South American dry forests have a complex and poorly understood biogeographic history. Based on the fragmented distribution of many Neotropical dry forest species, it has been suggested that this biome was more widely distributed and contiguous under drier climate conditions in the Pleistocene. To test this scenario, known as the Pleistocene Arc Hypothesis, we studied the phylogeography of the Rufous‐fronted Thornbird (Phacellodomus rufifrons), a widespread dry forest bird with a disjunct distribution closely matching that of the biome itself. We sequenced mtDNA and used ddRADseq to sample 7,167 genome‐wide single‐nucleotide polymorphisms from 74 P. rufifrons individuals across its range. We found low genetic differentiation over two prominent geographic breaks — particularly across a 1,000 km gap between populations in Bolivia and Northern Peru. Using demographic analyses of the joint site frequency spectrum, we found evidence of recent divergence without subsequent gene flow across those breaks. By contrast, parapatric morphologically distinct populations in northeastern Brazil show high genetic divergence with evidence of recent gene flow. These results, in combination with our paleoclimate species distribution modelling, support the idea that currently disjunct patches of dry forest were more connected in the recent past, probably during the Middle and Late Pleistocene. This notion fits the major predictions of the Pleistocene Arc Hypothesis and illustrates the importance of comprehensive genomic and geographic sampling for examining biogeographic and evolutionary questions in complex ecosystems like Neotropical dry forests.

Birds display a rainbow of eye colors, but this trait has received relatively little study compared to plumage coloration. Avian eye color variation occurs at all phylogenetic scales: it can be conserved throughout whole families or vary within a single species, yet the evolutionary importance of eye color variation within species and across the avian phylogeny is also understudied. Here, we provide an overview of eye color variation in birds, summarizing the state of knowledge about its causes at three primary levels: mechanistic, genetic, and evolutionary. Mechanistically, we show that common avian iris pigments include melanin and carotenoids, which also play major roles in plumage color, as well as purines and pteridines, which are found as pigments primarily in non-avian taxa. Genetically, we examine known associations between genes and eye color, primarily identified from classical breeding studies and recent genomic work in domesticated species. Finally, from an evolutionary standpoint, we present and discuss several hypotheses explaining the adaptive significance of eye color variation. Many of these suggest bird eye color plays an important role in intraspecific signaling, particularly as an indicator of age or mate quality, although the importance of eye color may differ between species and few evolutionary hypotheses have been directly tested. We suggest that future studies of avian eye color should focus on all three levels, including broad-scale iris pigment analyses across bird species, genome sequencing studies to identify loci associated with eye color variation, and behavioral experiments and comparative phylogenetic analyses to test adaptive hypotheses. By examining these proximate and ultimate causes of eye color variation in birds, we hope that our review will spur future research to understand the ecological and evolutionary significance of this striking avian trait.

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The Altillanura is a unique ecosystem within the Colombian Llanos, characterized by well-drained savannas and extensive riparian forests. The Altillanura harbors a rich assemblage of species, largely understudied and currently under threat by large-scale and unplanned agribusiness. Moreover, the number of public protected areas in the Colombian Llanos, particularly in the Altillanura, is insufficient to conserve the threatened habitats and species. Therefore, conservation efforts by private reserves are crucial for the protection of the region’s biodiversity. Here we present the first species list of the Tomogrande, a private nature reserve and scientific research field station in the municipality of Santa Rosalía, Vichada, Colombia. After ten years of ongoing research, we have recorded 299 species of plants, 189 species of birds, and 47 species of mammals. Compared to other private nature reserves in Vichada and the Tuparro National Park, the largest protected area in the region, Tomogrande makes a substantial contribution to the conservation of all three taxonomic groups. We advocate that better landscape planning and sustainable practices should become mandatory in the Altillanura to protect its biodiversity and the livelihoods of all stakeholders that inhabit this region.

North American sunfishes (Family Centrarchidae) are among the most popular sportfish throughout the United States and Canada. Despite the popularity of sunfishes, their ecological importance, and their extensive stocking and aquacultural history, few molecular studies have examined the evolutionary relationships and species boundaries among members of this group, many of which are known to hybridize. Here, we describe a chromosome-scale genome assembly representing Bluegill (Lepomis macrochirus), one of the most widespread centrarchid species. By combining long-read, Oxford Nanopore sequencing data with short-insert, whole genome and HiC sequence reads, we produced an assembly (Lm_LA_1.1) having a total length of 889 Mbp including 1,841 scaffolds and having a scaffold N50 of 36 Mbp, L50 of 12, N90 of 29 Mbp, and L90 of 22. We detected 99% (eukaryota_odb10) and 98% (actinopterygii_odb10) BUSCOs, and ab initio gene prediction performed using this new assembly identified a set of 17,233 genes that were supported by external (OrthoDB v10) data. This new assembly provides an important addition to the growing set of assemblies already available for spiny-rayed fishes (Acanthomorpha), and it will serve as a resource for future studies that focus on the complex evolutionary history of centrarchids.

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