Survival of Female Scaled Quail During the Breeding Season at Three Sites in the Chihuahuan Desert

Abstract

Scaled quail (Callipepla squamata) populations declined markedly across much of their range from 1988-2004, however little research has been conducted to investigate possible causes for the decline. As part of a larger study on scaled quail ecology and management, and in an attempt to determine whether breeding season survival could be implicated in this decline, we monitored survival of radiotagged female scaled quail during the breeding season at sites in Brewster and Pecos counties, Texas, and Sierra County, New Mexico, USA during 1999-2003. Survival rates were calculated using Kaplan Meier analysis for birds living >7 days post capture. Interval survival rates (S) from Mar-Aug ranged from 0.46 to 0.82 for populations in Pecos County, Texas, and from 0.56 to 0.69 in Brewster County, Texas; survival was lower at the New Mexico site (S ranging from 0.22 to 0.48). Predation by mammals was the leading cause of mortality at both Texas study sites, whereas predation by raptors was the primary cause of mortality at the New Mexico site. Several mortalities in Texas were attributed to drowning; 3 in a water trough and 2 others following a flash flood. Survival rates on Texas sites were not affected by moist soil management but were greater than survival on New Mexico sites. Survival on New Mexico sites was greater on areas with access to free-choice quail feeders (S = 0.48) relative to a non-fed site (S = 0.22). Survival rates of scaled quail during the breeding season were higher than those reported for radiotagged northern bobwhite in west Texas at similar latitudes. Survival of female scaled quail during the breeding season does not appear to be a bottleneck to recruitment, at least not on sites where conservative grazing management is practiced.