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Inland vagrancy and overland dispersal by seabirds arc rare phenomena for which the causes and consequences are poorly understood. Studying inland occurrences of seabirds is important because continental land masses form barriers to dispersal of genes and parasites; thus, the permeability of land barriers influences the extent to which seabird populations evolve on separate trajectories and co-evolve with distinct parasite faunas. The boobies (Sulci spp.) arc a clade of saltwater-obligate species occurring in tropical and subtropical oceans. Booby species tend to exhibit population generic structure among oceanic regions. Although they rarely wander inland, the Brown Booby (Sula leucogaster) has occurred numerous times as a vagrant in interior North America. Previous inland records from far western North America originated from Pacific populations (subspecies brewsteri), whereas those from eastern and midwestern North America originated from Caribbean populations (subspecies leucogaster). In this paper, we describe 2 new specimens of 5. leucogaster, first state records for New Mexico and Colorado, salvaged from localities nearly equidistant from Pacific and Caribbean source populations. We used mitochondrial DNA sequences to conclusively demonstrate that both specimens originated in the Caribbean. We next examined the helminth parasite fauna of the 2 S. leucogaster specimens and an inland-vagrant Blue-footed Booby (S. nebouxii) from New Mexico. The guts of these boobies contained a suite of helminths, including multiple freshwater-obligatc taxa. Based on our findings, wc suggest that susceptibility to freshwater parasites may cause overland dispersal to fail for boobies, or other seabirds. Thus, freshwater parasites may contribute to explaining the relative rarity of transcontinental dispersal, maintenance of strong inter-ocean population genetic structure, phylogenetic conservatism of specialization on salt-water habitats, and the strictly pelagic distributions of ocean-dwelling species from several avian families. Received 16 September 2022. Accepted 11 August 2023. Key words: freshwater, helminth, parasite, specimen, Sula, vagrancy. La errancia y dispersion en tierra adentro de las aves marinas son fenomenos raros cuyas causas y consecuencias se entienden poco. Estudiar registros en tierra adentro de aves marinas es importante ya que las masas continentales forman barreras a la dispersion de genes y parasitos; por lo tanto, la permeabilidad de las barreras terrestres influye en que tanto las poblaciones de aves evolucionan en trayectorias distintas y co-evolucionan con faunas parasitas distintas. Los alcatraces (Sula spp.) constituyen un ciado de especies obligadas de agua salada que se encuentran en oceanos tropicales y subtropicales. Las especies de alcatraces tienden a exhibir estructura genetica poblacional entre regiones oceanicas. Aunque raramente deambula en tierra firme, el alcatraz pardo (Sula leucogaster) se ha reportado muchas veces como errante en tierra adentro de Noneamerica. Previos reportes de tierra adentro en el lejano oeste Norteamericano se originaron de poblaciones del Pacifico (subespecies brewsteri), mientras que los del este y el medioeste de Norteamerica se originan de poblaciones del Caribe (subespecie leucogaster). En este articulo, describimos 2 especimenes nuevos de S. leucogaster, primeros registros estatales para Nuevo Mexico y Colorado, procedentes de localidades casi equidistantes de poblaciones fuente de Pacifico y el Caribe. Utilizamos secuencias de ADN mitocondrial para mostrar conclusivamente que ambos especimenes se originaron en el Caribe. Luego, examinamos ia fauna de helmintos parasitos de ambos especimenes de S. leucogaster y de un alcatraz de patas azules (S. nebouxii) que vagaba tierra adentro en Nuevo Mexico. Los intestinos de estos alcatraces contenian una serie de helmintos, incluyendo varios taxa obligadas de agua dulce. Con base en nuestros hallazgos, sugerimos que la susceptibilidad a los parasitos de agua dulce puede ocasionar que la dispersion en tierra adentro no sea exitosa para los alcatraces u otras aves marinas. Por lo tanto, los parasitos de agua dulce pueden contribuir a explicar la relativa rareza de la dispersion transcontinental, el mantenimiento de la fuerte estructura genetica inter-oceanica, la conservacion filogenetica de la especializacion en habitats de agua salada y la distribucion estrictamente pelagica de especies oceanicas pertenecientes a varias familias de aves. Palabras clave: agua dulce, errancia, especimen, helmintos, parasito, Sula., At least 254 bird species from 11 families are restricted to saltwater habitats (Howell and Zufelt 2019). The volant seabird species are strong fliers, characterized by high aspect-ratio wings. It [...]

