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Thursday, 26 May 2016

What's new for 'birdRS' in PubMed. May 2016, Week 3

birdRS - Latest Research News

PubMed Results
1.Molecular Ecological Insights into Neotropical Bird-Tick Interactions.
Miller MJ, Esser HJ, Loaiza JR, Herre EA, Aguilar C, Quintero D, Alvarez E, Bermingham E.
PLoS One. 2016 May 20;11(5):e0155989. doi: 10.1371/journal.pone.0155989. eCollection 2016.


In the tropics, ticks parasitize many classes of vertebrate hosts. However, because many tropical tick species are only identifiable in the adult stage, and these adults usually parasitize mammals, most attention on the ecology of tick-host interactions has focused on mammalian hosts. In contrast, immature Neotropical ticks are often found on wild birds, yet difficulties in identifying immatures hinder studies of birds' role in tropical tick ecology and tick-borne disease transmission. In Panama, we found immature ticks on 227 out of 3,498 individually-sampled birds representing 93 host species (24% of the bird species sampled, and 13% of the Panamanian land bird fauna). Tick parasitism rates did not vary with rainfall or temperature, but did vary significantly with several host ecological traits. Likewise, Neotropical-Nearctic migratory birds were significantly less likely to be infested than resident species. Using a molecular library developed from morphologically-identified adult ticks specifically for this study, we identified eleven tick species parasitizing birds, indicating that a substantial portion of the Panamanian avian species pool is parasitized by a diversity of tick species. Tick species that most commonly parasitized birds had the widest diversity of avian hosts, suggesting that immature tick species are opportunistic bird parasites. Although certain avian ecological traits are positively associated with parasitism, we found no evidence that individual tick species show specificity to particular avian host ecological traits. Finally, our data suggest that the four principal vectors of Rocky Mountain Spotted Fever in the Neotropics rarely, if ever, parasitize Panamanian birds. However, other tick species that harbor newly-discovered rickettsial parasites of unknown pathogenicity are frequently found on these birds. Given our discovery of broad interaction between Panamanian tick and avian biodiversity, future work on tick ecology and the dynamics of emerging tropical tick-borne pathogens should explicitly consider wild bird as hosts.

PMID: 27203693 [PubMed - as supplied by publisher]

2.Complete Genome Sequence of a Novel Avian Paramyxovirus (APMV-13) Isolated from a Wild Bird in Kazakhstan.
Karamendin K, Kydyrmanov A, Seidalina A, Asanova S, Sayatov M, Kasymbekov E, Khan E, Daulbayeva K, Harrison SM, Carr IM, Goodman SJ, Zhumatov K.
Genome Announc. 2016 May 19;4(3). pii: e00167-16. doi: 10.1128/genomeA.00167-16.


A novel avian paramyxovirus was identified during annual viral surveillance of wild bird populations in Kazakhstan in 2013. The virus was isolated from a white fronted goose (Anser albifrons) in northern Kazakhstan. Here, we report the complete genome sequence of the isolate, which we suggest should constitute a novel serotype.
PMID: 27198008 [PubMed]

3.Determinants of bird conservation action implementation and associated population trends of threatened species.
Luther DA, Brooks TM, Butchart SH, Hayward MW, Kester ME, Lamoreux J, Upgren A.
Conserv Biol. 2016 May 16. doi: 10.1111/cobi.12757. [Epub ahead of print]


Conservation actions, such as habitat protection, attempt to halt the loss of threatened species and help their populations to recover. Various research has examined the efficiency and the effectiveness of actions individually. However, conservation actions generally occur simultaneously so the full suite of implemented conservation actions should be assessed. We used the conservation actions underway for all threatened and near-threatened birds of the world (IUCN Red List of Threatened Species) to assess which biological (related to taxonomy and ecology) and anthropogenic (related to geo-economics) factors are associated with the implementation of different classes of conservation actions. We also assessed which conservation actions are associated with population increases in the species targeted. Extinction risk category was the strongest single predictor of the type of conservation actions implemented, followed by landmass type (continent, oceanic island, etc.) and generation length. Species targeted by invasive alien species control/eradication programs, ex situ conservation, international legislation, reintroduction, or education and awareness-raising activities were more likely to have increasing populations. These results illustrate the importance of developing a predictive science of conservation actions and the relative benefits of each class of implemented conservation action for threatened and near-threatened birds worldwide. This article is protected by copyright. All rights reserved.
PMID: 27197021 [PubMed - as supplied by publisher]

