Escape angles for solitary animals and groups of the lizard Pholidoscelis fuscatus

Abstract

Predation can be an important factor shaping the dynamics of animal groups. The lizard Pholidoscelis fuscatus forms small groups while foraging, providing the opportunity to examine how predation risk influences group dynamics. We studied the escape angles of P. fuscatus during simulated predator approaches, focusing on whether grouped lizards behaved differently from solitary animals and the extent to which group cohesion was maintained during escape. Both solitary and grouped lizards exhibited non-random escape angles, oriented away from the approaching predator. However, lizards in groups exhibited escape angles closer to 0° (i.e., more directly away from the predator) than solitary lizards. Groups maintained their cohesiveness during flight. Grouping by P. fuscatus could allow more effective escape behaviour to occur.

KEY WORDS:

• antipredator behaviour
• collective movement
• Dominica
• evasion
• Teiidae

ACKNOWLEDGEMENTS

All contributors observed appropriate ethical and legal guidelines and regulations, including the ASIH-HL-SSAR Guidelines for Use of Live Amphibians and Reptiles in Field Research (Beaupre et al. 2004). Our work was approved by permits issued by the Commonwealth of Dominica, Ministry of Agriculture and Fisheries, Forestry, Wildlife, and Parks Division to Douglas Eifler, and by Erell Institute’s Institutional Animal Care and Use Committee (IACUC) under permit number F2016–01. Bob Powell provided us will essential information and advice concerning working with P. fuscatus. Financial support was provided by Erell Institute, the James B. Pearson Fellowship from the Kansas Board of Regents awarded to D.A. Eifler, and grants from the Howleson Opportunity Fund and Nathan B. Parker Award to V.L. Grotbeck from the University of Kansas, Department of Ecology & Evolutionary Biology. We thank Bill Cooper and two anonymous reviewers for their recommended improvements to earlier versions of our manuscript.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

Additional information

Funding

Financial support was provided by the James B. Pearson Fellowship from the Kansas Board of Regents awarded to D.A. Eifler, and grants from the Howleson Opportunity Fund and Nathan B. Parker Award to V.L. Grotbeck from the University of Kansas, Department of Ecology & Evolutionary Biology.