Reproduction and Microhabitat Selection in a Sharply Declining Northern Bobwhite Population

Abstract

Northern Bobwhite (Colinus virginianus) populations have been declining throughout their range, but some of the sharpest declines have been documented in the Mid-Atlantic states. We conducted a 2 year (2006–2007) breeding season (1 May–30 Sep) telemetry study in southern New Jersey to collect baseline data on Northern Bobwhite reproductive rates, and nest and brood microhabitat selection. We located 23 Northern Bobwhite nests, of which 21 were usable for survival analyses. Incubation-period nest survival rate was 0.454 ± 0.010 (95% CI = 0.280–0.727). Mean clutch size was 14.2 ± 0.58 (range 10–19, n = 20) and hatching success was 96.1 ± 2.0% (range 86–100%, n = 10). The estimated probability that an individual that entered the breeding season would initiate incubation of ≥1 nest was 0.687 for females and 0.202 for males. Nest microhabitat selection was positively related to visual obstruction and percentage of litter. Brood microhabitat selection was positively related to visual obstruction, vegetation height, and percentage of forbs but negatively related to percentage of cool season grass and litter. Fecundity metrics for Northern Bobwhites in southern New Jersey appear similar to those reported elsewhere in the species' range. Conservation efforts to increase Northern Bobwhite reproductive success in southern New Jersey should focus on increasing the quantity of available breeding habitat.