Written by: D. Dobkin
Reviewed by: L. Mewaldt
Edited by: R. Duke

DISTRIBUTION, ABUNDANCE, AND SEASONALITY

     An uncommon resident restricted to cool, shaded canyons with rock outcrops in mountains
of the inner Coast Ranges and the Sierra Nevada (Grinnell and Miller 1944).  Found primarily
in riparian habitats, but vegetation apparently little affects distribution, except to regulate
availability of nest materials and foods.  Found from sea level to 2250 m (7500 ft) (Linsdale
1938, Grinnell and Miller 1944).  Usually found near water.  Absent along the coast north of
San Francisco Bay, from most of the Central Valley, and from southern desert lowlands.
There are sparse populations in southern desert mountains.

SPECIFIC HABITAT REQUIREMENTS

   Feeding:    Gleans insects, spiders, and other small invertebrates from rock surfaces or
ground, often in concealed sites.  Hops or creeps while searching for food.  Requires cliffs
and large tangles of boulders for foraging (Grinnell and Miller 1944, Bent 1948).

   Cover:    Small cliffs, talus, or rock outcrops provide foraging, nesting, and other cover.

   Reproduction:    Nests on ledge in rock cavern or crevice, in crevice of a cliff or bank, or on
shelf or in cavity of human-made structure (Harrison 1978).  Nest usually located near water
(Grinnell and Miller 1944) or in a stream-bearing canyon (Smyth and Coulombe 1971).  Nest
may be maintained and reused (Ehrlich et al. 1988).

   Water:    Prefers areas near water (Grinnell and Miller 1944).

   Pattern:    Frequents cool, shaded canyons with exposed rock outcrops, small cliffs, or
talus, usually in the vicinity of water.

SPECIES LIFE HISTORY

   Activity Patterns:    Yearlong, diurnal activity.

   Seasonal Movements/Migration:    Not migratory.  May wander locally in winter (McCaskie
et al. 1988).

   Home Range:    Miller and Stebbins (1964) never observed more than 1 pair per canyon.
Cody (1974) reported only 27% of available oak woodland habitat occupied in breeding
season, and only 34% occupied in winter.  Also scarce in chaparral, occupying only 22% of
this habitat in winter.

   Territory:    No data found.

   Reproduction:    Breeds from mid-March to mid-July, with peak from mid-April to mid-May
(Bent 1948).  Clutch size 4-6, mostly 5 or 6.  Male helps female build nest incubate eggs, and
feed altricial nestlings and fledglings (Verner and Willson 1969).

   Niche:    Very little life history information available.  Occasionally found in human-inhabited
areas with boulders or old stonework.

REFERENCES

Bent, A. C.  1948.  Life histories of North American nuthatches, wrens, thrashers, and their
     allies.  U.S. Natl. Mus. Bull.  195.  475pp.
Cody, M. L.  1974.  Competition and the structure of bird communities.  Princeton Univ. Press,
     Princeton, NJ.  318pp.
Ehrlich, P. R., D. S. Dobkin, and D. Wheye.  1988.  The birder's handbook.  Simon and
     Schuster, New York.  785pp.
Grinnell, J., and A. H. Miller.  1944.  The distribution of the birds of California.  Pac. Coast
     Avifauna No. 27.  608pp.
Harrison, C.  1978.  A field guide to the nests, eggs and nestlings of north American birds.  W.
     Collins Sons and Co., Cleveland, OH.  416pp.
Linsdale, J. M.  1938.  Environmental responses of vertebrates in the Great Basin.  Am. Midl.
     Nat.  19:1-206.
McCaskie, G., P. De Benedictis, R. Erickson, and J. Morlan.  1988.  Birds of northern
     California, an annotated field list.  2nd ed. Golden Gate Audubon Soc., Berkeley.
     Reprinted with suppl.  108pp.
Miller, A. H., and R. C. Stebbins.  1964.  The lives of desert animals in Joshua Tree National
     Monument.  Univ. California Press, Berkeley.  452pp.
Smyth, M., and H. M. Coulombe. 1971.  Notes on the use of desert springs by birds in
     California.  Condor  73:240-243.
Tramontano, J. P.  1964.  Comparative studies of the rock wren and the canyon wren.  M.S.
     Thesis, Univ. Arizona., Tucson.  59pp.
Verner, J., and M. F. Willson.  1969.  Mating systems, sexual dimorphism, and the role of
     male North American passerine birds in the nesting cycle.  Ornithol. Monogr. No. 9.  76pp.
 
Compiled from information from California Department of Fish and Game - California Interagency Wildlife Task Group