Search

In this study, we infer genus-level relationships within shrikes (Laniidae), crows (Corvidae), and their allies using ultraconserved elements (UCEs). We confirm previous results of the Crested Shrikejay (Platylophus galericulatus) as comprising its own taxonomic family and find strong support for its sister relationship to laniid shrikes. We also find strong support that the African-endemic genus Eurocephalus, which comprises two allopatric species (E. ruppelli and E. anguitimens), are not “true-shrikes”. We propose elevating the white-crowned shrikes to their own family, Eurocephalidae.

The complex island archipelagoes of Wallacea and Melanesia have provided empirical data behind integral theories in evolutionary biology, including allopatric speciation and island biogeography. Yet, questions regarding the relative impact of the layered biogeographic barriers, such as deep-water trenches and isolated island systems, on faunal diversification remain underexplored. One such barrier is Wallace’s Line, a significant biogeographic boundary that largely separates Australian and Asian biodiversity. To assess the relative roles of biogeographic barriers—specifically isolated island systems and Wallace’s Line—we investigated the tempo and mode of diversification in a diverse avian radiation, Corvides (Crows and Jays, Birds-of-paradise, Vangas, and allies). We combined a genus-level data set of thousands of ultraconserved elements (UCEs) and a species-level, 12-gene Sanger sequence matrix to produce a well-resolved supermatrix tree that we leveraged to explore the group’s historical biogeography and the effects of the biogeographic barriers on their macroevolutionary dynamics. The tree is well resolved and differs substantially from what has been used extensively for past comparative analyses within this group. We confirmed that Corvides, and its major constituent clades, arose in Australia and that a burst of dispersals west across Wallace’s Line occurred after the uplift of Wallacea during the mid-Miocene. We found that dispersal across this biogeographic barrier was generally rare, though westward dispersals were two times more frequent than eastward dispersals. Wallacea’s central position between Sundaland and Sahul no doubt acted as a bridge for island-hopping dispersal out of Australia, across Wallace’s Line, to colonize the rest of Earth. In addition, we found that the complex island archipelagoes east of Wallace’s Line harbor the highest rates of net diversification and are a substantial source of colonists to continental systems on both sides of this biogeographic barrier. Our results support emerging evidence that island systems, particularly the geologically complex archipelagoes of the Indo-pacific, are drivers of species diversification. [Historical biogeography; island biogeography; Melanesia; molecular phylogenetics; state-dependent diversification and extinction.]

Genomic approaches to phylogeography routinely reveal that our estimates of species level diversity within island systems are woefully underappreciated. A recent analysis of population genetics, ph...

Hybridization, introgression, and reciprocal gene flow during speciation, specifically the generation of mitonuclear discordance, are increasingly observed as parts of the speciation process. Genomic approaches provide insight into where, when, and how adaptation operates during and after speciation and can measure historical and modern introgression. Whether adaptive or neutral in origin, hybridization can cause mitonuclear discordance by placing the mitochondrial genome of one species (or population) in the nuclear background of another species. The latter, introgressed species may eventually have its own mtDNA replaced or “captured” by other species across its entire geographical range. Intermediate stages in the capture process should be observable. Two nonsister species of Australasian monarch-flycatchers, Spectacled Monarch (Symposiachrus trivirgatus) mostly of Australia and Indonesia and Spot-winged Monarch (S. guttula) of New Guinea, present an opportunity to observe this process. We analysed thousands of single nucleotide polymorphisms (SNPs) derived from ultraconserved elements of all subspecies of both species. Mitochondrial DNA sequences of Australian populations of S. trivirgatus form two paraphyletic clades, one being sister to and presumably introgressed by S. guttula despite little nuclear signal of introgression. Population genetic analyses (e.g., tests for modern and historical gene flow and selection) support at least one historical gene flow event between S. guttula and Australian S. trivirgatus. We also uncovered introgression from the Maluku Islands subspecies of S. trivirgatus into an island population of S. guttula, resulting in apparent nuclear paraphyly. We find that neutral demographic processes, not adaptive introgression, are the most likely cause of these complex population histories. We suggest that a Pleistocene extinction of S. guttula from mainland Australia resulted from range expansion by S. trivirgatus., Molecular Ecology, 30 (9), ISSN:0962-1083, ISSN:1365-294X

