The increased risk of predation enhances cooperation.
Theory predicts that animals in adverse conditions can decrease individual risks and increase long-term benefits by cooperating with neighbours. However, some empirical studies suggest that animals often focus on short-term benefits, which can reduce the likelihood that they will cooperate with others. In this experimental study, we tested between these two alternatives by evaluating whether increased predation risk (as a correlate of environmental adversity) enhances or diminishes the occurrence of cooperation in mobbing, a common anti-predator behaviour, among breeding pied flycatchers Ficedula hypoleuca. We tested whether birds would join their mobbing neighbours more often and harass a stuffed predator placed near their neighbours' nests more intensely in areas with a higher perceived risk of predation. Our results show that birds attended mobs initiated by their neighbours more often, approached the stuffed predator significantly more closely, and mobbed it at a higher intensity in areas where the perceived risk of predation was experimentally increased. In such high-risk areas, birds also were more often involved in between-pair cooperation. This study demonstrates the positive impact of predation risk on cooperation in breeding songbirds, which might help in explaining the emergence and evolution of cooperation.
Krams
Indrikis
I
Institute of Systematic Biology, University of Daugavpils, 5401 Daugavpils, Latvia. indrikis.krams@biology.lv
Bērziņs
Arnis
A
Krama
Tatjana
T
Wheatcroft
David
D
Igaune
Kristīne
K
Rantala
Markus J
MJ
D000818:Animals; D005075:Biological Evolution; D003299:Cooperative Behavior; D007844:Latvia; D019370:Observation; D046109:Passeriformes / Q000502:physiology*; D011235:Predatory Behavior / Q000502:physiology*; D018709:Statistics, Nonparametric