Swallowtail butterflies show positive edge responses predicted by resource use
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The prevalence of edges is increasing due to anthropogenic landscape change. Edge responses can vary considerably between and within species. Understanding species’ responses to edges, and the causes of variation in such responses is central to managing biodiversity in contemporary landscapes.
A resource distribution model predicts that species that require complementary resources in different land cover types will be most abundant at edges, displaying a positive edge response. Eastern tiger (Papilio glaucus) and spicebush (P. troilus) swallowtail butterflies use forest plant species for oviposition sites but open-habitat plants for nectar. They are excellent models for testing the positive edge response and exploring sources of variability in edge responses, such as species-specific traits or temporal effects.
In southwestern Ontario, we examined both the abundance and flight orientation of these species in relation to forest/meadow edges and at different times of day. We used a transect method similar to the Pollard walk and a catch and release method, respectively.
The distribution and flight behaviour of these butterfly species were overall consistent with a positive edge response. Both species were most abundant at the edge and oriented their flight towards the edge from the forest and meadow. However, P. glaucus demonstrated a much stronger positive edge response, while P. troilus showed temporal variation in its response.
Our results confirm the ability of the resource distribution model to predict species edge responses and movement behaviours, but also indicate that species-specific traits and time of sampling can influence such responses.
KeywordsHabitat Landscape Fragmentation Resource distribution Edge Butterfly Variation Temporal effects Flight orientation
We thank Sarah Kruis, Ryan Smith, and volunteers who helped with field work and data entry. The Nature Conservancy of Canada, Long Point Regional Conservation Authority, Mary Gartshore and Peter Carson, Brian Craig and Paula Jongerden, Jim and Carol Knack, and Kathryn Boothby kindly allowed us to work on their properties. This research was supported by the Canada Foundation for Innovation, Natural Sciences and Engineering Research Council of Canada (including a graduate scholarship to J. C. Siu), Canada Research Chairs, and Ontario Ministry of Research and Innovation. Handling of swallowtail butterflies was authorized by the Ontario Ministry of Natural Resources (Wildlife Scientific Collector’s Authorization No. 1067555).
- Bartoń K (2013) MuMIn: multi-model inference. R package version 1.9.18. http://cran.r-project.org/web/packages/MuMIn/. Accessed 19 Dec 2013
- Bates D, Maechler M, Bolker B, Walker S (2013) lme4: linear mixed-effects models using Eigen and S4. R package version 1.0-5. http://cran.r-project.org/web/packages/lme4/. Accessed 25 Oct 2013
- Benjamini Y, Hochberg Y (1995) Controlling the false discovery rate: a practical and powerful approach to multiple testing. J R Stat Soc 57:289–300Google Scholar
- Burnham KP, Anderson DR (2002) Model selection and multimodel inference: a practical information-theoretic approach, 2nd edn. Springer-Verlag New York Inc, New YorkGoogle Scholar
- Crins WJ (1997) Rare and endangered plants and their habitats in Canada. Can Field Nat 111:506–519Google Scholar
- Fletcher RJ Jr, Ries L, Battin J, Chalfoun AD (2007) The role of habitat area and edge in fragmented landscapes: definitively distinct or inevitably intertwined? This review is one of a series dealing with some aspects of the impact of habitat fragmentation on animals and plants. This series is one of severa. Can J Zool 85:1017–1030CrossRefGoogle Scholar
- Grossmueller DW, Lederhouse RC (1987) The role of nectar source distribution in habitat use and oviposition by the tiger swallowtail buterfly. J Lepid Soc 41:159–165Google Scholar
- Lund U, Agostinelli C (2013) Circular: circular statistics. R package version 30.4-3. http://cran.r-project.org/web/packages/circular/. Accessed 15 Feb 2013
- Pexioto PEC, Benson WW (2009) Daily activity patterns of two co-occurring tropical satyrine butterflies. J Insect Sci 9:1–14Google Scholar
- R Development Core Team (2013) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna. http://www.r-project.org/. Accessed 25 Sept 2013
- Scott JA (1986) The butterflies of North America: a natural history and field guide. Standford University Press, CaliforniaGoogle Scholar
- Skórka P, Nowicki P, Lenda M, Witek M, Śliwińska EB, Settele J, Woyciechowski M (2013) Different flight behaviour of the endangered scarce large blue butterfly Phengaris teleius (Lepidoptera: Lycaenidae) within and outside its habitat patches. Landscape Ecol 28:533–546Google Scholar
- Tscharntke T, Steffan-Dewenter I, Kruess A, Thies C (2002) Contribution of small habitat fragments to conservation of insect communities of grassland-cropland landscapes. Ecol Appl 12:354–363Google Scholar
- Zar JH (2010) Statistical analysis, 5th edn. Pearson Hall, Upper Saddle RiverGoogle Scholar