Summary
The predatory larvae of the caddis Plectrocnemia conspersa (Curtis) cause significant prey depletion in a habitat in which prey are patchily distributed. Optimal foraging theory predicts that under these circumstances a predator should stay in any given patch until the prey capture rate there drops to a value equal to the average for the habitat as a whole. This was tested using a combination of field and laboratory data and the results were in broad agreement with the prediction. A second prediction is that the marginal capture rate should be higher in a habitat richer in prey and this was not supported. It is argued that by using a simple rule-of-thumb (constant giving-up-time) P. conspersa is able to approach the optimal solution for much of the time.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Charnov EL (1976) Optimal foraging: the marginal value theorem. Theor Popul Biol 9:129–136
Gibb JA (1962a) Tinbergen's hypothesis of the role of specific search images. Ibis, 104:106–111
Gibb JA (1962b) Tits and their food supply in English pine woods: a problem in applied ornithology. Festschr. Vogelschutzwarte Hessen, Rheinland-Plalz und Saarland 58–66
Hildrew AG, Townsend CR (1976) The distribution of two predators and their prey in an iron-rich stream. J Anim Ecol 45:41–57
Hildrew AG, Townsend CR. (1980) Aggregation, interference and foraging by larvae of Plectrocnemia conspersa (Trichoptera: Polycentropodidae). Anim Behav 28:553–560
Krebs JR (1973) Behavioural aspects of predation. In: PPG Bateson and PH Klopfer (eds), perspectives in Ethology, Chapter 3, Plenum Press
Krebs JR (1978) Optimal foraging: decision rules for predators. In: JR Krebs and NB Davies (eds), Behavioural Ecology; an evolutionary approach. Blackwell Oxford
Krebs JR, Ryan JC Charnov EL (1974) Hunting by expectation or optimal foraging? A study of patch use by chickadees. Anim Behav 22:953–964
Pyke GH, Pulliam HR, Charnov EL (1977) Optimal foraging: a selective review of theory and tests. Q Rev Biol 52:137–154
Townsend CR, Hildrew AG (1978) Predation strategy and resource utilisation by Plectrocnemia conspersa (Curtis) (Trichoptera: Polycentropodidae). Proc, of the 2nd Symp on Trichoptera Junk The Hague
Townsend CR, Hildrew AG (1979a) Form and function of the prey catching net of Plectrocnemia conspersa larvae (Trichoptera). Oikos 33:412–418
Townsend CR, Hildrew AG (1979b) Resource partitioning by two freshwater invertebrate predators with contrasting foraging strategies. J Anim Ecol 48:909–920
Townsend CR, Hughes RN Maximizing net energy returns from foraging. In: CR Townsend and P Calow (eds) Physiological Ecology: an evolutionary approach to resource use. Blackwells Oxford (in press)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Townsend, C.R., Hildrew, A.G. Foraging in a patchy environment by a predatory net-spinning caddis larva: A test of optimal foraging theory. Oecologia 47, 219–221 (1980). https://doi.org/10.1007/BF00346824
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00346824