In addition to eagles, we often see ospreys in the air above the farm. In most cases, the osprey is high up either passing by or circling. On the occasion that an osprey perches in the vicinity, it usually is at a distance in one of the tall conifers in the forest that surrounds the farm. When I see a perched osprey, I try to take its picture. Even though I have a fine telephoto lens, these pictures of the far-away bird are quite a stretch for the camera. Nonetheless, the pictures are good enough to supplement the text with a characteristic image.
Figure 1 – Although ospreys don’t visit the farm per se, they do perch in the tops of tall trees in the nearby forest. It is not unusual for ospreys and eagles to carry out some of their aggressive encounters in the air above the farm.
9 May 2022 - morning
When I went out on the porch to set up the telescope, my attention was drawn to the nagging ‘caw’ of a distant crow. The crow was off to the west, flying above the trees, and harassing an eagle. But the eagle was chasing an osprey. The three of them flew in a tight, rising spiral with the osprey leading the way. I couldn't tell through the binoculars, but the osprey must have been carrying a fish, or else the eagle would not have been interested. The eagle was engaged in an act of kleptoparasitism – attempting to steal the fish that the osprey had caught. The crow, itself an avian thief of the first order, was pestering the eagle because that is what crows do when they are not out stealing something.
Higher and higher the spiraling trio rose until the eagle finally broke off the chase and flew north; whereupon the osprey flew south. The crow followed the eagle and continued to harass it as the pair of them flew out of sight.
Jean came out on the porch to witness the final act of this little drama and I continued my task of setting up the telescope. One of these days, I will be prepared with the scope and camera at ready and be in a position to photograph some part of these brief little skirmishes.
11 May 2022 - afternoon
Two days later, as I was touring the grounds, I saw Barley, the farm’s self-appointed guard dog, intently looking up and watching something in the sky. When I followed her line of sight, I saw an eagle and an osprey. This time, however, the osprey was chasing the eagle!
How is it that in one instance, the eagle, larger, stronger, and possessing the most formidable set of lethal talons in the bird world, chased the osprey and in another, the osprey, smaller than the eagle but still large with its own set of lethal talons, chased the eagle?
My guess is that in the first instance as I previously surmised, the eagle was attempting to steal a fish from the osprey as they are known to do. However, eagles not only steal fish from ospreys but are also notorious for taking osprey chicks out of the nest. In such instances, ospreys near the nest will attack eagles to protect their chicks. I think the osprey that Barley and I saw chasing the eagle had a nest nearby and was engaged in the parental defense of its young. Parental defense can bring out the most aggressive behavior a bird is capable of.
Figure 2. An ogre among birds - with dagger-like talons, flesh-tearing beak, large penetrating eye under a bony brow ridge, awesome size, and apparent strength the eagle’s impression is of a fearsome creature that perpetrates fear and deference among its feathered brethren. But this is true only to a certain extent as discussed below.
Put in Perspective
The Bald eagle is the region’s apex avian predator. One would think that the apex predator would be free of harassment and challenge by those that are further down the food chain. The two episodes above demonstrate that even the mighty top dog is vulnerable to pestering and attack. I could recount other instances in the past where I observed subordinate species aggressively attack and chase eagles. This goes beyond the simple annoyance that many small birds visit on eagles when situations arise that stimulate the small bird to protest the eagle’s presence and includes actual injury-causing combat between an aggressor bird, like a red-tailed hawk or a Canada goose, and the eagle.
These two recent eagle-osprey interaction sightings in the airspace above the farm suffice to demonstrate that life on the top is not all peaches and cream. In fact, the top predator must seek a narrow set of circumstances in order to exert its advantages and be successful in its way of life. Outside of these favorable circumstances, life, even for the top predator, can be traumatic and subject to jeopardy.