10.5061/DRYAD.B5MKKWHBQ
Pays, Olivier
0000-0001-8268-1804
University of Angers
Blanchard, Pierrick
University of Toulouse
Chamaillé-Jammes, Simon
French National Centre for Scientific Research
Valeix, Marion
French National Centre for Scientific Research
Loveridge, Andrew
Oxford University
Macdonald, David
Oxford University
Périquet, Stéphanie
French National Centre for Scientific Research
Van der Meer, Esther
Painted Dog Conservation
Duncan, Patrick
French National Centre for Scientific Research
Mtare, Godfrey
Parks and Wildlife Management Authority
Fritz, Herve
French National Centre for Scientific Research
Disentangling the roles of bottom-up and top-down drivers in the trade-off
between food acquisition and safety in prey with multiple predators
Dryad
dataset
2020
antipredator response
feeding rate
foraging strategy
herbivore
patch quality
Risk effect
Vigilance
2020-10-12T00:00:00Z
2020-10-12T00:00:00Z
en
73178 bytes
2
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
1. Prey face a trade-off between acquiring food and avoiding predation,
but food availability, and therefore its effect, is rarely measured in
field studies investigating non-lethal effects of predation. The main aim
of this study is to investigate the role of the presence of predators in
the functional adjustments of feeding parameters with patch quality in a
medium-size herbivore. 2. In Hwange National Park (Zimbabwe), we set up an
experiment by manipulating, over two years, patch quality for impala
(Aepyceros melampus), a medium-sized herbivore. We assess predation risk
by monitoring the presence of three GPS-equipped predators: African lions
(Panthera leo), spotted hyaenas (Crocuta crocuta) and African wild dogs
(Lycaon pictus). 3. In enriched, fertilised plots the impalas reduced step
rates (i.e. the rates of change in feeding stations), and increased their
number of bites per feeding station while bite rates were not affected.
Thus, the main adjustment of their feeding was the step rate. The total
time the impalas spent vigilant appeared to be a good predictor of the
variation of their bite rate. Although vigilance caused a reduction in
bite rate when at a feeding station, the impalas reduced the relative
costs of vigilance by continuing chewing and processing their food when
scanning for predators. 4. When predators were in the vicinity, the
impalas increased their exclusive vigilance (high-cost vigilance) but not
their vigilance while chewing (low-cost vigilance) and decreased their
bite rate while their step rate and the number of bites per feeding
station did not change significantly. The impalas were thus visually
disconnected from their patch, and reduced their bite rate when actually
foraging. Exclusive vigilance increased when both lions and hyaenas were
in the vicinity, and when wild dogs were nearby. 5. Patterns of vigilance
that altered bite rate were linked to the presence of predators during the
previous 24h. Over the long term patch quality was the main determinant of
the feeding parameters (step rate and bite rate). This study shows how
predators, by affecting the time prey devote to predator detection, shape
the functional adjustments of food acquisition by prey to local patch
quality.