科研之友
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摘要
Dispersal is a crucial feature for the long-term survival of metapopulations. Each individual that leaves the habitat and enters the matrix takes a risk. Consequently, even winged organisms, like butterflies, are often extremely sedentary and spend much of their lifetime in very restricted areas. For such species, large roads may be a serious obstacle for movement. Here, we aim to study if a large and highly frequented road in an alpine environment hinders the movement of relatively sedentary butterflies of the genus Erebia. We conducted a mark-release-recapture study on six alpine Erebia species (E. eriphyle, E. epiphron, E. gorge, E. pharte, E. pandrose and E. nivalis) in the Hohe Tauern National Park, Austria. We measured the following variables which we hypothesize to affect movement probability: (a) species identity, (b) nectar resource availability, (c) butterfly age or (d) patch isolation through the road. Population density estimates ranged from 230 +/- A 35 individuals for E. pharte to 1,316 +/- A 205 individuals for E. epiphron per hectare. More than 50 percent of recaptured butterflies were tracked within distances of %26lt; 25 m. The maximum flight distance recorded was 332 m (E. epiphron). Our data indicate that species identity generally did not have a significant effect on mobility patterns in the studied Erebia butterflies. Only one species, E. pharte, was more likely to change the plot than the others. High resource availability decreased butterfly movement. Age influenced mobility, with mid-aged butterflies being most likely to move between patches. The road hindered dispersal. Butterflies which had to cross the road to get to another suitable habitat patch were less likely to move than butterflies that did not have to cross the road.
- 出版日期2014-12
