Individual capture history affects site use and defensive behavior of foraging eastern copperheads at a recreational site

• Published in: Behavioral ecology and sociobiology Vol. 79; no. 1; p. 16
• Main Authors: Stratton, J. Benjamin, Richter, Stephen C.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.01.2025; Springer Nature B.V
• Subjects: Agkistrodon contortrix; Animal Ecology; Behavioral Sciences; Biomedical and Life Sciences; Body size; Body temperature; Cicadidae; Daniel Boone National Forest; Decision making; Defensive behavior; energy; Featured Student Research Paper; Forage; Foraging behavior; Kentucky; Life Sciences; mark-recapture studies; National forests; Predation; Recreational use; reproduction; Risk taking; Small mammals; Soil temperature; Temperature tolerance; Wildlife; Zoology; United States > US; Kentucky; Daniel Boone National Forest; Human tolerance; Copperhead; Capture history; Defensive behavior; Viper
• ISSN: 0340-5443; 1432-0762
• DOI: 10.1007/s00265-025-03562-y

To maximize energy available for foraging or reproduction, optimality theory suggests individuals allocate energy toward defensive behaviors equivalent to risk of predation. In this framework, repeat encounters with humans by wildlife that do not reduce individual fitness could result in a decreased defensive response toward humans in subsequent encounters. We investigated whether individual experience influenced the defensive behaviors and frequency of site use of foraging eastern copperheads ( Agkistrodon contortrix ) at Koomer Ridge Campground in the Daniel Boone National Forest, Kentucky. Beginning in 2015, this site has been used for annual mark-recapture studies of copperhead foraging ecology as they predate emerging annual cicadas ( Neotibicen tibicen ). Using a standardized behavioral trial, we tested how copperhead defensive behavior toward humans was influenced by capture history, body size, and soil temperature. Model averaging results indicated that the overall intensity of copperhead defensive response to humans increased with capture history length, and soil temperature was positively associated with likelihood to respond when touched. Number of years recaptured was a significant, positive predictor of foraging frequency in 2022. Therefore, copperheads with longer capture histories visit the site to forage more frequently and are more willing to defend their opportunity to forage, suggesting a degree of acquired tolerance absent from naïve snakes that fled readily. Collectively, these results provide evidence that eastern copperheads at our site modulate their foraging and defensive behavior based on previous capture experience to more efficiently predate a seasonally abundant prey item. Significance statement All species are faced with tradeoffs between foraging and avoiding predation. Although the decision of energetic investment between behaviors has been the subject of considerable research, the extent to which an individual’s experience plays a role in this decision-making process remains unclear, particularly for cryptic taxa like squamates. Using a long-term research site where eastern copperheads ( Agkistrodon contortrix) seasonally gather to predate emerging cicadas, we studied the foraging and defensive behaviors of individuals with known capture histories to determine if capture history influenced foraging frequency and the initiation and magnitude of defensive behavior towards humans. Through standardized behavioral trials and nightly monitoring of site foraging activity we documented that copperheads with longer capture histories foraged for cicadas more frequently and were more willing to defend their foraging opportunity to human approach than less experienced individuals.