N.H. deer are doing well, thanks to warmer winters

Warmer winters might be hurting, or at least confusing, a lot of species, but not white-tailed deer – as I reported in the Monitor on Thursday:

New Hampshire hunters killed more bucks – adult male deer with antlers – last season than in any other hunting season on record, an indication that the state’s deer population is growing, partly because winters are getting easier for them.

“In many parts of the state, the population is higher than it has been in a long time,” said Dan Bergeron, a wildlife biologist with the New Hampshire Fish and Game Department.

The total deer killed in the three 2017 hunting seasons – firearms, archery and muzzle-loaders – was 12,309, which is not a record but is one of the highest totals in the past three decades.

Notable was the number of bucks killed: 7,708. That is more than at any time since records started being kept in 1922, according to Fish and Game. It is even more than in the mid-1960s before modern hunting seasons were set, a time when so many deer were killed by hunters that the population crashed and the state took firmer control of seasons.

These numbers indicate a healthy herd, biologists say, because they show that many males are surviving into their second year, when they grow antlers.

It’s also good for the finances of Fish and Game because hunters prefer to get deer with antlers. Success may prod them into buying more hunting licenses, which is a major source of funding for the state’s game and non-game programs.

One factor in deer population growth is milder winters. Fish and Game has calculated what it calls a Winter Severity Index (WSI) since 1964-65, which counts the duration of snow depth greater than 18 inches and minimum temperatures below zero degrees at a number of locations from December through April.

“The statewide average WSI for the winter of 2016-17 was again below the long-term average,” according to Fish and Game’s annual report on hunting results, the Wildlife Harvest Summary, which says the trend of milder winters, especially in the North Country, will likely contribute to growing deer numbers.

Bergeron said that despite this winter’s extreme cold snaps and late-arriving snow, “the deer seem to have made it through pretty well,” perhaps because a warm spell in January and February broke up the stretch of difficult weather.

The number of deer killed by hunters in various locations, as well as the condition of the animals measured by state biologists at check stations during hunting season, has long been used as a way to determine the health of several species in New Hampshire, notably white-tailed deer.

Data recorded at check stations includes such things as age, general condition and size of antlers. In total, the numbers “suggest a deer population in good physical condition and below the biological carrying capacity of our deer habitat,” the report said.

Particularly in the state’s southeast quadrant – near the Seacoast – with milder weather and good soils supporting vegetation, the main issue facing the state is how to decrease the deer population, and to reduce interaction with people.

According to data from the past two years’ hunting seasons, the estimated deer population is twice what long-term management goals say it should be at the Seacoast and nearby Massachusetts border. In central New Hampshire – in the area around Concord, Laconia and Plymouth – the estimated population is between 5 and 14 percent higher than the long-term goal.

North of the White Mountains, however, the estimated population is as much as 50 percent less than is sought in the state’s long-term Big Game Management Plan.

Every two years, the state adjusts hunting seasons based on estimates of animal populations, which is why, for example, hunters can legally take one more deer in Rockingham County than they can around Concord.

“In a lot of the units, we’ve actually expanded hunting opportunities. The next two years there should be more opportunity for hunters, especially in the southern parts of the state,” Bergeron said.

New Hampshire is near the northern end of the white-tail deer’s traditional range.