|Variability of foraging in highshore habitats: dealing with unpredictability|Chapman, M.G. (2000). Variability of foraging in highshore habitats: dealing with unpredictability, in: Liebezeit, G. et al. Life at Interfaces and Under Extreme Conditions: Proceedings of the 33rd European Marine Biology Symposium, Wilhelmshaven, Germany, 7-11 September 1998. Developments in Hydrobiology, 151: pp. 75-87. https://dx.doi.org/10.1007/978-94-011-4148-2_7
In: Liebezeit, G.; Dittmann, S.; Kröncke, I. (Ed.) (2000). Life at Interfaces and Under Extreme Conditions: Proceedings of the 33rd European Marine Biology Symposium, Wilhelmshaven, Germany, 7-11 September 1998. Developments in Hydrobiology, 151. Springer Science+Business Media: Dordrecht. ISBN 978-0-7923-6468-9; e-ISBN 978-94-011-4148-2. VII, 210 pp. https://dx.doi.org/10.1007/978-94-011-4148-2, more
In: Dumont, H.J. (Ed.) Developments in Hydrobiology. Kluwer Academic/Springer: The Hague; London; Boston; Dordrecht. ISSN 0167-8418, more
Behaviour > Feeding behaviour > Foraging behaviour
Littorina unifasciata J. E. Gray, 1826 [WoRMS]
Intertidal areas are habitats at the border of two very different environments: the marine environment and the terrestrial environment. In contrast to many habitats at borders, intertidal areas are very variable in space and time. They have upshore and alongshore gradients of environmental conditions, which change through time in predictable (due to changing tides) and unpredictable (due to changing weather) ways. Because most animals and plants on rocky shores are marine in origin, extreme highshore levels are generally considered more harsh and unpredictable environments than are mid- or lowshore levels. In this study, the linear distances and directions dispersed by the littorinid Littorina unifasciata while foraging were compared across randomly-chosen mid- and highshore replicated sites to test the hypothesis that movement during foraging was more variable from place to place in complex midshore habitats. Experiments were repeated on different days to test the hypothesis that temporal variability in movement was greater at high- than at midshore levels because environmental conditions necessary for foraging were more variable high on the shore. Finally, the data were used to test models about differences in variability among individuals in the same patch of habitat according to their recent history of submersion/emersion. In contrast to expectations, dispersal was more variable in space and time within and among highshore sites. The implications of such variable behaviour are discussed with respect to the generalization of patterns of behaviour from sparse data and the levels of replication needed in the design of experiments to investigate behaviour of intertidal animals.