4.Rhythmic Continuous-Time Coding in the Songbird Analog of Vocal Motor Cortex.
Lynch GF, Okubo TS, Hanuschkin A, Hahnloser RH, Fee MS.
Neuron. 2016 May 18;90(4):877-92. doi: 10.1016/j.neuron.2016.04.021.


Songbirds learn and produce complex sequences of vocal gestures. Adult birdsong requires premotor nucleus HVC, in which projection neurons (PNs) burst sparsely at stereotyped times in the song. It has been hypothesized that PN bursts, as a population, form a continuous sequence, while a different model of HVC function proposes that both HVC PN and interneuron activity is tightly organized around motor gestures. Using a large dataset of PNs and interneurons recorded in singing birds, we test several predictions of these models. We find that PN bursts in adult birds are continuously and nearly uniformly distributed throughout song. However, we also find that PN and interneuron firing rates exhibit significant 10-Hz rhythmicity locked to song syllables, peaking prior to syllable onsets and suppressed prior to offsets-a pattern that predominates PN and interneuron activity in HVC during early stages of vocal learning.
PMID: 27196977 [PubMed - in process]

5.Continuous Time Representations of Song in Zebra Finches.
Troyer TW.
Neuron. 2016 May 18;90(4):672-4. doi: 10.1016/j.neuron.2016.05.013.


Neurons in the songbird nucleus HVC produce premotor bursts time locked to song with millisecond precision. In this issue of Neuron, Lynch et al. (2016) and Picardo et al. (2016) provide convincing evidence that the population of these bursts contain a continuous representation of time throughout song.
PMID: 27196971 [PubMed - in process]

Vaughan-Higgins R, Vitali S, Reiss A, Besier S, Hollingsworth T, Smith G.
J Wildl Dis. 2016 May 19. [Epub ahead of print]


Published avian reference ranges for plasma cholinesterase (ChE) and brain acetylcholinesterase (AChE) are numerous. However, a consistently reported recommendation is the need for species- and laboratory-specific reference ranges because of variables, including assay methods, sample storage conditions, season, and bird sex, age, and physiologic status. We developed normal reference ranges for brain AChE and plasma total ChE (tChE) activity for Carnaby's Black-Cockatoos (Calyptorhynchus latirostris) using a standardized protocol (substrate acetylthiocholine at 25 C). We report reference ranges for brain AChE (19-41 μmol/min per g, mean 21±6.38) and plasma tChE (0.41-0.53 μmol/min per mL, mean 0.47±0.11) (n=15). This information will be of use in the ongoing field investigation of a paresis-paralysis syndrome in the endangered Carnaby's Black-Cockatoos, suspected to be associated with exposure to anticholinesterase compounds and add to the paucity of reference ranges for plasma tChE and brain AChE in Australian psittacine birds.
PMID: 27195690 [PubMed - as supplied by publisher]

7.Impact of Management on Avian Communities in the Scottish Highlands.
Newey S, Mustin K, Bryce R, Fielding D, Redpath S, Bunnefeld N, Daniel B, Irvine RJ.
PLoS One. 2016 May 19;11(5):e0155473. doi: 10.1371/journal.pone.0155473. eCollection 2016.


