Wrens: Troglodytidae

Physical characteristics: The cactus wren measures in length from about 7.2 to 8.5 inches (18 to 21.6 centimeters) and is the largest species of wren in North America. In color, the bird is a chocolate brown on top with a plain cap. Its back is streaked very prominently in black and white, and the wings, which can spread to a length of 10.7 inches (over 27 centimeters), are barred with buff and black tones. The tail feathers vary between having blackish brown and gray-brown bars. The outer tail feathers are very noticeably barred black and white. The underparts of the bird are buff-white and are spotted heavily with black, especially on the chest. Eyes are reddish brown with a dull black bill that has a paler base. Its legs are a pinkish brown. Cactus wrens make their nests in the spiny cactus, and also eat cactus seeds and fruit, in addition to the animals they prey on. (Illustration by Barbara Duperron. Reproduced by permission.) Both sexes are similar in appearance. The juvenile bird has spots and streaks that are not as defined as the adult, and its eyes are muddy gray-brown.

Geographic range: Cactus wrens can be found from southeast California to southwest Nevada, and into southern Arizona and New Mexico, as well as southwest Texas through central Mexico. Cactus wrens are also throughout the Baja California peninsula.

Habitat: Cactus wrens inhabit areas that are desert or semi-desert; they also live along arid hillsides and locales that provide them with vegetation such as spiny cacti (KACK-tie, or KACK-tee) and cholla, which is used for nesting.

Diet: Cactus wrens are primarily carnivores (meat eaters), eating invertebrates, animals without a backbone, such as ants, wasps, spiders, and caterpillars, as well as small frogs and lizards. The vegetable matter they consume includes cactus seeds and fruit. They will visit bird feeders and eat pieces of bread and slices of potato or raw apple. They do not need to drink but will if water is available. They tend to be ground feeders, overturning ground litter and stones in order to find their prey.

Behavior and reproduction: Cactus wrens live in pairs or small family groups. When the bird is disturbed, it will run on the ground like a thrasher rather than fly. These birds are often unruly and noisy, with a song that is a loud, harsh series of "jar-jar-jar" notes, usually delivered from the top of a cactus or other perch.

The cactus wren is monogamous (muh-NAH-guh-mus). The breeding nest is an oval-like ball with a side entrance hole that is made of dry grasses and fibers lined with feathers. They are usually located right in spiny cacti and no effort is made to hide them. The female usually lays three to five eggs, though the number can range from two to seven, and they are light brown or pinkish in color with tiny speckles of reddish brown. The female alone incubates the eggs in a period that can last sixteen days. The newly hatched and young birds are fed by both sexes for nineteen to twenty-three days. The cactus wren might attempt up to six broods a year, though usually only three of those are successfully reared.

Cactus wrens and people: The cactus wren is a popular bird for observation due to human familiarity in its habitat. It has been recognized as the state bird of Arizona.

Conservation status: The cactus wren is not a threatened species, and in the most favorable habitats is one of the most common. This adaptable bird seems to need only spiny cactus in order to thrive. ∎