Ecological parameters of Coluber constrictor etheridgei, with comparisons to other Coluber constrictor subspecies
| Authors: | Robert R. Fleet, Craig Rudolph, J. D. Camper, J. Niederhofer |
| Year: | 2009 |
| Type: | Scientific Journal |
| Station: | Southern Research Station |
| Source: | Southeastern Naturalist 8(Special Issue 2): 31-40. |
Abstract
In 1998, we conducted a radio-telemetry study of Coluber constrictor
etheridgei (Tan Racer) in the Angelina National Forest in eastern Texas. Individuals
were located once daily from 12 June to 14 August. We determined home-range
size, movement distances, movement frequency, and habitat use for this short-term
study. We also determined food habits of this population by examination of fecal
samples. We compared these parameters to other Racer taxa in Utah (C. c. mormon
[Western Yellow-bellied Racer]), Kansas (C. c. fl aviventris [Eastern Yellow-bellied
Racer]), and South Carolina (C.c. priapus [Southern Black Racer]). Compared to
these populations, Texas Racers exhibited larger home ranges and greater movement
frequency and distances during the summer than Utah or Kansas populations, but approximately
equal to those of the South Carolina population. Available data on food
habits suggests that all populations are consumers of invertebrate and vertebrate prey.
We hypothesize that the basic diet of C. constrictor is composed of invertebrates captured
by active foraging in areas of abundant herbaceous vegetation, that differences
in home-range size and movement distances result from variations in patchiness of
suitable foraging habitat across populations, and that the proportion of vertebrate
prey in the diet of Coluber populations increases as home-range size and movement
distances increase due to increasing patchiness of foraging habitat, resulting in
increasing encounters with vertebrate prey.