The protection of biodiversity is a key national and international policy objective. While protected areas provide one approach, a major challenge lies in understanding how the conservation of biodiversity can be achieved in the context of multiple land management objectives in the wider countryside. Here we analyse metrics of bird diversity in the Scottish uplands in relation to land management types and explore how bird species composition varies in relation to land managed for grazing, hunting and conservation. Birds were surveyed on the heather moorland areas of 26 different landholdings in Scotland. The results indicate that, in relation to dominant management type, the composition of bird species varies but measures of diversity and species richness do not. Intensive management for grouse shooting affects the occurrence, absolute and relative abundance of bird species. While less intensive forms of land management appear to only affect the relative abundance of species, though extensive sheep grazing appears to have little effect on avian community composition. Therefore enhanced biodiversity at the landscape level is likely to be achieved by maintaining heterogeneity in land management among land management units. This result should be taken into account when developing policies that consider how to achieve enhanced biodiversity outside protected areas, in the context of other legitimate land-uses.
PMID: 27195486 [PubMed - in process] Free Article

8.Long-term climate impacts on breeding bird phenology in Pennsylvania, USA.
McDermott ME, DeGroote LW.
Glob Chang Biol. 2016 May 19. doi: 10.1111/gcb.13363. [Epub ahead of print]


Climate change is influencing bird phenology worldwide, but we still lack information on how many species are responding over long temporal periods. We assessed how climate affected passerine reproductive timing and productivity at a constant effort mist-netting station in western Pennsylvania using a model comparison approach. Several lines of evidence point to the sensitivity of 21 breeding passerines to climate change over five decades. The trends for temperature and precipitation over 53 years were slightly positive due to intraseasonal variation, with the greatest temperature increases and precipitation declines in early spring. Regardless of broodedness, migration distance, or breeding season, 13 species hatched young earlier over time with most advancing >3 days per decade. Warm springs were associated with earlier captures of juveniles for 14 species, ranging from 1-3 days advancement for every 1°C increase. This timing was less likely to be influenced by spring precipitation; nevertheless, higher rainfall was usually associated with later appearance of juveniles and breeding condition in females. Temperature and precipitation were positively related to productivity for seven and eleven species, respectively, with negative relations evident for six and eight species. We found that birds fledged young earlier with increasing spring temperatures, potentially benefiting some multi-brooded species. Indeed, some extended the duration of breeding in these warm years. Yet, a few species fledged fewer juveniles in warmer and wetter seasons, indicating that expected future increases could be detrimental to locally breeding populations. Although there were no clear relationships between life history traits and breeding phenology, species-specific responses to climate found in our study provide novel insights into phenological flexibility in songbirds. Our research underscores the value of long-term monitoring studies and the importance of continuing constant effort sampling in the face of climate change. This article is protected by copyright. All rights reserved.
PMID: 27195453 [PubMed - as supplied by publisher]

9.How to reduce the costs of ornaments without reducing their effectiveness? An example of a mechanism from carotenoid-based plumage.
Surmacki A, Ragan A, Kosiński Z, Tobółka M, Podkowa P.
Behav Ecol Sociobiol. 2016;70:695-700. Epub 2016 Feb 29.

Carotenoid-based ornaments are often considered to be honest indicators of individual quality assessed by potential mates. However, males can use a variety of strategies that minimize the amount of costly carotenoids used while retaining the effectiveness of color signaling. Birds could do this by altering pigment intake, metabolism, or its presentation to a potential signal receiver. Here, we propose a new mechanism of lowering the costs of carotenoid displays in birds: differential allocation of pigments within single feathers. We studied the coloration of the yellow terminal tail bands of rectrices of male Bohemian waxwings. Using reflectance spectrometry, we show that the two central rectrices are most intensively colored compared to other rectrices. More detailed analyses reveal that these differences result from feather-specific patterns of rectrices coloration. The outer feather vanes of the outermost rectrices are more intensively colored compared to the inner vanes. However, the central rectrices have equally colored vanes that are, on average, more intensively pigmented than the outermost rectrices. When the waxwing tail is folded, the outermost rectrices are covered by other feathers, except for the narrow, outer vane. Central rectrices, however, form the outermost layers which are not obscured by other tail feathers. Thus, the feather vanes that are the most visible to potential viewers are also the most pigmented. These results support the occurrence of a previously overlooked mechanism to reduce the costs of carotenoid-based ornaments: precise pigment distribution to maximize efficiency of signals within single feathers.

