Behav Processes. 2015 Nov;120:50-3. doi: 10.1016/j.beproc.2015.08.009. Epub 2015 Aug 28.
- 1International
Birding and Research Centre in Eilat, P.O. Box 774, Eilat 88000,
Israel; Department of Life Sciences, Ben Gurion University, Beer Sheva,
Israel.
- 2Department of Avian Biology and Ecology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, Poznań 61-614, Poland. Electronic address: kudlaty@amu.edu.pl.
Abstract
The
selection of an ambush-cum-foraging site and proper prey are
indispensable for maintaining an adequate energy intake by sit-and-wait
predators to optimize survival and future fitness. This is important for
snakes, where an ambush site has suitable ambience. We studied the
foraging strategy of the Palestine Saw-scaled Viper (Echis coloratus) at
an avian migratory stopover site. Following initial observations, we
hypothesized that vipers are able to discern the body mass of a perched
bird and hunt accordingly. We implemented an experiment where vipers
chose between four groups of migratory Blackcaps with different body
mass. Prey choice by vipers of both age classes was not random and
adults focused on Blackcaps with the lightest body mass. Juveniles
displayed a variability of prey choice but selected mainly birds from
the lightest categories. We concluded that Saw-scaled Vipers hunt prey
based on thermal cues; juveniles practice on different prey groups prior
to perfecting their foraging techniques i.e., hunting
is a learned process; and that they prefer birds with the lowest body
mass. The last because Blackcaps, when on migration, save energy by
entering a state of deep torpor in which they sacrifice their vigilance
capabilities.
Copyright © 2015 Elsevier B.V. All rights reserved.
KEYWORDS:
Avian migrants; Body mass; Echis coloratus; Foraging; Sylvia atricapilla; Vigilance
