abundant during 1980 and 1981 than during the previous, 

 1976-1977 low in microtine populations. 



Quantitative data on small mammal populations on the 

 study area were not collected prior to 1976, but data existed 

 from other studies in central Montana (Cada 1968, Tschache 

 1970, Reichelt unpubl . ) . Also, qualitative information from 

 a variety of sources such as narratives of game range 

 personnel (Appendix D) , annual reports of various individuals 

 and agencies, area newspapers, and field notes provided basis 

 for estimating probable trends in abundance back to the 1930s. 

 Murie's (1935) notations, for example, indicate that both 

 jackrabbits and microtines had probably reached simultaneous 

 peaks around 1932 or 1933. Thereafter the narratives 

 indicated peaks in jackrabbit populations at 10-12 year 

 intervals (early 1930s, early 1940s, 1949-1950, late 1950s, 

 and 1970-1971). Lows generally were noted near the middle 

 years of each decade; ca. 1945, 1955-1957, 1965-1966, and 

 1973-1977. Our data indicated a subsequent peak in 1983 and 

 a low during 1985-1987. Microtine population highs can be 

 documented during 1963-64, 1968-69, 1978-79, 1982-83, and 

 1986-87. Moderately high numbers apparently occurred during 

 1974-75, but the irruption was much less distinct and the peak 

 lower than in 1978-79. Information on deer mouse populations 

 was less complete, but highs apparently occurred in central 

 Montana in 1968 and 1973. Populations on the study area 

 increased from lows during 1977 to a peak in 1983, crashed 

 abruptly in 1984, and subsequently increased through 1986. 



Although microtine populations apparently began to 

 increase in summer 1974 and were moderately high during early 

 1975, fawn survival was poor in contrast to other periods of 

 microtine abundance. However, because the microtines never 

 became exceptionally abundant and deer mice and lagomorph 

 populations, especially jackrabbits, were at cyclic lows 

 during 1973-1977, the combined small mammal prey base was 

 relatively low and did not deter predation on deer. 



Some coyote control using compound 1080 was practiced on 

 the area until 1972, although the extent and intensity of 

 efforts was considerably reduced from the late 1940s and 

 1950s. Narrative reports and field notes indicated that 

 poison bait stations became less effective after the early-mid 

 1950s when coyotes either learned to avoid the stations and/or 

 poisoning selected for survival of individuals that killed, 

 rather than scavenged for food. Thus, despite at least some 

 effort at control and additional mortality to hunting and 

 trapping, coyotes were common, if not abundant on the area 

 through the 1960s and into the early 1970s. A peak in coyote 

 numbers may have occurred in 1973 as a result of simultaneous 

 peaks in microtine and jackrabbit populations during 1969-1971 

 and high overwinter mortality of deer in 1971-72. Such a peak 



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