Movement ecology of adult and juvenile spotted turtles (Clemmys guttata) in a seasonally dynamic environment

Understanding the temporal and spatial scales at which wildlife move is vital for conservation and management. This is especially important for semi-aquatic species that make frequent inter-wetland movements to fulfil life-history requirements.

We aimed to investigate the drivers of movement and space-use of the imperilled spotted turtle (Clemmys guttata), a seasonal wetland specialist, in three large, isolated wetland complexes in Virginia, USA.

We used VHF radio-transmitters to radio-locate adult and juvenile turtles, and estimated movement and space-use during their active and aestivation seasons (March–August). We then used generalised linear mixed models to examine how movement and space-use varied, based on intrinsic turtle characteristics and extrinsic wetland and climatic factors.

We show that, on average, individual spotted turtles used five wetlands per year (range 3–13), and that their inter-wetland movement and 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 further 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.

Turtle responses to variation in season and wetland configuration highlight the need for complex and dynamic landscapes required to sustain this species.

This study has important conservation implications showing that spotted turtles rely on a large number of diverse wetlands, as well as upland habitat, to fulfil their resource needs – and that these habitat associations vary seasonally. Results from our study can aid the understanding of 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 organisms that occupy patchy habitat complexes.