J Anim Ecol. 2016 Dec 14. doi: 10.1111/1365-2656.12623. [Epub ahead of print]
- 1Centre of Ecology and Conservation, University of Exeter, Cornwall Campus, Penryn, TR10 9FE, UK.
- 2Icelandic Institute of Natural History, Urridaholtsstraeti, 212, Gardabaer, Iceland.
- 3Irish Brent Goose Research Group, 100 Strangford Road, Downpatrick, County Down, BT30 7JD, UK.
- 4Irish Brent Goose Research Group, Mahee Island, Comber,, County Down, BT23 6EP, UK.
- 5RSPB Centre for Conservation Science, RSPB Northern Ireland, Belvoir Park Forest, Belfast, BT8 7QT, UK.
Abstract
The
manner in which patterns of variation and interactions among
demographic rates contribute to population growth rate (λ) are key to
understanding how animal populations will respond to changing climatic
conditions. Migratory species are likely to be particularly sensitive to
climatic conditions as they experience a range of different
environments throughout their annual cycle. However, few studies have
provided fully integrated demographic analyses of migratory populations
in response to changing climatic conditions. Here, we employed
integrated population models (IPM) to demonstrate that the environmental
conditions experienced during a short, but critical period, play a
central role in the demography of a long-distance migrant, the
light-bellied Brent goose (Branta bernicla hrota). Female survival was
positively associated with June North Atlantic Oscillation (NAO) values,
whereas male survival was not. In contrast, breeding productivity was
negatively associated with June NAO, suggesting a trade-off between
female survival and reproductive success. Both adult female and adult
male survival showed low temporal variation, whereas there was high
temporal variation in recruitment and breeding productivity. In
addition, while annual population growth was positively correlated with
annual breeding productivity a sensitivity analysis revealed that
population growth was most sensitive to changes in adult survival. Our
results demonstrate that the environmental conditions experienced during
a relatively short-time window at the start of the breeding season play
a critical role in shaping the demography of a long-distant Arctic
migrant. Crucially, different demographic rates responded in opposing
directions to climatic variation, emphasizing the need for integrated
analysis of multiple demographic traits when understanding population
dynamics. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
KEYWORDS:
Annual routine; Canadian Arctic; capture-mark-recapture; climate change; population demography