Flying animals of different masses vary widely in body proportions, but the functional implications of this variation are often unclear. We address this ambiguity by developing an integrative allometric approach, which we apply here to hummingbirds to examine how the physical environment, wing morphology and stroke kinematics have contributed to the evolution of their highly specialised flight. Surprisingly, hummingbirds maintain constant wing velocity despite an order of magnitude variation in body weight; increased weight is supported solely through disproportionate increases in wing area. Conversely, wing velocity increases with body weight within species, compensating for lower relative wing area in larger individuals. By comparing inter- and intraspecific allometries, we find that the extreme wing area allometry of hummingbirds is likely an adaptation to maintain constant burst flight capacity and induced power requirements with increasing weight. Selection for relatively large wings simultaneously maximises aerial performance and minimises flight costs, which are essential elements of humming bird life history.

An adult Buteo was found dead as a road-kill south of Sacramento, California, and was thought to represent the first state record of the eastern Red-shouldered Hawk (B. lineatus lineatus;). It is now a specimen in the Museum of Wildlife and Fisheries Biology (WFB 4816) at the University of California, Davis. We examined this specimen and found that many of its plumage characters differed from all other adult Red-shouldered Hawks examined, including nominate adults. Plumage markings and measurements were intermediate between Red-tailed Hawk (Buteo jamaicensis, ssp calurus) and Red-shouldered Hawk (ssp elegans), leading us to hypothesize that the bird was a hybrid. However, mtDNA sequences and nuDNA microsatellites proved definitively that the bird was a Red-shouldered Hawk, most likely of eastern origin. This case illustrates that apparent hybrids or apparent vagrants could be individuals with anomalous phenotypes caused by rare genetic variation or novel epigenetic effects.

More than tools for managing physical and digital objects, museum collection management systems (CMS) serve as platforms for structuring, integrating, and making accessible the rich data embodied by natural history collections. Here we describe Arctos, a scalable community solution for managing and publishing global biological, geological, and cultural collections data for research and education. Specific goals are to: (1) Describe the core features and implementation of Arctos for a broad audience with respect to the biodiversity informatics principles that enable high quality research; (2) Highlight the unique aspects of Arctos; (3) Illustrate Arctos as a model for supporting and enhancing the Digital Extended Specimen concept; and (4) Emphasize the role of the Arctos community for improving data discovery and enabling cross-disciplinary, integrative studies within a sustainable governance model. In addition to detailing Arctos as both a community of museum professionals and a collection database platform, we discuss how Arctos achieves its richly annotated data by creating a web of knowledge with deep connections between catalog records and derived or associated data. We also highlight the value of Arctos as an educational resource. Finally, we present the financial model of fiscal sponsorship by a nonprofit organization, implemented in 2022, to ensure the long-term success and sustainability of Arctos. [ABSTRACT FROM AUTHOR]

Parasite host switches may trigger disease emergence, but prehistoric host ranges are often unknowable. Lymphatic filariasis and loiasis are major human diseases caused by the insect-borne filarial nematodes Brugia, Wuchereria and Loa. Here we show that the genomes of these nematodes and seven tropical bird lineages exclusively share a novel retrotransposon, AviRTE, resulting from horizontal transfer (HT). AviRTE subfamilies exhibit 83-99% nucleotide identity between genomes, and their phylogenetic distribution, paleobiogeography and invasion times suggest that HTs involved filarial nematodes. The HTs between bird and nematode genomes took place in two pantropical waves, >25-22 million years ago (Myr ago) involving the Brugia/Wuchereria lineage and >20-17 Myr ago involving the Loa lineage. Contrary to the expectation from the mammal-dominated host range of filarial nematodes, we hypothesize that these major human pathogens may have independently evolved from bird endoparasites that formerly infected the global breadth of avian biodiversity.

