It causes up to one billion deaths a year, perhaps even more, and they are preventable.

That is the number of birds killed by crashing into windows.

Dr. Daniel Klem, Jr., Sarkis Acopian Professor of Ornithology and Conservation Biology at Muhlenberg College, describes the problem and gives solutions in his book “Solid Air: Invisible Killer- Saving Billions of Birds from Windows” (224 pages; $24.95, print; $9.95, digital; 2021).

“There were many reports about the number of birds killed due to the Exxon Valdez oil spill of 1989. But each year, one million birds die from collisions in the U.S. alone. It is the equivalent of at least 333 Exxon Valdezs, and there is no one talking about windows,” says Klem in his Muhlenberg office.

“It is a universal tragedy that is occurring everywhere,” says Klem.

“Every bird species is vulnerable. The victims have no one but us to speak for them.

“We know how to solve this. We can do it. We just have to have the will, and be convinced that the effort is worthwhile and meaningful.”

This might be seen as a mostly urban problem caused by tall, glass-fronted buildings.

However, Smithsonian research in 2014 found that less than one percent of the fatalities are caused by skyscrapers. The research states that 44 percent of the casualties came from collisions into buildings one to three stories high.

A 2019 study published in the journal Science states that the North American bird population has decreased by 2.9 billion breeding adults since 1970. Habitat reduction is responsible, as well as window crashes. Cats also contribute.

Klem believes that the threat of cats has been overstated since many of the birds captured have already been killed or injured by flying into buildings or homes.

“Cats, like all predators, look for the weakest prey,” says Klem, adding that, looking at the numbers, “there is astronomically more plate glass than cats.”

Klem notes that whenever people tell him they do not have a bird-window problem, he finds evidence like skeletons when he visits their home, and tells them whenever they hear a bump against a window it is likely to be from a fatal or injurious contact.

The book lists a number of easy and inexpensive solutions for homeowners. Tape, blinds, curtains, shades, screens and even tempura paint can be used. “These are not as visually invasive as people think. They are not obstructive at all. People can see through them,” he says.

Retrofitting, or fixes to standing structures, are what he calls short-term solutions.

Long-term solutions described in the book involve architectural design for window placement and the type of glass used in construction. Certain films, or patterns built into windows, can make them visible to birds.

One method that shows promise is the use of ultraviolet light reflection. “It is an elegant solution that is still a work in progress,” he says.

“Solid Air” reflects the 48 years of research Klem has done since he became a professor at Muhlenberg in 1979. But even though it contains an extensive bibliography, the book is not weighed down by scientific jargon.

“I’m trying to reach the everyday person. I’m not telling people what to do. I’m just sharing information. And I use some humor to capture people’s attention.”

The book tells about the challenges Klem had trying to raise awareness of the bird-window problem. “It took years to get my colleagues to accept my publications for review,” he says.

Klem, who lives with his wife in Upper Macungie Township, is especially hopeful the problem will be solved because of the young scientists who have been attracted by his research.

He ends the book with the words: “There have been many successes dealing with the bird-window issue, and they are growing ... I am confident we will make our windows safe for birds because it is the right thing to do.”

“Literary Scene” is a column about authors, books and publishing. To request coverage, email: Paul Willistein, Focus editor, pwillistein@tnonline.com