In 2014, the Palos Verdes Peninsula Land Conservancy (Conservancy) initiated a Citizen Science Cactus Wren
program to utilize volunteers to observe the coastal cactus wrens
within the Preserve.
These nests are principally those of the cactus wren
and the curved-bill thrasher.
Construction will obliterate an estimated 30 pairs of gnatcatchers and 44 pairs of coastal cactus wrens
. In addition, a once-pristine parcel of habitat will now be girdled by pavement.
Several bird species designated as 'special status' also have been recorded on campus, including one of only three aggregations of the coastal cactus wren
. The Springs fire that occurred in May 2013 completely surrounded the campus and severely damaged nesting areas for the coastal cactus wren
and the coastal California gnatcatcher.
The first bird on their 4,000-species list was the cactus wren
, Arizona's state bird.
This study provides the first description of the chromosomes of seven of these species: Cactus Wren
(Campylorhynchus brunneicapillus), Rock Wren (Salpinctes obsoletus), Canyon Wren (Catherpes mexicanus), Carolina Wren (Thryothorus ludovicianus), Bewick's Wren (Thryomanes bewickii), Sedge Wren (Cistothorus platensis), and Marsh Wren (Cistothorus palustris).
The cactus wren
(Campylorhynchus brunneicapillus) nests in a variety of spinescent trees and shrubs, e.g., cholla cactus (Opuntia sp.), columnar cacti (Cereus sp.), acacia (Acacia sp.), and mesquite (Prosopis sp.), and rarely in other native, non-spinescent vegetation, e.g., mistletoe (Phoradendron sp.) and hackberry (Celtis reticulata; Bent, 1948; Anderson and Anderson, 1973; Harrison, 1979).
The noisy warble of a cactus wren
may break the silence.
For species of residents with >10 captures (n = 6), captures of crissal thrashers, cactus wrens
, and black-throated sparrows did not differ between arroyos and uplands (P = 0.610, 0.780, and 0.420, respectively), whereas verdins, rufous-crowned sparrows, and canyon towhees were caught more often in arroyos (P = 0.002, <0.001, and <0.001, respectively).
On one visit, I saw cactus wrens
nesting in the middle of one jumping cholla cactus, and a curved-billed thrasher's nest in another.
Native animal and plant species numbering in the hundreds include rare and endangered Gila monsters, cactus wrens
, vultures, quails, coyotes, deer, and javelina (wild boars).