Effects of predator presence on territorial establishment

Authors: LaManna, Justin R.¹; Eason, Perri K.²

Source: Behaviour, Volume 144, Number 9, 2007 , pp. 985-1001(17)

Publisher: BRILL

Buy & download fulltext article:

Price: $35.00 plus tax (Refund Policy)

Abstract:

A variety of factors can affect defensive costs of territorial residents, including familiarity with neighbors, frequency of intrusions, and the topography of the territory. Here we investigate the effects of a predator's presence on fighting during territorial settlement. In a laboratory study of a cichlid fish, the blockhead (Steatocranus casuarius), we manipulated the focal fish's perception of predation risk by showing the fish a predator in an adjacent aquarium in half the trials, and we found that fish attempting to establish territories were affected in several ways by the increased risk. First, they reduced the amount of time spent fighting, with fish able to see a predator fighting less than one-tenth as much as fish that never saw a predator. In addition, the blockheads spent more time in refuges when the predator was present, and they reduced the intensity level of the fights that they did have, avoiding for example high-intensity acts that involved physical contact in favor of low-level displays. Finally, fish that saw a predator accepted territories that were smaller than those of fish that did not see a predator suggesting that predation risk could influence territory size in the field, particularly during the period of territorial settlement.

Keywords: TERRITORIALITY; PREDATION; CICHLID

Document Type: Research article

DOI: http://dx.doi.org/10.1163/156853907781871824

Affiliations: 1: Department of Biology, University of Saint Mary, Leavenworth, KS 66048, USA;, Email: lamannaj@stmary.edu 2: Department of Biology, University of Louisville, Louisville, KY 40292, USA

Publication date: 2007-09-01