I never met Bill Silliker Jr., but I am a fan of his work. He was a nature photographer who passed away in 2003. He was based in Maine, and his specialty was moose. His work graced calendars, magazines, books, you name it. The other day I pulled his book “Moose — Giant of the Northern Forest” off the shelf. He wrote it in 1998 and it is, of course, richly illustrated with his fantastic moose photos.

Again, I never met Mr. Silliker, but his writing comes across as down-to-earth, compassionate and deeply caring about the animals he photographed. The book’s chapters discuss various aspects of moose: history, behavior, rut, etc. At the end of the book, he discusses the many threats to moose. Among them are car and train accidents, predation by bear and wolves (Alaska and western U.S.), and humans by way of pollution and habitat destruction.

He also notes that brainworm “may be the most serious health hazard moose face in regions where their range overlaps with that of the parasite’s carrier, the white-tailed deer.” That concern is indeed playing out, particularly in southern New England, where brainworm is thought to be the chief enemy of the moose population, according to biologists in the region.

Mr. Siliker also writes that tick infestations “sometimes play a role in depleting the health and resistance of moose.” Fast forward 20 years from the book’s publishing and ticks have played a major role — perhaps the major role — in the sad and precipitous decline of moose in northern New England and other parts of its range.

Ticks are mentioned in only one sentence in the book. If the book were revised, ticks could be a whole chapter or more. N.H. Fish and Game biologists say mild winters that start later in the year are the reason these “winter ticks” are able to thrive.

A later-starting winter gives the ticks that much more time to find a host. As I have heard it described, winter ticks quest (look for a host) as a group so when one tick finds a host, hundreds of other interlocked ticks come along for the ride. That’s how tens of thousands of ticks can end up on one animal. Once on the moose, the ticks are set for the winter as they are protected from the weather by the moose’s thick hair and fed by the animal’s blood.

There’s not much that can be done about it, other than hope for the return of colder winters, which does not seem imminent. You can’t spray pesticides on millions and millions of acres of forest, and you can’t capture all the moose to equip them with collars that would need to be replaced periodically. Neither option is at all practical. Hope, however, is not a good strategy, and I’m confident biologists are working on solutions to the problem that has essentially cut in half New Hampshire’s moose population from 7,500 in the 1990s to between 3,000 and 4,000 now.

We are four years into N.H. Fish and Game’s Game Management Plan, which is revisited every 10 years. The tick problem started more than four years ago, so I am hopeful the current plan is having a positive impact or at least being further analyzed.

I visited moose country in northern New Hampshire last month. I saw three moose during one canoe ride: a cow with twin calves. I can recall a visit in the early 2000s when I watched four moose at once grazing in that same small pond at dusk. I likely saw three or four moose on the way back to camp that night too.

Those days appear to be gone, but hopefully not forever. I bet Mr. Silliker would feel the same way.