This evening I joined a group of about 40 people at the North Brookfield Senior Center to hear a talk by David Stainbrook, Program Manager for Moose and Deer for the Massachusetts Division of Fisheries and Wildlife. Cynthia Henshaw, Executive Director of East Quabbin Land Trust, the organization instrumental in protecting North Brookfield’s flagship piece of conservation land, Wendemuth Meadow, introduced the speaker.
David works at the Division’s headquarters in Westborough; there’s only one of him, so he has a range of responsibilities. He spends 10% of his time on moose and the remaining time on deer, particularly in the eastern part of the state, where deer are more of a problem.
Moose are large animals: males, or bulls, weigh between 600-1000 pounds and stand 6.5 feet tall at the shoulders. Their height makes them dangerous to cars; at night, drivers cannot see their eyeshine because it’s above their line of sight. Females, or cows, weigh between 500-700 pounds. Females give birth to 1-2 calves, between late May and early July. Moose mothers are very aggressive in protecting their calves (unlike deer mothers, who will leave their fawns camouflaged when they go out to feed). A moose’s range can be over 15 square miles.
In Massachusetts, moose are at the southern limit of their range, which means they get heat-stressed easily. (Four North American sub-species have been identified; ours is Alces alces americana.) In our state, moose prefer living at the higher elevations, especially in the Berkshires and Central Highlands, especially in early successional forest. The Division estimates that the moose population numbers approximately 1000 individuals, though these numbers are educated guesses; Quabbin Reservoir appears to have the highest density. Moose cannot be hunted in Mass; but even without hunting, the numbers are not rising, due to stress and mortality, caused by vehicle collisions, diseases, and parasites.
The moose population peaked in 2004 and has since stabilized. Our best estimate of the population comes from collision data, which remain stable at 25-30 per year. Collisions are highest in the western Pike area and on Route 2 near the Quabbin; risk is highest in spring, when yearlings move to new territory, and in fall during mating season. Mass Wildlife also emails a survey to hunters each year, to about 15,000 addresses. This survey asks respondents if they sighted any moose; the responses are used to corroborate estimates.
Because hunting is not allowed, the Division has a harder time managing moose. They can manage habitat, so this is the preferred method, using forest cutting. The target is now 1 moose per square mile (and 10-15 deer); above that there would be forest impacts. The diet of moose and deer are basically the same, except moose really like striped maple and hemlock.
Serious moose health issues are caused by brainworm, a nematode carried by deer, spread by snails, and affecting moose specifically (it has a complex lifecycle). Historically, it wasn’t an issue, and it also is not contagious and doesn’t seem to affect the deer.
The winter tick is also a problem; this tick is large (unlike the deer or dog tick); it attaches to the moose in fall and spends the winter feeding on blood. A single moose can have tens of thousands of these ticks; since each can ingest 3 ml of blood, this is a significant parasite load, especially for the young. Moose try desperately to rub them off; you can sometimes see that their fur has bare patches. Affected yearlings tend to die in a 3-week period at the end of March and beginning of April (ticks will die off if there is still snow cover at that time).
Deer have a longer and more complex story. The goal is a healthy, balanced population (meaning good physical condition, balanced sex ratio, and varied age structure). The ideal is < 20 deer per square mile of forest. Mass Wildlife aims for 6-18 deer per square mile of forest. Management ranges are divided into two groups and 14 zones. The zones begin at 1 in the western part of the state and end at 14 in the Islands. In most of these zones, the population density is within range, but in some zones the density is above, slightly above, or significantly above, as in Zones 13-14, which are the Islands, where the deer have no natural predators.
One strategy Mass Wildlife uses to manage the deer population is by allocating hunting permits, such as antlerless deer (meaning, females) permits by zones. Stainbrook noted that the number of hunting permits has dropped dramatically, from 150,000 at peak to 50,000 today. Mass Wildlife also tracks numbers of deer killed, which last year was over 13,000. Deer health, he reported, is generally good; health is monitored by use of check stations, where deer are weighed, aged, and for male yearlings, measured for antler beam diameter (below 15 mm indicates the deer is stressed).
In terms of age structure, Stainbrook said a good management plan would prevent taking 70% of 1.5 year old bucks (this can be managed by implementing point restrictions). Hence Mass Wildlife analyzes harvest data for trends — right now the age distribution is near ideal. And now, for the first time ever, they’re conducting pellet count surveys and deer browse surveys (checking for forest damage). In Eastern Mass, where the density of deer is more of an issue, the deer population still appears healthy and the age structure is not a cause for concern.
Right now, there is a regulation change request before the state legislature, which is to extend the archery season to two weeks earlier in WMZ 10-14 (in Eastern Mass, some townships prohibit discharge of firearms); the total length of the season would be extended from 6 to 8 weeks. Stainbrook noted that Mass Wildlife doesn’t have as much regulatory authority as they might want, to better fulfill their mandate of managing wildlife populations.
Personally, I have never seen a moose (in real life), though I would like to. However, I do not like deer at all and would rather see more of them dead. I understand that the relationship between mice, ticks, and deer is not unambiguous, but I’m surprised that the phrase “Lyme disease” did not come up in the conversation tonight. To my knowledge, deer are a critical transmission vector for this terrible disease which has afflicted so many in the Northeast.