Cooperative Fish and Wildlife Research Units Program: Michigan
Education, Research and Technical Assistance for Managing Our Natural Resources


Lassiter, E.V., J.H. Sperry, and B.A. DeGregorio. 2023. Movement ecology of adult and juvenile spotted turtles (Clemmys guttata) in a seasonally dynamic environment. Wildlife Research

Abstract

Context. Understanding the temporal and spatial scale at which wildlife move is vital for conservation and management. This is especially important for semi-aquatic species which make frequent inter-wetland movements to fulfill life-history requirements.
Aims. We investigate the drivers of movement and space-use of the imperiled spotted turtle (Clemmys guttata), an ephemeral wetland specialist, in three large, isolated wetland complexes in Virginia, U.S.A.
Methods. We use VHF radio-transmitters to radio-locate adult and juvenile turtles and estimate movement and space-use during their active and aestivation seasons (March - August). We then use generalized linear mixed models to examine how movement and space-use varied based on intrinsic turtle characteristics and extrinsic wetland and climatic features.
Key results. We showed that on average individual spotted turtles used 5 wetlands per year (range 3 – 13) and that their inter-wetland movement and daily movement distance varied seasonally in accordance with wetland availability and breeding phenology. Spotted turtle movement and space-use was influenced by the arrangement and size of the wetland complexes, with turtles moving farther and occupying larger home-ranges as size and distance between wetlands increased. Inter-wetland movement was not influenced by intrinsic turtle effects but larger adult turtles moved further, used more wetlands, and had larger home-ranges than smaller turtles.
Conclusions. Turtle response to variation in season and wetland configuration highlight the need for complex and dynamic landscapes that are required to sustain this species.
Implications. This study has important conservation implications showing that spotted turtles rely on a large number of diverse wetlands as well as upland habitat to fulfill their resource needs and that these habitat associations vary seasonally. And more broadly, results from our study can aid in the understanding of the spatial and temporal variation in patch characteristics (e.g. quality and extent) and inter-patch movement by organisms, which is critical for the conservation and management of semi-aquatic species and other species that occupy patchy habitat systems.