Your tax dollars are funding research on the sex lives of squirrels. (ABCNEWS.com)

Last year, American taxpayers funneled nearly a trillion dollars into the U.S. treasury. Hundreds of millions of those dollars funded scientific research aimed at finding a cure for cancer, heart disease and Alzheimer's disease. But millions of American tax dollars have also been spent on studies that critics say have little benefit for taxpayers.

The study about the evolution of squirrel breeding is a prime example. Government waste groups contend that studying the sex habits of African squirrels is exactly the kind of research taxpayers shouldn't be paying for.

"Squirrel mating seems to be on the low end of the priority scale ... with all the other priorities in this country," said Tom Schatz, president of the Washington-based Citizens Against Government Waste, the nation's largest taxpayer advocacy group. "People are dying of heart disease, cancer, Parkinson's and AIDS and we're looking at how squirrels mate."

In the first of a three-part Good Morning America series, called "You Paid for It," ABCNEWS' Bob Woodruff took a look at some of the things your tax dollars are paying for.

Studying Sex and Squirrels

Jane Waterman is the researcher studying squirrels, through a National Science Foundation grant. The University of Central Florida biologist travels to Africa as part of a five-year project to observe ground squirrels.

"What I study is sex and squirrels," Waterman said.

She says the furry animals are fascinating because male African squirrels are so friendly to each other. They only time they spend with females is for sex and they don't fight over females as American squirrels do.

"They hang out in large male bands and they like each other," she said. That is a remarkable thing to see in a ground squirrel and a mammal. Waterman believes that studying the evolution of squirrel breeding gives us a better understanding of our environment, and ourselves.

Be that as it may, Waterman's critics argue that taxpayers should not be footing the $600,000 bill.

"Haven't these guys heard of private universities, private endowments, private foundations," asked Pete Sepp of the National Taxpayers Union. "There are lots of people interested in these issues but there are 120 million taxpayers who want to know why are we funding this?"

Study Looks at Monkey Anxiety

At the Oregon Health and Science University in Portland, monkeys are part of a taxpayer-funded study to determine if shyness in children can lead to depression later in life. In one of the studies, researchers startled monkeys with toy cars to measure how threats affect anxious behavior.

Researchers also flew gliders over the monkey's heads, monitoring their heart rates and conducting blood tests to measure anxiety levels.

Dr. Judi Cameron, the researcher conducting the monkey studies, declined an interview.

But the university said that her work is of tremendous scientific and clinical value in trying to uncover the causes of anxiety and depression in children. Cameron is testing new medications to reduce anxious behavior.

‘Priorities Out of Whack’

Federal tax dollars have also funded 92 studies on pigeons since the early 1970s. The studies, funded by the National Institute of Mental Health, have focused on how pigeons learn, and what they are thinking. Critics say while pigeon studies are funded, other studies involving mental illness that affect millions of Americans have been rejected.

"The average citizen would be shocked at what their money is being spent on," said Dr. E. Fuller Torrey, president of the Treatment Advocacy Center in Arlington, Va. "They've turned down projects on the mentally ill homeless. They've turned down projects on developing new medications that would be useful for people with schizophrenia, manic-depressive illness."

Torrey issued a report in 1999 that showed a little more than a third of your tax dollars go to researching serious mental illness.

But Torrey found that mental health funds are being used for other kinds of studies. The government spent $210,000 in tax funds to study music, looking at the timing, dynamics and articulation that make music expressive. Another $200,000 was spent on analyzing adolescent romantic relationships. Plus, there was $68,000 to study sentence processing in Japanese and English, and the interaction of grammar in particular languages.

"I think anyone would say the priorities are really out of whack here," Torrey said. "Something's wrong."

In a statement, the National Institute of Mental Health said that it funds more than $103 million in major studies to find treatments for schizophrenia, depression and other diseases. The institute also says that the research on animals has paid off. By studying birds, scientists have figured out how the human brain generates new nerve cells.

Researchers say that mankind will not progress without money to fund basic science. A mission that may sound odd to outsiders has a different meaning for scientists, the squirrel researcher said.

"We need to have a broader view of our exploration of the universe," Waterman said.