Cat + patio = catio. It’s an outdoor enclosure for your cat! But...why? These elaborate structures—equipped with pagodas, picture frame cages, and suspended catwalks—might look like fancy play forts for your cat, but catios are actually "for the birds."

Here's the situation: of the injured animals annually brought to the Audubon Society's Wildlife Care Center, 40 percent received their wounds from cats—and of those injured, only 16 percent survive. Over the past 20 years, the Wildlife Care Center has documented around 20,000 cat-related intakes, with the majority of injured animals being birds. (The Audubon Society estimates domestic cats, "considered a global invasive species," kill up to 3.7 billion birds each year in the Lower 48.)

Now in its fourth year, the Annual Catio Tour (Saturday, Sept. 10)—a partnership between the Feral Cat Coalition of Oregon and the Audubon Society of Portland—hopes to raise awareness for cat-related wildlife injuries. See our slideshow above of this year's stops: eight of Portland’s most impressive catios.

“The fewer cats we have free-roaming the better for the cats—and it’s better for wildlife because there is less predation from cats,” says Karen Kraus, Executive Director of the Feral Cat Coalition of Oregon.

The self-guided tour will have you exploring four houses in SE Portland, three in SW and one at the Oregon Yacht Club (it’s on a boat!). With registration, each guest receives a guidebook with information about each tour stop and tips on for creating your very own catio. 

The 4th Annual Catio Tour takes places from 10 a.m. to 2 p.m. on Saturday, Sept 10.