Nest occurrence and survival of King Rails in fire‐managed coastal marshes in North Carolina and Virginia

Prescribed burning maintains marsh habitat, but its impact on breeding King Rails (Rallus elegans) is poorly understood. This practice may serve as a means to enhance populations of a species whose numbers are declining in the southeastern United States. We used call-broadcast surveys and nest searches to categorize the state of occupied plots by the presence or non-presence of nesting activity in the Back Bay region, North Carolina and Virginia, in 2010. We also used nest video surveillance to estimate nest survival in 2009 and 2010. The probabilities that a surveyed plot was occupied (psi(1)) and contained an active nest (psi(2)) were higher in recently burned marsh plots (0-1 year-since-burn [YSB]) than in plots with 2 YSB at Mackay Island and Back Bay National Wildlife Refuges (NWRs). Highest probabilities were recorded in 0-1 YSB plots at Mackay Island NWR (psi 1 = 0.96 0.04, psi 2 = 0.75 0.18), and the lowest in 2 YSB plots at Back Bay NWR (psi 1 = 0.21 +/- 0.10, psi 2 = 0.03 +/- 0.04). Nest survival from egg laying to hatching (31 d) was 0.48 (95% confidence interval [CI] = 0.06-0.83), with an estimated 0.79 (95% CI = 0.29-0.96) survival rate for the incubation stage (21 d). These nest survival estimates for King Rails in fire-managed marshes were similar to estimates for other populations. Measures of vegetation cover, proxies for concealment, did not differ between nest sites and unused sites, even within recently burned marshes. This lack of differences in vegetation structure suggests that regrowth occurs rapidly during the period between burning (winter months) and the onset of reproduction (late April). Thus, recently burned marshes may benefit nesting King Rails by providing nest concealment. In addition, burned marshes may enhance availability of many invertebrates. Although we found that the probability that surveyed plots contained active nests was higher in recently burned marsh plots, estimates of fledging success are needed before marsh burns can be considered an effective means of fostering population growth.