Influence of abundance of small-mammal burrows and conspecifics on the density and distribution of spotted salamanders (Ambystoma maculatum) in terrestrial habitats

Abstract

Spotted salamander (Ambystoma maculatum) distributions were studied within eighteen 272-m2 field enclosures in upland deciduous forest adjacent to two breeding ponds. The enclosures were subsequently used in experiments involving (i) removal of small-mammal burrows to determine if burrow abundance influenced salamander density and (ii) manipulation of salamander densities to determine if increased density was associated with decreased growth, fecundity, or probability of re-emerging to breed. Mean density of salamanders wintering in enclosures <65 m from the breeding ponds was 1.0/100 m2 (SD = 1.1/100 m2, n = 17, range = 0–4.0/100 m2). Density declined as distance to the nearest breeding pond increased, and the sex ratio was skewed sharply toward males (8:1) wintering close (<65 m) to the pond but not farther from the pond (1:1). Males residing within the enclosures weighed more than males wintering farther from the breeding ponds. Migrating salamanders were over 3 times more likely to leave burrow-removal plots than control plots prior to the summer inactive period. Salamanders housed at high density (15/enclosure) were less likely to re-emerge to breed than were salamanders housed at low density (5/enclosure), but we observed no effects on growth or fecundity. Results suggest that conspecific distribution and burrow availability might affect the density of spotted salamanders within terrestrial habitats.

Conserving pool-breeding amphibians in human-dominated landscapes through local implementation of Best Development Practices

“…Site clearing around pools for roads or other hard structures alters and eliminates critical overwintering habitat (Windmiller 1996;Regosin et al 2003a).…”

“…Baldwin, unpublished data). Ambystomatid salamanders and ranid frogs often travel hundreds of meters to and from breeding ponds and among wetlands during the non-breeding season (Semlitsch 2002;Regosin et al 2003a). Reported maximum travel distances from breeding pools for adult abystomatid salamanders range from 198 m for adult A. laterale Hallowell to 625 m for A. jeffersonianum Green.…”

Life-history costs of reproductive behaviors in a wetland-breeding amphibian

“…The breeding migration of spotted salamanders is influenced by a variety of environmental factors, and several studies have provided the detailed descriptions of these migration movement patterns. Namely, high site fidelity (i.e., return to the same wetland location) is observed during spotted salamander annual migrations with males arriving earlier than females and females traveling a greater distance than males (Whitford & Vinegar 1966;Regosin et al 2003;Tennessen & Zamudio 2003;McDonough & Paton 2007). During the time spent in the breeding pond, spotted salamanders are thought to consume little prey (Smallwood 1928;Petranka 1998), thereby making body mass changes a potential correlate of reproductive effort.…”

The influence of habitat provisioning: use of earthworm burrows by the terrestrial salamander, Plethodon cinereus

“…This behavior likely affects all aspects of their population ecology. To our knowledge, no researcher has tested whether salamanders in the genus Plethodon may rely on underground habitat that was provided by another animal, though salamanders in the genus Ambystoma appear to use small mammal burrows (e.g., Regosin et al 2003). Although salamanders can use underground refuges formed by natural fissures or tunnels left by decaying tree roots, our empirical demonstrations show that earthworms cause behavioral changes within a salamander population across age-classes.…”