During breeding season, the male common shelduck has a brilliant red knob on top of his bill that becomes duller in color and smaller in size throughout the rest of the year.
What They Eat
These ducks selectively feed on small marine invertebrates like snails.
Where They Live
Found in both Europe and Asia, they tend to live in sandy or muddy areas near the coast or on inland brackish lakes and marshes. These ducks are more terrestrial than other species of ducks.
What They Do
Common shelducks form long-term breeding pairs. Their nests are usually made in anything enclosed, including man-made items, hollows in large trees, gnarled roots, sheltered bays, and even the holes of other animals like rabbits or badgers. Males act as sentinels, monitoring the surrounding area where the female’s nest is hidden. In zoos, this behavior helps zookeepers find their nest sites.
How They’re Doing
The population of common shelduck is of least concern for extinction and is actually increasing.
- Males are larger and have a brilliant red bill, while females do not.
- Both males and females appear to be black and white from afar, but have iridescent greenish black heads and necks with a chestnut band across their chest and a dark strip along their belly.
- Common shelducks are not vocal, except during breeding season when females make a loud, rapid chattering or growling sound.
- They are the only waterfowl that feed by walking forward with the tip of their bill buried just beneath the substrate, sweeping it back and forth. This behavior is called scything.
- They also stomp their feet, possibly to bring snails to the surface and loosen the substrate for feeding.
- Common Shelducks are intertidal feeders, so they typically feed at night, with the ebb and flow of the tide.
- Common Shelducks lead their young one mile or more to a ‘nursery’ where, at a couple weeks old, many young from different parents form crèches.
- The group size and composition alter frequently with young joining and leaving different parents.
- Most parents leave their young before fledging to migrate to their molting grounds. The young are left with adult plumaged birds that are non or failed breeders that do not migrate to molt. Shelducks are the only ducks to do this.
- Ducklings are fledged at about 7 weeks of age.
Grey-winged trumpeter populations are decreasing due to deforestation and hunting. Forests of the Amazon River basin are being cleared for roads, cattle ranching, and crop production. The trumpeter’s poor ability to fly also leaves them prime targets for hunters. Trumpeters are likewise commonly caught and kept as pets due to their natural “guard dog” like behavior.
Sherman, P.T., Kirwan, G.M. & Sharpe, C.J. (2014). Grey-winged Trumpeter (Psophia crepitans). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/53566 on 27 July 2015).