Living in desert landscapes, there may be a lack of conventional nesting sites and opportunities to gather materials needed to craft a suitable shelter in which to raise young.
But cactus wrens have mastered the art of adapting to their inhospitable surroundings by creating some particularly impressive predator-proof nests. Keep reading to find out all you need to know about cactus wren nesting habits.
As their names suggest, the natural habitat of cactus wrens is a landscape dominated by cacti and thorny desert plants. As well as feeding in desert landscapes, cactus wrens construct their intricate and unique nest structures on top of cacti and other similar vegetation.
Cactus wrens’ nests are made from a collection of grasses and twigs, crafted together into football-shaped nests, with an inner chamber linked to the outside world by a narrow passageway.
They navigate the prickles and cactus spines to create several nests during a breeding season, which are then used not only for breeding but double up as comfortable and safe roosting spots.
To learn more about how cactus wrens successfully raise young in such hostile arid landscapes, please read on.
Cactus wren nest in cholla cactus
Cactus wrens breed in arid scrubland in the southwestern United States. Elaborate nest constructions are built on cacti and other thorny desert vegetation and used not only for raising young, but also for overnight roosting outside of the breeding season.
Cactus wrens make their nests in cactus plants, particularly jumping cholla, prickly pear and saguaro, as well as in yucca and other native thorny desert vegetation.
Multiple nests are usually built during a single breeding season and nests from previous years are never reused. Some structures may be used as adult roosting nests, and are not as sturdy as the nests that are used for raising young. A fresh nest is constructed for each new brood.
In arid regions, where a backyard contains desert plants, such as jumping cholla and prickly pear, it could certainly prove attractive to nesting cactus wrens.
Xeriscaped landscapes (land that does not need to be irrigated) are particularly attractive to cactus wrens, and planting backyards with drought-resistant plants is a trend enjoying a popularity surge in parts of the southern U.S.
Cactus wren during nest building - In Arizona's Sonoran desert
On rare occasions, cactus wrens have been reported to have set up home in artificial nest boxes, where the structures are placed in cactus-rich scrubland.
Typically the species will construct their own nests from scratch, but when there is a lack of available natural sites and nesting materials, breeding pairs may take advantage of a manmade nest box.
Jumping cholla is the leading choice for cactus wrens to select as a nest site, although prickly pear, giant saguaro, and soaptree yucca are also popular. Spiny desert trees provide a perfect natural predator deterrent.
On average, cactus wrens construct their nests around 1 m (3.3 ft) off the ground. Nest structures are typically lower than 3 m (10 ft) above ground level, but nests as high as 9.1 m (30 ft) have been observed.
Cactus wren perched on a rock
Cactus wren nests are football-shaped structures, consisting of a narrow entry tunnel that leads into a larger inner chamber in which the chicks are raised. The bulky rounded construction is formed from twigs and dried grasses, and lined with softer feathers.
An external perch is added, offering a handy vantage point.
The internal nest chamber of a cactus wren’s nest is around 18 cm (7 in) in diameter, with the entrance passage tube significantly narrower, at around 9 cm (3.5 in) across. The entire structure measures around 30 cm (12 in) from end to end, and weighs around 180 g (6 oz).
Close up of a Cactus wren nest
The breeding season for cactus wrens begins in late February and continues until early June. Earlier and later examples may be observed, with later nesting observed at higher altitudes.
Nest building takes up to 6 days, and once complete, eggs are laid on a daily basis until the clutch of between two and seven eggs is completed. Brooding begins, at least on a partial basis, once the first egg has been laid, and continues for around 16-17 days before hatching begins.
Once hatched, young cactus wrens are brooded and fed in the nest for around 21 days before they are ready to fledge.
All in all, cactus wrens total nesting period is usually around 40 to 45 days in total.
March is the prime egg-laying month for cactus wrens. One egg a day is added to the clutch, and partial incubation is thought to begin from when the first egg is laid. Eggs may be laid as early as January and as late as August, although early clutches are less likely to be raised with success.
Cactus wrens remain in their territory all year round, and outside of the breeding season, they continue to use the nests that have been used to raise their young as a safe roosting spot.
Breeding pair of Cactus wrens perched on top of a cactus
Nesting material is brought to a nest site chosen by a female cactus wren, usually located in the upper arms of a cactus or tucked in the branches of a spiny desert tree.
The domed, football-shaped construction, formed from sticks, twigs, grass, feathers and weeds, is woven into shape, with a long tubelike entrance leading to an internal nest chamber.
Male and female cactus wrens work together, for up to three hours a day, until the nest is complete. The process takes an average of 2.7 days, or anything from 1 to 6 days to finish.
The bottom is completed first, then the sides are added, followed by the domed top. The construction of the entrance passageway is the final step.
Twigs, larger sticks, thick grasses and weeds are woven together to form the outer structure of a cactus wren’s nest. The inside is lined with soft feathers and plant parts.
While the female cactus wren is usually the first to start nest construction, once a site has been selected and building has commenced, both the male and female work together to create the nest over a period of between one and six days.
Cactus wren building the nest, Joshua Tree National Park, Black Rock Campground Yucca Valley, California
Cactus wrens’ eggs are glossy and an off-white shade tinged with salmon pink. They are an elongated oval in shape, measuring around 25mm by 16 mm (1 in by 0.6 in) and weighing around 3.57g (0.13 oz ).
Three or four eggs are typical for cactus wrens, although anything between 2 and 7 eggs is considered normal.
Incubation is by the female cactus wren alone. The male continues to bring the female food, but does not sit on the eggs, and does not develop an incubation patch.
Cactus wren gathering nesting materials
Cactus wrens are ready to leave the nest when they reach around 21 days on average. Some may fledge at 17 days, and the latest fledglings are ready to leave by 23 days.
They remain dependent on parental support for several more weeks after leaving the nest, but are driven off from the territory before the next breeding season begins.
One to two broods are usual, although up to six may be attempted in a season, all of which will require a new nest. As soon as the young from one brood fledge, the female may immediately busy herself with laying a fresh brood in a secondary nest.
Fledgling Cactus wren perched on a cactus
Not all cactus wren nests are strong and stable enough to support raising a brood of young, so it is fairly common for nests to be abandoned during construction. Abandoned nests may be used for overnight roosting.
Nests can be readily abandoned at later stages too, if the site is threatened by a predator.
Nest sites selected by cactus wrens are typically at least 1 m (3 ft 3in) off the ground, tucked in among cactus spines, offering maximum protection against opportunistic predators.
Cactus wrens use non-breeding nests for overnight roosting, as they offer a safe, off-ground space to shelter. Several nests can be built in a breeding season, and those not used for raising young may instead be used to nest each night.
Unlike many bird species, cactus wrens do not require a nearby source of fresh drinking water, but instead prefer a landscape that is rich in desert vegetation that needs no irrigation. Jumping cholla is the preferred cactus species chosen as a nest location.
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