Are there Trumpeter Swans in California?

The trumpeter swan (Cygnus buccinator) is the largest native waterfowl species in North America. Once widespread across the continent, trumpeter swan populations declined sharply in the 19th and early 20th centuries due to overhunting and habitat loss. Conservation efforts over the past few decades have helped trumpeter swan numbers recover in some parts of their historical range, but their distribution remains patchy.

In this article, we’ll take a closer look at the current status of trumpeter swans in California and answer some key questions:

– What is the historical range of trumpeter swans in California?
– What caused their decline in the state?
– Do wild trumpeter swans still exist in California? If so, where are they found?
– Have there been any reintroduction efforts in California?
– What is the current legal status and conservation outlook for trumpeter swans in California?

Historical Range and Abundance in California

Trumpeter swans were once fairly widespread in California, although likely not as abundant as in wetland habitats further north. Historical records indicate trumpeter swans bred and wintered across much of the state prior to the 19th century.

Their breeding range extended south to the wetlands of the Central Valley and possibly as far south as Buena Vista Lake near Bakersfield. Trumpeter swans wintered along both coastal and interior wetlands. Major wintering sites likely included the Sacramento-San Joaquin River Delta, Suisun Marsh, San Francisco Bay, Lake Earl in northern California, and various lakes, marshes, and flooded agricultural fields of the Central Valley.

There are no precise historical estimates of trumpeter swan abundance in California. Early accounts suggest they were locally common in some areas. For example, explorer John C. Fremont described seeing flocks of hundreds of swans during his 1844 expedition in the vicinity of Buena Vista Lake. But even at this early date, trumpeter swan numbers were already declining in California due to overhunting and wetland reclamation.

Timeline of Trumpeter Swan Decline in California

– Early 1800s: Trumpeter swans still fairly widespread across Central Valley and coastal wetlands but populations decreasing due to hunting and habitat loss.

– 1860s: Trumpeter swans extirpated from southern half of Central Valley following extensive wetland drainage. Only scattered reports from northern Central Valley.

– 1870s-1890s: hunting pressure and development continues to reduce trumpeter swan occurrence in CA.

– 1910s: Trumpeter swans nearly extirpated as breeding species, with only a few pairs remaining in northeast CA.

– 1930s: Trumpeter swans extirpated as winter migrants to CA with last reports from Delta region.

Causes of Decline

The disappearance of trumpeter swans from California by the early 20th century was driven by a combination of factors:

– **Overhunting:** Trumpeter swans were heavily hunted in the 19th century for their feathers and meat. Their large size and unwary nature made them easy targets for market and subsistence hunters. Even the protection of the Migratory Bird Treaty Act in 1918 came too late to save the last remnant trumpeter swan populations in California.

– **Wetland loss:** Beginning in the mid-1800s, CA lost close to 95% of its historical wetland acreage to agricultural and urban development, especially in the Central Valley. This destroyed trumpeter swan nesting and foraging habitat.

– **Disturbance:** Expanding settlement likely displaced swans from remaining wetland refuges through grazing, pollution, and other human disturbances.

By 1935, the trumpeter swan was officially extirpated as a breeding species in California, with no more sightings of wintering birds after the 1920s. A combination of protective laws and wetland conservation came too late to save trumpeter swans from extirpation in the state.

Current Presence in California

After being absent for over 60 years, trumpeter swans began appearing again in California in the 1990s. These initial vagrants possibly wandered west from reintroduced populations in Nevada and Oregon.

Over the past three decades, the number of trumpeter swans observed wintering or even attempting to breed in California has gradually increased. However, there is still no established, self-sustaining wild population in the state.

Wintering Distribution

Most trumpeter swan observations in California still occur during the winter months. The Central Valley holds the majority of wintering trumpeter swans, especially in the following regions:

– Sacramento-San Joaquin Delta: Yolo Bypass Wildlife Area, Cosumnes River Preserve

– Northeastern Sacramento Valley: Sacramento NWR, Grey Lodge WA, Upper Butte Basin WA

– Suisun Marsh

– San Luis Refuge Complex

Coastal wintering is rarer, but flocks have been spotted at locations like Morro Bay, Crescent City Marsh, and Humboldt Bay.

