University of Oulu

Pakanen, VM., Ahonen, E., Hohtola, E. et al. Oecologia (2018) 188: 991.

Northward expanding resident species benefit from warming winters through increased foraging rates and predator vigilance

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Author: Pakanen, Veli-Matti1; Ahonen, Eveliina1; Hohtola, Esa1;
Organizations: 1Ecology and Genetics Research Unit, University of Oulu
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 0.8 MB)
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Language: English
Published: Springer Nature, 2018
Publish Date: 2019-01-31


Species distributions shift northwards due to climate change, but the ecological mechanisms allowing range expansions are not fully understood. Most studies have concentrated on breeding seasons, but winter warming may also be important. Wintering distributions are restricted by food availability and temperature, which may also interact. Foraging in cold conditions requires adaptations as individuals have to be efficient in foraging, while staying warm and vigilant for predators. When the ambient temperature declines, foraging rates should be reduced due to increased time spent on warming behaviours. In addition, predator vigilance should decline, because more time has to be invested in foraging. Cold weather should limit northward expanding southern species in particular, while northern species should perform better in cold conditions. We tested this by studying temperature responses (between 0 and − 35 °C) among wintering birds at feeders. We compared foraging behaviours of two northward expanding southern species, the great tit (Parus major) and the blue tit (Cyanistes caeruleus) to a northern species, the willow tit (Poecile montanus). Foraging rate and vigilance decreased, and warming behaviour increased when temperatures declined. Importantly, the performance in these traits was poorer in the southern species compared to the willow tit. Furthermore, the response to decreasing temperatures in foraging rates and warming behaviour was stronger in the great tits than willow tits. As the winters become warmer, these mechanisms should increase wintering success of southern species wintering at high latitudes, and lead to higher survival, increased population growth, and consequent range expansion.

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Series: Oecologia
ISSN: 0029-8549
ISSN-E: 1432-1939
ISSN-L: 0029-8549
Volume: 188
Issue: 4
Pages: 991 - 999
DOI: 10.1007/s00442-018-4271-7
Type of Publication: A1 Journal article – refereed
Field of Science: 1181 Ecology, evolutionary biology
Funding: Open access funding provided by University of Oulu including Oulu University Hospital. VMP was supported by the Finnish Cultural Foundation.
Copyright information: © The Author(s) 2018. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.