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Exploring sources of (co-)variation
in timing and total daily feeder
visits in a wild population of black-
capped chickadees
Nathan L. Hobbs1, Deborah M. Hawkshaw1, Jan J. Wijmenga1 and Kimberley J.
Mathot1,2
1Department of Biological Sciences, and 2Canada Research Chair in Integrative Ecology, Department of Biological
Sciences, University of Alberta, Edmonton, Alberta, Canada
NLH,0009-0006-7707-152X; DMH,0000-0001-7844-155X; JJW,0000-0002-3817-2153;
KJM,0000-0003-2021-1369
The timing and amount of foraging in birds are shaped by many of the
same extrinsic factors, including temperature and daylength, as well as
intrinsic factors, such as sex and age. Here, we investigate co-variation
between these traits. We observed a population of 143 individually marked
black-capped chickadees (Poecile atricapillus) over a 90 day period during
the winter. For each day, we recorded the time an individual began and
ended feeder use relative to sunrise/sunset, and the total number of feeder
visits. Within-individuals, both earlier first feeder visit and later last feeder
visit were associated with higher total daily feeder visits but lower feeding
rates. Individuals also differed consistently in the timing of first and last
feeder visits, and individuals that consistently started feeder use earlier
in the day ended feeder use later and had higher total daily feeder visits
compared with those that started later, but had no difference in feeding
rate. Our study demonstrates that variation in the timing of foraging can
have important consequences for energy acquisition at both the within- and
among-individual levels.
1. Introduction
Variation in the timing of activity has been widely reported both within- and
among-individuals from the same population [1–4]. For example, within-
individuals, timing of activity (e.g. wakefulness, movement and foraging)
often varies with ambient temperature [3,5–7], season [1,5,6], daylength [7,8],
predation risk [9,10] and weather conditions [5,8]. In songbirds, daylength
and ambient temperature are important extrinsic factors that shape the timing
of activity; shorter days and colder temperatures generally result in shorter
active periods [3,8]. Consistent among-individual differences in the timing of
activity have also been reported [11]. In songbirds, individuals can generally
be divided into either more active or less active types; individuals that start
activity earlier in the day tend to remain active later [8,12,13]. Differences in
activity types have been related to sex and age [1,3,4,8,14], body mass [15–17]
and metabolic rate [15,18].
Similarly, within- and among-individual variation in songbird foraging
behaviour is well established [19–22], with many of the same factors that
shape timing of activity (see above) also shaping foraging. For example,
lower ambient temperatures are often associated with increased daily food
intake [20,21], but see [23], and shorter days with larger peaks in foraging
[20]. Additionally, foraging rates often differ across age and sex classes [24].
© 2024 The Author(s). Published by the Royal Society. All rights reserved.
Research
Cite this article: Hobbs NL, Hawkshaw DM,
Wijmenga JJ, Mathot KJ. 2024 Exploring sources
of (co-)variation in timing and total daily feeder
visits in a wild population of black-capped
chickadees. Biol. Lett. 20: 20240365.
https://doi.org/10.1098/rsbl.2024.0365
Received: 26 June 2024
Accepted: 24 October 2024
Subject Category:
Animal behaviour
Subject Areas:
behaviour, ecology
Keywords:
diurnal activity patterns, foraging behaviour,
among-individual differences, within-individual
differences, small bird in winter
Author for correspondence:
Kimberley J. Mathot
e-mail: mathot@ualberta.ca
Electronic supplementary material is available
online at https://doi.org/10.6084/
m9.figshare.c.7569742.