Occupancy of the Ethiopian endemic Moorland Francolin in pristine and degraded Afroalpine biome using a camera trap approach.

Occupancy modeling is an essential tool for understanding species-habitat associations, thereby helping to plan the conservation of rare and threatened wildlife species. The conservation status and ecology of several avian species, particularly ground-dwelling birds, are poorly known in Ethiopia. We used camera trap-based occupancy modeling to investigate habitat covariate influence on occupancy (Ψ) and detection probability (ρ) estimates of Moorland Francolins Scleroptila psilolaema from spatially replicated surveys across both relatively pristine and disturbed landscapes in the Afroalpine biome of Ethiopia. Model-averaged estimate of ψ^ across all sites was 0.76 (SD = 0.28) and ρ^ was 0.77 (SD = 0.13) in the pristine landscape. The ψ^ of the species in the disturbed landscape was 0.56 (SD = 0.19) and ρ^ was 0.48 (SD = 0.06). As hypothesized, based on our model-averaged beta coefficient estimates (ßmean ± SE), predators significantly negatively influenced the occupancy of Moorland Francolins in pristine habitat. We also found a significant positive association of occupancy with herb species richness. Contrary to our prediction, distance to road significantly negatively influence the occupancy of the species, suggesting that occupancy probability was highest in proximity to roadsides and trails in the pristine habitat. There was no significant influence of habitat covariates on the occupancy of the species in the disturbed habitat. The most important covariates that significantly influence the detectability of the species in pristine habitat included sampling occasion and precipitation. The greater occupancy and detectability of this endemic species in the pristine habitat could be linked with the particular conservation status and management of this biodiversity hotspot in the central highlands of Ethiopia. Our results suggest that strict legal enforcement is required to sustainably preserve Moorland Francolins and the ecological integrity of the entire Afroalpine biome. We recommend using camera traps in order to develop realistic and effective conservation and management strategies for rare, sensitive, cryptic, and ground-dwelling animals in the region.

Speciation and population divergence in a mutualistic seed dispersing bird.

Bird-mediated seed dispersal is crucial for the regeneration and viability of ecosystems, often resulting in complex mutualistic species networks. Yet, how this mutualism drives the evolution of seed dispersing birds is still poorly understood. In the present study we combine whole genome re-sequencing analyses and morphometric data to assess the evolutionary processes that shaped the diversification of the Eurasian nutcracker (Nucifraga), a seed disperser known for its mutualism with pines (Pinus). Our results show that the divergence and phylogeographic patterns of nutcrackers resemble those of other non-mutualistic passerine birds and suggest that their early diversification was shaped by similar biogeographic and climatic processes. The limited variation in foraging traits indicates that local adaptation to pines likely played a minor role. Our study shows that close mutualistic relationships between bird and plant species might not necessarily act as a primary driver of evolution and diversification in resource-specialized birds.

AVONET: morphological, ecological and geographical data for all birds.

Functional traits offer a rich quantitative framework for developing and testing theories in evolutionary biology, ecology and ecosystem science. However, the potential of functional traits to drive theoretical advances and refine models of global change can only be fully realised when species-level information is complete. Here we present the AVONET dataset containing comprehensive functional trait data for all birds, including six ecological variables, 11 continuous morphological traits, and information on range size and location. Raw morphological measurements are presented from 90,020 individuals of 11,009 extant bird species sampled from 181 countries. These data are also summarised as species averages in three taxonomic formats, allowing integration with a global phylogeny, geographical range maps, IUCN Red List data and the eBird citizen science database. The AVONET dataset provides the most detailed picture of continuous trait variation for any major radiation of organisms, offering a global template for testing hypotheses and exploring the evolutionary origins, structure and functioning of biodiversity.

Asymmetric allelic introgression across a hybrid zone of the coal tit (Periparus ater) in the central Himalayas.

In the Himalayas, a number of secondary contact zones have been described for vicariant vertebrate taxa. However, analyses of genetic divergence and admixture are missing for most of these examples. In this study, we provide a population genetic analysis for the coal tit (Periparus ater) hybrid zone in Nepal. Intermediate phenotypes between the distinctive western "spot-winged tit" (P. a. melanolophus) and Eastern Himalayan coal tits (P. a. aemodius) occur across a narrow range of <100 km in western Nepal. As a peculiarity, another distinctive cinnamon-bellied form is known from a single population so far. Genetic admixture of western and eastern mitochondrial lineages was restricted to the narrow zone of phenotypically intermediate populations. The cline width was estimated 46 km only with a center close to the population of the cinnamon-bellied phenotype. In contrast, allelic introgression of microsatellite loci was asymmetrical from eastern P. a. aemodius into far western populations of phenotypic P. a. melanolophus but not vice versa. Accordingly, the microsatellite cline was about 3.7 times wider than the mitochondrial one.

