodium lineages that were generalists, infecting multiple species across several families. One Plasmodium species, P. homopolare, was found in 84 individual birds representing 9 host species from 5 families, but primarily from Emberizidae. This is the first avian haemosporidian study utilizing molecular methods in California, which increases our understanding of the diversity and prevalence of avian haemosporidia affecting Passeriformes in this region and beyond.

Shell thinning due to embryo development in eggs of a small passerine bird
Grzegorz Orłowski , Lucyna Hałupka, Ewelina Klimczuk, Hanna Sztwiertnia

Over four study years we have investigated hatching success and failure, the presence of an embryo and other egg biometrics, and eggshell thickness of the Eurasian Reed Warbler Acrocephalus scirpaceus. Of 1354 eggs from 350 nests, 940 (69.4 %) survived until hatching, of which 159 (16.9 %) were incubated but failed to hatch, while 273 (20.2 % of all) were in nests destroyed during incubation. Of 161 intact unhatched eggs from 97 nests, 64 (39.8 %) had no visible embryo and 88 (54.7 %) had a visible embryo. Eggs without visible embryos were present in 42.7 % of normally incubated clutches; among deserted clutches over 50 % had no visible embryo. Eggshell thickness at the egg equator (the widest part) was negatively correlated with clutch size and the presence of an embryo. A similar relationship was found for the blunt end of the eggs but was not statistically significant. Shells at the equator of eggs with visible embryos were significantly thinner (on average 8.0 % less) than the shells of eggs without embryos. Our study clearly implies that shell thickness decreases in the course of embryonic development. It also indicates that comparison of eggshell thickness data without controlling for the presence of an embryo in eggs can produce biased results, and may, therefore, fail to identify the actual causes of eggshell thinning. Our findings also suggest that shell thickness at the blunt end is a reliable estimator of shell thickness, irrespective of embryonic development.

Spatial effects of artificial feeders on hummingbird abundance, floral visitation and pollen deposition
Jesper Sonne , Peter Kyvsgaard, Pietro Kiyoshi Maruyama, Jeferson Vizentin-Bugoni, Jeff Ollerton, Marlies Sazima, Carsten Rahbek, Bo Dalsgaard

Providing hummingbirds with artificial feeders containing sugar solution is common practice throughout the Americas. Although feeders can affect hummingbird foraging behavior and abundance, it is poorly understood how far this effect may extend. Moreover, it remains debated whether nectar-feeders have a negative impact on hummingbird-pollinated plants by reducing flower visitation rates and pollen transfer close to the feeders. Here, we investigated the effects of distance to nectar-feeders on a local hummingbird assemblage and the pollination of Psychotria nuda (Rubiaceae), a hummingbird-pollinated plant endemic to the Brazilian Atlantic Rainforest. At increasing distance (0–1000 m) from a feeding-station, where hummingbirds have been fed continuously for the past 13 years, we quantified hummingbird abundance, and rates of flower visitation and pollen deposition on P. nuda. We found that hummingbird abundance was unrelated to distance from the feeders beyond ca. 75 m, but increased steeply closer to the feeders; the only exception was the small hummingbird Phaethornis ruber, which remained absent from the feeders. Plants of P. nuda within ca.125 m from the feeders received increasingly more visits, coinciding with the higher hummingbird abundance, whereas visitation rate beyond 125 m showed no distance-related trend. Despite this, pollen deposition was not associated with distance from the feeders. Our findings illustrate that artificial nectar-feeders may locally increase hummingbird abundance, and possibly affect species composition and pollination redundancy, without necessarily having a disruptive effect on pollination services and plants’ reproductive fitness. This may apply not only to hummingbirds, but also to other animal pollinators.

Physiological conditions influence stopover behaviour of short-distance migratory passerines
Sara Lupi , Wolfgang Goymann, Massimiliano Cardinale, Leonida Fusani

During migration, birds spend more than 80 % of the time at stopover sites to rest and refuel before and after crossing ecological barriers such as deserts or seas. Since stopover has intrinsic costs in terms of energy and time, birds should try to minimize its duration, which is dependent on the combined effects of environmental factors, endogenous programmes, and physiological conditions. Previous studies on long-distance migrants caught after crossing an ecological barrier have indicated that body condition strongly influences the decision whether to prolong stopover or resume migration, with lean birds staying longer than fat birds. In short-distance migrants, evidence is still scarce regarding a determinant role for physiological condition in stopover behaviour after crossing an ecological barrier. Here, we studied whether migratory restlessness (Zugunruhe) at a stopover site is dependent on physiological condition in three European short-distance migratory passerines: black redstarts, European robins, and European stonechats. In all species, an integrated measure of condition based on body mass, amount of subcutaneous fat, and thickness of pectoral muscles predicted the intensity of Zugunruhe. Overall, our results confirmed the importance of energy reserves in determining stopover duration, illustrating similar stopover strategies in short- and long-distance migrants.

