Wind energy proponents brushed off Republican presidential nominee Donald Trump's latest attack on wind farms a day after he declared that wind power "kills all your birds."

Speaking in Pennsylvania Monday night, Trump railed against solar and wind power, especially the latter. Trump, who has a history of fighting wind turbine projects near his golf course in Scotland, claimed wind turbines are destroying bird populations.

"The wind kills all your birds. All your birds. Killed," he said. "You know the environmentalists never talk about that."

The U.S. Fish and Wildlife Service estimates about 500,000 birds are killed by wind turbines every year. By comparison, house cats kill about 2.4 billion birds each year, according to a 2014 report by the Nature Conservancy.

David Ward, director of public affairs at the American Wind Energy Association, argued wind power has one of the lowest impacts on wildlife among any form of energy generation.

He said Trump's statements about wind turbines' appearance — Trump said wind turbines are "driving you loco when you look at them" because they are ugly — are not necessarily representative of the rest of the population, either.

"Wind turbines help keep the family on the farm and keep the farm in the family. They are good for the economy by producing clean electricity that is two-thirds cheaper over six years, keeping more money in the pockets of consumers, and support a record-high 88,000 jobs," Ward said.

"Polls shows 91 percent of likely voters favor 'expanding wind power,' that includes 81 percent of self-described conservatives."