Males of many bird species use bright carotenoid-based plumage coloration to attract females. These traits are physiologically expensive such that only individuals in prime condition can develop the most vivid colors. Males often "cheat" to obtain attractive appearances at lower costs. We showed that this goal could be achieved by differential deposition of pigments into the most conspicuous feather regions. Bohemian waxwing males have yellow tips on their rectrices of which the outer vanes are more brightly colored compared to the inner vanes. These inner feather vanes are usually covered by other feathers and are, thus, less visible to conspecifics. The only exception is the pair of central rectrices that are fully exposed, and both feather vanes are equally colored. In this species, males minimize the use of costly carotenoid pigments while maintaining elaborate ornamentation of plumage regions that are most visible to potential mates.
PMID: 27194821 [PubMed]

10.Food supplementation mitigates dispersal-dependent differences in nest defence in a passerine bird.
Récapet C, Daniel G, Taroni J, Bize P, Doligez B.
Biol Lett. 2016 May;12(5). pii: 20160097. doi: 10.1098/rsbl.2016.0097.


Dispersing and non-dispersing individuals often differ in phenotypic traits (e.g. physiology, behaviour), but to what extent these differences are fixed or driven by external conditions remains elusive. We experimentally tested whether differences in nest-defence behaviour between dispersing and non-dispersing individuals changed with local habitat quality in collared flycatchers, by providing additional food during the nestling rearing period. In control (non-food-supplemented) nests, dispersers were less prone to defend their brood compared with non-dispersers, whereas in food-supplemented nests, dispersing and non-dispersing individuals showed equally strong nest defence. We discuss the importance of dispersal costs versus adaptive flexibility in reproductive investment in shaping these differences in nest-defence behaviour between dispersing and non-dispersing individuals. Irrespective of the underlying mechanisms, our study emphasizes the importance of accounting for environmental effects when comparing traits between dispersing and non-dispersing individuals, and in turn assessing the costs and benefits of dispersal.
PMID: 27194287 [PubMed - in process]

11.Bone-associated gene evolution and the origin of flight in birds.
Machado JP, Johnson WE, Gilbert MT, Zhang G, Jarvis ED, O'Brien SJ, Antunes A.
BMC Genomics. 2016 May 18;17(1):371. doi: 10.1186/s12864-016-2681-7.


Bones have been subjected to considerable selective pressure throughout vertebrate evolution, such as occurred during the adaptations associated with the development of powered flight. Powered flight evolved independently in two extant clades of vertebrates, birds and bats. While this trait provided advantages such as in aerial foraging habits, escape from predators or long-distance travels, it also imposed great challenges, namely in the bone structure.
We performed comparative genomic analyses of 89 bone-associated genes from 47 avian genomes (including 45 new), 39 mammalian, and 20 reptilian genomes, and demonstrate that birds, after correcting for multiple testing, have an almost two-fold increase in the number of bone-associated genes with evidence of positive selection (~52.8 %) compared with mammals (~30.3 %). Most of the positive-selected genes in birds are linked with bone regulation and remodeling and thirteen have been linked with functional pathways relevant to powered flight, including bone metabolism, bone fusion, muscle development and hyperglycemia levels. Genes encoding proteins involved in bone resorption, such as TPP1, had a high number of sites under Darwinian selection in birds.