Spatial variation in haemoglobin concentration of nestling Blue Tits (Cyanistes caeruleus): a long-term perspective
Michał Glądalski , Mirosława Bańbura, Adam Kaliński, Marcin Markowski, Joanna Skwarska, Jarosław Wawrzyniak, Piotr Zieliński, Jerzy Bańbura

An understanding of the influences of anthropogenic disturbance and variation in habitat quality on organism condition and breeding success may improve future management and conservation decisions. Some authors consider haemoglobin concentration to be a simple biochemical indicator of bird condition. The main goal of this paper is to examine if the level of haemoglobin displays any consistent pattern of variation across habitats differing in quality. We present results concerning long-term variation in haemoglobin concentration in the blood of about 14-day-old nestling Blue Tits (Cyanistes caeruleus) in central Poland in an 11-year period (2003–2013), in two landscapes (an urban parkland and a deciduous forest). The most important findings of the study are: (1) the concentration of haemoglobin of the nestlings from the same brood tended to be consistently similar, with most variation occurring between broods, (2) mean levels of haemoglobin varied between years, and were correlated with caterpillar abundance peaks in the forest study site, (3) mean haemoglobin concentration was significantly higher in the forest area than in the parkland area, (4) haemoglobin levels were positively correlated with breeding and fledging success. We confirmed that haemoglobin concentration displays a spatio-temporal pattern and that the level of haemoglobin is a reliable condition and habitat quality indicator in nestling Blue Tits in the study populations. Although, strictly speaking, the analysed differences are between two particular sites, we think that they reflect differences between urban and non-urban habitats.

Stress response assessment during translocation of captive-bred Greater Rheas into the wild
A. Lèche , M. Vera Cortez, N. S. Della Costa, J. L. Navarro, R. H. Marin, M. B. Martella

Translocation is an extensively used conservation tool that involves exposing animals to stressful situations that may influence the post-release survival. In this study, 20 Greater Rhea (Rhea americana) adults hatched and reared in captivity were translocated to a wildlife refuge. After transport and before release, animals were kept in pens at the liberation site to make a “soft-release” strategy. Fecal glucocorticoid metabolites (FGM) were monitored during pre-transportation, post-transportation and pre-release, and post-release phases as an indicator of the stress of translocation and acclimation to the new environment. During pre-transportation phase, FGM levels found were consistent with the baseline concentrations described for this species for males and females, respectively. On day 1 after transportation, FGM levels were increased in both sexes, returning to baseline values during the maintenance in the pens. Although the handling and transportation triggered an acute stress response, the procedures used and the soft release in pens allowed Rheas to reestablish quickly baseline FGM levels. After release into the novel wildlife refuge, FGM levels were increased again and remained similarly increased during the following 2 months of the study. Findings suggest a strong chronic stress response, probably triggered by a combination of many factors (i.e. novelty, attacks from predators, social interactions, human related disturbances such as poaching, vehicular noise, hunting dogs) that may reduce the bird’s ability to solve new challenging situations, especially the illegal hunting pressure that seems to be a significant threat in this species.

Genetic evidence of female specific eggshell colouration in the Common Crane (Grus grus)
Henriette Höltje , Wolfgang Mewes, Martin Haase, Angela Schmitz Ornés

The large variation in colouration and patterning of bird eggs suggests a variety of functions. For instance, in cases of intra- and inter-specific brood parasitism, the recognition of own eggs by the parents could be essential for their reproductive success. However, individual specific signatures may also be of interest from an applied point of view, as it would be possible to monitor individual females across breeding seasons by identifying their eggs. This would be of particular importance for species that are difficult to catch and ring such as the Common Crane (Grus grus). Since 2004, nest monitoring of this species has been conducted by one of us (W.M.) in north-east Germany, which led to the development of a semi-quantitative method to identify female cranes by diagnostic egg features including ground colour and spots of eggshells. In order to verify this approach, we quantitatively determined the spot patterns on eggshells from eggs of 19 females identified by this method. We used standardised photographs of the eggs laid across three seasons and the computer program “Egg Shell Pattern ANAlysis” (ESPANA). The resulting data were statistically analysed by conducting principal coordinate analyses and analyses of similarity. To prove the identity of the putative females, we extracted DNA for microsatellite analyses from eggshell pieces collected after hatching from up to seven breeding seasons. Our analyses confirmed that Common Cranes lay eggs with individual specific patterns and confirmed the reliability of the semi-quantitative method of identification. Microsatellite genotypes based on nine loci were identical for all samples from each particular, putative female. Therefore, the semi-quantitative approach of identifying females based on their clutches is indeed an innovative monitoring tool that will make many species accessible for addressing important issues in population biology, ecology and conservation.

