title: Combining measures of dispersal to identify conservation strategies in fragmented landscapes.
abstract: Understanding the way in which habitat fragmentation disrupts animal dispersal is key to identifying effective and efficient conservation strategies. To differentiate the potential effectiveness of 2 frequently used strategies for increasing the connectivity of populations in fragmented landscapes-corridors and stepping stones-we combined 3 complimentary methods: behavioral studies at habitat edges, mark-recapture, and genetic analyses. Each of these methods addresses different steps in the dispersal process that a single intensive study could not address. We applied the 3 methods to the case study of Atrytonopsis new species 1, a rare butterfly endemic to a partially urbanized stretch of barrier islands in North Carolina (U.S.A.). Results of behavioral analyses showed the butterfly flew into urban and forested areas, but not over open beach; mark-recapture showed that the butterfly dispersed successfully through short stretches of urban areas (<500 m); and genetic studies showed that longer stretches of forest (>5 km) were a dispersal barrier, but shorter stretches of urban areas (≤5 km) were not. Although results from all 3 methods indicated natural features in the landscape, not urbanization, were barriers to dispersal, when we combined the results we could determine where barriers might arise: forests restricted dispersal for the butterfly only when there were long stretches with no habitat. Therefore, urban areas have the potential to become a dispersal barrier if their extent increases, a finding that may have gone unnoticed if we had used a single approach. Protection of stepping stones should be sufficient to maintain connectivity for Atrytonopsis new species 1 at current levels of urbanization. Our research highlights how the use of complementary approaches for studying animal dispersal in fragmented landscapes can help identify conservation strategies.
authors.affiliation: Department of Biology, North Carolina State University, Raleigh, NC 27695, USA. aleidner@gmail.com
authors.forename: Allison K
authors.initials: AK
authors.lastname: Leidner
authors.forename: Nick M
authors.initials: NM
authors.lastname: Haddad
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D002080:Butterflies / Q000235:genetics / Q000502:physiology*; D003247:Conservation of Natural Resources / Q000379:methods* / Q000706:statistics & numerical data; D003710:Demography; D017753:Ecosystem; D005828:Genetics, Population; D005843:Geography; D009657:North Carolina; D014197:Trees