boreal owls in lodgepole pine habitat types with scattered meadows 

 or grass/sage openings. This discrepancy with the prevalent habitat 

 type reported may be due to the limited amount of spruce/fir stands 

 available at higher elevations in the Little Belt Mountains, or may 

 be a factor of the habitat classification methods used in this 

 survey. 



Boreal owls in the Little Belts may have problems with warm 

 summer temperatures since boreal owls are easily heat stressed 

 (Hayward et al. 1987). Therefore, dense stands of timber which 

 would provide cool moist sites for roosting may be important to 

 boreal owls in the Little Belts. Also the high level of wood 

 cutting on the district (Sasse pers. comm.) may limit the 

 availability of suitable nesting snags for boreal owls. Hayward 

 (pers. comm. in Mullen 1990) suggested that clearcuts may provide 

 edge habitat used by owls for hunting. However, Mullen (1990) 

 warned that man-made openings also are often accompanied by the 

 potential for increased human disturbance and the invasion of 

 competing owl species, especially great horned owls. 



Boreal owls have extremely variable calling activity (Hayward 

 et al. 1986, Palmer 1987). Variations in prey populations directly 

 influence calling activity by reducing breeding activity during 

 periods of low prey populations (Hayward 1987) . Bondrup and Nielsen 

 (1978) found that pair formation will also cause the male to stop 

 calling. Hayward (1983) noted that one male did not respond to 

 surveys during the normal courtship period because he was already 

 paired. Palmer (1987) found courtship periods ranging from 4 to 59 



17 



