Figure 331. First recorded in California in 1981, the Barred Owl was considered a sparse resident of the state’s northwestern corner by 1990 and has since expanded its range considerably, both along the coast and in the Sierra Nevada. This individual—the only one ever detected in the state away from potentially suitable breeding habitat—spent two consecutive winters at Tule Lake NWR in Siskiyou County. This photograph was taken on 28 November 1986, the day of its discovery (1987-085; Ray Ekstrom).

 

 

 

 

 

 

BARRED OWL Strix varia Barton, 1799

Accepted: 8 (100%)	Treated in Appendix H: no
Not accepted: 0	CBRC review: records through 1989
Not submitted/reviewed: 8	Color image: none

Historically, this owl’s range was limited to North America east of the Great Plains, with disjunct populations in western and southern Mexico. Westward expansion through the boreal forests of Canada was in evidence by the 1940s (Wright and Hayward 1998, Houston and McGowan 1999), and the species reached British Columbia and western Montana by the 1960s (Grant 1966, Shea 1974). Within a few years the range had crept into Idaho, Washington, and Oregon (Taylor and Forsman 1976, Sharp 1989, Dark et al. 1998), as well as southeastern Alaska. In 2004, this owl was recorded in north-central New Mexico (NAB 58:411, 576).

The first Barred Owl to be identified in California was a long-staying individual initially found on 12 March 1982 in Crescent City, Del Norte County. This bird’s positive identification prompted realization that an owl heard the previous summer at Salyer, Trinity County, had also been a Barred, and hence California’s first. The only CBRC-reviewed record of a Barred Owl away from potential breeding habitat involves a bird present at Tule Lake NWR during consecutive winters in the late 1980s (Figure 331). Committee review was suspended in 1989, when it was clear that Barred Owls had infiltrated the state’s northwestern corner. Hunter et al. (2005) reported a minimum of 37 Barred Owls in Humboldt County alone by the fall of 1998, and by spring 2002 the known range extended south along the coast to Muir Woods in Marin County (NAB 56:353). Dark et al. (1998) published a detailed review of this adaptable owl’s expansion into California. This was updated by Steger et al. (2006), who photographed a male in June 2004 along Sequoia Creek in Tulare County, well south of previous California records.

As summarized by Courtney et al. (2004), Barred Owls appear to be displacing Spotteds in parts of the Pacific Northwest, and the species are hybridizing in other parts. The same dynamics appear to be operating in the Sierra Nevada, where in Placer County a Spotted Owl × Barred Owl was studied during summer 2003 at a territory previously occupied by a pair of Spotted Owls (Seamans et al. 2004); see also Steger et al. (2006).

 

[BOREAL OWL Aegolius funereus (Linnaeus, 1758) – see hypothetical section]