Cactus wren

The largest wren in the U.S., which jams a football-shaped nest deep inside a cholla cactus's own thorns for protection.

Cactus wren at a glance

Campylorhynchus brunneicapillus CAK-tus wren; Campylorhynchus brunneicapillus is kam-pih-loh-RINK-us broo-nee-kap-ILL-us

Type
Bird · wren
Diet
Insectivore
Size
About as long as an unsharpened pencil (7.1 to 8.7 inches / 18 to 22 cm), and light enough that four or five of them together would barely outweigh a stick of butter (1.2 to 1.7 ounces / 33 to 48 grams each).
Lifespan
Most live only a few years in the wild. Bird-banding records list the oldest known individual at more than 8 years old.
Conservation
Least concern

Eats ants, beetles, grasshoppers, wasps, spiders, some cactus fruit and seeds

A cactus wren forages almost entirely on the ground, walking and hopping under shrubs and cactus, flipping leaf litter and small rocks aside with its bill to expose insects hiding underneath. It also works low branches and cactus pads for the same prey, and will eat cactus fruit or seeds when insects are scarce.

Should you worry?

None. A cactus wren is small, loud, and bold around people at picnic areas and campgrounds, but it has no interest in a person beyond stolen crumbs. The only real hazard is the cactus its nest sits inside; don't reach in after it.

Wedged three to ten feet up in the tangled middle of a cholla’s spines sits a nest the size and shape of a football, its only opening a narrow tunnel too small for anything but the bird that built it. Before a family spots the nest, they’ll hear the builder: a raspy, mechanical “char-char-char,” repeated eight or ten times in a row, like a car engine that won’t turn over.

The cactus wren turns the thorns into its own defense system. A pair picks the spiniest, most tangled part of a cholla or other cactus and packs grass and feathers into a chamber deep inside, where the plant’s own barbs block snakes, roadrunners, and anything else too big to squeeze through that tunnel entrance behind the bird.

One nest is rarely the whole story. Cornell’s Birds of the World breeding account describes cactus wren pairs building extra nests around the same territory all year, structures they never lay a single egg in but use to sleep in overnight, and biologists think the decoys exist to confuse any predator hunting for the one nest that actually holds the eggs. Find three football-shaped nests in the same patch of cholla, and odds are only one of them has ever held a chick.

Did you know?

  • The cactus wren's song is a raspy, mechanical-sounding series of "char-char-char" notes, repeated 8 to 12 times, that carries up to 1,000 feet across open desert. Many desert visitors describe it as sounding like a car engine that won't turn over.
  • A cactus wren pair defends the same patch of desert, roughly 3 to 5 acres, together all year. They don't migrate and don't really leave.
  • It's the largest wren in the United States, noticeably bigger and chunkier than the house wrens and canyon wrens that share its range.

Common questions

Why does a cactus wren build its nest inside a cactus?

The spines protect the eggs and chicks from snakes, roadrunners, and other predators that would otherwise raid the nest. The wren squeezes through a narrow tunnel entrance that most other animals can't follow it through.

What does a cactus wren sound like?

A harsh, repeated "char-char-char," often compared to a car engine that won't start. You can hear it well before you see the bird.

Are cactus wrens dangerous to kids?

No. They're small, loud, and unafraid of people, but they don't attack or bother anyone. Just don't reach into a cholla after one.

What do cactus wrens eat?

Mostly insects and spiders, found by flipping over leaves and small rocks on the ground. They'll also eat cactus fruit and seeds.

Does a cactus wren build more than one nest?

Yes. Beyond the nest where it actually raises chicks, a pair builds extra "dummy" nests nearby to sleep in and, biologists believe, to confuse predators looking for the real one.

Where it lives

Where we got this