The table below summarizes mid-winter trumpeter swan survey data from 2010-2020 to illustrate wintering distribution and trends in California:

The data indicate trumpeter swan wintering numbers have slowly increased in California over the past decade, particularly in Suisun Marsh and the San Joaquin Valley. However, wintering flocks rarely exceed 15-25 birds.

Breeding Attempts

There have been a few isolated reports of trumpeter swans nesting in northeastern California and the Sierra Nevada since the 1990s. But these nests have largely been unsuccessful at producing young.

The most consistent breeding attempt has been by a pair at Susanville Ranch Park in Lassen County. This pair has nested annually since 2003, although nests have usually been abandoned before hatching.

In 2015, a trumpeter swan pair did successfully hatch 3 cygnets at Eagle Lake in Lassen County, marking the first documented trumpeter swan breeding in California in over 75 years. However, these cygnets did not survive to fledge.

Successful breeding and recruitment of young swans in California has likely been hampered by the small population size, lack of suitable wetland habitat, and occasional hybridization with introduced mute swans.

Reintroduction Efforts

There have not been any large-scale trumpeter swan reintroduction programs initiated in California to date.

Small releases occurred at Sacramento NWR in 1987 (4 birds) and 1961-62 (27 birds). But these birds soon disappeared without establishing a population.

In 2012, the Yolo Bypass Wildlife Area raised and released 6 trumpeter swan cygnets. However, this one-time effort did not result in the birds returning to breed.

Some conservationists and wildlife agencies have suggested starting a more concerted trumpeter swan reintroduction program in California, likely using eggs from Alaska or Canada to establish captive breeding populations. But funding and logistical challenges have stalled any such plans from moving forward.

The lack of secure wetland habitat with sufficient food resources year-round is still a major obstacle to trumpeter swan reintroduction success in California. Large-scale restoration projects now underway, like the 2020 California Water Resilience Portfolio, may eventually create more suitable habitat conditions for trumpeter swans and other wildlife.

Legal Status and Conservation Outlook

Here is a summary of the current legal protections and conservation outlook for trumpeter swans in California:

– **State:** The trumpeter swan is listed as a State Threatened species in California, first receiving protection in 1983. This makes it illegal to hunt, pursue, or collect trumpeter swans in CA without a permit.

– **Federal:** Trumpeter swans are protected under the Migratory Bird Treaty Act of 1918 and the Bald and Golden Eagle Protection Act of 1962. Both acts prohibit killing, selling, or otherwise harming trumpeter swans, their nests, or eggs.

– **IUCN Red List:** Trumpeter swans are classified as Least Concern globally. But the isolated California flocks are listed as Critically Endangered.

– **Audubon:** California’s trumpeter swans are designated as a Red WatchList species, indicating it is a species of global conservation concern.

– **Wetlands:** Ongoing wetland restoration initiatives in the Central Valley and Suisun Marsh may create more wintering and breeding habitat. However, habitat availability remains a key long-term challenge.

– **Threats:** Small population size, hybridization with mutes, lead poisoning, and displacement by increasing mute swan populations remain threats.

– **Outlook:** Without a concerted reintroduction program, the return of wild trumpeter swans to California breeding grounds still appears a distant prospect. But continued growth of overwintering numbers could provide a foundation for future reestablishment.

Conclusion

In conclusion, trumpeter swans have begun returning to California after an absence of over half a century, but their presence remains small and sporadic. Establishing a truly wild, self-sustaining population breeding within the state will likely require a more concerted reintroduction strategy targeting key historical wetland strongholds, as well as continued habitat protection and restoration. With time, trumpeter swan bugles may once again trumpet from California wetlands as a symbol of ecological renewal.