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Endangered Spotlight: Western Snowy Plover

(Charadrius alexandrinus nivosus)

By Nina Bubert



Western Snowy Plovers.
Photo: MojosCoast

As you take your next stroll down the shoreline, be sure to keep an eye out for the cleverly camouflaged western snowy plover. Arguably the cutest bird in the Sanctuary, the snowy plover is one of the many endangered species that live and travel through the Bay Area.

In each edition of Upwelling this year, we will be spotlighting one of the endangered creatures in our Sanctuary, and proffering what you can do to protect them and ensure their survival.

Although western snowy plovers can be found on Bay Area beaches and mudflats year round, the population does not consist of the same individuals.  The birds we see on our coasts during the winter months have migrated south after nesting in Oregon.  The central coast population migrates north or south to wintering grounds from Bandon, OR, to Baja Sur, Mexico.  Mid spring brings local breeders back to our coastal beaches and lagoons.

Physical Characteristics

The western snowy plover is a small shore bird, with a short neck and moderately long legs.  The back is a pale brown with white under parts and dark bands on the sides of the neck reaching around to the top of the chest.  There is a dark tip to the center of the tail while the outer tail feathers are white.  The bird has brown eyes and legs and a dark bill.

Snowy plovers are polyandrous and polygynous, forming a sexual union with more than one male or female during the breeding season, respectively.  Females on the Pacific coast will frequently double brood (sometimes even triple brood where the breeding season is long).  Such is the case in California, where the breeding season can last up to 16 weeks.

The eggs of a snowy plover are camouflaged to look like the substrate in which they nest (such as sand or dirt). The typical clutch size is three eggs with a range of two to six.  The chicks are covered in down feathers and are able to leave the nest once the down dries, usually within 3 hours of hatching.

Snowy plovers forage for small invertebrates, such as sand crabs, from the surface of coastal beaches or tide flats.  They will sometimes forage on kelp, marine mammal carcasses, or low foredune vegetation.

Endangered Status

The snowy plover is currently listed as a threatened species on the endangered species list.  In 2002 and 2003, petitions were submitted to U.S. Fish and Wildlife Service to delist the western snowy plover.  This led to a 5-year review of its threatened status.

The review concluded that the petition had no merit and indeed the population of western snowy plovers was threatened.  A recovery plan has been drafted and can be viewed here.

Reasons for the decline of this species are varied.  The main threat is habitat degradation caused by coastal development and increased recreational use.  The introduction of beach grass to stabilize sand dunes has caused a decrease in nesting habitat.  Increased egg failure has also been linked to high mercury levels.

Coyotes, raccoons, falcons and owls are some of the plover’s natural predators. However, humans have introduced or helped propagate species that predate on plovers.  These species include the red fox, crows, ravens, gulls and domestic dogs.

The recovery plan aids the management of this species by making recommendations for the protection and restoration of snowy plover habitat and for monitoring and research. 

The most widely used management strategies have been nest protection with predator exclosures; signage and fencing around nesting areas; restrictions on motorized vehicles near nests; dog-on-leash laws; and public education and outreach.

With a recovery plan in place, Federal and State agencies are working together to protect this exceptional little bird.  You, the public can do your part too and help the western snowy plover become a success story.

 

Photo credits: MojosCoast and NOAA