Helen F. James

The Hawaiian honeycreepers, one of the world’s most iconic adaptive radiations, are facing a human-mediated extinction crisis. More than 60 Hawaiian honeycreepers (Fringillidae: Carduelinae: Drepanidini) evolved from a single rosefinch-like ancestor that colonized the Hawaiian Islands. Only 17 Hawaiian honeycreeper taxa are known to be extant, of which only the common ‘amakihi ( Chlorodrepanis virens ) and ‘apapane ( Himatione sanguinea ) are classified as “Least Concern.” Using mitogenome, whole-genome, and hybridization-capture data, we present a comprehensive phylogeny of the historically known Hawaiian honeycreeper radiation. We also place two taxa known only from paleontological specimens ( Vangulifer neophasis and cf. Xestospiza conica ) in their phylogenomic context. We demonstrate that most Hawaiian honeycreeper lineages diversified in a “Big Bang” of adaptive radiation correlating with the formation of O‘ahu and that interspecies introgression likely played a role in this process. Using whole-genome data, we confirm putative interspecies admixture [N. A. S. Przelomska et al. , Biol. Lett. 21 , 20250265 (2025)] between the ‘ō‘ū ( Psittirostra psittacea ) and Lāna‘i hookbill ( Dysmorodrepanis munroi ) and document ongoing gene flow across the ‘amakihi species complex. Furthermore, we reject the synonymization of Vestiaria (‘i‘iwi) and Drepanis (Hawai‘i and black mamo). Instead, the mamo species form an extinct clade with no close extant relatives, demonstrating a greater loss of phylogenomic diversity than previously understood.

Synopsis: The three bird species within the family Anhimidae (screamers) are of great interest to the big picture of avian evolution due to both their phylogenetic position and their unusual combination of features. As screamers are early diverging members of Anseriformes (waterfowl), which itself is an early diverging clade within the extant bird radiation, their anatomy may help shed light on that of the common ancestor of both Anseriformes and crown-group birds as a whole. To reveal new information about the wing anatomy of anhimids, we generated a three-dimensional musculoskeletal model of the flight apparatus of the extant Southern Screamer (Chauna torquata) using diffusible iodine-based contrast-enhanced computed tomography (diceCT). We found that the wing muscle anatomy of Chauna reflects the soaring flight style employed by anhimids, as opposed to the rapid continuous wingbeats used by most other anseriforms. In Chauna, this manifests as a more distal insertion of the pectoralis muscle on the humerus to facilitate slower, stronger wingbeats, and a reduction in the length of antebrachial muscle origins and insertions that serves to reduce the distal inertia of the wing. Our three-dimensional dataset represents a typical musculoskeletal system of a bird with strong flight capabilities. This, combined with our observation that most flight-related muscles in Chauna leave recognizable osteological correlates associated with their attachments to the skeleton, means that this work can help form a basis for future comparative studies of the avian musculoskeletal system, with implications for reconstructing the flight apparatus of fossil birds.

The Hawaiian honeycreepers simultaneously represent one of the most spectacular avian adaptive radiations and are one of the most endangered avian groups. This clade’s few geographically widespread species can serve as a model to understand population-level processes shaping differentiation and characterizing decline. One such species is the likely extinct ʻōʻū ( Psittirostra psittacea ), a parrot-like beaked honeycreeper with a frugivorous feeding ecology. We compiled morphological and hybridization-captured ancient DNA datasets for the ʻōʻū from museum specimens from across the Hawaiian archipelago. We find (i) genomic differentiation among ʻōʻū from Kauaʻi, Lānaʻi, and the remaining Hawaiian Islands and (ii) a larger phenotype on Kauaʻi and smaller Maui Nui morphological phenotypes. While the differentiated population on Kauaʻi is likely a result of Kauaʻi’s geographical isolation, the divergent population on Lānaʻi is harder to explain by biogeography alone. Thus, we investigated whether the unexpected divergence of Lānaʻi ʻōʻū could be attributed to inter-species admixture with the geographically overlapping, now extinct ‘parrot-billed’ Lānaʻi hookbill ( Dysmorodrepanis munroi ) or a critically endangered Maui endemic, the kiwikiu ( Pseudonestor xanthophrys ). We detect significant admixture between the Lānaʻi ʻōʻū population and the Lānaʻi hookbill, possibly explaining the observed population structure and associating interspecific breeding with populations on the precipice of extinction.

Lithornithids are an assemblage of Palaeogene fossil birds thought to represent stem-group members of Palaeognathae. Among extant palaeognaths, which include flightless ratites such as ostriches, only tinamous can fly, though only in anaerobic bursts. Despite their limited dispersal capabilities, the phylogenetic interrelationships and geographic distributions of palaeognaths imply that their early relatives were capable of long-distance dispersal, although quantitative skeletal evidence has not been applied to this question. We investigate the flight capabilities and ecology of the Palaeogene lithornithid Lithornis promiscuus using a three-dimensional geometric morphometric dataset spanning the avian crown group. Our models reject the hypothesis that Lithornis would have relied on tinamou-like burst flight, and show that its sternum morphology is consistent with a range of aerobic, flapping flight styles—closely resembling those of many extant birds exhibiting pronounced dispersal capabilities. Our results are consistent with inferences from lithornithid wing shape, supporting the hypothesis that at least some stem palaeognaths were capable of long-distance flight, helping to clarify the origins of the transoceanic distributions of extant flightless ratites.

