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Wednesday, December 7, 2011
American Avocets (Recurvirostra americana) are beautiful, elegant birds which are found in water-filled areas such as marshes, coastal bays, mudflats and saline lakes. During the summer months the American Avocet makes its way to the western Great Plains of America and are dotted through Saskatchewan, Alberta, Montana, North and South Dakota, New Mexico and Texas. In the winter months they migrate to California and Mexico as well as along the coast that runs from North Carolina to Texas. American Avocet’s are listed with the Federal Migratory Bird Treaty Act as being a threatened species due to habitat destruction.
The American Avocet is a shorebird with a distinctive long, upward curving black bill. Its long legs are grey-blue in color and thus it has received the nickname “blue shanks”. Its back and sides are clearly marked with white and black stripes. It measures about 43-47 cm, with a wingspan of 72 cm. Its eyes are dark brown. When it is breeding season, the head and neck turn a pink-tan color, but are usually gray-white. Female American Avocets are a bit smaller than the males and the bill is more curved and shorter. When bird watching along the shoreline, listen out for the call of the avocet, a high-pitched “kleek” sound.
American Avocets feed on aquatic invertebrates found in their habitat. They will forage in shallow water, whilst wading or swimming. The avocet will swing its unusual bill along the ground under the water so as to disturb the aquatic prey, grabbing it for a tasty meal.
American Avocets engage in complex courtship displays when breeding season arrives. This display involves the male avocet preening himself with water. The intensity increases into a massive splashing and then he mounts the female to mate. Following copulation the avocet pair run along with their necks intertwined. American Avocet nests are simply a scrape in the ground that is carefully lined with vegetation, feathers and so forth. Between 3 and 4 little green-brown eggs with dark spots are laid in the nest. Whilst in the nesting phase the avocets become very aggressive, even attacking intruders. They will use a number of methods, such as dive-bombing, to distract predators from the nest. Incubation lasts 22 – 24 days and is carried out by both the male and female. The young hatchlings are able to fend for themselves immediately after making their way out into the world.
American Avocets had a major drop in numbers during the 1960s and 70s due to wetland destruction and contamination. In 1995 special provision was made to protect the wetland habitats of California. The avocets are battling to get their numbers up, but it is hoped that they will flourish in the future.
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