Incubation behavior and dispersal patterns in the Mountain Plover (Charadrius montanus)

Abstract

The rapid multi-clutch mating system of the Mountain Plover (Charadrius montanus) provides an interesting opportunity to examine sex differences in natal and breeding dispersal. I used nest locations from a breeding population of plovers in north-central Montana over a 13-year period (1995-2007) to examine patterns of sex bias in their dispersal. Additionally, I looked at the influence of prior experience and sylvatic plague on breeding dispersal in successive years. I also modeled successive nest fate using breeding dispersal distance with sex, previous nest fate, and presence of sylvatic plague as covariates in the model. I found no sex-bias in natal dispersal or within-year breeding dispersal. The mean dispersal distance of male plovers in consecutive years was 2.75 km (95% CI 1.51 to 4.00) and for females was 4.64 km (95% CI 2.76 to 5.52). Birds that were successful moved 3.02 km (95% CI 1.87 to 4.17) on average between nesting attempts, while those whose nests had failed moved 5.06 km (95% CI 2.53 to 7.58). The best model of between-year breeding dispersal contained the full set of parameters, with sex of the tending adult and prior nest fate having the strongest effects. The estimate of dispersal distance for females was positive ( β Female = 0.86, 95% CI 0.67 to 1.05) as well as the estimate of dispersal distance for birds whose nests had failed the previous year ( β Fail = 0.82, 95% CI 0.52 to 1.13). There was a year effect but no effect of sylvatic plague on dispersal. This study not only provides a better understanding of dispersal in an uncommon mating system but also is important in understanding the movements of a species of conservation concern.