Cactus Wren

The cactus wren is the largest wren in the United States. It is between 18 and 19 cm (7.1 and 7.5 in) long, and weighs between 33.4 and 46.9 g (1.18 and 1.65 oz), with an average of 38.9 g (1.37 oz). It has a thick, heavy bill that is dull black, curves slightly downwards, and is about the same length as the head. The lower mandible is grayish and pale, and the tail is long and rounded. The cactus wren's coloration is brown with white speckles. The crown is chocolate-brown with a light red tinge. A distinctive white supercilium (eyebrow) runs from the bill to the nape of its neck, which is brown with white markings. The chin is white, while the neck has black markings on a mostly white background. Their chest is white with brown or black speckles, and the belly is generally white with some brown or black streaks. The rump and back are gray to brown with white and black streaks. Both the lower underparts and the flanks are cinnamon-buff colored. The cactus wren's ten primary and nine secondary flight feathers are barred, alternating between black and off-white. Its twelve rectrices are barred, alternating between brownish-black and pale gray-brown. The outer rectrices are white tipped. When flying, a white band can be seen on the underside of the tail feathers. The tail is barred in alternating stripes of black, white, and brown. …

The cactus wren is a bird of arid and semi-desert regions, and generally requires spiny cacti to nest in. Its range includes the Sonoran and Chihuahuan Deserts. The cactus wren is not migratory, and establishes a permanent territory which it defends vigorously. Territories are typically 1.3 ha (3.2 acres) to 1.9 ha (4.7 acres). The size and shape of territories change very little throughout the season. Territory is defended from other birds by fluffing tails and feathers and vocal scolding. Persistent trespassers may cause the wrens to give chase. The cactus wren is found only in the United States and Mexico. In the U.S., it is present in California, Nevada, Utah, Arizona, New Mexico, and Texas. In California, it is found mainly as southern coastal populations existing below 600 m (2,000 ft), but some have been found up to 950 m (3,120 ft). Nevada represents the northernmost extent of its range; it is found in the southern tip of the state and the northernmost breeding population is found in Nye County, near Tonopah. In Utah, it is found only in the extreme southwest. Its range in Arizona is widespread in the southern part of the state and along the Colorado River, where it is found from sea-level up to 1,400 m (4,600 ft). Populations in New Mexico exist in the south, down to along the Rio Grande and into Mexico. Its range in both New Mexico and Texas may be expanding northward. …

Cactus wrens generally feed and live in pairs, or in family groups from late spring through winter. Flocks of cactus wrens have been reported, and are pretty common. Flocking has been observed only in areas of abundant forage and does not last longer than a few hours. As ground feeders, they spend much of their time on the ground and are not strong fliers, with any flights being somewhat erratic – switching between rapid wing flapping and gliding.

Breeding and nesting. Cactus wrens form permanent pair bonds, and the pairs defend a territory where they live year-round. There is a distinctive greeting ceremony between pair members, where they spread their wings and tails and give a harsh call. The same motions are used as a breeding display, but with a non-ritualized duet call. Since males and females are identical, birds recognize members of the opposite sex not by size or color but by behavioral differences. Males are more aggressive and are more frequent singers. Mating displays begin with a growl-like noise, and end in gentle pecking. Displays are much shorter than in most bird species, lasting only two to three seconds. Mating season begins in late February and runs through March. Nests are built in cacti (commonly cholla, prickly pear, and saguaro), thorny desert trees, or yucca. Where available, jumping cholla is overwhelmingly preferred. …