The Cactus Wren

Cactus wren

Cactus wren, image from Wikimedia

The cactus wren is found in the Mojave, Sonoran, and Chihuahuan Deserts; it is found in southern California, Nevada, Arizona, and deep into Mexico. The bird is easily observed flitting about the desert in search of insects, and its nests may be found in various large cacti including chollas (Cylindropuntia), saguaro (in holes), and some other columnar or barrel cacti. Sometimes the bird will nest in yucca plants.

 Males and females resemble each other, and both search for ants, beetles, grasshoppers, and bees, etc, though they might eat a bit of fruit now and then or seeds. The birds are remarkably efficient at extracting water from their food, and they seldom need to drink.

I’ve seen this bird throughout the Mojave desert, but irregularly so. The nests are hard to miss, typically a scramble of twigs (with a roof and tunnel entry) in a large cholla or perhaps a Joshua tree. The white eye stripe and the black breast spots are useful for identification; there is no other bird like it.

Cactus wren next in Opuntia acanthodes, Kingman, AZ

Cactus wren nest in Opuntia acanthodes, Kingman, AZ

Posted by: Joe Shaw shawjoej@gmail.com

Hogs, Birds, and Opuntias

Opuntia ficus-indica

Opuntia ficus-indica, Mallorca Spain, by Frank Vincentz

An article in 2002 (by Gimeno and Vila, in Acta Oecologica, vol. 23, page 239) describes some of the processes that might lead to Opuntia species colonizing parts of Europe. The plants were taken to Europe hundreds of years ago and have established themselves in areas with a Mediterranean climate. But the plants don’t just “sit still,” they are on the move and their progeny can colonize new areas. The article reports:

 “In Europe, many agricultural areas are now abandoned and hence can be invaded by exotic species. The abundance and spatial distribution patterns of two Opuntia species were studied in old olive groves in the Parc Natural del Cap de Creus, Catalonia (Spain)…. However, although most seedlings were recruited beneath Opuntia [adults], some (10–30%) were found away from putative parental plants. This may be due to seed dispersal by birds and wild boars.”

 It is interesting to think of native American plants species assisting animals on other continents by providing them with fruit and seeds to eat. Its long been known that birds enjoy Opuntia fruits and that cattle will feed on Opuntia cladodes, but I never thought about pigs feeding on Opuntia and serving to move the seeds about.

Posted by: Joe Shaw shawjoej@gmail.com

Other Plants: Selenicereus anthonyanus

Selenicereus anthonyanyus

Selenicereus anthonyanyus, by Paul Kaluschke

Selenicereus anthonyanus is called the fishbone cactus because its stems have the zig-zag appearance reminiscent of fish vertebrae attached to the backbone. S. anthonyanus is named after Dr. Anthony, who first encouraged the species to flower in greenhouses. The species is from Chiapas, Mexico and perhaps the natives of that region first got the plant to flower in cultivation. The plant grows as an epiphyte in rainforests and is tender to frosts. It is tempting to speculate that the large open flowers are pollinated by bats.

S. anthonyanus is mostly propagated solely from plants of the original collection. Few new collections have been made according to Wikipedia.

Posted by: Joe Shaw shawjoej@gmail.com

Gila Woodpecker and the Saguaro

Gila Woodpecker and saguaro

Gila Woodpecker and Saguaro, by Searchnet Media

Male and female Gila Woodpeckers (Melanerpes uropygialis) resemble each other, but the males have a red cap. The birds are commonly found in the Sonoran Desert where they feed on insects, cactus fruits, and various berries. The birds may create cavities in saguaro plants or trees or may even nest in human-made structures.

In this photograph, the bird seems to be looking for insects or nectar in a saguaro flower. Bats commonly fertilize saguaro, but perhaps woodpeckers assist in some small way.

Posted by: Joe Shaw shawjoej@gmail.com