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Idaho Fish and Game

Fawn Mortality Normal Except in Southeast

Mule deer fawns appear to be surviving the winter in normal numbers across southern Idaho except in southeast Idaho. The Idaho Fish and Game Commission heard a report on winter fawn mortality when it met in Boise March 13-15. Fawn mortality trends and causes are sampled in a large study involving the capture and radio-collaring of significant numbers of young mule deer across the southern part of Idaho. The report noted that mortality had increased in the last two weeks in most sampled areas, a trend expected toward the end of a long winter. Most of the increase in mortality was attributed to malnutrition and lion predation. Low fawn mortality was noted in units 32, 36B, 39 and 50. Compared to previous mild winters, units 39 and 54 were at normal survival rates for the time of year while unit 67 mortality was slightly worse than normal. Mortality has been high in units 56, 72 and 73A where biologist Mark Hurley estimates total losses could be 80 percent or more before summer. Unit 67 might lose 60 percent of last spring's young. Biologists are not seeing significant losses of adult does in these units, however, an indication that the effects of this particular winter will be shortlived. Biologists cautioned that fawn losses do not end as soon as spring greenup starts.