Burrow sites of the “Texas Brown” tarantula in southeastern Colorado

Tarantulas are a charismatic arthropod of the short-grass steppe, where the main land use is cattle grazing. Little is known about nesting sites of even the most common tarantula species, nor how grazing affects nest density. We compared nesting sites of Aphonopelma hentzi living in Southeastern Colorado by examining soil conditions, proximal ground cover, and the density of nests at sites that were grazed and ungrazed by domestic cattle (Bos taurus). The density of A. hentzi nests were determined using distance sampling at five sites within the Southern Plains Land Trust. We visually estimated the ground cover within a 30 cm² area around each burrow and at control locations every 200 meters. Initial results showed that burrow density was higher in locations that were more frequently grazed with higher amounts of loose soil. Ranching has a strong effect on the lands used for grazing and can drastically alter the ecosystem. Understanding how A. hentzi nesting preferences are affected by ranching can help to predict how the populations in Southeastern Colorado may respond to common human activities in the area and we can better co-exist with tarantulas by maintaining habits that encourage tarantulas to nest in areas that will not find them in conflict with humans.