The Cumberland Bone Cave Local Fauna (CBCLF) is the most significant Irvingtonian vertebrate fauna in the eastern United States north of Florida. Excavation of a railroad cut near Cumberland, Allegany County, Maryland in 1912 revealed a deposit of well-preserved Pleistocene fossils comprising 154 component taxa. Of these, 109 are vertebrates of which 28 are extinct and comprise about 26% of the total recorded vertebrate taxa or about 22% of the total CBCLF. Twenty holotype specimens have been named from CBCLF. Dating of peccary molars from the cave using U-series Electron Spin Resonance (US-ESR) provided dates of 722 ± 64 and 790 ± 53 KA. Between 1912 and 2012, the cave was excavated by eleven expeditions from five institutions over 79 years. This work resulted in 24 papers with ‘Cumberland’ in the title. Papers that utilize specimens from the CBCLF for taxonomic reviews or regional interpretations are far greater in number. This paper attempts to collate, standardize, summarize, and, when necessary, update the taxonomy, intrasite stratigraphy, collecting localities, geochronology, and paleoecology of the CBCLF and contrast it with other middle Irvingtonian local faunas from the Middle Atlantic Appalachian Region. Specimens collected from the CBCLF can be stratigraphically subdivided into two depositional units, a red clay found on both the north and south sides of the railroad cut and those from a brown to tan fine-grained, loose, noncemented fill largely recovered from the north side of the cut. Faunal composition from all locations within Cumberland Bone Cave is similar. Except for rare Holocene intrusions, all the CBCLF taxa are compatible with other Irvingtonian local faunas in the region. We interpret the CBCLF to represent conditions slightly cooler than those at present, but with summer high temperatures being somewhat lower within mixed hardwood forests and some open grassy areas.

Convergence provides strong evidence for adaptive evolution as it reflects shared adaptive responses to the same selection pressures. The waterfowl (order Anseriformes) are an ideal group in which to study convergent evolution as they have repeatedly evolved morphotypes putatively correlated with diet (i.e., dabbler, grazer, diver). Here, we construct the most robust evolutionary hypothesis to date for waterfowl and reveal widespread morphological convergence across the order. We quantified the shape of the skull and hindlimb elements (femur, tibiotarsus, and tarsometatarsus) of 118 species of extant waterfowl using geometric morphometrics. Multivariate generalized evolutionary models provide strong support for a relationship between dietary ecology and skull shape, and evidence for convergent evolution across lineages that share dietary niches. Foraging behavior better explained the evolution of hindlimb shape, but diet still contributed significantly. We also find preliminary evidence for integration across all three measured hindlimb elements with each other and with the skull. We demonstrate that dietary ecology drives morphological convergence within waterfowl, that this convergent evolution involves multiple integrated skeletal structures, and that morphological changes are associated with shifts in the rate of phenotypic evolution.

Adaptive avian radiations associated with the diversification of bird beaks into a multitude of forms enabling different functions are exemplified by Darwin’s finches and Hawaiian honeycreepers. To elucidate the nature of these radiations, we quantified beak shape and skull shape using a variety of geometric measures that allowed us to collapse the variability of beak shape into a minimal set of geometric parameters. Furthermore, we find that just two measures of beak shape—the ratio of the width to length and the normalized sharpening rate (increase in the transverse beak curvature near the tip relative to that at the base of the beak)—are strongly correlated with diet. Finally, by considering how transverse sections to the beak centreline evolve with distance from the tip, we show that a simple geometry-driven growth law termed ‘modified mean curvature flow’ captures the beak shapes of Darwin’s finches and Hawaiian honeycreepers. A surprising consequence of the simple growth law is that beak shapes that are not allowed based on the developmental programme of the beak are also not observed in nature, suggesting a link between evolutionary morphology and development in terms of growth-driven developmental constraints.

