Cape Thick-knee

Cape Thick-knee

[ Burhinus bistriatus ]

Quick Facts

BODY LENGTH: 18 inches 
WILD DIET: chopped smelt, soaked dog chow, raw ground meat, crickets, and mealworms
ZOO DIET: small animals, including worms, rodents, snakes, insects, and mollusks
DISTRIBUTION: southern Mexico and Costa Rica, along the Caribbean coast of South America, in northern and eastern Colombia, and in northwestern Brazil; they have also been reported in southern Texas; thick-knees are not endangered
HABITAT: open dry desert, grassland, or savannah, usually with lots of stones and pebbles


Ground-Dwelling Desert Birds

The name game
Although their name gives no clue as to what kind of animal they are, "cape thick-knee" describes these birds rather well. They are large desert birds---about 45 cm (18 inches) long---with black stripes along the tops of their eyebrows, and thick "knee" joints. But what looks like their knees mid-way up their legs are actually their heels! They have long legs and weak wings and so prefer running to flying. When threatened, they lower their heads and hit the sand running!

Nighttime is the right time
Cape thick-knees are active mainly at night (they are nocturnal), a strategy that allows them to avoid the heat of the day. During the day they crouch on the ground, depending on their brown plumage to help them blend into their stony desert habitat. At dusk, thick-knees become active. You can hear their loud, high-pitched repetitive screams, from two kilometers (more than a mile) away.

Sand, stones, and seasons
Cape thick-knees live in open, dry country that ranges from sandy desert to stony grassland, to savannah. Sometimes they live on farmland and ranches, and generally do well in areas that have been deforested.

These birds usually nest during the driest part of the year, in April or May. A breeding pair will lay two brownish-green, blotchy eggs in a simple hole in the ground. Males sit on the nest to incubate the eggs more often than the females do.

Worms are yummy
Being ground-dwellers, thick-knees eat small animals they find on or under the ground. Almost any small creature is fair game, including insects, mollusks, lizards, frogs, snakes, rodents, and of course---worms.

A midwestern relative
cape thick-knees do not live in the midwestern U.S., their close relative, the killdeer, does. Killdeer look a bit like miniature thick-knees, and the two species have similar nesting habits, vocalizations, and habitat preferences. You can commonly see killdeer in flat, pebbly open habitat across most of the U.S.

Cape thick-knees at Brookfield Zoo
You can see cape thick-knees in the desert aviary in Feathers and Scales: Birds and Reptiles. Usually you can get right up to the front of the exhibit, so it should be easy for you to see these very large birds.

Get Involved

Conservation Fund of the Chicago Zoological Society