-7- 



Food Habits of the Burrowing Owl (Speotuto cuniaularia ) in Montana 



The status of the burrowing owl in Montana is presently unknown, but is 

 believed to be declining. Zarn (197A) indicates that this decline is a 

 general phenomena over much of the species' range. Reasons for the decline 

 are generally believed to be (a) poisoning of rodents, and (b) development 

 of owl habitat. Both factors serve to reduce the availability of burrows 

 to owls, thus limiting owl numbers. Preliminary observations in Montana 

 suggest that this is not the case here. In areas where prairie dogs 

 (Cynomys tudovicianus) are abundant, burrowing owls are either absent or 

 poorly represented. 



Investigations of food habits and foraging ecology will be undertaken to 

 help identify factors limiting this species in Montana. About 200-250 

 burrowing owl pellets have been collected to date, but these have not yet 

 been analyzed. Additional work will be done by Pat Nichols, an M.S. degree 

 candidate at the University of Montana and department nongame personnel. 



Raptor' Investigations 



Statewide Raptor Survey Route System 



The objective of the Raptor Survey Route System is to establish trend data 

 on abundance and distribution of 17 species of diurnal raptors in Montana. 

 Usefulness of these data will be very limited in the early years, but will 

 increase in value in future years. 



This system is a series of vehicle routes which are run twice yearly. 

 One route is located in each of the state's latilongs (degree blocks), 

 and is approximately 50 miles long. Route were initially located in 

 consultation with local game wardens, biologists and BLM personnel. Methods 

 used and a form for recording observations are presented as Appendix I and 



11 respectively. 



During June 1977, 43 routes were completed. Observers drove a total of 

 2,260 miles and recorded 438 diurnal raptors. Species compilation is 

 presented in Table 2, and latilong distribution of most species is presented 

 in Figures 1 through 11. 



Prior to the January, 1978 sample-period, cooperators were polled via 

 questionnaire (Appendix III) as to the adequacy of the methods employed. 

 Survey methods were altered accordingly and new instructions were printed 

 for use during subsequent survey periods (Appendix IV) . 



During January, 1978, severe weather prevailed across most of Montana and 

 only 33 routes were completed. Observers drove a total of 1,687 miles 

 and recorded 172 diurnal raptors. Species compilation is presented in 

 Table 3, with latilong distribution for most species presented in Figures 



12 through 19. 