Turnover in species composition between sites, or beta diversity, is a critical component of species diversity that is typically influenced by geography, environment, and biotic interactions. Quantifying turnover is particularly challenging, however, in multi-host, multi-parasite assemblages where undersampling is unavoidable, resulting in inflated estimates of turnover and uncertainty about its spatial scale. We developed and implemented a framework using null models to test for community turnover in avian haemosporidian communities of three sky islands in the southwestern United States. We screened 776 birds for haemosporidian parasites from three genera (Parahaemoproteus, Plasmodium, and Leucocytozoon) by amplifying and sequencing a mitochondrial DNA barcode. We detected infections in 280 birds (36.1%), sequenced 357 infections, and found a total of 99 parasite haplotypes. When compared to communities simulated from a regional pool, we observed more unique, single-mountain haplotypes and fewer haplotypes shared among three mountain ranges than expected, indicating that haemosporidian communities differ to some degree among adjacent mountain ranges. These results were robust even after pruning datasets to include only identical sets of host species, and they were consistent for two of the three haemosporidian genera. The two more distant mountain ranges were more similar to each other than the one located centrally, suggesting that the differences we detected were due to stochastic colonization–extirpation dynamics. These results demonstrate that avian haemosporidian communities of temperate-zone forests differ on relatively fine spatial scales between adjacent sky islands. Null models are essential tools for testing the spatial scale of turnover in complex, undersampled, and poorly known systems.

Little is known of the natural history of the Solomons Nightjar (Eurostopodus nigripennis) due to its restricted range and reclusive nature. Here we describe the breeding biology of E. nigripennis based on nests found in the Western Province, Solomon Islands, between June and October 2019. Four nests were discovered on 3 small islands: Tetepare, Hehevai, and Nanakatopa; the latter 2 are first island records for this species. We observed all stages of the species' nesting cycle, from egg to post-fledging care of juveniles by adults, each with a single nestling (n = 4). We describe the eggs, nestlings, and juvenile plumage of the species with additional detail on nesting habitat and document new breeding locations in the Western Province.

The honeyeaters are the most species-rich clade of birds east of Wallace’s Line. They occupy a wide range of habitats, from desert to rainforest, and occur throughout Australia, New Guinea,...

Niche expansion is a critical step in the speciation process. Large brains linked to improved cognitive ability may enable species to expand their niches and forage in new ways, thereby promoting speciation. Despite considerable work on ecological divergence in brain size and its importance in speciation, relatively little is known about how brain shape relates to behavioral, ecological, and taxonomic diversity at macroevolutionary scales. This is due in part to inherent challenges with quantifying brain shape across many species. Here we present a novel, semiautomated approach for rapidly phenotyping brain shape using semilandmarks derived from X-ray computed microtomography scans. We then test its utility by parsing evolutionary trends within a diverse radiation of birds: kingfishers (Aves: Alcedinidae). Multivariate comparative analyses reveal that rates of brain shape evolution (but not beak shape) are positively correlated with lineage diversification rates. Distinct brain shapes are further associated with changes in body size and foraging behavior, suggesting both allometric and ecological constraints on brain shape evolution. These results are in line with the idea of brains acting as a "master regulator" of critical processes governing speciation, such as dispersal, foraging behavior, and dietary niche.

— There is limited information on the breeding biology of members of the speciose genus Hemitriccus (Aves: Tyrannidae), published nest descriptions exist for only six of the 22 species. The Black-throated Tody-Tyrant (Hemitriccus granadensis) is one of these species that lacks information regarding its nesting biology. We provide the first nest, egg, nestling, and incubation behavior descriptions for the species with notes on its courtship behavior. We found three nests and observed one courtship display at three field sites, two in Colombia and one in Peru. The nest of H. granadensis is an enclosed “purse-like” pendant pouch inside of a moss ball suspended from a small branch with a side entrance and obscured by vegetation. Two nests had a single egg, which averaged 18.1 × 12.9 mm and 1.55 g. Egg appearance varied between nests, the egg at the Colombian site was tan and unmarked, whereas the egg at the Peruvian site was bright white with a few scattered, red specks. We cannot describe the full i...