Annual cycle and migration strategies of a habitat specialist, the Tawny Pipit Anthus campestris, revealed by geolocators
Martins Briedis , Václav Beran, Steffen Hahn, Peter Adamík

Habitat specialist species occupy narrow ecological niches, typically utilizing similar habitat types throughout the annual cycle. Their strict requirements for specific habitats may make them vulnerable to environmental changes, especially in small, local populations. Therefore, detailed knowledge of the species’ ecology is crucial for conservation purposes. In this study, we used light-level geolocators to identify migration routes and non-breeding areas of a distinct specialist for dry habitats, the Tawny Pipit Anthus campestris, from a currently declining central European breeding population. During autumn and spring migration, the majority of the birds followed a route along the northwest of the Alps and via the Iberian Peninsula, with stopover sites mainly in northern Africa. In each migration season, however, one of two different individuals took a detour around the eastern side of the Alps. When crossing the main ecological barrier, the Sahara Desert, three of six birds followed the Atlantic coastline in autumn, whereas all five birds migrated near the coast in spring. Non-breeding areas of all tracked pipits were uniformly located in the Western Sahel, with five of six birds utilizing two main non-breeding sites, the second of which was always located west of the first. On average, the tracked birds spent 48 % of the year at the non-breeding areas, 27 % on migration, and 25 % at the breeding site. Our findings demonstrate strong migratory connectivity in Tawny Pipits which may have future implications for conservation of this long-distance migrant.

Speciose opportunistic nectar-feeding avifauna in Cuba and its association to hummingbird island biogeography
Bo Dalsgaard , Andrea C. Baquero, Carsten Rahbek, Jens Mogens Olesen, James W. Wiley

Island organisms often have wider feeding niches than mainland organisms, and migratory birds breeding on continents often widen their niches when overwintering on islands. Cuba’s low hummingbird richness has puzzled ornithologists for decades. Here, we show that the Cuban hummingbird fauna is less rich than expected based on Cuba’s elevation, when compared to the rest of the West Indian islands. Thereafter, we report nectar-feeding behaviour by 26 non-Trochilidae bird species in Cuba, encompassing pigeons/doves, woodpeckers and passerines, and endemic, resident and migratory species. We discuss if Cuba’s speciose non-Trochilidae nectar-feeding avifauna may be associated with its depauperate hummingbird fauna.

Hot footing eggs: thermal imaging reveals foot mediated incubation in White-tailed Tropicbirds, Phaethon lepturus
Lorinda A. Hart, Colleen T. Downs , M. Brown

Birds generally incubate eggs by transferring body heat from an exposed abdominal area known as a brood patch. However, there are exceptions to this where some species use foot-mediated incubation. It was previously thought that, although White-tailed Tropicbirds, Phaethon lepturus, lack a brood patch, the heat generated by their feet was too low to incubate their eggs. Using modern thermal imaging techniques, our results indicate the opposite, revealing that tropicbird feet are an important heat source when incubating their eggs.

Isolation, characterization and multiplex PCR development of Bean Goose (Anser fabalis) microsatellite loci
Oddmund Kleven , Rolf T. Kroglund, Jan E. Østnes

DNA from non-invasively collected samples may be used to identify individuals for monitoring birds. Here we describe 36 novel microsatellite loci from Bean Goose (Anser fabalis) identified using a next-generation sequencing approach. From 34 variable loci, we selected 12 tetranucleotide loci with short amplicon sizes, combined these into two multiplex PCR sets, and included a sex-typing marker. In 31 Bean Geese from a population in central Norway, we found 4–10 alleles per locus and observed heterozygosity ranging from 0.58 to 0.87. The combined probability of identity for the 12 loci was 6.5 × 10−13. These novel microsatellite loci and their multiplex PCR assays will be useful for genetic analyses of the Bean Goose, including typing of non-invasive samples such as molted feathers. Cross-species application of the two multiplex PCR assays revealed that all 12 loci amplified successfully in four other Anser species.

No evidence for effects of formalin storage duration or solvent medium exposure on avian sperm morphology
Tim Schmoll , Romina Sanciprian, Oddmund Kleven

Morphometric analysis of avian spermatozoa from sperm samples preserved in formalin is a frequently adopted procedure in basic science (e.g. evolutionary ecology) and applied disciplines (e.g. animal breeding). Many research questions such as individual-based longitudinal studies of sperm traits require comparisons of formalin-stored sperm samples collected across multiple sampling events, which may be separated by years. Such analyses presuppose that prolonged storage in formalin does not affect sperm morphology, an assumption often implicitly made in the analysis of avian sperm morphology. This assumption, however, has never been tested, although for many study designs a potential effect of sperm storage duration may well confound the focal analysis. Based on pairwise comparisons of 22 experimental ejaculates from three passerine bird species, we found no evidence that differential storage duration of more than 1 year had affected the total length of spermatozoa stored in a 5 % formaldehyde solution. This suggests that formalin-stored sperm samples from long-term studies or museum collections can be merged in combined analyses without confounding differential storage duration with natural between-year variation in sperm dimensions or age effects in longitudinal studies. Based on pairwise comparisons of 29 split ejaculates, we also found no evidence that spermatozoa differed in length when solved initially in either phosphate buffered saline or Dulbecco’s Modified Eagle Medium, a standard medium for videotaping live sperm, prior to preservation and storage in formalin. Sperm samples treated differently in this respect may thus be merged into combined analyses, too.

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