Western Snowy Plover- Chloe Knowd

Western Snowy Plover

(Charadrius alexandrinus nivosus)

Chloe Knowd

Fig. 1, western snowy plover father and chick

Fig. 2, typical habitat 

Description and Ecology

The western snowy plover (Charadrius alexandrinus nivosus) is a small shorebird in the family Charadriidae, weighing 34-58 grams and ranging from 15 to 17 centimeters in length. This species can be identified by its white collar, dark breast patches, brown upper coloring and white under coloring. Males may exhibit a rufous crown during the breeding season of March through September. However, sexes cannot be determined from out of season plumage because all breeding markings disappear. Nests of the western snowy plover are usually shallow scrapes or depressions in the ground on flat, open areas of sparsely vegetated, sandy substrate. The egg-incubating process takes about 28 days, with females sitting on the nest during the day and males on call at night. Fledgling juveniles can be visually

Fig. 3, nest

distinguished from adults by the “buffy edges” of their upper parts until the July-October after hatching. Once the fledglings molt and feather, they are indistinguishable from the adults and are considered breeding adults after one year of hatching. As a foraging species, the western snowy plover typically feeds on invertebrates in wet sand, washed-up kelp, salt marshes or sandy areas above high tide.

Fig. 4, Pacific coast population range

Geographic and Population Changes 

The Pacific coast population of the western snowy plover can be found from southern Washington to southern Baja California, Mexico. Before 1970, the coastal populations of this species were thought to have nested in over 50 locations in California. Currently, there are about 28 breeding sites left and fewer than 1,500 breeding individuals along the California coast. Results from the Point Reyes Bird Observatory (PRBO) surveys conducted during the 1977 to 1980 breeding seasons suggested that the western snowy plover had disappeared from significant parts of its coastal California breeding range by 1980. Following surveys by PRBO in 1989 and 1991 showed a further decline in numbers of breeding adults along the California coast. A coast-wide survey during the summer of 1995 showed about a 20 percent decline in numbers of breeding adult western snowy plovers since the initial 1977 to 1980 surveys.

Listing and Type of Listing

Currently, ICUN red list considers the western snowy plover to be a ‘Near Threatened’ species. In California, the western snowy plover is a Bird Species of Special Concern. This species was listed as threatened by the Oregon Fish and Wildlife Commission in 1975, and listed as endangered by the Washington Department of Game Policy No. 402 in 1981.

Fig. 5, dog chasing western snowy plovers

Cause of Listing and Threats to Continued Existence

Primary threats to western snowy plovers include disturbance, predation and habitat loss. Since these small birds are well-camouflaged, beach visitors can disturb resting birds or walk through nesting areas without knowing of the damage they caused. Human activities like fires, fireworks and kites can cause stress to the western snowy plover. In fact, even domesticated animals like dogs and cats pose a threat to western snowy plovers by chasing, catching and preying on them. A combination of native predators like skunk crows, ravens and shrikes and exotic predators like the non-native fox place further pressure on this species. 

Fig. 6, nest exclosure

Description of Recovery Plan

Fortunately, there is a recovery plan for western snowy plovers that focuses on managing habitat by eliminating threats and maximizing productivity. In some cases, wire exclosures are utilized to protect the birds and their nests from predation. For long-term protection and management, there will be establishment of recovery unit working groups, management plans for government and private lands, and educational programs for public outreach. Once the Pacific coast population of western snowy plovers reaches an average of 3,000 breeding adults and has been maintained for over 10 years, then the species will be considered for delisting.

 

Fig. 7, plover sign for beach visitors

What can you do?

Western snowy plover nesting season aligns with beach season, so there are many things you can do to avoid and minimize disturbance to the birds. Beach visitors should obey all posted signage, avoid fenced areas, limit fire use to designated areas, only bring dogs to authorized places and should never approach birds or nests. Properly disposing of garbage will avoid attracting gulls (a predator) and leaving driftwood/kelp on the beach will provide nesting and feeding habitat for these birds. Remembering these tips during your next beach trip on the Pacific coast could save lives of western snowy plovers!

Fig. 8, western snowy plover

Want to learn more?

Kerrie Palermo's research on western snowy plovers

In-depth description of the western snowy plover

Get Involved!

Volunteer to help western snowy plovers at your local Audubon Chapter

Text Citations

“Charadrius nivosus (Snowy Plover).” The ICUN Red List of Threatened Species, 2017, www.icunredlist.org/details/22725033/0

Hornaday, Kelly, et al. “Recovery Plan for the Pacific Coast Population of the Western Snowy Plover (Charadrius alexandrinus Nivosus).” Recovery Plan, vol. 1.

“Western Snowy Plover.” Arcata Fish and Wildlife Office, U.S. Fish and Wildlife Service, www.fws.gov/arcata/es/birds/wsp/plover.html

“Western Snowy Plover (Charadrius alexandrinus Nivosus).” ECOS Environmental Conservation Online System, U.S. Fish and Wildlife Service,

ecos.fws.gov/ecp0/profile/speciesProfile?spcode=B07C.

Photo sources

Fig1:http://www.westernsnowyplover.org/why_save.html

Fig2: https://localwiki.org/islavista/Coal_Oil_Point%2C_Western_Snowy_Plovers%2C_and_The_Snowy_Plover_Docent_Program

Fig3:https://sites.google.com/site/snowyplovernx2011/survival-adaptations

Fig4:https://lpfw.org/our-region/wildlife/western-snowy-plover/

Fig5:https://wildequity.org/park-equity-project/western-snowy-plover/

Fig6:https://www.nps.gov/pore/learn/nature/birds_snowyplover.htm

Fig7:https://localwiki.org/islavista/Western_Snowy_Plover_Habitat_at_the_Coal_Oil_Point_Reserve

Fig8:https://www.montereybayaquarium.org/animal-guide/birds/western-snowy-plover