jdevos

In virtually all studies that I am aware of, even those done in harsh environmental periods, most does are pregnant with twin fawns. `If you look at the literature, parturition rates are about 1,6 to 1.7 fawns per doe, which yields about 160 fawns to 100 does. In the last portion of where the enclosure was closed, there were times approximately 100 fawns per 100 does were detected on the deer drive in fall, so it is clear that a sizable portion of the fawns drop is lost and not recruited. The factors that influence this are many and include weather patterns, habitat quality, predation, poor nutrition whereby the doe is unable to effectively feed and raise her twins, presence of alternative prey for predators etc. In my mind, I think that these factors interact with eachother to determine the potential success a doe has to raise her fawns. While I try to look at predation as a portion of mortality that occurs to the fawn segment of the population i do believe that many factors influence this relationship. The primary goal of this research is to try and develop an understanding of the interacting factors that influence fawn survival and recruitment. Sorry for the long answer to a simple question, but yes, even in the enclosure, a substantial portion of the fawns dropped each year died before the deer drive in early winter. Jim deVos

This is a short follow up to the posting by Amanda relative to the Three-Bar capture. This is a segment of several studies that have been conducted on the Three-Bar relative to low fawn survival. The focus of this portion is to determine cause-specific mortality rates. The implants will drop out when the fawns are born and will be captured by the biologists and marked with telemetry and tracked to determine their fate. As an interesting note, all of the does that were captured were pregnant and the majority of them were carrying twins. This project is being supported by Arizona Game and Fish Department, the Arizona Deer Association and Texas Tech University. The results of this study will help develop better information on how to manage mule deer in the Southwest. As indicated, this is another segment of the series of studies done to learn about causes of low fawn survival. Work that is being written up now showed that deer in the enclosure increased in numbers to very high densities even in an era with low precipitation inside the enclosure while they remained at very low densities outside. This finding lead to the current study to document the cause of fawn mortality. Jim deVos