Denver’s resident Canada geese could be saved from a summer culling this year thanks to several control strategies and the potential impact of the ongoing avian flu outbreak.
In 2019 and 2020, over 2,000 geese were killed in a controversial effort to control the population of year-round residents of Denver’s parks, and after two years of not needing the culling, this year is “looking pretty good” for the geese as well.
Denver Parks and Recreation, in partnership with the U.S. Department of Agriculture’s Wildlife Services, used all the nonlethal control strategies under their management program in 2022, including hazing, egg oiling and coyote decoys, said Denver Parks and Recreation’s Wildlife Program Administrator Vicki Vargas-Madrid, and saw only a small increase in the resident geese population over the past year.
“Looking into 2023, a lot of people are asking if we’re going to use ‘lethal control’ (culling) in 2023, and the answer to that is: ‘We don’t believe so’,” Vargas-Madrid said.
The USDA is still gathering the statistics for the 2022 goose populations for Denver’s various parks, but Vargas-Madrid said a lot of factors point to the control strategies being successful in stabilizing the city’s parks.
Negative human-geese interaction complaints and damage to parklands have decreased, and water quality in parks has improved.
“It’s looking pretty good,” Vargas-Madrid said. “We’re seeing more of a stabilization in our populations, so they’re not growing fast every year. There’s just a small increase in the resident populations.”
That small increase in populations is due to Denver Parks and Recreation hazing more than 100,000 geese in 2022 and oiling about 1,300 eggs.
Hazing of geese involves using a remote-controlled Goosinator machine to create an environment that feels unsafe for the geese
to reside permanently, and oiling eggs halts egg development and decreases the number of goslings hatched in the parks.
Another factor that could limit population growth and prevent the need for culling is avian flu. Highly Pathogenic Avian Influenza, which has already affected over 58 million poultry in the United States, has spread to wild birds and affected over 6,000 birds.
In Colorado, 162 have been affected, according to the USDA; 23 of those are in Denver.
Vargas-Madrid said Denver’s geese population is being affected and some geese are dying of the flu. It’s hard to say, though, how much the resident geese are affected since avian flu arrived in Denver in winter, the same time a large number of migratory geese arrived as well.
“Avian flu is affecting both migratory and resident goose populations,” she said. “Right now we have both of those populations hanging around in our parks, and right now is when we’re seeing the dead geese.”
If the flu had arrived in summer, officials would be able to see how much the resident goose population was affected, but for now, Vargas-Madrid said, they’ll just have to wait until the migrating geese leave to determine how hard the residents were hit.
“All we can say right now is we think that it’s impacting and keeping the population from growing,” she said. “Hopefully, we can add that data to what we collect throughout the year and show that the population isn’t growing as fast as it has in the past.”
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