Story last updated at 12/23/2009 - 12:19 pm
To say bald eagles are kleptomaniacs wouldn't be quite correct-they do have a persistent impulse to steal, but for them it is not abnormal. More precisely, they engage in kleptoparasitism. A parasite takes without making any useful return and for the eagle it is parasitism by theft-a form of feeding in which one steals another animal's food rather than hunting for themselves. Of course eagles hunt, but I'm amazed at the amount of energy eagles expend chasing other animals, especially birds, in an effort to appropriate their dinner. Watching them from around my remote cabin, it appears they are unsuccessful more often than not.
Eagles commonly target osprey for food stealing as I observed one summer afternoon from a boat in the bay at Whale Pass. A mature bald eagle gave chase to an osprey that had just nabbed a nice fish, sending both raptors into a high speed circling of several small islands. The eagle was in hot pursuit for a few laps until it suddenly just gave up and took a seat with a view in a treetop. It wasn't long before the osprey had another fish and the relentless eagle couldn't resist its kleptoparasitismizing tendencies-but again without success.
Mink and river otter can be intimidated into abandoning their food (usually rock crab) when they notice a diving eagle intent on ruining their day. They'll sacrifice their brunch entree for a chance to hunt again tomorrow. Crabless mink aren't always so lucky and may get plucked off the beach before reaching the safety of rocks or rootwads. Such are the intricacies of food chain hierarchy blackmail.
If you spend enough time in remote areas, you can see all kinds of interesting animal interactions. One day last summer as I paddled my kayak along the shoreline, I sensed something and, glancing to my left, was astonished to find an eagle flying right alongside me, heading for a tree where it alighted next to another eagle. A small black bear was immersed in feeding in the tall grass below the tree.
Suddenly the two-feathered figures flew down and landed near the bear with the closest eagle just a few feet away, on the other side of a small log. The startled bear stared at the eagle for about 10 seconds, then surprised me by hopping over the log and right up to the eagle, nudging it playfully. It now displeased the eagle to have this curious bear in its personal space and it made haste to return aloft where bears are seldom found.
The bear, by the way, continued tearing and chewing the grass noisily until I began to paddle, at which time it finally noticed me, looking back with a puzzled stare and a comical mouthful of grass protruding in all directions.
Sometimes our national bird will settle for leftovers, like when they join the river otters on my small, anchored float. The otters think it is their designated picnic area, even requesting beach umbrellas one time. They are constantly on the float slurping sculpin and crab, which naturally attracts eagles. Adult otters are generally a little hefty for an eagle to haul off so the eagles land on the float and crowd around the otters who seem to ignore them, although I'm sure they would prefer privacy. I haven't noticed any real aggression on the part of either species and the otters will finally swim away, leaving a meal of succulent fish heads for the patient eagles.
The good news for animals with the potential to become eagle fodder is deer hunting season. The discarded carcasses are a welcome source of food now that the salmon are gone. Scavengers that they are, I expect eagles appreciate the easy food. Ravens and crows must also be grateful as well along with, indirectly, poodles, who are typically in favor of well fed eagles.
One way or another the bald eagle prevails in Southeast Alaska, a place that suits their lifestyle. It's great to have them around!
Carla Petersen may be reached at firstname.lastname@example.org.