Keyword: Strix occidentalis lucida

Winter Movements and Range Use of Radio-marked Mexican Spotted Owls: An Evaluation of Current Management Recommendations

We summarized existing knowledge on winter movements and range and habitat use of radio-marked Mexican spotted owls. In light of that information, we evaluated the adequacy of current management guidelines. Seasonal movement or "migration" appears to be a regular feature of the winter ecology of Mexican spotted owls.

Associations between forest fire and Mexican spotted owls

In 1993, the US Fish and Wildlife Service listed the Mexican spotted owl (Strix occidentalis lucida) as threatened, in part because of the rising threat to its habitat from stand-replacing wildfires. In 1997, we surveyed 33 owl sites that, in the previous four years, had burned at various levels ranging from light controlled burns to stand-replacing fires.

Calling behavior of spotted owls in Northern Arizona

I studied the calling behavior of radio-tagged Mexican Spotted Owls (Strix occidentalis lucida) in northern Arizona. Owls used a variety of calls, with three call types (Four-note Location Call, Contact Call, and Bark Series) accounting for 86% of calling bouts heard. These calls were used by both sexes, but in significantly different proportions.

Evaluating desired conditions for Mexican spotted owl nesting and roosting habitat

The Mexican spotted owl (Strix occidentalis lucida) was listed as a threatened species in 1993, primarily because of concerns over the loss of late seral forest habitat to timber harvest and wildfire.

Using terrestrial ecosystem survey data to identify potential habitat for the Mexican spotted owl on National Forest System lands: a pilot study

We assessed the usefulness of Terrestrial Ecosystem Survey (TES) data as a means of identifying habitat for the Mexican spotted owl (Strix occidentalis lucida) in three National Forests in Arizona. This spatial data set incorporates information on soils, vegetation, and climatic conditions in defining a set of ecological "map units" showing potential vegetation.

Activity patterns of nesting Mexican Spotted Owls

We collected 2,665 hr of behavioral information using video surveillance on 19 Mexican Spotted Owl (Strix occidentalis lucida) pairs between 25 April and 26 July 1996. Prey deliveries per day increased as the nesting season progressed, with an average of 2.68 prey deliveries during incubation, 4.10 items during brooding, and 4.51 items during the nestling phase.

Habitat selection by Mexican Spotted Owls in Northern Arizona

We compared use of seven habitat types to availability of those types within the home ranges of eight radio-tagged Mexican Spotted Owls (Strix occidentalis lucida). When all habitat types were considered simultaneously, habitat use differed from habitat availability for each owl. Patterns of habitat use varied among individuals and with respect to activity.

Metabolic rate and evaporative water loss of Mexican Spotted and Great Horned Owls

We measured rates of oxygen consumption and evaporative water loss (EWL) of Mexican Spotted (Strix occidentalis lucida) and Great Horned (Bubo virginianus) owls in Arizona.

Roost sites of radio-marked Mexican spotted owls in Arizona and New Mexico: sources of variability and descriptive characteristics

To increase understanding of roosting habitat of Mexican Spotted Owls (Strix occidentalis lucida) and factors that influence use of roosting habitat, we sampled habitat characteristics at 1790 sites used for roosting by 28 radio-marked Mexican Spotted Owls in three study areas in Arizona and New Mexico.

Comparative habitat use of sympatric Mexican spotted and great horned owls

To provide information on comparative habitat use, we studied radiotagged Mexican spotted owls (Strix occidentalis lucida: n = 13) and great horned owls (Bubo virginianus: n = 4) in northern Arizona. Home-range size (95% adaptive kernel estimate) did not differ significantly between species during either the breeding or nonbreeding season.