A Ground-nesting Wood Duck

Le résumé fourni par la source

A ground-nesting Wood Duck.--While conducting a study of nesting Wood Ducks (Aix sponsa) at Great Swamp National Wildlife Refuge, Morris County, New Jersey, we found a female Wood Duck that incubated and eventually hatched a clutch in a grassy field approximately 10 m from a pond and 15 m from a small marsh.The nest was discovered accidentally at noon on 29 May 1976 when Zipko came within one meter of the nest before the female flushed.While incubating she had apparently fashioned a makeshift roof from the surrounding vegetation.This remained essentially intact as she flew, without an alarm call or defecation, exposing 10 eggs with down in a ring.At 0825 on 5 June, Zipko again approached within a meter of the nest before the female flushed, flapping her wings while running into the pond.She continued to feign injury for several seconds then flew, without a sound, to the marsh.The nest now contained 11 incubated eggs.At 1045 on 9 June, Kennington came within 0.5 m and noted the characteristic white eye-ring and other plumage features as the female flushed, exposing 10 eggs with no sign as to the fate of one missing egg.At 0840 on 24 June, Zipko found eggshell fragments, five chorioallantoic membranes, and one previously numbered egg, along with scattered grayish down feathers.Although Roberts (1955, A manual for the identification of birds of Minnesota and neighboring states, Minneapolis, Univ.Minnesota Press p. 247) refers to second-hand reports of Wood Ducks nesting on the ground in western Minnesota, we found no other literature references to ground-nesting Wood Ducks.Previous studies by Roscoe (MS) and Zipko (MS) have indicated a dense Wood Duck nesting population at Great Swamp relative to available nest boxes and natural nest sites.Perhaps the paucity of suitable nest sites caused this bird to select a ground nest site.

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