Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2015 Dec;61(6):951-958.
doi: 10.1093/czoolo/61.6.951. Epub 2015 Dec 1.

Morphology, flight performance, and water crossing tendencies of Afro-Palearctic raptors during migration

Affiliations

Morphology, flight performance, and water crossing tendencies of Afro-Palearctic raptors during migration

Nicolantonio Agostini et al. Curr Zool. 2015 Dec.

Abstract

Raptors primarily use soaring-gliding flight which exploits thermals and ridge lifts over land to reduce energetic costs. However during migration, these birds often have to cross water surfaces where thermal currents are weak; during these times, birds mainly use flapping (powered) flight which increases energy consumption and mortality risk. As a result, some species have evolved strategies to reduce the amount of time spent over water by taking extensive detours over land. In this paper, we conducted a meta-analysis of water-crossing tendencies in Afro-Palearctic migrating raptors in relation to their morphology, their flight performance, and their phylogenetic relationships. In particular, we considered the aspect ratio (calculated as the wing span squared divided by wing area), the energetic cost of powered flight, and the maximum water crossing length regularly performed by adult birds. Our results suggest that energy consumption during powered flight predominately affects the ability of raptors to fly over water surfaces.

Keywords: Aspect ratio; Migration; Powered flight; Raptors; Water crossing; Wing tip.

PubMed Disclaimer