Observations and models of across-wind flight speed of the wandering albatross

Richardson, P. L. and Wakefield, E. D. (2022) Observations and models of across-wind flight speed of the wandering albatross. Royal Society Open Science, 9(11), 211364. (doi: 10.1098/rsos.211364) (PMID:36465680) (PMCID:PMC9709578)

Abstract

Wandering albatrosses exploit wind shear by dynamic soaring (DS), enabling rapid, efficient, long-range flight. We compared the ability of a theoretical nonlinear DS model and a linear empirical model to explain the observed variation of mean across-wind airspeeds of GPS-tracked wandering albatrosses. Assuming a flight trajectory of linked, 137° turns, a DS cycle of 10 s and a cruise airspeed of 16 m s−1, the theoretical model predicted that the minimum wind speed necessary to support DS is greater than 3 m s−1. Despite this, tracked albatrosses were observed in flight at wind speeds as low as 2 m s−1. We hypothesize at these very low wind speeds, wandering albatrosses fly by obtaining additional energy from updrafts over water waves. In fast winds (greater than 8 m s−1), assuming the same 10 s cycle period and a turn angle (TA) of 90°, the DS model predicts mean across-wind airspeeds of up to around 50 m s−1. In contrast, the maximum observed across-wind mean airspeed of our tracked albatrosses reached an asymptote at approximately 20 m s−1. We hypothesize that this is due to birds actively limiting airspeed by making fine-scale adjustments to TAs and soaring heights in order to limit aerodynamic force on their wings.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Wakefield, Dr Ewan
• Authors: Richardson, P. L., and Wakefield, E. D.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Royal Society Open Science
• Publisher: The Royal Society
• ISSN: 2054-5703
• ISSN (Online): 2054-5703
• Published Online: 30 November 2022
• Copyright Holders: Copyright © 2022 The Authors
• First Published: First published in Royal Society Open Science 9(11): 211364
• Publisher Policy: Reproduced under a Creative Commons License
• Data DOI: 10.5061/dryad.zs7h44j96

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
171561		Seabirds and wind - the consequences of extreme prey taxis in a changing climate	Ewan Wakefield	Natural Environment Research Council (NERC)	NE/M017990/1	Institute of Biodiversity, Animal Health and Comparative Medicine