Vicki Friesen The Loye and Alden Miller Research Award is given annually for lifetime achievement in ornithological research. Loye Holmes Miller and his son, Alden, left a remarkable legacy to the field of ornithology. Together they mentored 30 Ph.D. students, 28 in avian biology, and their students went on to train in turn a total of 166 scientists. Alden served as a long-standing editor of The Condor during his distinguished career at the Museum of Vertebrate Zoology at the University of California, Berkeley. This year, the American Ornithological Society (AOS) is presenting the 2023 AOS Loye and Alden Miller Research Award to Vicki Friesen. Vicki Friesen is a professor in the Department of Biology at Queen’s University, Kingston, Ontario, Canada. Dr. Friesen’s distinguished research career has mostly focused on the evolution and conservation genetics of seabirds. With students and colleagues, Dr. Friesen uses novel approaches to examine mechanisms of speciation and tackle complex conservation questions such as the potential for adaptation to rapid environmental change in Arctic seabirds. She is also using a variety of cutting-edge genetic techniques to understand ­individual and population-level variation in seabird behavior, disease resistance and breeding phenology. Dr. Friesen has published more than 130 peer-reviewed articles in Nature, Proceedings of the National Academy of Sciences of the United States, Environmental Science & Technology, and Molecular Ecology. And she is a recipient of the Doris Huestis Speirs Award from the Society of Canadian Ornithologists/Société des Ornithologistes du Canada (SCO–SOC) for her outstanding lifetime contributions to Canadian ornithology. Dr. Friesen has been an AOS Elective Member since 2000 and an AOS Fellow since 2006.

Jacques Balthazart (left) and Gregory F. Ball (right) The Elliott Coues Award recognizes outstanding and innovative contributions to ornithological research with no limitation to geographic area, sub-discipline(s) of ornithology, or the time course over which the work was done. This award was established in honor of Elliott Coues, a pioneering ornithologist of the western United States and a founding member of the American Ornithologists’ Union (AOU). The award consists of the Elliott Coues Medal and an honorarium. In 2023, the American Ornithological Society (AOS) is presented jointly to Gregory F. Ball and Jacques Balthazart. Gregory F. Ball is the Vice President for Research and professor in the Department of Psychology at the University of Maryland, USA. Jacques Balthazart is the Director Emeritus of the Behavioral Neurobiology Research Group, GIGA Neurosciences, at the University of Liège, Belgium. Gregory F. Ball and Jacques Balthazart have enjoyed a highly productive long-term collaboration since they published their first paper together in 1989. They are well known for their innovative work on avian endocrinology and neurobiology. This includes work on the steroid hormone regulation of sexual behavior in quail and seasonal neuroplasticity in songbirds. They have also investigated sex differences in the avian brain in relation to the control of courtship and other reproductive behaviors. Their basic work on the chemical neuroanatomy of the avian brain has contributed to revised views of avian and mammalian brain homologies. They have published more than 150 papers together among their 300 (Ball) and 500 (Balthazart) total research papers and have co-organized numerous symposia at the International Symposium on Avian Endocrinology meetings and the International Ornithological Congress. Ball and Balthazart have both served as president of the Society for Behavioral Neuroendocrinology, and both are Fellows of the American Association for the Advancement of Science (AAAS). Balthazart received the Farner Medal for distinguished work in avian endocrinology (2016) and has been an Honorary Fellow of the AOS since 1985. Ball has been an AOS Elective Member since 1992 and an AOS Fellow since 2005.

Cristina Yumi Miyaki Maren Vitousek The William Brewster Memorial Award is given each year to the author or coauthors of the most meritorious body of work (book, monograph, or series of related papers) on birds of the Western Hemisphere published during the past 10 years. This year, the American Ornithological Society (AOS) is announcing two Brewster Awards: one to Cristina Yumi Miyaki and one to Maren Vitousek. Selecting individuals for the William Brewster Memorial Award is particularly challenging given the amazing pool of candidates, according to Dr. Marty Leonard, Chair of the Senior Professional Awards Committee. “We are delighted to recognize Drs. Miyaki and Vitousek for their outstanding contributions to ornithology with this prestigious award,” Dr. Leonard said. Cristina Yumi Miyaki is a Professor in the Department of Genetics and Evolutionary Biology at the University of Sao Paolo, Brazil. Dr. Miyaki is a world-renowned phylogeneticist and biogeographer of the Neotropical avifauna, including parrots and endemic taxa of the Atlantic Forest region of ­Brazil. Her body of research is based on molecular genetics and ­evolutionary analysis of several avian lineages. She is also a broad-scale collaborator on large themes of psittacine evolution, cognition, and conservation genetics. She is a frequent presenter at international conferences and has published more than 140 papers, including those on birds in Nature Communications, Current Biology, Proceedings of the Royal Society B, and Molecular Ecology. Dr. Miyaki has supervised 17 master’s degree students and 12 PhD students and co-supervised 2 master’s degree students and 2 PhD students. She was elected as an Honorary Fellow of the American Ornithologists’ Union (now AOS) in 2005 and was subsequently elected as an Elective Member (2015) and Fellow (2019) of the Society. Dr. Miyaki has also served on the AOS Committee for the Nomination of Fellows and Elective Members. She is a corresponding member of the German Ornithologists Society, and a member of various working groups for the conservation of endangered species for the Brazilian government, a member of the Conservation Genetics Specialist Group for the International Union for Conservation of Nature, and a focal point of contact for the Species Survival Commission of the Brazilian International Union for Conservation of Nature Committee.