Demography of Snowy Plovers (Charadrius nivosus) on the Missouri River

Snowy Plovers (Charadrius nivosus) have recently expanded their breeding range into the northern Great Plains. We studied the nest success and survival of Snowy Plovers nesting on the Missouri River between Nebraska and South Dakota from 2008–2011 by monitoring nests every 2–3 days and banding adults and chicks. We used the logistic exposure method to estimate nest success and capture-recapture models in Program MARK to estimate adult and chick survival. Snowy Plover nests had a daily survival rate of 0.978 ± 0.008, and annual adult apparent survival rate was 0.588 ± 0.119. In addition, we estimated that 0.63 ± 0.12 of Snowy Plover chicks survived to fledging (30 days) during our study. The results for Snowy Plovers were similar to results for Piping Plovers (Charadrius melodus) breeding in the same area, and the demographic rates in this study were similar to those reported from established portions of the species' range. Recent breeding range expansion may be due to spring flooding on established breeding grounds coupled with the drying of lakes and reservoirs in the northern Great Plains. Continued monitoring of breeding populations in this region should determine if expansion of the breeding area described in this study will persist, offering a rare opportunity to learn about population dynamics at the forefront of a species' range expansion.