Behavioral Ecology and Sociobiology

, Volume 30, Issue 3–4, pp 239–244 | Cite as

Behavioral resource depression and decaying perceived risk of predation in two species of coexisting gerbils

  • Burt P. Kotler


Behavioral resource depression occurs when the behavior of prey individuals changes in response to the presence of a predator, resulting in a reduction of the encounter rate of the predator with its prey. Here I present experimental evidence on the response of two species of gerbils (Gerbillus allenbyi and G. pyramidum) to the presence of barn owls. I conducted the experiments in a large aviary. Both gerbils responded to the presence of barn owl predators by foraging in fewer resource patches (seed trays) and by quitting foraged resource patches at a higher resource harvest rate (giving-up density of resource; GUD). This reduced the amount of time gerbils were exposed to owl predation, and hence the encounter rate of owls with gerbils, i.e., behavioral resource depression. Thus, the presence of owls imposes a foraging cost on gerbils due to risk of predation, and also on the owls themselves due to resource depression. I then examined how resource depression relaxed over time following exposure to owls. In the days following an encounter with the predator, the reduction in foraging activity for both gerbil species eased. Increasing numbers of trays were foraged each day, and GUDs in seed trays declined. The two gerbils differed in their rate of recovery, with G. pyramidum returning to prepredator levels of foraging after 1 or 2 nights and G. allenbyi taking 5 nights or longer. Interspecific differences in recovery rates may be based on differences between the species in vulnerability to predation and/or ability to detect the presence of predators. The differences in recovery rates may be due to optimal memory windows or decay rates, where differences between species are based on risk of predation or on how perceived risk changes with time since a predator was last encountered. Finally, differences between or among competitors in recovery from resource depression may provide foraging opportunities in time for the species which recover most quickly and may have implications for species coexistence.


