Comparison of Fine Scale Vegetative Parameters at Active and Inactive Gulf Coast Kangaroo Rat Burrow Sites


Meeting Abstract

P3-139  Saturday, Jan. 7 15:30 – 17:30  Comparison of Fine Scale Vegetative Parameters at Active and Inactive Gulf Coast Kangaroo Rat Burrow Sites BELL, MM; Texas State University mmb151@txstate.edu

The Texas endemic Gulf-coast kangaroo rat (Dipodomys compactus, GCKR) belongs to the family Heteromyidae and ranges from Mustang and Padre Islands inland to Bexar and Gonzales counties in Texas. Although listed as globally secure by the International Union for Conservation of Nature, it is listed as vulnerable on Texas Parks and Wildlife Conservation Action Plan. Despite the need to develop holistic management plans for inconspicuous/understudied species, few ecological studies on habitat requirements have been conducted on GCKR. Since April 2016, I have monitored seasonal changes in vegetation and GCKR burrowing activity at 63 randomly selected sites on a working ranch located in Guadalupe County. I recorded monthly data at sites occupied by GCKR in April 2016 and occupied thereafter. I recorded percent cover using the Daubenmire frame and cover estimate technique. I also identified dominant species of forbs and grasses and recorded percent woody canopy cover. From the site center, I measured distance to the nearest burrow complex and woody canopy cover. At this time, 19 of 63 sites had active burrows for at least one month. For active and inactive/non-burrow sites, canopy cover was 1% and 29% and distance to the nearest canopy was 64m and 35m, respectively. Percent cover of bare ground (29% vs 13%) and forbs (32% vs 19%) was higher at active compared to inactive sites. At inactive sites, percent cover of litter (33% vs 14%) and grasses (25% vs 20%) was higher than at active sites. Standing dead herbaceous cover was similar. The dominant herbaceous species for active sites were Lazy Daisy (Aphanostephaus spp.), Rosette Grass (Dichanthelium spp.), and Thin Paspalum (Paspalum setaceum), while Little Bluestem (Schizachyrium scoparium), Rosette Grass, and Woolly Croton (Croton capitatus) were dominant for inactive sites.

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