Using multiple metrics to estimate seasonal landscape connectivity for Blanding’s turtles (Emydoidea blandingii) in a fragmented landscape
- First Online:
Landscapes and animal behavior can exhibit temporal variability and connectivity estimates should consider this phenomenon. In many species, timing of activities such as nesting, mate searching, and hibernation occurs during distinct periods in which movement events may differ, along with physical characteristics of the surrounding landscape.
We estimate movement, landscape conductance, and patch importance for a turtle species across two seasonal activity periods (spring, late summer) in a fragmented agricultural region. Three connectivity approaches are compared to identify their advantages and disadvantages.
A least-cost distance model, circuit-based approach, and patch-based index were used to collectively describe the potential functional connectivity of Blanding’s turtle (Emydoidea blandingii) across a multi-temporal scale in an agricultural region of south western Ontario.
Connectivity decreased further into the active season exhibited through lower conductance of the landscape and fewer pathways, while the importance of habitat nodes shifted due to temporal variability in the number and distribution of nodes. Models provided different yet complimentary information, with least-cost models overestimating discrete pathways yet providing a secondary measure of landscape barriers. The circuit-based model estimated corridors of least resistance providing an overall characterization of the landscape, while patch-based indices provided key information on the importance of individual habitat patches.
Findings highlight the importance of including a temporal aspect in connectivity modelling as results demonstrate a change in functional connectivity over time. We also recommend employing multiple connectivity metrics to capture variation in movement behavior.
KeywordsConnectivity Blanding’s turtle Agricultural Seasonal Multi-temporal Circuit theory Least cost path Patch-based index
- Castilho CS, Marins-Sá LG, Benedet RC, Freitas TO (2011) Landscape genetics of mountain lions (Puma concolor) in southern Brazil. Mamm Biol 76:476–483Google Scholar
- Congdon JD, Graham TE, Herman TG, Lang JW, Pappas MJ, Brecke BJ (2008) Conservation biology of freshwater turtles and tortoises. Conserv Biol Freshw Turtles Tort 5:015.2–015.12Google Scholar
- Lesbarrères D, Ashpole SL, Bishop CA, Blouin-Demers G, Brooks RJ, Echaubard P, Govindarajulu P, Green DM, Hecnar SJ, Herman T, Houlahan J, Litzgus JD, Mazerolle MJ, Paszkowski CA, Rutherford P, Schock DM, Storey KB, Lougheed SC (2014) Conservation of herpetofauna in northern landscapes: Threats and challenges from a Canadian perspective. Biol Conserv 170:48–55CrossRefGoogle Scholar
- McRae BH, Kavanagh DM (2011) Linkage mapper connectivity analysis software. The Nature Conservancy, Seattle. www.circuitscape.org/linkagemapper
- Mui AB (2015) A multi-temporal remote sensing approach to freshwater turtle conservation: In: Chapter 3—modelling seasonal wetland habitat suitability for Blanding’s turtles (Emydoidea blandingii) using optical satellite remote sensing imagery. PhD thesis, University of TorontoGoogle Scholar
- Mui AB, Edge CB, Paterson JE, Caverhill B, Johnson B, Litzgus JD, He Y (2015a) Nesting sites in agricultural landscapes may reduce the reproductive success of populations of Blanding’s Turtles (Emydoidea blandingii). Can J Zool 94:1–7Google Scholar