Parental Activities of Nesting Wood Storks Relative to Time of Day, Tide Level and Breeding Stage

In 1995, parental activities of Wood Storks (Mycteria americana) were monitored in three coastal colonies during a series of 24-h long observation periods to document attendance, foraging, and other activities in relation to time of day, tide level, and breeding stage. During 5,400 nest-hours of observations, nest attendance declined and feeding rates increased with nestling developmental stage. Although some feeding arrivals occurred during darkness, the great majority of arrivals (including feeding) occurred during daylight periods. Mean times of return from feeding trips varied significantly among colonies and nestling developmental stages. Feeding arrivals were linked to tides, suggesting that most foraging occurred during the preceding low tide period. Inter-colony variation in foraging arrival times and interactions with tides were likely associated with differences in proximity to foraging sites and availability of both tidal and non-tidal (freshwater) foraging habitats.