Collective detection in escape responses of temporary groups of Iberian green frogs

José Martín, Juan José Luque-Larena and Pilar López

Behavioral Ecology, 2006, vol. 17, issue 2, 222-226

Abstract: When confronted with a predator, prey are often in close proximity to conspecifics. This situation has generated several hypotheses regarding antipredator strategies adopted by individuals within groups of gregarious species, such as the "risk dilution," "early detection," or "collective detection" effects. However, whether short-term temporary aggregations of nongregarious animals are also influenced in their escape decisions by nearby conspecifics remains little explored. We simulated predator approaches to green frogs (Rana perezi) in the field while they were foraging at the edge of water, either alone or spatially aggregated in temporary clusters. "Flight initiation distances" of frogs (i.e., the distance between the simulated predator and the frog at the time it jumped) that escaped by jumping into the water were influenced by microhabitat variables (vegetation at the edge and in water and the initial distance of the frog to the closest water edge) and also by the responses of nearby individuals. In clusters, risk dilution did not influence the first individual to respond to the predator simulation or the average response of all frogs in the cluster as the frog's responses were independent of group size. Also, flight initiation distances of individuals that first responded to the predator within clusters did not differ from those of solitary individuals, which is contrary to the predictions of the early detection hypothesis. However, the remaining frogs in the cluster had longer flight initiation distances than expected from the comparison with solitary individuals. We suggest that this pattern originated because the response of the first frog within a cluster triggered the sequential response of the remaining frogs in the cluster, which agrees with the expectations from the collective detection hypothesis. Our findings give insight into an early stage in the evolution of grouping as they suggest that individual frogs may benefit from being part of a cluster, even for short periods of time. Copyright 2006.

Keywords: antipredator behavior; collective detection; escape behavior; frogs; group-size effect (search for similar items in EconPapers)
Date: 2006
References: Add references at CitEc
Citations:

Downloads: (external link)
http://hdl.handle.net/10.1093/beheco/arj024 (application/pdf)
Access to full text is restricted to subscribers.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:oup:beheco:v:17:y:2006:i:2:p:222-226

Ordering information: This journal article can be ordered from
https://academic.oup.com/journals

Access Statistics for this article

Behavioral Ecology is currently edited by Louise Barrett

More articles in Behavioral Ecology from International Society for Behavioral Ecology Oxford University Press, Great Clarendon Street, Oxford OX2 6DP, UK.
Bibliographic data for series maintained by Oxford University Press ().