You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Experimental Evidence for Intra- and Interspecific Competition in Two Species of Rock-Dwelling Land Snails
Bruno Baur and Anette Baur
Journal of Animal Ecology
Vol. 59, No. 1 (Feb., 1990), pp. 301-315
Published by: British Ecological Society
Stable URL: http://www.jstor.org/stable/5174
Page Count: 15
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
(1) The rock-dwelling land snails Chondrina clienta and Balea perversa were found sympatrically and allopatrically on the Baltic island of Oland, Sweden. To examine intra- and interspecific interactions, juvenile snails of both species were kept for 1 year at different densities in single- and mixed-species groups on their natural substrate and food (pieces of limestone providing epi- and endolithic lichens). In a second experiment, the relative importance of exploitation and interference competition in the two snail species was evaluated. (2) In both species, juvenile growth rate, time to complete growth, adult shell size and survival were significantly influenced by the density of conspecifics, indicating intraspecific competition. (3) The presence of B. perversa lowered the juvenile growth rate and increased the time to complete growth of C. clienta, while the latter increased the time to complete growth of B. perversa. Thus, the influence of interspecific competition on different fitness components was asymmetric among these two land snail species. (4) In both species, smaller individuals died in higher proportions than did larger ones, suggesting that small snails were competitively inferior. (5) The observed competitive interactions appeared to be a result of both exploitation competition and interference by mucus trails. (6) Our experiments provide evidence for the potential importance of interspecific competition in two species of obligatory herbivores.
Journal of Animal Ecology © 1990 British Ecological Society