Abstract

To predict how organisms cope with habitat fragmentation we must understand their dispersal biology, which can be notoriously difficult. We used a novel, multi-pronged approach to study dispersal strategies in the endangered saproxylic hermit beetle Osmoderma eremita, exploiting its pheromone system to intercept high numbers of dispersing individuals, which is not possible with other methods. Mark-release-recapture, using unbaited pitfall traps inside oak hollows and pheromone-baited funnel traps suspended from tree branches, was combined with radio telemetry (in females only) to record displacements. Dispersal, modelled as a probability distribution of net displacement, did not differ significantly between sexes (males versus females recaptured), observation methods (females recaptured versus radio-tracked), or sites of first capture (pitfall trap in tree versus pheromone trap - distance from original dispersal point unknown). A model including all observed individuals yielded a mean displacement of 82 m with 1% dispersing > 1 km. Differences in body length were small between individuals captured in pitfall versus pheromone traps, indicating that dispersal is rarely a condition-dependent response in O. eremita. Individuals captured in pheromone traps were consistently lighter, indicating that most dispersal events occur relatively late in life, which agrees with trap catch data. In addition, most (79%) females captured in pheromone traps were mated, showing that females typically mate before leaving their natal tree. Our data show that integrating odour attractants into insect conservation biology provides a means to target dispersing individuals and could greatly improve our knowledge of dispersal biology in threatened species.

Keywords

Dispersal; Mark-release-recapture; Radio tracking; Pheromone traps; Modelling; Oviposition experiments; Conservation

Published in

Biodiversity and Conservation
2011, Volume: 20, number: 13, pages: 2883-2902
Publisher: SPRINGER

SLU Authors

• Larsson, Mattias

  • Department of Plant Protection Biology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Zoology
Ecology


Publication identifier

DOI: https://doi.org/10.1007/s10531-011-0150-9

Permanent link to this page (URI)

https://res.slu.se/id/publ/44037