The Wood Stork is a large bird and has a long breeding period compared to most birds. From the formation of a pair to the fledging of the young may take 110 days. The start of breeding varies with latitude and season, as early as November in south Florida and as late as April in Georgia and South Carolina. This species nests in colonies of up to tens of thousands of pairs, but more usually tens to hundreds. Colonies are in areas surrounded by standing water, often in cypress swamps, mangrove swamps, coastal islands, islands within ponds and impoundments. Courtship precedes nestbuilding, with males displaying, vocalizing and defending a nest site, and females approaching to display to males. Males and females probably do not stay paired for more than a single nesting season.
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Generally nests are built of sticks, and are placed in larger trees at or above the canopy level. The nest is a very shallow cup, often described as a sort of platform. Both members of the pair build the nest, incubate eggs, and rear young. Between 1 and 5 creamy white eggs (more usually 2 – 4) are laid over the course of 4 – 9 days, and incubated for 27 – 32 days. Young hatch sequentially, are covered with white down at hatching, and must be brooded
Aerial view of a Wood Stork breeding
colony in the Florida Everglades. Each white dot represents an adult,
most of which are sitting on nests. |
constantly for the first week. After that time, they can stand at 2 – 3 weeks, and walk or climb away from the nest at 3 – 4 weeks. Young feed voraciously and call loudly during
the first five weeks of age. Parents feed young by regurgitating food directly into their bills; when its hot, the parents may regurgitate water over the chicks to cool them. Storks also defecate on their legs as a way to use evaporative cooling – thus their dark-colored legs often appear white. Young begin to leave the nest for short trips between 50 and 60 days of age, though parents may continue to feed them for some time thereafter. No parental care is shown after the young leave the nest.
During the breeding period, each nest may need 150 kg of fish to produce between 1 and 3 nestlings. As a result, colonies tend to produce a lot of feces, which places a lot of nutrients into the soil and surrounding water. This may result in local changes in the appearance and types of vegetation in the colony, as well as increased production and densities of aquatic animals in the immediate vicinity of the colony.