BREEDING HABITAT OF THE MEXICAN SPOTTED OWL IN THE TULAROSA MOUNTAINS, NEW-MEXICO

We studied nest and roost habitat characteristics of Mexican Spotted O wls (Strix occidentalis lucida) in the Tularosa Mountains, New Mexico. Owls selected both nesting and roosting sites in mixed-conifer forest s that contained an oak (Quercus sp.) component more frequently than e xpected by chance. With the exception of one cliff site, no owls were observed using pinon pine (Pinus edulis)/alligator juniper (Juniperus deppeana) woodlands for nesting or roosting. Owls selected nest and ro ost sites in forests characterized by mature (dbh > 45.5 cm) trees wit h high variation in tree heights and canopy closure > 75%. Because we found little difference between nest microsites and their surrounding forest patches, the presence of a suitable nest structure may have det ermined nest-site selection within nest stands. Characteristics that b est described nest sites in the Tularosa Mountains were also applicabl e to Mexican Spotted Owl nest sites in surrounding mountains. Seventy- five percent (n = 28) of nests were in Douglas-fir (Pseudotsuga menzie sii), and 61% (n = 28) of nest structures were on clumps of limbs caus ed by dwarf mistletoe (Arceuthobium sp.) infections. Nest trees averag ed 163.7 years of age (SD = 44.8) and 60.6 cm in diameter (SD = 22.4).