Habitat
Cactus Wrens live in scrubby areas in the Chihuahuan, Sonoran, and Mojave Deserts as well as in coastal sage scrub in California and thorn-scrub areas in Tamaulipas, Mexico. They inhabit areas with cholla, saguaro, and prickly-pear cacti, catclaw acacia, mesquite, whitethorn, desert willow, yucca, palo verde, and other desert shrubs. Small patches of prickly-pear and cholla cacti mixed with short sagebrush and buckwheat are great spots for Cactus Wrens in coastal California and northwestern Baja California, Mexico. Back to top
Food
Cactus Wrens eat mostly spiders and insects such as beetles, ants, wasps, grasshoppers, and butterflies. They find these while hopping on the ground and turning over leaves or by searching bushes and tree bark. Cactus Wrens also eat fruit, particularly cactus fruits. They get the majority of their water from the food they eat and rarely drink free-standing water. Back to top
Nesting
Nest Placement
The female initiates nest building, but after she selects the spot, the male jumps in to help out. They build the nest 3–10 feet above the ground in a cholla, palo verde, acacia, mesquite, or other desert vegetation where the nest is surrounded by thorns.
Nest Description
Male and female Cactus Wrens build large football-shaped nests with tunnel-shaped entrances. The pair amasses coarse grass and plant fibers to create a nest about 7 inches in diameter and 12 inches long, which weighs in at 6 ounces. The entrance is very small—large enough for the parents to squeeze in, but small enough to keep most potential predators out—and often necessitates a "doorstep" or perch near the entranceway, as the narrow entry may even be too small for a flying bird to easily gain entrance. Once inside, the passageway to the nest widens. The birds line the inside of the nest with feathers. The pair builds the nest in 1–6 days, but most of the construction takes place within the first 3 hours of each morning.
Nesting Facts
Clutch Size: | 2-7 eggs |
Number of Broods: | 1-3 broods |
Egg Length: | 0.8-1.0 in (2-2.6 cm) |
Egg Width: | 0.6-0.7 in (1.5-1.8 cm) |
Incubation Period: | 16-17 days |
Nestling Period: | 17-23 days |
Egg Description: | Salmon pink to buff with reddish brown spots. |
Condition at Hatching: | Mostly naked with patches of fluffy white down along spine, wing edges, and head. Eyes closed. |
Behavior
Cactus Wrens are inquisitive wrens that make their presence well known, singing atop tall shrubs and hopping around on the ground in the open. Cactus Wrens are active all hours of the day and spend most of their time foraging in open areas, but they move into shady areas to forage when temperatures increase. Unlike most birds, they use their nests year-round, not just for breeding. After sunset they head back to their nests for the night. They are not particularly strong fliers and generally make jerky flights alternating between rapid wingbeats and short glides. Adults pair up for the breeding by first uttering a growling sound with their wings and tail spread before they gently peck each other. In extreme droughts some pairs may forgo breeding, but in normal conditions, Cactus Wrens breed every year and sometimes raise 3 broods in a season. They defend their territories year-round. When another bird enters their territory, they spread their tails, fluff up their feathers, scold, and even give chase. If they discover a predator such as a snake near their nest they will scold and mob the predator. Snakes, domestic cats, hawks, and Greater Roadrunners prey on adults, eggs, and nestlings. Back to top
Conservation
Cactus Wren populations declined by approximately 1.3% per year resulting in a cumulative decline of about 51% from 1966 to 2019, according to the North American Breeding Bird Survey. Partners in Flight estimates the global breeding population at 8.5 million and rates them 12 out of 20 on the Continental Concern Score. It is included on the list of Common Birds in Steep Decline for species that are still too numerous or widely distributed to warrant Watch-List status but have been experiencing troubling long-term declines. If declines continue at the present rate, their numbers will be halved in 20 years. Urban and agricultural expansion threaten Cactus Wren habitat especially when cacti and desert shrubs are lost altogether.
Back to topCredits
Hamilton, Robert A., Glenn A. Proudfoot, Dawn A. Sherry and Steven L. Johnson. (2011). Cactus Wren (Campylorhynchus brunneicapillus), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.
Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.
Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.
Rosenberg, K. V., J. A. Kennedy, R. Dettmers, R. P. Ford, D. Reynolds, J. D. Alexander, C. J. Beardmore, P. J. Blancher, R. E. Bogart, G. S. Butcher, A. F. Camfield, A. Couturier, D. W. Demarest, W. E. Easton, J. J. Giocomo, R. H. Keller, A. E. Mini, A. O. Panjabi, D. N. Pashley, T. D. Rich, J. M. Ruth, H. Stabins, J. Stanton, and T. Will (2016). Partners in Flight Landbird Conservation Plan: 2016 Revision for Canada and Continental United States. Partners in Flight Science Committee.
Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2019). The North American Breeding Bird Survey, Results and Analysis 1966–2019. Version 2.07.2019. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.