The Occurrence of Quill Mites (Arachnida: Acariformes: Syringophilidae) on Bee-Eaters (Aves: Coraciiformes: Meropidae: Merops) of Two Sister Clades.

We studied the quill mite fauna of the family Syringophilidae, associated with bee-eaters. We examined 273 bird specimens belonging to nine closely related species of the genus Merops, representing two phylogenetic sister clades of a monophyletic group. Our examination reveals the presence of two species of the genus Peristerophila, as follows: (1) a new species Peristerophila mayri sp. n. from Merops viridis in the Philippines, M. leschenaulti in Nepal and Sri Lanka, and M. orientalis in Sri Lanka; and (2) P. meropis from M. superciliosus in Tanzania and Egypt, M. persicus in Sudan, Tanzania, Liberia, Senegal, Kenya, and D.R. Congo, M. ornatus in Papua New Guinea, M. philippinus in Thailand, Indonesia and Sri Lanka, and M. americanus in the Philippines. The prevalence of host infestations by syringophilid mites varied from 3.1 to 38.2%. The distribution of syringophilid mites corresponds with the sister clade phylogenetic relationships of the hosts, except for P. meropis associated with Merops americanus. Possible hypotheses for the host lineage shift are proposed.

Isotope record tracks changes in historical wintering ranges of a passerine in sub-Saharan Africa.

Billions of birds migrate from the Palaearctic to sub-Saharan Africa, yet we are unaware about where exactly they stay over winter and how consistent they have been using these wintering areas over historical times. Here, we inferred the historical wintering areas of Eurasian Golden Orioles (Oriolus oriolus) from stable isotope ratios of feathers. Over the past 200 years, Golden Orioles used two major wintering grounds. Between 1895 and 1971, the relative use of these areas depended on local rainfall intensities. Golden Orioles may depend strongly on humid wintering areas in sub-Saharan Africa, which may put this species at stake when the global climate continues to change.

Direct and plant-mediated effects of climate on bird diversity in tropical mountains.

AIM: Although patterns of biodiversity across the globe are well studied, there is still a controversial debate about the underlying mechanisms and their generality across biogeographic scales. In particular, it is unclear to what extent diversity patterns along environmental gradients are directly driven by abiotic factors, such as climate, or indirectly mediated through biotic factors, such as resource effects on consumers. LOCATION: Andes, Southern Ecuador; Mt. Kilimanjaro, Tanzania. METHODS: We studied the diversity of fleshy-fruited plants and avian frugivores at the taxonomic level, that is, species richness and abundance, as well as at the level of functional traits, that is, functional richness and functional dispersion. We compared two important biodiversity hotspots in mountain systems of the Neotropics and Afrotropics. We used field data of plant and bird communities, including trait measurements of 367 plant and bird species. Using structural equation modeling, we disentangled direct and indirect effects of climate and the diversity of plant communities on the diversity of bird communities. RESULTS: We found significant bottom-up effects of fruit diversity on frugivore diversity at the taxonomic level. In contrast, climate was more important for patterns of functional diversity, with plant communities being mostly related to precipitation, and bird communities being most strongly related to temperature. MAIN CONCLUSIONS: Our results illustrate the general importance of bottom-up mechanisms for the taxonomic diversity of consumers, suggesting the importance of active resource tracking. Our results also suggest that it might be difficult to identify signals of ecological fitting between functional plant and animal traits across biogeographic regions, since different species groups may respond to different climatic drivers. This decoupling between resource and consumer communities could increase under future climate change if plant and animal communities are consistently related to distinct climatic drivers.

Projected impacts of climate change on functional diversity of frugivorous birds along a tropical elevational gradient.