Aim Kingfishers are the most species-rich family in the avian order, Coraciiformes. Their modern distribution is largely pantropical; however, global species diversity is unevenly distributed. For example, 19 of the 114 kingfisher species occur in New Guinea, whereas only six species occur in the entire New World. This disparity in diversity suggests regions with high species richness could represent the ancestral range of the family. Furthermore, some clades of kingfishers (Ceyx, Todiramphus) are thought to be the product of rapid insular radiations. Here, we investigated the biogeographical history and speciation dynamics of the Alcedinidae using a fully sampled molecular phylogeny. Location Global. Taxon Kingfishers (Aves: Coraciiformes: Alcedinidae). Methods We inferred a time-calibrated, species-level phylogeny of kingfishers from DNA sequences. Our data set comprised up to five Sanger-sequenced gene regions for all species (one mitochondrial, one nuclear exon and three nuclear introns), plus genus-level sampling of thousands of ultraconserved elements. We estimated ancestral ranges of kingfishers and explored macroevolutionary rate shifts and diversification rates across the phylogeny. Results We recovered a well-supported phylogeny of kingfishers that includes 34 species whose phylogenetic relationships were not previously known. The pygmy-kingfishers (subfamily Alcedininae) sit on a long branch, sister to all other kingfishers: subfamilies Cerylinae and Halcyoninae. Crown-group kingfishers originated in the Indomalayan region approximately 27 Ma with subsequent colonizations into Africa (six times), the New World (twice) and Australasia (representing several major radiations). Main conclusions Oceanic islands of Wallacea, the Philippines and Oceania promoted multiple, independent radiations in three species-rich genera: Ceyx, Actenoides and Todiramphus. In particular, Todiramphus showed patterns consistent with explosive and recent diversification relative to the background speciation rate of non-Todiramphus kingfishers, which we attribute to recent colonization of the vast archipelagos of Wallacea and the Pacific.

We know little about the breeding behavior of most nocturnal raptors. Nest attendance and prey delivery rates can be used as indices of relative habitat quality or extent of parental care. We used video cameras to document and observe prey delivery rates, nest attendance and bout durations at two northern saw-whet owl (Aegolius acadicus) nests in two artificial nest boxes in north-central Oregon. We collected 858 hours of video surveillance between 21 March and 01 June 2014. The number of prey deliveries per night increased as the nesting season progressed: 1.25 during laying, 1.33 during incubation, and 4.0 during the nestling phase. Prey was delivered most often between 2100 and 2200. Nest attendance by females was high during pre-laying (97.8%), laying (97.9%) and incubation (98.2%), but decreased during the nestling phase (55.7%). Nest attendance was higher during diurnal hours than nocturnal hours across all nesting phases. Duration of off bouts (recesses) was similar during pre-laying and l...

Despite a long history of biological exploration, there remains much to learn about the avifauna of the Solomon Islands. Here, we report new records of the Blue-faced Parrotfinch (Erythrura trichroa) on Malaita and Makira islands, thus expanding the known distribution of the species in the geographic Solomon Islands to include Bougainville, Kolombangara, Guadalcanal, Malaita, and Makira islands. Morphometric comparison of specimens from these populations showed no consistent differences in plumage or measurements, although sample sizes were small for all populations (n = 1–2 comparable specimens from 3 populations). Likewise, mitochondrial DNA sequence data showed little genetic differentiation among these populations. Our results suggest that the Blue-faced Parrotfinch exhibits some of the lowest interpopulation divergence of any montane bird species in the Solomon Islands and provides useful comparison to biogeographic patterns in other bird populations that share a similar distribution across multiple Pleistocene islands. Our discovery of 2 new populations of Blue-faced Parrotfinches highlights the need for continued biodiversity work in the region for both conservation and research.

The birds of the Solomon Islands have received ample historical attention by explorers, collectors and researchers. Despite this, knowledge of the region's avifauna is categorised by BirdLife International as ‘poor’ and multiple new populations of birds have been found in recent years, highlighting our incomplete knowledge of the region's avifauna. Here, we present new information on the elevational occurrence, abundance and natural history for ten bird species we observed on Isabel Island. The data we present are based on three weeks of field work at three field sites that included the restricted montane forests above 1,000 m elevation on the Kubonitu-Sasari massif. In this poorly known montane area we observed multiple Island Leaf Warblers Phylloscopus maforensis for the first time since it was discovered on Isabel in 1927.

Tapaculo (Scytalopus) nests are difficult to find because they are well-hidden in cavities, hence, there is limited information available for this genus. We provide additional data for the...