Recovery Rate Encounter Rate Interspecific Difference Individual Change High Resource 
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  1. Abrahams MV, Dill LM (1989) A determination of the energetic equivalence of the risk of predation. Ecology 70:999–1007Google Scholar
  2. Abramsky Z, Pinshow B (1989) Changes in foraging effort in two gerbil species with habitat type and intra- and interspecific activity. Oikos 56:43–53Google Scholar
  3. Abramsky Z, Brand S, Rosenzweig ML (1985) Geographical ecology of gerbilline rodents in sand dune habitats of Israel. J Biogeogr 12:363–372Google Scholar
  4. Abramsky Z, Rosenzweig ML, Pinshow B, Brown IS, Kotler BP, Mitchell WA (1990) Habitat selection: an experimental field test with two gerbil species. Ecology 71:2358–2369Google Scholar
  5. Bar Y, Abramsky Z, Gutterman Y (1984) Diet of gerbilline rodents of the Israeli desert. J Arid Environ 7:371–376Google Scholar
  6. Brown JS (1988) Patch use as an indicator of habitat preference, predation risk, and competition. Behav Ecol Sociobiol 22:37–47Google Scholar
  7. Brown JS (1989a) Desert rodent community structure: a test of four mechanisms of coexistence. Ecol Monogr 59:1–20Google Scholar
  8. Brown JS (1989b) Coexistence on a seasonal resource. Am Nat 133:168–182Google Scholar
  9. Brown JS, Kotler BP, Smith RJ, Wirtz WO II (1988) The effects of owl predation on the foraging behavior of heteromyid rodents. Oecologia 76:508–415Google Scholar
  10. Charnov EL, Orians GH, Hyatt K (1976) Ecological implications of resource depression. Am Nat 110:247–259Google Scholar
  11. Cowie RJ, Krebs JR (1979) Optimal foraging in patchy environments. In: Anderson RM, Turner BD, Taylor RL (eds) Population dynamics. Blackwell Scientific, Oxford, pp 183–206Google Scholar
  12. Crawford LL (1983) Local contrast and memory windows as proximate foraging mechanisms. J Comp Ethol 63:283–293Google Scholar
  13. Dill LM (1987) Animal decision making and its ecological consequences: the future of aquatic biology and behavior. J Zool 65:803–811Google Scholar
  14. Edwards AL (1987) Multiple regression and the analysis of variance and covariance. WH Freeman, San FranciscoGoogle Scholar
  15. Edwards J (1983) Diet shifts in the moose due to predator avoidance. Oecologia 60:185–189Google Scholar
  16. Harley CB (1981) Learning the evolutionary stable strategy. J Theor Biol 89:611–633Google Scholar
  17. Holt RD (1977) Predation, apparent apparent competition, and the structure of prey communities. Theor Popul Biol 12:197–229Google Scholar
  18. Jedrzejewski W, Jedrzejewska B (1990) Effect of a predator's visit on the spatial distribution of bank voles: experiments with weasels. Ann Zool Fennici 27:321–328Google Scholar
  19. Kats LB, Petranka JW, Sih A (1988) Antipredator defenses and the persistence of amphibian larvae with fishes. Ecology 69:1865–1870Google Scholar
  20. Kotler BP (1984) Harvesting rates and predatory risk in desert rodents: a comparison of two communities on different continents. J Mammal 65:91–96Google Scholar
  21. Kotler BP, Brown JS (1990) Harvest rates of two species of gerbilline rodents. J Mammal 71:591–596Google Scholar
  22. Kotler BP, Brown JS, Hasson O (1991) Factors affecting gerbil foraging behavior and rates of owl predation. Ecology 71:2249–2260Google Scholar
  23. Kotler BP, Brown JS, Slotow RH, Goodfriend WL, Strauss M (In press) Predator facilitation: the influence of snakes on the foraging behavior of gerbils. OikosGoogle Scholar
  24. Kotler BP, Holt RD (1989) Predation and competition: the interaction of two types of species interactions. Oikos 54:256–260Google Scholar
  25. Lima SL (1987) Distance to cover, visual obstructions, and vigilance in house sparrows. Behaviour 102:231–238Google Scholar
  26. Lima SL, Valone TJ, Caraco T (1985) Foraging efficiency-predation risk trade-off in the gray squirrel. Anim Behav 33:155–165Google Scholar
  27. Linder Y (1988) Seasonal differences in thermoregulation in Gerbillus allenbyi and g. pyramidum and their contribution to energy budgets. Unpublished Thesis, Ben-Gurion University of the Negev, Beer Sheva, Israel (Hebrew, with english abstract)Google Scholar
  28. McNamara JM, Houston AI (1985) Optimal foraging and learning. J Theor Biol 117:231–249Google Scholar
  29. McNamara JM, Houston AI (1987) Memory and the use of information. J Theor Biol 125:385–395Google Scholar
  30. Milinski M, Heller R (1978) Influence of a predator on the optimal foraging behavior of sticklebacks (Gasterosteus aculeatus L.). Nature 275:642–644Google Scholar
  31. Milinski M, Regelman K (1985) Fading short-term memory for patch quality in sticklebacks. Anim Behav 33:678–680Google Scholar
  32. Mitchell WA, Brown JS (1990) Density-dependent harvest rates by optimal foragers. Oikos 57:180–190Google Scholar
  33. Mitchell WA, Abramsky Z, Kotler BP, Pinshow B, Brown IS (1990) The effects of competition on foraging activity in desert rodents: theory and experiments. Ecology 71:844–854Google Scholar
  34. Nonacs P, Dill LM (1990) Mortality risk versus food quality trade-offs in a common currency: ant patch preferences. Ecology 71:1886–1892Google Scholar
  35. Ohman MD, Frost BW, Cohen EB (1983) Reverse diel vertical migration: an escape from invertebrate predators. Science 220:1404–1407Google Scholar
  36. Ollason JG (1980) Learning to forage — optimally? Theor Popul Biol 18:44–56Google Scholar
  37. Peckarsky BL, Dodson SI (1980) Do stonefly predators influence benthic distributions in streams? Ecology 61:1275–1282Google Scholar
  38. Sih A (1980) Optimal behavior: can foragers balance two conflicting demands? Science 210:1041–1043Google Scholar
  39. Sih A (1982) Foraging strategies and the avoidance of predation by an aquatic insect, Notoneeta hoffmanni. Ecology 63:786–796Google Scholar
  40. Werner EE, Gilliam JF, Hall DJ, Mittlebach GG (1983) An experimental test of the effects of predation risk on habitat use in fish. Ecology 64:1540–1548Google Scholar

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • Burt P. Kotler
    • 1
  1. 1.Jacob Blaustein Institute for Desert Research, Mitrani Center for Desert EcologyBen-Gurion University of the NegevSede Boqer CampusIsrael

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