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Alternative risk‐taking styles: The case of time‐budgeting strategies of terrestrial gastropods
Author(s) -
Rollo C. D.,
Vertinsky I. B.,
Wellington W. G.,
Kanetkar V. K.
Publication year - 1983
Publication title -
population ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 59
eISSN - 1438-390X
pISSN - 1438-3896
DOI - 10.1007/bf02515607
Subject(s) - competitor analysis , biology , competition (biology) , surprise , ecology , nocturnal , adaptive value , marketing , psychology , social psychology , business
Summary The terrestrial slugs Arion ater, Limax maximus and Ariolimax columbianus have similar morphological designs but differ remarkably in their life history tactics and behavioural time budgets. The adaptive value of particular risk‐taking styles was investigated using a comprehensive computer simulation model. The model allowed each species' success (growth rates, food acquisition) and costs (distance travelled, hydration deficits, injury from aggressive encounters) to be evaluated in various types of weather (benign, harsh and surprise). This was interpreted in terms of the species' life history design. In addition, each species was simulated with the behavioural strategy of the other two species substituted for its natural programming. The simulation experiments demonstrated how variations in a few simple rules could lead to divergent cost‐benefit consequences. The model also illustrated that coarsely‐tuned sensitivity to the environment may be better than finely‐tuned responses, depending on the animal's ability to respond quickly and the degree of risk. The simulations suggested that competition has shaped the time‐budgeting tactics of A. ater and L. maximus . Each species actually performed better in harsh weather, using the behavioural program of the other. L. maximus is an aggressive species with a narrow, nocturnal activity period. The concentrated activity of L. maximus may allow it to displace competitors more effectively, whereas the broader time span of A. ater's activity may be necessary to avoid L. maximus .