Effects of prickly pear control on survival and nest success of northern bobwhite in Texas

Control of prickly pear cactus (Opuntia spp.) with a tandem of prescribed fire and picloram (4-amino-3,5,6-trichloropicolinic acid) is a common practice in the Rolling Plains of Texas. The effects of such a practice on the northern bobwhite (Colinus virginianus) have not been documented. We evaluated the effect that prickly pear control (2-3 years post-treatment) has on survival and nest success of northern bobwhites. We captured and radiomarked 217 bobwhites (n=66 males, n=151 females) within 2 treated (burned and sprayed) and 2 nontreated pastures during spring and summer of 1997-1998 in Shackelford County, Texas. Treated pastures were burned in February 1995 and subsequently sprayed in April 1995 with 0.27 kg/ha of picloram. Season survival (15 Mar-15 Aug) did not differ between treated (0.17) and nontreated pastures (0.36) in 1997 (P=0.12) or 1998 (0.58 vs. 0.61, respectively; P=0.72). Eighty-one nests were located, 48 in treated pastures and 33 in nontreated pastures. Nest success did not differ between treated (46%) and nontreated (46%) sites (P=0.96). Prickly pear control did not affect seasonal survival or nest success of northern bobwhites 2-3 years post-treatment.

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