OK, so it sounds weird, but I have to give up my skull collection to make room for my book collection as I downsize into a smaller office.

They are my pretties, these skulls, which I started collecting after a friend who was in charge of the dermestid beetle room in the local natural history museum showed me how easy it was to clean an animal head you might find on the side of the road. Of course, demestid beetles are not pets you want to keep laying around the house, since in addition to eating skin and such, they also eat fabric—from clothes to carpets. One demestid beetle species is a menace to violin players, feeding on the horsehair in their bows stored away in their cases.

I started my collection with mammal skulls, almost unexpectedly, after my sweet yellow Labrador retriever was out on a hike with me and spotted a woodchuck headed back to its den. He caught the hapless creature in a flash and with a quick headshake it was all over. Somehow I thought I could atone for this negligent act by preserving the cranium as a totem. Not having beetles handy, I opted for the boiling method at my girlfriend’s house —add a little Clorox to a large pot of water over high heat. The relationship did not survive, but I got my first elegant whitened skull.

You really do not appreciate how closely related a woodchuck is to a squirrel, a muskrat or a beaver until you have lined up their three crania next to each other. Or at least I didn’t. Ah, rodentia, what beautiful teeth you have!

By the time I had graduated to the furbearers and found the skulls of mink, marten and river otters, I was on my way.

While I was still cruising timber, sympathetic trappers were quite helpful. Soon friends were sending me little gifts they had found. Married at this point, I had learned it was better to clean the skulls outdoors on a Coleman stove, actually as far away in the back yard as possible. Our boys somehow never really caught the fever.

But there’s still time.

My wife did draw the line at adding the skulls of family pets to the collection, which had seemed to me a way we might experience an intimation of their immortality. Feline skulls are so foreshortened next to canines.

When I started surveying islands, an intact seal skull became a true treasure. My mother-in-law even got into the act. Ever wonder what to give your daughter’s difficult-to-shop-for husband on his birthday? A bit of a seal carcass is just the thing.

On a trip to the Florida Keys, I found a bottle-nosed dolphin skull, which has a brain cavity bigger than mine, huge side-mounted eye sockets and the strangest looking nose projection you could ever imagine.

Bird skulls also became an obvious passion on island surveys. Gull skulls are ubiquitous, but absolutely elegant. If you think of their raucous calling as irritating, find a skull and you will be mesmerized by its beauty. A heron skull is bizarre, but looks small next to a pelican skull from Florida. And in less complicated days, friends journeying to the tropics brought me back a toucan skull from the Ecuadorian rainforest and an albatross skull from the Galapagos.

But the absolute prize in my skull collection came from a voyage to the remote coast of Kamchatka in the Russian Far East, on a fabulous expedition vessel, Turmoil, commissioned by my late, great friend Gary Comer, founder of Lands’ End.

We were one of the first private vessels to be allowed to cruise along this previously heavily fortified coastline facing Alaska’s military outposts across the Bering Sea. All our papers were in order describing how we would be allowed to go ashore. We had a translator from Moscow aboard, who informed us that we would be allowed everywhere we requested except for one wildlife island that was closed to protect the wildlife. When we got to the last town before we headed east to cruise along the Aleutians, our translator got off and we cast off, headed for America.

Our course happened to take us past the wildlife island that we could see was teeming with horned puffins, auks and murres so we lowered the outboard to cruise under the magnificent white-streaked cliffs. Photographing away at the variety of seabird life under crystal blue skies and flat calm seas, we noticed a small beach under one of the cliffs and decided we would rather ask forgiveness than permission, and landed.

Almost immediately we understood why the island had really been closed. There was a slightly weathered walrus skull with the ivory missing along with a significant chunk of the back of its incredibly thick cranium. Clearly, in the confusion and corruption of post-Soviet time, ivory hunters had preceded us. That, along with a bacculum, which if you Google, you will discover is how various marine mammals participate in reproductive fun, are the highlights of the collection. The size of the bacculum gets the giggles, but the enormity of the skull astounds me even more.

As I prepare to bring my collection of island history, ecology and reference books back to my home office, I need to make shelf space. The skulls should find a new home, maybe at the local high school biology teacher’s room.

But on second thought, maybe the books should go to the town library”¦.

Philip Conkling is president and founder of the Island Institute.