Long-term decline in fledging body condition of Flesh-footed Shearwaters (Ardenna carneipes)

Abstract - Marine systems are under increasing pressure from anthropogenic activities. In recent decades, the deteriorating condition of the world’s seabird populations suggests these pressures have reached a tipping point. For young birds, body mass can significantly influence survival in the critical period between nest departure and recruitment to the breeding population. On Lord Howe Island, we measured Flesh-footed Shearwater (Ardenna carneipes) fledglings in the colony and adjacent beaches to determine how body condition changed during 2010–2022. Overall, we found chick body mass as well as wing, culmen, and head + bill length declined over time with larger declines observed in beach-washed birds. Culmen and head + bill length declined by 0.17 and 0.23 mm/year, respectively, and body mass by 16.1 g/year. The number of chicks fledging at &lt;400 g has increased sharply in recent years, meaning significant numbers of birds are unlikely to survive after departing the island. Our results point to a deepening of the division in the shearwater population: adult birds who can successfully provision sufficient nutrient reserves so their chick fledges successfully, and those who cannot. In this latter group, failure at the fledging stage (beached birds) is resulting in birds in increasingly poor condition, the likes of which were seldom documented 13 years ago.

Citation

J L Lavers, A L Bond, Long-term decline in fledging body condition of Flesh-footed Shearwaters (Ardenna carneipes), ICES Journal of Marine Science, Volume 80, Issue 4, May 2023, Pages 1113–1119, https://doi.org/10.1093/icesjms/fsad048

Type

Journal Article

Item Description

Copyright © The Author(s) 2023. Published by Oxford University Press on behalf of International Council for the Exploration of the Sea. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. The attached file is the published version of the article.
NHM Repository

ISSN

1054-3139

EISSN

1095-9289