Chicago's Lincoln Park Zoo will offer a foreboding new exhibit Thursday on the birds and the bees.

Hundreds of free condoms, themed around endangered species like the horned lizard and monarch butterfly, will be given away at the city's free zoo as part of a program created by the Center for Biological Diversity to bring awareness to the effect of human population growth on wildlife.

The colorful condom packages include species threatened by population growth, the zoo says, and slogans like “Wrap with care, save the polar bear” and “When you’re feeling tender, think about the hellbender.”

“As our population grows, and urban sprawl and agricultural development destroy wild spaces, species we know and love pay the price,” said Sarah Baillie, a population and sustainability intern at the center, in a statement. “People may recognize that we’re crowding out monarch butterflies and horned lizards, but they often don’t realize that there’s a big way individuals can make a difference. Pillow Talk helps people understand how conscientious family planning can protect wildlife.”

The event is part of the center’s Pillow Talk program coupling with zoos, museums and science centers across the country.

The program’s launch is in honor of World Population Day (July 11). World Population Day was designated by the United Nations in 1989 to raise awareness about global population issues, the center said in a release.

In the past 50 years, as human population has more than doubled, wildlife populations have been halved, the center says. The United Nations predicts that global population will reach 9.8 billion by 2050 and exceed 11 billion by 2100. In May the population of the United States surpassed 325 million.

“There are more than 7.5 billion people on the planet, with the United States ranked as the third-most populous country,” the release reads.

Pillow Talk uses “creative media” to promote access to family planning and reproductive health services, as well as equal rights for women and girls, the center says.

The Center for Biological Diversity is a nonprofit conservation organization with more than 1.3 million members, it says.

The Pillow Talk event is open to adults 21 years and older.