Craters of the Moon National Monument And Preserve Deer Survey 2005

Munts, Michael

Mule deer surveys were performed during the spring and fall of 2005. These included unstructured spring surveys as well as the systematic fall surveys in the north end of the monument. Systematic road surveys were continued on the loop road in addition to the usual informal count during May and June. The number of does continued to decline from the previous three year period. Numbers were about a third of the 15 year average. Yearlings were also down with numbers about a third of the 15 year average. Over-winter survival of fawns was not calculated and reported due a very small and statistically skewed sample size. The fall survey recorded numbers that were half or less the of 15 year average for all age classes. The fawn to adult ratio increased following a major decline that started in 2000. This may indicates a slight increase birth rates or an increase in early fawn survival. The total population estimate also showed a continued decline with estimates less than half of the 15 year average. This is likely a result of drought conditions continuing through most of the last five years. When the data was averaged into three year intervals the deer population shows a general pattern of decline since the mid 1980s and reaching its lowest point in the current year. The numbers of all age/sex classes have continued a decline started in 2000.