Climate change forces many species to move their ranges to higher latitudes or elevations. Resulting immigration or emigration of species might lead to functional changes, e.g., in the trait distribution and composition of ecological assemblages. Here, we combined approaches from biogeography (species distribution models; SDMs) and community ecology (functional diversity) to investigate potential effects of climate-driven range changes on frugivorous bird assemblages along a 3000 m elevational gradient in the tropical Andes. We used SDMs to model current and projected future occurrence probabilities of frugivorous bird species from the lowlands to the tree line. SDM-derived probabilities of occurrence were combined with traits relevant for seed dispersal of fleshy-fruited plants to calculate functional dispersion (FDis; a measure of functional diversity) for current and future bird assemblages. Comparisons of FDis between current and projected future assemblages showed consistent results across four dispersal scenarios, five climate models and two representative concentration pathways. Projections indicated a decrease of FDis in the lowlands, an increase of FDis at lower mid-elevations and little changes at high elevations. This suggests that functional dispersion responds differently to global warming at different elevational levels, likely modifying avian seed dispersal functions and plant regeneration in forest ecosystems along tropical mountains.

Revising the phylogenetic position of the extinct Mascarene Parrot Mascarinus mascarin (Linnaeus 1771) (Aves: Psittaciformes: Psittacidae).

The phylogenetic position of the extinct Mascarene Parrot Mascarinus mascarin from La Réunion has been unresolved for centuries. A recent molecular study unexpectedly placed M. mascarin within the clade of phenotypically very different Vasa parrots Coracopsis. Based on DNA extracted from the only other preserved Mascarinus specimen, we show that the previously obtained cytb sequence is probably an artificial composite of partial sequences from two other parrot species and that M. mascarin is indeed a part of the Psittacula diversification, placed close to P. eupatria and P. wardi.

The Corvids Literature Database--500 years of ornithological research from a crow's perspective.

Corvids (Corvidae) play a major role in ornithological research. Because of their worldwide distribution, diversity and adaptiveness, they have been studied extensively. The aim of the Corvids Literature Database (CLD, http://www.corvids.de/cld) is to record all publications (citation format) on all extant and extinct Crows, Ravens, Jays and Magpies worldwide and tag them with specific keywords making them available for researchers worldwide. The self-maintained project started in 2006 and today comprises 8000 articles, spanning almost 500 years. The CLD covers publications from 164 countries, written in 36 languages and published by 8026 authors in 1503 journals (plus books, theses and other publications). Forty-nine percent of all records are available online as full-text documents or deposited in the physical CLD archive. The CLD contains 442 original corvid descriptions. Here, we present a metadata assessment of articles recorded in the CLD including a gap analysis and prospects for future research. Database URL: http://www.corvids.de/cld.

Functional importance of avian seed dispersers changes in response to human-induced forest edges in tropical seed-dispersal networks.

Although seed-dispersal networks are increasingly used to infer the functioning of ecosystems, few studies have investigated the link between the properties of these networks and the ecosystem function of seed dispersal by animals. We investigate how frugivore communities and seed dispersal change with habitat disturbance and test whether relationships between morphological traits and functional roles of seed dispersers change in response to human-induced forest edges. We recorded interaction frequencies between fleshy fruited plants and frugivorous bird species in tropical montane forests in the Bolivian Andes and recorded functional bird traits (body mass, gape width and wing tip length) associated with quantitative (seed-removal rate) and qualitative (seed-deposition pattern) components of seed-dispersal effectiveness. We found that the abundance and richness of frugivorous birds were higher at forest edges. More fruits were removed and dispersed seeds were less clustered at edges than in the interior. Additionally, functional and interaction diversity were higher at edges than in the interior, but functional and interaction evenness did not differ. Interaction strength of bird species increased with body mass, gape width and wing tip length in the forest interior, but was not related to bird morphologies at forest edges. Our study suggests that increases in functional and interaction diversity and an even distribution of interaction strength across bird morphologies lead to enhanced quantity and tentatively enhanced quality of seed dispersal. It also suggests that the effects of species traits on ecosystem functions can vary along small-scale gradients of human disturbance.

Differentiation in neutral genes and a candidate gene in the pied flycatcher: using biological archives to track global climate change.

