State legislation signed into law earlier this month will allow invasive mute swans to be taken or possessed at any time by those with a valid California hunting license beginning Jan. 1, 2026.

The legislation, which has a sunset date of Jan. 1, 2031, was introduced to address the growing concerns about the spread of these destructive, non-native species throughout the state.

Mute swans now join the short list of invasive nongame birds – the English sparrow and the European starling being the two others – listed in the California Fish and Game Code, Section 3801 that can be taken at any time by licensed hunters. Landowners and lessees may also take or possess mute swans at any time without needing a hunting license or depredation permit.

Mute swans were first detected in the Suisun and Napa marshes during the California Department of Fish and Wildlife’s (CDFW) annual Waterfowl Breeding Population Survey in 2007. Since that time, they’ve expanded their range with the most current population estimate at 6,900 birds. Mute swans are regularly reported to the CDFW’s Invasive Species Program and Waterfowl Unit as they are classified as a restricted and detrimental species unlawful to import, transport or possess under the California Code of Regulations, Title 14, Section 671.

Mute swans are generally nonmigratory and present year-round. They are not protected under the federal Migratory Bird Treaty Act unlike native waterfowl species since mute swans were introduced from Europe to North America during the mid-1800s and considered highly invasive.

Mute swans are very territorial, aggressive and do not typically intermix with other wintering waterfowl. Mute swans prefer permanent and semi-permanent wetland habitat feeding primarily on submerged aquatic vegetation. These habitats are limited in California and are essential for many sensitive native species as well as for breeding ducks and other wetland-dependent birds.

AB 764 was introduced by Assemblymember Jeff Gonzalez, R-Indio, and sponsored by the California Waterfowl Association to provide additional tools to control this invasive species population. Governor Gavin Newsom signed the bill into law Oct. 6.

The public is encouraged to report the take or possession of any mute swan to CDFW’s Invasive Species Program online or by e-mail at invasives@wildlife.ca.gov.

More information on mute swans is available at CDFW’s Invasive Species Program web page, including a Swan Identification Sheet to help distinguish mute swans from native tundra and trumpeter swans, which cannot be hunted, taken or possessed at any time in California.