Western Snowy Plover and California Least Tern
Oceano Dunes SVRA, a popular OHV park with over 1.6 million visitors per year, also provides some of the most productive breeding habiat along the California coast for two special-status ground nesting birds—the state and federally endangered California least tern and the federally threatened Western snowy plover.
Snowy plovers are small, light colored gound-nesting shorebirds. The snowy plover population at the Park is comprised partly of resident birds, present year-round, and partly of migrant birds, present only during the breeding or wintering season. Least terns are present only during the breeding season, generally for April to September.They are the smallest tern in North America, similar in size to the snowy plover (~6 inches), but with a longer wing span. Least terns feed on small fish caught from the surface of the water of the ocean or nearby fresh water lakes. While plover chicks hunt and capture their own food, least tern chicks are dependent on the adults to bring them appropriately sized fish. Park staff have been monitoring breeding least terns since 1991 and snowy plovers since 1992. Management efforts include:
- maintaining an approximate 300-acre fence exclosure seasonally from March to October,
- extensive seasonal habitat enhancement,
- intensive daily monitoring of nests and chicks by Park staff and contractors,
- color banding of all chicks,
- predator management,
- educating Park visitors, and
- enforcement of resource protection regulations.
These efforts continue to help in the recovery of the least tern and snowy plover populations while keeping OHV use and other recreational opportunities available to the public.
Western Snowy Plover Breeding Statistics:
With increased and adaptive management efforts by the park and help from visitors, the Western snowy plover population has improved. The number of breeding snowy plover adults at the park has steadily increased, from 32 breeding birds in 2002 to 190 in 2020. One chick fledged per breeding male is the estimated number needed to prevent the population from declining and 1.2 chicks fledgling per male allows for moderate population growth (US Fish & Wildlife Service 2007). For the 19-year period 2002-2020, average productivity at Oceano Dunes was 1.45 chicks fledged per breeding male (California Department of Parks and Recreation 2020). Oceano Dunes SVRA strives to continue in efforts to protect and contribute to the population of Western snowy plovers.
California Least Tern Breeding Statistics:
Similar to the snowy plovers, the tern population at Oceano Dunes has benefited from increased protections in place. From 1991 to 1996, the park had a very small least tern colony averaging 0-5 breeding pairs, the average increasing to 19-21 for the years 1997 to 2002, and to 41-45 for the 18-year period from 2003-2020. From 2006-2020, the average fledglings per pair was 1.10-1.18 (California Department of Parks and Recreation 2020). For all least tern colonies in California, the average number of fledglings per pair has ranged from 0.09-0.68 for 2005-2016 (Frost 2017). Although the colony is small, Oceano Dunes has been one of the top contributors to the number of juveniles produced each year in California, playing an important role in the overall recovery of the species.
For the safety of others around you and wildlife obey the posted 15 MPH speed limit and avoid driving through flocks of birds.
California Department of Parks and Recreation, 2020. Nesting of the California least tern and western snowy plover at the Oceano Dunes State Vehicular Recreation Area, San Luis Obispo County, California 2020 Season. Unpublished Report, CDPR, Off-Highway Motor Vehicular Recreation Division.
Frost, N. 2017. California least tern breeding survey, 2016 season. California Department of Fish and Wildlife, Wildlife Branch, Nongame Wildlife Program Report, 2017-03. Sacramento, CA. 20 pp + Appendices.
US Fish & Wildlife Service, 2007. Recovery Plan for the Pacific Coast Population of the Western Snowy Plover (Charadrius alexandrinus nivosus). In two volumes. Sacramento, CA. xiv+751pp
Protect Your Right to Play ...
Remember, Wildlife Has the Right of Way!
What do you need to know?
- You may not always see wildlife where you recreate, but at Oceano Dunes SVRA there is an abundance of wildlife, especially shorebirds. Two of them, the threatened Western snowy plover and the endangered California least tern, are protected by the federal Endangered Species Act.
- March 1 – September 30 these birds are nesting on the sands of Oceano Dunes SVRA.
- Winter months the plovers are most vulnerable because they are typically inactive. They often crouch in small depressions in the sand, which make them very well camouflaged and extremely hard to see.
- Year round, shorebirds are easily disturbed by people and dogs. Please keep your distance.
How do I protect my recreational opportunities?
Reduce your impact by obeying the following laws and park policies:
- Obey the posted 15 mph speed limit.
- Dogs must be kept on leashes and under your control at all times.
- Do not drive into flocks of birds. Give all birds the right of way.
- Dispose of trash properly. Trash attracts predators.
- Do not enter posted nesting areas.
- Parking/camping is prohibited within 100 feet of posted nesting areas.
- No kite flying south of Pier Avenue March 1-September 30 (Nesting Season). Kites look like predators.
- Please report to park staff any nests, threats or disturbances to plovers.