Animals that sustain high levels of aerobic activity under hypoxic conditions (e.g., birds that fly at high altitude) face the physiological challenge of jointly optimizing blood-O2 affinity for O2 loading in the pulmonary circulation and O2 unloading in the systemic circulation. At high altitude, this challenge is especially acute for small endotherms like hummingbirds that have exceedingly high mass-specific metabolic rates. Here we report an experimental analysis of hemoglobin (Hb) function in South American hummingbirds that revealed a positive correlation between Hb-O2 affinity and native elevation. Protein engineering experiments and ancestral-state reconstructions revealed that this correlation is attributable to derived increases in Hb-O2 affinity in highland lineages, as well as derived reductions in Hb-O2 affinity in lowland lineages. Site-directed mutagenesis experiments demonstrated that repeated evolutionary transitions in biochemical phenotype are mainly attributable to repeated amino acid replacements at two epistatically interacting sites that alter the allosteric regulation of Hb-O2 affinity. These results demonstrate that repeated changes in biochemical phenotype involve parallelism at the molecular level, and that mutations with indirect, second-order effects on Hb allostery play key roles in biochemical adaptation.

Insertion/deletion (indel) mutations, which are represented by gaps in multiple sequence alignments, have been used to examine phylogenetic hypotheses for some time. However, most analyses combine gap data with the nucleotide sequences in which they are embedded, probably because most phylogenetic datasets include few gap characters. Here, we report analyses of 12,030 gap characters from an alignment of avian nuclear genes using maximum parsimony (MP) and a simple maximum likelihood (ML) framework. Both trees were similar, and they exhibited almost all of the strongly supported relationships in the nucleotide tree, although neither gap tree supported many relationships that have proven difficult to recover in previous studies. Moreover, independent lines of evidence typically corroborated the nucleotide topology instead of the gap topology when they disagreed, although the number of conflicting nodes with high bootstrap support was limited. Filtering to remove short indels did not substantially reduce homoplasy or reduce conflict. Combined analyses of nucleotides and gaps resulted in the nucleotide topology, but with increased support, suggesting that gap data may prove most useful when analyzed in combination with nucleotide substitutions.

Abstract Background Microinversions are cytologically undetectable inversions of DNA sequences that accumulate slowly in genomes. Like many other rare genomic changes (RGCs), microinversions are thought to be virtually homoplasy-free evolutionary characters, suggesting that they may be very useful for difficult phylogenetic problems such as the avian tree of life. However, few detailed surveys of these genomic rearrangements have been conducted, making it difficult to assess this hypothesis or understand the impact of microinversions upon genome evolution. Results We surveyed non-coding sequence data from a recent avian phylogenetic study and found substantially more microinversions than expected based upon prior information about vertebrate inversion rates, although this is likely due to underestimation of these rates in previous studies. Most microinversions were lineage-specific or united well-accepted groups. However, some homoplastic microinversions were evident among the informative characters. Hemiplasy, which reflects differences between gene trees and the species tree, did not explain the observed homoplasy. Two specific loci were microinversion hotspots, with high numbers of inversions that included both the homoplastic as well as some overlapping microinversions. Neither stem-loop structures nor detectable sequence motifs were associated with microinversions in the hotspots. Conclusions Microinversions can provide valuable phylogenetic information, although power analysis indicates that large amounts of sequence data will be necessary to identify enough inversions (and similar RGCs) to resolve short branches in the tree of life. Moreover, microinversions are not perfect characters and should be interpreted with caution, just as with any other character type. Independent of their use for phylogenetic analyses, microinversions are important because they have the potential to complicate alignment of non-coding sequences. Despite their low rate of accumulation, they have clearly contributed to genome evolution, suggesting that active identification of microinversions will prove useful in future phylogenomic studies.