Global climate change is one of the major driving forces for adaptive shifts in migration and breeding phenology and possibly impacts demographic changes if a species fails to adapt sufficiently. In Western Europe, pied flycatchers (Ficedula hypoleuca) have insufficiently adapted their breeding phenology to the ongoing advance of food peaks within their breeding area and consequently suffered local population declines. We address the question whether this population decline led to a loss of genetic variation, using two neutral marker sets (mitochondrial control region and microsatellites), and one potentially selectively non-neutral marker (avian Clock gene). We report temporal changes in genetic diversity in extant populations and biological archives over more than a century, using samples from sites differing in the extent of climate change. Comparing genetic differentiation over this period revealed that only the recent Dutch population, which underwent population declines, showed slightly lower genetic variation than the historic Dutch population. As that loss of variation was only moderate and not observed in all markers, current gene flow across Western and Central European populations might have compensated local loss of variation over the last decades. A comparison of genetic differentiation in neutral loci versus the Clock gene locus provided evidence for stabilizing selection. Furthermore, in all genetic markers, we found a greater genetic differentiation in space than in time. This pattern suggests that local adaptation or historic processes might have a stronger effect on the population structure and genetic variation in the pied flycatcher than recent global climate changes.

Constant properties of plant-frugivore networks despite fluctuations in fruit and bird communities in space and time.

Human-induced changes in anthropogenic landscapes are a predominant threat to biodiversity and have been documented to affect mutualistic interactions between plants and animals, such as avian seed dispersal. Interactions between fleshy-fruited plants and frugivorous birds are highly seasonal in temperate ecosystems. Nevertheless, combined effects of landscape modification and seasonal variation on plant-frugivore interactions have never been assessed from a network perspective. Here, we present the first study that simultaneously investigates effects of landscape modification and seasonal variation on plant-frugivore interactions and on functional and interaction diversity of plant-frugivore networks. We recorded visitation rates of 39 frugivorous bird species to 28 fruiting-plant species in Central Germany from early summer to late autumn in hedgerows within three landscape types arranged along a gradient of decreasing anthropogenic modification and increasing structural diversity (i.e., farmland, orchard, forest edge). We analyzed how species richness, abundance, and community composition, as well as functional and interaction diversity of fruiting plants and frugivorous birds changed with landscape type, fruit availability, and season. We found that visitation rates of frugivorous birds were lower in farmland, but only in summer. In autumn, visitation rates were similar in all landscape types and strongly increased with increasing local fruit availability. The functional diversity of fruits and frugivorous birds and their interaction diversity remained surprisingly constant in all landscape types. Due to seasonal changes in communities of fruiting plants and frugivorous birds, functional dispersion of fruiting plants was lower in autumn than in summer, whereas functional richness and dispersion of frugivorous birds was higher in autumn than in summer. Our results indicate that seasonal changes in fruit availability influence the abundance of frugivorous birds along gradients of structural diversity at the landscape scale. Although seasonal fluctuations influenced the functional diversity of avian frugivore communities, we found constant interaction diversity of plant-frugivore networks in space and time, probably due to the functional redundancy of frugivorous birds. These findings indicate a high robustness of avian frugivory to moderate levels of human-induced landscape modification in temperate ecosystems and call for studies testing the generality of these findings for ultimate avian seed dispersal functions.

Utility of arsenic-treated bird skins for DNA extraction.

BACKGROUND: Natural history museums receive a rapidly growing number of requests for tissue samples from preserved specimens for DNA-based studies. Traditionally, dried vertebrate specimens were treated with arsenic because of its toxicity and insect-repellent effect. Arsenic has negative effects on in vivo DNA repair enzymes and consequently may inhibit PCR performance. In bird collections, foot pad samples are often requested since the feet were not regularly treated with arsenic and because they are assumed to provide substantial amounts of DNA. However, the actual influence of arsenic on DNA analyses has never been tested. FINDINGS: PCR success of both foot pad and body skin samples was significantly lower in arsenic-treated samples. In general, foot pads performed better than body skin samples. Moreover, PCR success depends on collection date in which younger samples yielded better results. While the addition of arsenic solution to the PCR mixture had a clear negative effect on PCR performance after the threshold of 5.4 µg/µl, such high doses of arsenic are highly unlikely to occur in dried zoological specimens. CONCLUSIONS: While lower PCR success in older samples might be due to age effects and/or DNA damage through arsenic treatment, our results show no inhibiting effect on DNA polymerase. We assume that DNA degradation proceeds more rapidly in thin tissue layers with low cell numbers that are susceptible to external abiotic influences. In contrast, in thicker parts of a specimen, such as foot pads, the outermost horny skin may act as an additional barrier. Since foot pads often performed better than body skin samples, the intention to preserve morphologically important structures of a specimen still conflicts with the aim to obtain optimal PCR success. Thus, body skin samples from recently collected specimens should be considered as alternative sources of DNA.