Deer, as you probably know, are one of the major carriers of the black-legged tick that spreads Lyme and other nasty parasitic diseases when it bites us. Therefore, having fewer deer around would help control the ailment.
But how many deer is enough? An essay by a Maine-based writer published in Undark Magazine (you can read it here) argues that four per square mile is a good number because research indicates that it greatly cuts the ability of ticks to thrive and move around. (Not everybody agrees – see research linked in the first comment below.)
New Hampshire has somewhere between 10 and 20 deer per square mile, depending on what part of the state you’re in. Counter-intuitively, deer populations are denser in much of the south and southeast than in the North Country because they like human-altered habitat.
So why don’t we kill more of them off? Because, the essay argues, we have established desirable amounts of deer based on the wishes of hunters, who need a certain amount of targets around to make their hunting trips successful.
Due to their status as a primary source of funding for wildlife agencies, this small group (that is, hunters) exerts disproportionate influence over wildlife management planning. As a result, wildlife agencies have a strong incentive to maintain deer — a favored species for hunting — at numbers far larger than would naturally occur in a healthy ecosystem.
The solution, ironically, would be to let hunters kill more deer. Although I’m not sure how successful that would be, since the number of hunters is declining. I suspect that particularly in Rockingham and Hillsborough counties, that wouldn’t make much of a dent.
The essay also argues an unpopular point: Create a tax “on non-hunting outdoor gear” to replace the dependence on hunting licenses for conservation revenue. I don’t think that would go over too well, even if it is a good idea.
Killing might slow the spread of Lyme disease but the “deer” tick can live on any warm blooded furry animal. If there are no deer the ticks will just move on to the next host.
A recent feature on this same topic ran on NHPR Something Wild.
audio here: https://www.nhpr.org/post/something-wild-deer-hunter
There are legitimate concerns for both human health AND forest health where deer densities are too high. Agree that white footed mice are probably the more significant vector for black legged ticks and hence the name change from “deer tick.” Ultimately it is oak acorn mast cycles that drive the number of mice and deer and then the number of ticks and ensuing rates of human Lyme disease