Effects of nest success and mate fidelity on breeding dispersal in a population of snowy plovers (Charadrius nivosus)

The long breeding season and sequentially polygamous mating system of the Snowy Plover (Charadrius nivosus) presents an opportunity to examine breeding dispersal in association with factors that affect an individual's experience. I used nest locations of male and female Snowy Plovers breeding in northern coastal California over a 10-year period to examine the effects of nest success, mate fidelity, residency, exclosures, and age on within- and between-season breeding dispersal distance. Within-season, females moved a median distance of 2.2 km (0.4 - 5.8) after changing mates; males moved a median of 0.9 km (0.3 - 2.5). Between-seasons, plovers moved the shortest distances when they retained a mate from the prior year and were successful in hatching eggs (males = 0.2 km [0.1 - 0.5], females = 0.3 km [0.1 - 2.3]). When mate change was coupled with nest failure in the prior year, females moved a median of 13.0 km (2.6 - 37.5) as compared to a median of 2.6 km (1.1 - 6.4) moved by males. Most plovers remained within a "site". This creates conservation challenges since breeding sites are managed by different federal, state, and local agencies with site-specific management concerns (e.g., predators, humans).