As a kid, I was a deadly predator. I spent hours and hours hunting and fishing. Even though Dad was a wildlife photographer and I worked for him in summer – mostly doing errands and yard chores – I had little if any interest in cameras or birds. The few photos I took under Dad's direction did not ignite passion.

My lack of interest in photography continued through college where I majored in English literature. Upon graduation in 1971, I was ill-prepared for the work-a-day world, and took a job as a substitute teacher in the Cincinnati public schools. A year of that was altogether too much. So I went back to work for Dad, this time full-time. In a way it made sense. I loved the outdoors, and here was a job that offered almost unlimited access. Now all I had to do was to learn how to use and love cameras.

The first part of the learning process – how to use a camera – proved embarrassingly difficult. Exposing a still picture properly in those days before anything was automatic required accurately balancing three different figures – film speed, shutter speed, and light intensity. All had their own bizarre number systems – for example, film speed was measured in ISO numbers ranging from 16 to 400; shutter speeds were in odd fractions of a second – or in some cases multiples of seconds; and light intensity was measured in an arcane unit called candlepower. Add to this things such as lens lengths, filters, reciprocity factors, depth-of-field and the mystifying task of determining an object of neutral density so you could get an accurate reflective light reading, and this former literature student nearly became a failure. It took at least a year to get consistent, decently exposed results.

The second part – learning to love photography – came later.

In 1975 we bought our first 35 mm camera, complete with a motor drive, to take on a trip to Canada's Victoria Island, which is a couple of hundred miles north of the Arctic Circle. Shorebirds like black-bellied plovers, ruddy turnstones, and red phalaropes thronged there for nesting. Ducks did, too, especially common eiders. To find photo subjects we would just start walking out across the tundra to see what stirred. Shorebirds usually snuck off their nest as we approached, but if we backed off 100 yards or so and watched with binoculars, the birds would generally lead us to the nest. The eiders stayed put, and sometimes you could even reach down and touch the incubating hen. I especially remember one hen that flushed when I lingered to take a photo. She had an even dozen eggs. After we left she returned to the nest, and whenever we passed her way again we could see her still sitting tight.

But the nest that made the difference belonged to snowy owls. We spotted it literally a mile away. The female stood out like a big white plastic bag on the pristine brown and green tundra. We set up a blind some distance back and gradually moved it in as the birds grew accustomed to it. When it was finally time to photograph, I used the new 35 mm camera, which was like a toy and fun to shoot compared to the very serious and cumbersome medium-format we had been using. The owls brought in a surprising variety of prey, perhaps because lemmings were scarce that year. Included were a char (a salmon-like fish) and a variety of shorebirds. But the item I remember best was the carcass of a common eider. An eider is a big duck and the owl struggled as she flew across the barren landscape with that huge piece of meat dangling from her talons. I used the motor drive to shoot the action, following her through the lens like it was the sight of a shotgun. It was as exciting as any hunt.

But that's not the whole story. Later that day we passed by the eider nest, and the hen wasn't on it. We checked the eggs. Several had been pipped, but all were cold. The owls were eating the hen. Maybe she moved too much while the ducklings were trying to hatch. In any event, the loss of that hen meant 12 fewer young birds would be added to the world's total eider population. A dozen! This was a really graphic illustration of natural population control right before our eyes – and recorded on film. To me, this was dramatic stuff – the science of life.

During the remaining few days we had on Victoria Island the owls continued to harvest birds we had already photographed. In particular, there was a string of eider ducklings. A hen we knew with ducklings on a nearby pond was now soon swimming all alone.

That owl nest more clearly than I could have imagined illustrated the biological principles I touched upon as a wildlife photographer – and hunter and angler. For some reason, from then on, pursuit of animals with a camera rather than a gun or rod satisfied my "primitive" urges. That is not to say that I have completely given up hunting. I still enjoy being in the woods or along the stream; but when I harvest deer and turkey there is no longer sport in the kill. I want the meat – whose purity and wholesomeness I trust more than that from the supermarket. Maybe that snowy owl nest made me a better predator, because photography satisfies my need for the outdoors. Now I no longer play when I go for the kill.