Patterns of positive selection observed in bird ossification genes suggest that there was a period of intense selective pressure to improve flight efficiency that was closely linked with constraints on body size.
PMID: 27193938 [PubMed - in process] Free Article

12.Is Cerebellar Architecture Shaped by Sensory Ecology in the New Zealand Kiwi (Apteryx mantelli).
Corfield JR, Kolominsky J, Craciun I, Mulvany-Robbins BE, Wylie DR.
Brain Behav Evol. 2016 May 19. [Epub ahead of print]


Among some mammals and birds, the cerebellar architecture appears to be adapted to the animal's ecological niche, particularly their sensory ecology and behavior. This relationship is, however, not well understood. To explore this, we examined the expression of zebrin II (ZII) in the cerebellum of the kiwi (Apteryx mantelli), a fully nocturnal bird with auditory, tactile, and olfactory specializations and a reduced visual system. We predicted that the cerebellar architecture, particularly those regions receiving visual inputs and those that receive trigeminal afferents from their beak, would be modified in accordance with their unique way of life. The general stripe-and-transverse region architecture characteristic of birds is present in kiwi, with some differences. Folium IXcd was characterized by large ZII-positive stripes and all Purkinje cells in the flocculus were ZII positive, features that resemble those of small mammals and suggest a visual ecology unlike that of other birds. The central region in kiwi appeared reduced or modified, with folium IV containing ZII+/- stripes, unlike that of most birds, but similar to that of Chilean tinamous. It is possible that a reduced visual system has contributed to a small central region, although increased trigeminal input and flightlessness have undoubtedly played a role in shaping its architecture. Overall, like in mammals, the cerebellar architecture in kiwi and other birds may be substantially modified to serve a particular ecological niche, although we still require a larger comparative data set to fully understand this relationship.
PMID: 27192984 [PubMed - as supplied by publisher]

13.The influence of fire on the assemblage structure of foraging birds in grasslands of the Serra da Canastra National Park, Brazil.
Reis MG, Fieker CZ, Dias MM.
An Acad Bras Cienc. 2016 May 13. pii: S0001-37652016005006101. [Epub ahead of print]


Grasslands are the most threatened physiognomies of the Cerrado biome (Brazilian savanna), a biodiversity hotspot with conservation as a priority. The Serra da Canastra National Park protects the most important remnants of the Cerrado's southern grasslands, which are under strong anthropogenic pressure. The present study describes the structure of bird assemblages that directly use food resources in burned areas, comparing areas affected by natural fire to the areas where controlled fires were set (a management strategy to combat arson). The tested null hypothesis was that different bird assemblages are structured in a similar manner, regardless of the post-fire period or assessed area. Between December/2012 and January/2015, 92 species were recorded foraging in the study areas. The results indicate that both types of burnings triggered profound and immediate changes in bird assemblages, increasing the number of species and individuals. Natural fires exhibited a more significant influence on the structure (diversity and dominance) than prescribed burnings. Nevertheless, all the differences were no longer noticeable after a relatively short time interval of 2-3 months after prescribed burnings and 3-4 after natural fires. The findings may help the understanding of prescribed burnings as a management strategy for bird conservation in grasslands.
PMID: 27192195 [PubMed - as supplied by publisher] Free Article

14.Frugivory and seed dispersal of Solanum granuloso-leprosum Dunal (Solanaceae) by birds in deciduous seasonal forest.
Jacomassa FA.
Braz J Biol. 2016 May 17. pii: S1519-69842016005112113. [Epub ahead of print]


The goal of this study was to identify which bird species consume Solanum granuloso-leprosum fruits and disperse its seeds. 60 hours of focal observations were carried out between April and May 2006 on the edge of a deciduous forest fragment in the Uruguay River region, Rio Grande do Sul state, Brazil. Ten species were observed in total removing 443 fruits. Saltator similis removed 61.8% of the fruits, followed by Tangara sayaca (17.1%), Pipraeidea bonariensis (11.7%), and T. preciosa (6.8%), while the remaining six species accounted for only 2.5% of the fruits removed. Most fruit removal occurred early in the day or mid-afternoon. The most common feeding behaviors were picking (60.7%), followed by stalling (23%) and hovering (16%). Birds flew more than 10 m from the fruit plant in 62% of the removal events. All bird species observed here may be considered potential dispersers of S. granuloso-leprosum, as they moved the seeds away from the mother plant where strong competition and predation are likely to occur. Results also suggest that S. granuloso-leprosum may be useful in ecological restoration programs.
PMID: 27191463 [PubMed - as supplied by publisher] Free Article

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