The common shelduck is not sexually dimorphic, meaning males and females look alike. The only distinguishing characteristic is that males have a “knob” between their bill and forehead during the summer. These large ducks have white plumage, with dark green coloration on the head and random spots on the back. They also have brown coloration under the tail and in a band across the chest. Outside of the breeding season and as juveniles, these colors will appear somewhat duller. They also have pink legs and a red bill.
These birds can be found on temperate coasts and wetlands in Europe, Africa, and Asia. They nest in western Europe through the Middle East and Central Asia into northeast China, while spending their winters south of this region through North Africa.
Tadorna tadorna is a widespread breeder in coastal areas of north-west and southeast
Europe, which accounts for less than half of its global breeding range. Its
European breeding population is relatively small (
Common shelducks will feed on a variety of small invertebrates, including insects and crustaceans.
This species has a large range, with an estimated global Extent of Occurrence of 1,000,000-10,000,000 km². It has a large global population estimated to be 580,000-710,000 individuals (Wetlands International 2002). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]
These ducks are very social and tend to live in large flocks, some containing up to 50 birds. These birds are monogamous, so when a mating pair is formed, they stay together for life. They build nests in caves, deserted burrows, and other similar places. Females will lay their eggs in May and lay as many as twelve eggs in a clutch, which can take up to one month to hatch. Both parents help care for the young, which are able to fly six to eight weeks after hatching. Shortly thereafter, they will leave the nest.
British population mainly resident, but with regular, short, seasonal movements, deserting small breeding pools and meres to winter on some large reservoirs. Flocks develop September-December and disperse March-April. Increasing records in continental Europe show that some birds wander further afield. Migratory in North America, withdrawing from breeding range (except in California) to winter in Pacific, Atlantic and Gulf coastal states of USA and south into Mexico, Belize, and Guatemala
- spanwidth min.: 100 cm
- spanwidth max.: 120 cm
- size min.: 55 cm
- size max.: 65 cm
- incubation min.: 29 days
- incubation max.: 31 days
- fledging min.: 33 days
- fledging max.: 45 days
- broods 1
- eggs min.: 8
- eggs max.: 10
- Conservation Status