Human observers impact habituated samango monkeys’ perceived landscape of fear

Katarzyna Nowak, Aliza le Roux, Shane A. Richards, Ciska P.J. Scheijen and Russell A. Hill

Behavioral Ecology, 2014, vol. 25, issue 5, 1199-1204

Abstract: Humans and human infrastructure are known to alter the relationship between predators and prey, typically by directly or indirectly shielding one of the species from the other. In addition to these overt changes to animals’ behavior, observers may have more subtle impacts on animals’ foraging decisions. However, the anthropogenic alteration of risk-taking behavior has rarely been acknowledged or quantified, particularly in behavioral ecological studies reliant on habituated animals. We tested the magnitude of the "human shield effect" experimentally on 2 groups of samango monkeys, Cercopithecus mitis erythrarcus, at a site with high natural predator density and no human hunting pressure. In general, giving-up densities—the density of food remaining in a patch when a forager leaves—were greatest at ground level (0.1 m) relative to 3 tree canopy levels (2.5, 5, and 7.5 m), highlighting a strong vertical axis of fear. When human followers were present, however, giving-up densities were reduced at all 4 heights; furthermore, for 1 group, the vertical axis disappeared in the presence of observers. Our results suggest that human observers lower monkeys’ perceived risk of terrestrial predators and, thereby, affect their foraging decisions at or near ground level. These results have significant implications for future studies of responses to predation risk based on habituation and observational methods.

Date: 2014
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
http://hdl.handle.net/10.1093/beheco/aru110 (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:25:y:2014:i:5:p:1199-1204.

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 ().