A new law in California will allow year-round killing of non-native swans starting next year – a move that some officials have said is essential to protect the state’s already diminished wetlands and native waterfowl, but which others have labeled as “inhumane”.
Mute swans, which have been valued as ornamental birds, have rapidly expanded across California, where wildlife officials say they degrade habitats and aggressively displace native species.
Assembly bill 764, signed into law by California’s governor Gavin Newsom earlier this month, adds mute swans to the list of invasive birds that can be hunted with few restrictions, joining the English sparrow and starling. The law goes into effect on 1 January.
“The challenge is that their numbers have proliferated and they do a lot of damage to the wetlands,” said Peter Tira, information officer at the California department of fish and wildlife (CDFW). “California has lost between 90 and 95% of its historic wetlands, and these birds occupy those wetlands and do a lot of damage.”
Mute swans can alter wetlands when they move into areas where they have not previously been.
“Because they’re big birds, they do tend to consume quite a lot of vegetation,” said Margaret Rubega, an ornithologist and professor of ecology and evolutionary biology at the University of Connecticut. “They eat aquatic vegetation, stuff that will grow with its roots underwater, and they not only eat a lot of it, but they will tend to dig it up at the roots, so they’re disturbing the bottom.”
“They really have the capacity to alter the nature of the wetland a lot, and in a way that will change it for, not only the other birds, but for all kinds of other plants and animals,” added Rubega.
Once they establish a territory, especially during breeding season when they are protecting eggs or chicks, mute swans aggressively chase away other birds that enter their feeding area.
“It’s sort of like the equivalent of taking a 17-year-old high school student and putting him in the school yard at a middle school,” said Rubega. “He’s going to win every encounter.”
According to a statement by the CDFW, mute swans are not protected under the federal Migratory Bird Treaty Act since they were introduced to North America in the mid-1800s.
Mute swans are native to northern and central Eurasia and were brought to the United States by private breeders. Photograph: Dave Stevenson/Alamy
Republican Jeff Gonzalez authored the bill, with sponsorship from the California Waterfowl Association, a non-profit that advocates for hunting and waterfowl conservation in California. The bill also received support from the American Bird Conservancy, the Grassland Water District, the Tulare Basin Wetlands Association and others.
Besides licensed hunters, the law allows property owners and their tenants with written permission to hunt mute swans without a license.
Mute swans are native to northern and central Eurasia and have been domesticated in western Europe since the 12th century. They were brought to the United States by private breeders to be displayed in zoos, public parks and on private estates. Some escaped captivity, while others were released on purpose.
“For a lot of folks, the idea that they’re not native is sort of tenuous,” Rubega said. “If it’s been around your whole life long, you think of that as one of our birds. They’ve been in North America for a very long time.”
According to Tira, the second-largest threat to California’s native species, after habitat loss, is invasive species.
“This is certainly a problematic species, but now there’s at least one tool to help address it,” Tira said.
Not everyone supported the bill. Friends of Animals, an animal advocacy group based in New York, released a statement in August urging Californians to call and write their representatives to oppose the bill, which they called “inhumane”.
“It is a desperate attempt by a dying hunting industry to add another ‘bird to the bag’, and we won’t stand by and let it happen!” reads the statement.
These swans are currently still bought in some states for aesthetic landscaping, to control aquatic vegetation or to rid other waterfowl. In California, mute swans are listed as a restricted species and cannot be imported, transported or possessed without a permit, according to the CDFW page.
Mute swans eat up to 8lbs of vegetation per day, and weigh 25-30lbs. They can grow up to 5.5ft in length, with a wingspan up to nearly 8ft. They have caused serious injuries to children and pets, according to CDFW.
“When they have eggs or they have chicks, they are very aggressive indeed and perfectly capable of hurting a human,” Rubega said.
“They’ll definitely come at you, not only with their beak, but they’ll sort of raise their wings and flap the front edge of their wing at something they consider to be invading their territory. They’re capable of breaking your wrist by whacking you.”
