Summary
We generated a computer model to analyse the effects of ‘shadow’ competition for sit-and-wait predators, particularly antlion larvae. The model used a simple foraging assessment rule to determine the quality of an antlion's location, and antlions relocated randomly in their habitat when a location proved to be of low quality. Shadow competition, or competition for food caused when one sit-and-wait predator intercepts moving prey before a second sit-and-wait predator is encountered, was incorporated into the model by restricting antlions to a bounded arena, and having prey for the antlions enter from the arena periphery. Antlions responded to shadow competition by relocating their pits to peripheral areas of their habitat. This peripheral accumulation of pits was most pronounced when antlion densities were high, and when prey availabilities were intermediate. An experimental test with the antlionMyrmeleon immaculatus supported the importance of shadow competition as a cause of observed pit distributions. Only the treatment which incorporated shadowing had pit distributions near the periphery, while the pit distributions in the control treatments did not differ from randomly generated distributions. We conclude that shadowing can influence sit-and-wait predator distributions when the prey distributions and movement patterns generate the conditions necessary for shadowing. But when prey availability is unpredictable, making assessment of patches difficult, or when prey do not originate in the periphery of the habitat, other factors, such as temperature or moisture, could be more important.
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References
Gillespie, R. G. (1987) The role of prey availability in aggressive behavior of the orbweaving spiderTetragnatha elongata.Anim. Behav. 35, 675–81.
Griffiths, D. (1980) The feeding biology of ant-lion larvae: growth and survival inMorter obscurus.Oikos 34, 364–70.
Griffiths, D. (1985) Phenology and larval-adult size relations in the ant-lionMacroleon quinquemaculatus.J. Anim. Ecol. 54, 573–81.
Hart, D. D. (1986) The adaptive significance of territoriality in filter-feeding larval blackflies (Diptera: Simuliidae).Oikos 46, 88–92.
Hart, D. D. (1987) Feeding territoriality in aquatic insects: cost-benefit models and experimental tests.Amer. Zool. 27, 371–86.
Heinrich, B. and Heinrich M. J. E. (1984) The pit-trapping foraging strategy of the ant lion,Myrmeleon immaculatus DeGeer (Neuroptera: Myrmeleontidae).Behav. Ecol. and Sociobiol. 14, 151–60.
Hildrew, A. G. and Townsend, C. R. (1980) Aggregation, interference and foraging by larvae ofPlectrocnemia conspersa (Tricoptera: Polycentropodidae).Anim. Behav. 28, 553–60.
Hinton, H. E. (1981)Biology of Insect Eggs. Pergamon Press, Oxford.
Linton, M. C. (1988) Field measurement of prey availability and its variability in space and time for antlion larvae.Bull. Ecol. Soc. Amer. 69, 209–10.
Lucas, J. R. (1985) Metabolic rates and pit-construction of two antlion species.J. Anim. Ecol. 54, 295–309.
Malmqvist, B. and Bronmark, C. (1985) Reversed trends in the benthic community structure in two confluent streams; one spring-fed, the other lake-fed.Hydrobiologia 124, 65–71.
McClure, M. S. (1976) Spatial distribution of pit-making ant lion larvae (Neuroptera: Myrmeleontidae): density effects.Biotropica 8, 179–83.
Olive, C. (1982) Behavioral response of a sit-and-wait predator to spatial variation in foraging gain.Ecology 6, 912–20.
Oswood, M. W. (1979) Abundance patterns of filter-feeding caddisflies (Tricoptera:Hydropsychidae) and seston in a Montana (USA) lake outlet.Hydrobiologia 63, 177–83.
Richardson, J. S. (1984) Effects of seston quality on the growth of a lake-outlet filter feeder.Oikos 43, 386–90.
Riechert, S. E. (1974) The pattern of local web distribution in a desert spider: mechanisms and seasonal variation.J. Anim. Ecol. 43, 733–46.
Riechert, S. E. (1976) Web-site selection in the desert spiderAglenopsis aperta Oikos 27, 311–15.
Riechert, S. E. and Tracy, C. R. (1975) Thermal balance and prey availability: bases for a model relating web-site characteristics to spider reproductive success.Ecology 56: 265–84.
Riechert, S. E., Reeder, W. G. and Allen, T. A. (1973) Patterns of spider distribution (Aglenopsis aperta (Gertsh)) in desert grassland and recent lava bed habitats, south-central New Mexico.J. Anim. Ecol. 42, 19–35.
Simberloff, D. (1979) Nearest neighbor assessments of spatial configurations of circles rather than points.Ecology 60, 679–85.
Simberloff, D., King, L., Dillon, P., Lowrie, D. and Schilling, E. (1978) Holes in the doughnut theory: the dispersion of ant-lions.Brenesia 14–15, 13–46.
Sokal, R. R. and Rohlf, F. J. (1981)Biometry, 2nd edn. W.H. Freeman and Company, New York.
Stephens, D. W. and Krebs, J. R. (1986)Foraging Theory. Princeton University Press, Princeton.
Turnbull, A. L. (1964) The search for prey by a web building spider,Achaearanea tepidariorum (C. L. Koch) (Araneae, Theridiidae).Can. Ent. 96, 568–79.
Uetz, G. W. (1988) Group foraging in colonial web-building spiders: evidence for risk sensitivity.Behav. Ecol. Sociobiol. 22, 265–70.
Vollrath, F. (1980) Male body size and fitness in the web-building spiderNephila clavipes.Z. Tierpsych. 53, 61–78.
Wheeler, W. M. (1930)Demons of the Dust. W. W. Morton & Co., Inc., New York.
Wilson, D. S. (1974) Prey capture and competition in the ant lion.Biotropica 6, 187–93.
Wise, D. H. (1975) Food limitation of the spiderLinyphia marginata: experimental field studies.Ecology 56, 637–46.
Wise, D. H. (1979) Effects of an experimental increase in prey abundance upon the reproductive rates of two orb-weaving spider species (Araneae: Araneidae).Oecologia 41, 289–300.
Wise, D. H. (1983) Competitive mechanisms in a food-limited species: relative importance of interference and exploitative interactions among labyrinth spiders (Araneae: Araneidae).Oecologia 58, 1–9.
Wotton, R. S. (1988) The ecology of lake-outlet blackflies. InBlackflies: Ecology, Population Management, and a World Annotated List (K. C. Kim and R. W. Merritt, eds) pp. 146–154. Pennsylvania State University Press, University Park.
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Linton, M.C., Crowley, P.H., Williams, J.T. et al. Pit relocation by antlion larvae: A simple model and laboratory test. Evol Ecol 5, 93–104 (1991). https://doi.org/10.1007/BF02270826
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DOI: https://doi.org/10.1007/BF02270826