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Habitat Heterogeneity and Survival in a Bush Cricket Metapopulation
Author(s) -
Kindvall Oskar
Publication year - 1996
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.2307/2265670
Subject(s) - metapopulation , ecology , habitat , grassland , extinction (optical mineralogy) , population , local extinction , spatial heterogeneity , biology , threatened species , endangered species , geography , biological dispersal , demography , sociology , paleontology
The bush cricket, Metrioptera bicolor Philippi (Orthoptera, Tettigoniidae) lives in a restricted area with grassland patches separated by mainly pine forest. The regional population dynamics can be described as a metapopulation with local extinctions and colonizations. I used inventory data in order to test the following hypotheses: (1) temporal variability of local population size should be negatively correlated with habitat heterogeneity, when habitat quality changes in relation to fluctuating weather conditions; (2) extinction risk should be higher on homogeneous habitat patches than on heterogeneous patches. Both hypotheses are convincingly corroborated and I find a compensatory effect between patch area and heterogeneity. Local extinctions may occur on large, but homogeneous patches, and local populations can survive quite well on small patches that contain a mosaic of several types of grassland vegetation with different humid conditions. I discuss the implications of these findings for the preservation of endangered species that are susceptible to regional stochasticity.