Happy Earth Day to everyone!

The first Earth Day was celebrated on April 22, 1970, by 20 million people across the country, and every year since then concerned citizens in America have tried to mark this day as a moment to raise awareness about our environment. If you’d like to read about how Senator Gaylord Nelson organized the first Earth Day back in 1970, visit the Wilderness Society website for more information.

In honor of this day, I thought it would be a good time to talk about the interesting relationship that exists between eagles and ospreys — the two wonderful raptors that we celebrate with our web cams. Eagle and osprey populations in the U.S. were not always as healthy as they are today. In the post World War II years, large amounts of the insecticide DDT were introduced into their environment, and the poison affected the ability of eagles and ospreys to reproduce successfully — much in the same way that DDT in the waters off California is affecting the reproductive success of eagles in the Channels Islands today. The eventual recovery of eagle and osprey populations was greatly helped by the environmental awareness that grew out of events like Earth Day and the publication of Rachel Carson’s seminal book Silent Spring. In fact, DDT was banned in America two years after the first Earth Day was held.

Eagles and Ospreys

Blackwater National Wildlife Refuge is fortunate in that it has a large population of both eagles and ospreys, so confrontations between the birds here is not uncommon. Often when the two raptor species tangle, the battle is about fish. Ospreys are considered perhaps the best anglers in nature, and while eagles are also skilled at catching fish, they are better known for being opportunists that will sometimes use their larger size and greater power to steal a fish from an osprey rather than catch it themselves.

The bald eagle’s propensity for theft is what gave it a less than noble reputation in the eyes of founding father Ben Franklin. In a letter to his daughter, Franklin voiced his objections about the eagle:

“For my own part I wish the Bald Eagle had not been chosen the Representative of our Country. He is a Bird of bad moral Character. He does not get his Living honestly. You may have seen him perched on some dead Tree near the River, where, too lazy to fish for himself, he watches the Labour of the Fishing Hawk; and when that diligent Bird has at length taken a Fish, and is bearing it to his Nest for the Support of his Mate and young Ones, the Bald Eagle pursues him and takes it from him.”

Biologists today are not as critical of the bald eagle and recognize this fish-stealing habit as an effective survival skill rather than a moral defect. And the eagle does often find success because despite efforts on the part of the osprey to keep its fish, many accounts of the birds’ battles end with the osprey being forced to drop its meal. But if the osprey puts up a fight, then you might see something more dramatic.

In the book The Bald Eagle: Haunts and Habits of a Wilderness Monarch, one of the authors describes an event on a Saskatchewan lake that showed a surprising twist to the usual skirmish:

“The eagle attacked from a few feet above and to one side of the Osprey — once, twice, and then a third time. On each pass the Osprey visibly flinched, for the eagle’s talons barely cleared its back. We anxiously awaited the outcome. Many observers had described how typically the Osprey drops its fish, and with surprising agility the Bald Eagle snatches the fallen prey in midair. We were not prepared for what happened. After three unsuccessful attacks, the eagle turned to brute force. This time coming up fast from behind and below, the eagle flipped onto its back, thrust its talons upward, and ripped the fish right out of the Osprey’s grasp. What a sight! After quickly righting itself, the eagle turned and flapped leisurely to deposit the booty on its nest.”

During the times when the osprey comes out on top, it’s often because it outsmarts the eagle. For example, sometimes osprey couples will team up to protect their food from the eagles. Our Blackwater ranger, Tom Miller, witnessed this when he saw an osprey fly toward an eagle to intercept it while the osprey’s partner quickly flew to the home nest with the fish.

In addition, ospreys can be even more aggressive if they’re protecting their young and their home nest. At Pelican Island National Wildlife Refuge in Florida, local photographer Bob Montanaro captured this type of event on film as he watched a group of four ospreys drive off a group of immature bald eagles that were flying too close to the ospreys’ nests. Be sure to view these amazing photos where you can see the osprey aggressively flying at the immature eagle and making it clear that the ospreys will not tolerate the eagles in their territory.

At Blackwater, our ospreys at the Osprey Cam nest will react to bald eagles that are perched in the woods to the left of the nest. You can’t see these woods on the cam image, but it’s an area where eagles sometimes like to sit, and the close proximity to the osprey platform makes the ospreys agitated when an eagle is there.

A few years ago, I was at the Refuge with my video camera and was lucky enough to capture an episode showing the cam mother chasing off an eagle that was trying to perch in the trees near the cam. The first video below shows the eagle flying into the trees near our Osprey Cam nest and the other shows the mother consequently dive-bombing the eagle. In this instance, the mother did a good job of sending a strong message to the eagle, but it was somewhat risky for her to have to leave the chicks alone to do this. (Left-click on the Windows Media Video file links below to play, or right-click on the links and choose “Save Target As” to download to your computer):

Eagle Flyby (3.5MB)
Osprey Dive-bombing (2.5MB)

Just recently, photographer Bob Quinn was out at the Refuge and witnessed a similar episode between our Osprey Cam birds and an eagle that had been sitting in those trees. His photo (on the right) offers a dramatic glimpse at how these aerial battles look when a smaller raptor tries to take on a much bigger challenger.

Even with all the ospreys’ spunk and determination, there is no denying the fact that bald eagles are more powerful. A great example of this can be seen on a YouTube video I saw recently that shows a bald eagle taking a fish away from an osprey on Lake Merwin in Washington state. The speed with which the eagle overtakes the osprey is truly amazing to watch. The chirping you hear in the background is the osprey “yelling” at the eagle for stealing its meal. In such a situation, there’s not a lot the osprey can do but accept the fact that the eagle won this battle.

[A sidenote to teachers and parents — this video includes a slightly muffled profanity at the end by one of the observers in the video who got excited watching the scene, so just a little warning for the youngsters in our audience.]

Happy Earth Day!

Until next time,
Lisa - webmaster
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eagles, wildlife refuge, eagle cam, osprey cam, Blackwater Refuge, Maryland

 

This entry was posted on Tuesday, April 22nd, 2008 at 6:51 am and is filed under Eagle Videos, Blackwater NWR, Immature Eagles. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.