TY - JOUR
T1 - Foraging tactics of a terrestrial salamander
T2 - Costs of territorial defence
AU - Jaeger, Robert G.
AU - Nishikawa, Kiisa C.B.
AU - Barnard, Debra E.
N1 - Funding Information:
We thank the following persons for their helpful suggestions and criticisms during the course of this study: Jerram Brown, Daniel Formanowicz,: Jr., Douglas Fraser, William Gergits, Jennifer Hill, Murray Itzkowitz, Patricia Lehrer, Jeffrey Lucas, H. Ronald Pulliam, Andrew Sih and Margaret Stewart. We are indebted to Scott Fisher, Raymond Joseph, Donna Kalvarsky, Audrey Rubin and Naomi Shimizu for their help in collecting and maintaining the experimental animals. Research was supported by grant 1523 from the American Philosophical Society and by NSF grant DEB-8017447.
PY - 1983/2
Y1 - 1983/2
N2 - Red-backed salamanders, Plethodon cinereus, established territories in laboratory chambers. Their foraging tactics, on two types of prey differing in caloric profitability and defence behaviour, were observed under a series of experimental conditions in which competitive threat was increased: no competitor present < familiar conspecific's pheromones present < unfamiliar conspecific's pheromones present < familiar conspecific intruder present < unfamiliar conspecific intruder present. As the degree of competitive threat increased, more time was devoted to territorial defence (displays and biting) at the expense of foraging. Simultaneously, the territorial residents gradually shifted from a specialized diet on the more profitable prey type to an indiscriminate diet, even though prey densities and the residents' encounter rates with each prey did not change. The presence of unfamiliar pheromones and both intruders led to approximately a 50% decrease in the residents' rates of net energy gain, about 80% of which was due to the time withdrawn from foraging and 20% due to change in diet. Changes in foraging time and diet both reflected the costs of territorial defence.
AB - Red-backed salamanders, Plethodon cinereus, established territories in laboratory chambers. Their foraging tactics, on two types of prey differing in caloric profitability and defence behaviour, were observed under a series of experimental conditions in which competitive threat was increased: no competitor present < familiar conspecific's pheromones present < unfamiliar conspecific's pheromones present < familiar conspecific intruder present < unfamiliar conspecific intruder present. As the degree of competitive threat increased, more time was devoted to territorial defence (displays and biting) at the expense of foraging. Simultaneously, the territorial residents gradually shifted from a specialized diet on the more profitable prey type to an indiscriminate diet, even though prey densities and the residents' encounter rates with each prey did not change. The presence of unfamiliar pheromones and both intruders led to approximately a 50% decrease in the residents' rates of net energy gain, about 80% of which was due to the time withdrawn from foraging and 20% due to change in diet. Changes in foraging time and diet both reflected the costs of territorial defence.
UR - http://www.scopus.com/inward/record.url?scp=0001542598&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0001542598&partnerID=8YFLogxK
U2 - 10.1016/S0003-3472(83)80188-2
DO - 10.1016/S0003-3472(83)80188-2
M3 - Article
AN - SCOPUS:0001542598
SN - 0003-3472
VL - 31
SP - 191
EP - 198
JO - Animal Behaviour
JF - Animal Behaviour
IS - 1
ER -