Martin, E.Sherratt, E.2024-11-112024-11-112023Evolutionary Ecology, 2023; 37(6):945-9590269-76530269-7653https://hdl.handle.net/2440/143212The remarkable diversity of ecological niches that birds have evolved to inhabit have resulted in their status as model organisms to study how the same morphological features can adapt to different environments. Not least of these features is the avian foot, which has diversified into a wide range of forms suited to several different ecological functions. In this investigation, we examine how a potential trade-off between two such functions is expressed in the foot morphology of the Australian avifauna; namely, the impact that specialising for either walking or grasping has on the proportions of the phalanges. The lengths of the body, foot, third digit and its phalanges, and the hallux were recorded from 106 preserved skins belonging to 22 species. Our analysis of these data shows that this functional specialisation presents a similar morphological gradient in Australian birds as has been previously observed in American species, with a few unique exceptions. Generally, species that are reliant on the foot to grasp (e.g., perching and gripping prey) display greater distal phalanx and hallux lengths than species that are specialised for walking or wading. However, the terrestrial Megapodes of Australia demonstrate a more intermediate morphology, potentially as a result of the unique mound construction behaviour occurring in this clade. These findings have relevance not only for use in identifying the ecology of cryptic or extinct species from morphology, but also for determining future evolutionary changes in different avian groups.en© The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Morphology; Aves; Trade-offs; Australian faunaJournal article10.1007/s10682-023-10261-52024-10-31644341Martin, E. [0000-0003-1285-1390]Sherratt, E. [0000-0003-2164-7877]