Mexican Spotted Owl Inventory and Monitoring Protocols for Bryce Canyon National Park

Foster, Dan

In the spring of 1993, the Mexican spotted owl (Strix occidentalis lucida) was listed as a threatened species by the US Fish and Wildlife Service. Bryce Canyon National Park (BRCA) has many areas that meet the definition of suitable canyon dominated habitat. These areas may include: 1) small patches of vegetation including Douglas fir, mixed conifer, Pinyon-Juniper and deciduous riparian or deciduous upland trees, or may be void of trees, 2) inner canyon width in the range of 3-917 meters, 3) inner canyon height in the range of 12-428 meters, 4) outer canyon width in the range of 1223-2201 meters, 5) outer canyon height in the range of 186-1223 meters, and 6) slopes of between 87 and 105 degrees. From locations where owls have been found, the birds also prefer cooler (not cold) temperatures. The survey protocols call for multiple night transects with calling stations at predesignated points. Because of limited personnel, surveys are to visit each area four times representing breeding, laying, hatching and fledging / post-fledging times. Inventory and monitoring objectives include 1) determination of distribution and absence and presence of Mexican spotted owl, 2) define habitat of use for owls discovered, and 3) aid in delineation of Mexican spotted owls on the Colorado Plateau.