INTRODUCTION 



The boreal owl ( Aegolius funereus) is a small, nocturnal owl 

 found in northern forests around the world (Hayward 1989) . 

 Boreal owls are gernerally observed in mature-old growth high 

 elevation forests with a major component of subalpine fir ( Abies 

 spp.) and spruce (Picea spp.). The breeding season begins in 

 February and continues through March. During this time, male 

 boreal owls can be identified by hearing their distinctive 

 winnowing territorial song (Palmer 1987) . 



The flammulated owl (Otus f lammeolus ) is also a small, 

 nocturnal owl found in northwestern forests of North America 

 during the summer months. This owl is believed to be migratory 

 in the northern part of its range (Balda et al. 1975). The 

 flammulated owl feeds primarily on insects and has been observed 

 in mature-old growth montane yellow-pine forests consisting of 

 ponderosa pine ( Pinus ponderosa ) or Jeffrey pine ( Pinus 

 ief freyi ) , but has also been found in western larch ( Larix 

 occidentalis ) , Douglas fir ( Pseudotsuqa menziesii ) , and aspen 

 ( Populus tremuloides ) forests among or near yellow pine forests 

 (Reynolds and Linkhart 1984) . The breeding season begins in May 

 and continues into June and during this time males can be 

 identified by hearing their distinctive low toned "boop. . .boop" 

 territorial song (Reynolds and Linkhart 1984) . 



Both species are secondary cavity nesters and depend on 

 medium-large size woodpeckers for excavating nest cavities 



