Fidelity and Survival of Breeding Mallards in the Nebraska Sandhills

Assessment of demographic parameters of a population allows managers to better understand factors affecting populations and increase efficiency of conservation efforts. Few data on demographics exist for mallards (Anas platyrhynchos) breeding in the Nebraska Sandhills. Thus, we used banding data to estimate probabilities of fidelity, survival, band recovery, and recapture of mallards banded in the eastern Sandhills, 2005–2008. Our recapture probability estimate for mallards was 0.074 (95% CI: 0.033–0.158), and the recovery probability estimate was 0.300 (95% CI: 0.156–0.497). Mallard annual survival was 0.795 (95% CI: 0.609–0.906) with a fidelity probability of 0.618 (95% CI: 0.283–0.868). High annual survival of mallards breeding in the Sandhills appears to be the result of low nest success and mixing with other regional populations during harvest. High probabilities of fidelity compared to other breeding areas may be related to more stable habitats and potential differences in mating strategies by males. A simple population modeling exercise suggested that generally high fidelity and survival for mallards in the Sandhills may not be enough to balance low nest survival. Mallards in the Sandhills could act as a reservoir of younger females with high survival rates that are available to move to other breeding habitat in future years, but our model suggests that immigration is needed to maintain the population in the Sandhills. Small-scale dynamics, such as those observed in the Sandhills may assist in understanding the complex dynamics of the mid-continent population of mallards