Lessons from Travels: Alaska Predators

by Carl Strang

My thesis research back in the early 1970’s focused on glaucous gulls as predators.

Glaucous gulls, like the other gull species, have a very broad diet.

Glaucous gulls, like the other gull species, have a very broad diet.

My host, the U.S. Fish & Wildlife Service, was especially interested in the gulls as predators of goose eggs and goslings.

Goose egg probably consumed by a glaucous gull.

Goose egg probably consumed by a glaucous gull.

I found that coastal gulls were mainly after seafood. They were opportunists that took advantage of exposed nests and broods, but birds were not their main target. In fact, geese often nested within the gull nesting colonies.

A gull stands at its nest while a brant makes clear that they aren’t buddies even if they share a nest pond.

A gull stands at its nest while a brant makes clear that they aren’t buddies even if they share a nest pond.

Inland gulls were more focused on terrestrial prey, but they were widely scattered pairs and so their impact was limited. I spent many hours watching predator activity.

This observation tower built by Pete Mickelson, a previous researcher on the inland site, was one of several observation posts. A raven used the storage box, which was open on one side, as its overnight roost.

This observation tower built by Pete Mickelson, a previous researcher on the inland site, was one of several observation posts. A raven used the storage box, which was open on one side, as its overnight roost.

Even that far north, the number of species of both predators and prey was impressive, and as I watched the predators working the landscape I sensed the turns of the ecological dance they were performing in the summer. Here are some of the major players on the predator side, in addition to the glaucous gulls, in western Alaska.

Parasitic jaegers had a strong interest in shorebirds and waterfowl as prey.

Parasitic jaegers had a strong interest in shorebirds and waterfowl as prey.

The smaller long-tailed jaegers focused more on small rodents, but also fed on the smaller birds.

The smaller long-tailed jaegers focused more on small rodents, but also fed on the smaller birds.

Red foxes could prey on adults of the smaller geese, but ducks, eggs, goslings and rodents were more important to them.

Red foxes could prey on adults of the smaller geese, but ducks, eggs, goslings and rodents were more important to them.

Arctic foxes reminded me of little puppy dogs. I remember them systematically removing and caching goose eggs in the tundra for later consumption.

Arctic foxes reminded me of little puppy dogs. I remember them systematically removing and caching goose eggs in the tundra for later consumption.

The mew gull, a species much smaller than the glaucous gull, seldom showed interest in avian prey, focusing on invertebrates and small fish.

The mew gull, a species much smaller than the glaucous gull, seldom showed interest in avian prey, focusing on invertebrates and small fish.

The lesson was to attend to the predators in any landscape, and it informs me to this day.

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