New Salem Block Deer Population Study Report

by Charley Eiseman

In June 1998 the FOQ board expressed its concern about continuation of the Quabbin Deer Hunt without an in-depth review, and voted to support a study of the deer population in the New Salem block of Quabbin Reservation. That study was undertaken in January 1999 by Charley Eiseman, a student at UMass, who conducted field observations and data analysis during the winter and spring, utilizing course training in The Dynamics and Management of Animal Populations, and Habitat Assessment. His work was supervised by a UMass faculty member, and assistance was provided by MDC. Here is his report.

Over the past month, I have visited the different parts of the Quabbin’s New Salem Block, attempting to assess the condition of the deer population. I have concluded (and have been advised by wildlife biologists) that the deer density is too low for counts of droppings, or of deer actually seen, to produce any meaningful results. In fact, after roughly twenty hours of searching, I haven’t seen a single deer pellet, let alone an actual deer.

I devised a crude method of population estimation, which involved making rectangular plots in the snow, 1/32 of a square mile in size. So far I have made six of these, totaling 2.5% of the management block, thoroughly searching them for deer tracks made within the past day. Although five of these were what I would call ideal deer habitat (judging by water availability and abundance of mature oaks and hemlocks), only one contained any deer tracks at all, and after following these tracks for half a mile, I concluded that this deer was alone. I realize that this has virtually no statistical significance, but a simple extrapolation from these data suggests that there are 5.3 deer per square mile; probably an overestimate. This happens to come very close to the MDC’s estimate from catch-per-unit-effort analysis that in 1995 the density was 5.4 per square mile, or a total of 40 deer.

From what I have seen outside of my six plots, which were evenly distributed across the New Salem Block, I can say reasonably confidently that there are at least 20 deer. I can also say that any additional plots I made (if it were to snow again this winter) would probably bring my estimate closer to 20, but not any lower. In my opinion, it would be a waste of time and money to try to narrow this 20-deer range of uncertainty: even if I could convince MDC biologists that my methods are valid, it is doubtful that their management strategy would differ significantly for a population of 20 deer as opposed to 40.

Although wildlife biologists assure me that it is impossible to measure deer density with any precision at such low population levels, I would like to report these observations, which I think are significant. Besides the tracks that ran through my second plot, in all the time I spent exploring the New Salem Block, I found only two other instances of deer tracks that were recent enough to be recognizable. One was a set of tracks, made either by a single deer or by several very carefully stepping deer, that crossed a road. The other was a series of tracks along a brook, made by a number of deer over several days.

In any other forest in this area I see more deer tracks, without even looking, in the space of five or ten minutes than I saw in twenty hours at the Quabbin. Yet I have never heard anyone suggest that all of western Massachusetts is heading towards “savannah” conditions. It seems to me that the Quabbin watershed could sustain a larger deer population, and that thirty or forty deer pose no more threat to water quality than do the various logging operations I observed during my visits.