Amphibian terrestrial habitat selection and movement patterns vary with annual life-history period

Abstract

Identification of essential habitat is a fundamental component of amphibian conservation; however, species with complex life histories frequently move among habitats. To better understand dynamic habitat use, we evaluated Wood Frog (Lithobates sylvaticus (LeConte, 1825)) habitat selection and movement patterns during the spring migration and foraging periods and described the spatiotemporal variability of habitats used during all annual life-history periods. We radio-tracked 71 frogs in Maine during 2011–2013 and evaluated spring migration, foraging activity center (FAC), and within-FAC habitat selection. Telemetered frogs spent the greatest percentage of each field season in hibernacula (≥54.4%), followed by FACs (≥25.5%), migration habitat (≥16.9%), and breeding sites (≥4.5%). FACs ranged 49 – 1 335 m2 (568.0 ± 493.4 m2) and annual home ranges spanned 1 413 – 32 165 m2 (11 780.6 ± 12 506.1 m2). During spring migration, Wood Frogs exhibited different movement patterns (e.g., turn angles), selected different habitat features, and selected habitat features less consistently than while occupying FACs, indicating that the migration and foraging periods are ecologically distinct. Habitat-use studies that do not discriminate among annual life-history periods may obscure true ecological relationships and fail to identify essential habitat necessary for sustaining amphibian populations.

Landscape genetics reveals unique and shared effects of urbanization for two sympatric pool‐breeding amphibians

“…Several characteristics make these species excellent subjects for evaluating the effects of urbanization with a landscape genetics approach. For instance, the species have small annual home ranges (spotted salamanders: up to 301 m 2 , Ousterhout and Burkhart, 2017;wood frogs: up to 32,165 m 2 , Blomquist & Hunter, 2010;Groff, Calhoun & Loftin, 2017), relatively short generation times (spotted salamanders: maturity in 2-7 years, Flageole & Leclair, 1992; wood frogs: maturity in 2-3 years, Sagor, Ouellet, Barten, & Green, 1998), and high rates of philopatry (Vasconcelos & Calhoun, 2004). Both species are vulnerable to degradation of the breeding sites they share within their overlapping ranges in the northeastern United States (Harper, Rittenhouse, & Semlitsch, 2008).…”

Post-Breeding Migration and Habitat of Unisexual Salamanders in Maine, USA

“…We measured 22 microhabitat variables within plots based on studies of A. jeffersonianum, A. laterale, and other amphibians (Faccio, 2003;Rittenhouse and Semlitsch, 2007;Ryan and Calhoun, 2014;Groff et al, 2017). We recorded land use as forest, yard/field, or wetland.…”

Behavior in a Changing Landscape: Using Movement Ecology to Inform the Conservation of Pond-Breeding Amphibians

“…A key conclusion to draw from all these studies is that movements linked to habitat complementation at the scale of a patch are essential components of population persistence and are strongly impacted by multiple human-driven landscape modifications. When it is not possible to preserve a buffer zone of favorable terrestrial habitats around a pond (Semlitsch, 1997;McDonough and Patton, 2007), the best way to restore connectivity at this scale is to maintain a permeable matrix or straight-line corridors between essential habitat components (i.e., ponds, terrestrial habitats, and wintering habitats) (Groff et al, 2017). Stable corridors should serve to enhance the inheritance of migration direction, increasing connectivity effectiveness in the long term.…”

“…Exploratory behavior has been deeply neglected in studies on amphibians. In the many recent studies on monitoring movement in the wild using telemetry, any movement is qualified as exploratory behavior, while the term itself is never used (Miaud et al, 2000;Muths, 2003;Indermaur et al, 2009;Constible et al, 2010;Heemeyer and Lannoo, 2012;Humphries and Sisson, 2012;Sinsch et al, 2012;Liang, 2013;Browne and Paszkowski, 2014;Timm et al, 2014;Frei et al, 2016;Groff et al, 2017;Pitt et al, 2017). As the main objectives of these studies were to establish the length of landward migrations, the size of the home range, and the components of terrestrial habitats, the movement characteristics themselves (e.g., the pathway or function) were most often not analyzed.…”