Abstract:
The eastern worm snake (Carphophis amoenus) is a fossorial species that often uses
coarse woody debris (CWD) refuges when it is not beneath the ground. The purpose of
this study was to determine whether CWD the worm snakes select as refugia differ from
available CWD within the microhabitat. This study took place at Huntley Meadows
Park, Alexandria, Virginia, and Jug Bay Wetlands Sanctuary, Lothian, Maryland. Snakes
were found by searching CWD refuges. Microclimate, ground cover and canopy cover
measurements were taken at used and available refuges. There was no significant
difference between refuges selected by different sexes or by individuals undergoing
ecdysis and the general population. Refuge temperatures were significantly lower than
ambient air temperatures, but there was no significant difference between the
microclimate characteristics of used and available refuges. Used refuges had
significantly more decayed CWD and a higher proportion of CWD cover. They were also more likely to contain active ant colonies and less likely to contain earthworms.
CWD refuges were within the optimal temperature range of worm snakes for
significantly more days per year than underground, indicating that thermoregulation may
be a driving factor guiding microhabitat selection.
In addition to studying worm snakes, the amphibians and reptiles of Huntley
Meadows Park were surveyed to determine their status, which was last assessed in 1989.
The comprehensive survey extended across the park and included time-constrained
searches of coarse woody debris, anuran calling surveys, vernal pool monitoring, visual
encounter surveys and a mark-recapture study of Spotted turtles (Clemmys guttata).
Spotted turtle populations were higher than expected and one new species, Green
treefrogs (Hyla cinerea), had moved into the park since the previous survey. However,
three species of amphibian and five species of reptile have been extirpated from the park:
Northern cricket frog (Acris crepitans), Upland chorus frog (Pseudacris feriarum), Redspotted
newt (Notophthalmus viridescens), Ring-neck snake (Diadophis punctatus),
Ground skink (Scincella lateralis), Mole kingsnake (Lampropeltis calligaster), Northern
brown snake (Storeria dekayi), and Red-bellied snake (Storeria occipitomaculata). A
further two amphibian species (Fowler’s toad, Anaxyrus fowleri, and Wood frog,
Lithobates sylvaticus) appear to be on the cusp of extirpation. Factors that may have
contributed to the loss of species include a decrease of meadows and wetlands within the
park, increased urbanization surrounding the park, the vulnerability of amphibians and
reptiles to road effects, and the closing of habitat corridors between the park and other
areas of suitable habitat.
