Factors associated with breeding site fidelity in a nomadic shorebird with extremely low local return rates

Birds that breed across multiple years can either return to the same breeding location or disperse to a different location. The propensity to return to the previous breeding site differs substantially between species, populations and individuals. In biparental socially monogamous birds (>90% of species), breeding site fidelity is typically high. Site fidelity in these species is often associated with higher breeding success and may be favoured by the benefits of remating with the same partner. In uniparental polygamous birds, which form no (or only short) pair-bonds, return rates are typically low, but factors associated with site fidelity are rarely investigated in these species. We examined factors associated with breeding site fidelity in the pectoral sandpiper, an Arctic-breeding polygynous shorebird with female-only care that is largely nomadic, with both sexes showing extremely low site fidelity between years. We individually marked 524 males and 366 females over a period of 4 years and found that the likelihood of returning to the same breeding area in the following year was higher for males (2.4%) than for females (0.5%). Breeding site fidelity of males was predicted by their siring success and tenure: those that had sired offspring with more females and had resided in the breeding area longer were more likely to return. Moreover, males that returned to the study area had higher siring success than males that had not been in the study area the previous year. Breeding site fidelity may be a beneficial strategy for individuals that are successful in a certain location, even in species that are generally nomadic.