Spatial and Temporal Use of Caves by Eleutherodactylus marnockii and Craugastor augusti in the Western Edwards Plateau of Central Texas
Terry, William G.
Understanding the spatial and temporal habitat associations of rarely encountered species is an important component of understanding their ecology. Barking frogs (Craugastor augusti) and Cliff-chirping frogs (Eleutherodactylus marnockii) are rarely encountered inhabitants of the rugged limestone terrain of the western Edwards Plateau of Texas. In order to explore the mechanisms of co-occurrence between these two species in a spatially restricted environment I examined the habitat-use and dispersion patterns within and between these species. Six caves varying in length from 6 m to 120 m were surveyed monthly from January through December 2017. Additionally, one cave was also surveyed at 6 h intervals across a 24 h period, quarterly. The location of individuals with respect to cave entrance were recorded during each survey. Caves were not used as daily or seasonal refugia as both species were present day and night throughout the year with peak numbers observed during spring-summer and summer-fall for E. marnockii and C. augusti respectively. Both species were found throughout the lengths of caves but differed in patterns of microhabitat use. Cave occupancy was not restricted temporally during the 24 h period or seasonally. As well, E. marnockii but not C. augusti exhibited seasonal patterns of aggregation. However, inspection of near-neighbor distances consistently failed to reveal evidence of interspecific repulsion with the curious exception being during peak abundance of C. augusti, E. marnockii displayed a repulsed pattern of dispersion towards this species. This study is a primer to further investigations into the ecological interactions between these anurans.
Anura, Craugastoridae, Dispersion-patterns, Eleutherodactylidae, Karst fauna
Terry, W. G. (2019). <i>Spatial and temporal use of caves by Eleutherodactylus marnockii and Craugastor augusti in the Western Edwards Plateau of Central Texas</i> (Unpublished thesis). Texas State University, San Marcos, Texas.