I live in a part of Connecticut where we have alot of estuaries and rivers leading into the sea. And every year, the Bald Eagles follow the Ice down from the North and winter in my area. This morning I saw a large Osprey pick up a decently large fish - probably a sea trout - out of the Connecticut River. It was a magnificent sight, not one I get to see very often.
Anyway, I got to wondering: If an adult eagle weighs say 15lbs, how much weight can it lift up off the ground, or out of the water and effectively carry a distance?
Furthermore, if anyone has seen a hawk or eagle pounce on something on dry land and kill it, it is quite a dramatic sight. There is usually a lot of jumping, and squeezing of the talons to kill the prey. Anyone know how much force those talons exert on any given prey? Are we talking breaking bones strong? Or just razor sharp, mutilating strong?
Just some anectdotal stuff here. I have done some wildlife veterinary work earlier in my career. Working on a golden eagle, we had one person holding each foot. The leg muscle strength was impressive.
I met a man once who attempted to treat a bald eagle solo before his coworkers arrived at the bird rehab/sanctuary where he worked. He caught the bird (It was unable to fly), then gave it an injection. The bird managed to get a foot loose and grabbed the man’s forearm. He attempted to maintain the other leg and tried to work the talons out of his flesh. Blood made this slippery work and he lost hold eventually of both feet. The bird repeatedly repositioned its grip.
If I were the one being mangled by an eagle I would have broken the birds neck first thing. But this guy refused to kill the bird. Took him a long time to work free of the bird’s grasp. Today (twenty years later) he looks like his arm was chewed up by a bear. Not pretty.
I’m guessing the tallons can exert a few hundred pounds of force. I’m basing this on what the avian vet and bird expert at Flamingo Gardens (A wondrous place in Florida dedicated to rescuing, healing, and preserving wildlife and to teaching tourists that nature should be respected rather wrapped in plastic and exploited) told us about a crippled owl. She wore a very thick leather glove when showing the birds. IIRC The two front talons pick up the prey. The back talon either crushes or stabs the prey to death. The woman mentioned that she sometimes got bruises through the glove. This was most obvious when she tried to put the birds down. They were very fond of her, didn’t want to be put down, and dug in with their talons.
Phlosphr Remember that both Colibri and Brachyrhincos have ornithological type degrees. So, if you can endure the Monty Python references until one of them arrives, you’ll get a thoroughly detailed scientifical answer.
To The Python Quoters
He said Conneticut! We are discussing neither African or European birds. BTW- Your father reeks of owl droppings. Now, go away or I will taunt you a second time.
Thanks Colbri - I was watching the Osprey again this morning, though they didn’t fetch anything out of the river, they were impressive to watch! I cannot believe how massive they are. I wonder fi they are bigger than the Bald eagles that are coming soon.
I have friends who are into falconry. One of them for a while did some work “hacking” young (but full size) golden eagles - getting them ready for release to the wild.
On a couple of occasion I’ve had these birds on my arm and experienced their grip strength. I made no measurements, but it is certainly impressive. It should be noted that the strength is largely for the purpose of closing their talons (as they would be used to puncture and kill prey). If they had that same strength available to, say, twist their legs, you could easily believe they could break your arm at will - but they don’t, and this is not a danger.
But if they decide to get nasty (which is rare, and usually happens when they think someone may be interfering with their meal) they can be dangerous. The gloves are of thick leather, but probably not nearly thick enough to stop a talon.
Interestingly, though their beaks could also be a formidable weapon, they rarely or never seem to use them this way. I’m told this is because of the possible danger to ther eyes, which are probably a bird of prey’s most valuable asset.
No, Ospreys are only about a third the size of Bald Eagles. They weigh up to 2 kg (4.4 lb) while Bald Eagles weigh 6.3 kg (14 lb).
In general, birds of prey can lift and fly with prey weighing up to about one-third to one-half their body weight. Ospreys typically take fish around 300 g (0.7 lb), though they can occasionally take them up to 1.2 kg (2.6 lb).
The heaviest eagles are the Harpy Eagle of the rainforests of tropical America, and the Steller’s Sea Eagle of the North Pacific, both of which weigh in at up to 9 kg (20 lb).
Harpies regularly take monkeys and sloths. Three-toed sloths weigh up to about 5.5 kg (12 lb) and are within the eagle’s capacity to carry. Larger prey can be taken, but the eagle must either eat it on the ground or dismember it if it is to be carried back to the nest. We had a captive-bred Harpy here in Panama that had been released into the wild and was being radio-tracked. On one occasion he killed a young deer, but he ate it on the ground.
The largest birds of prey of all are the Lappet-faced Vulture of Africa, weighing up to 14 kg (30 lb) in captivity (but normally much less), and the Andean Condor, one of the heaviest flying birds, which weighs upt to 15 kg (33 lb). However, these are both scavengers.
This month I have been working mostly on a raptor project. Every year most of the North American population of Turkey Vultures, Broad-winged Hawks, and Swainson’s Hawks pass through Panama en route to wintering areas in South America. This year, working with the Panama Audubon Society and Hawk Mountain Observatory in the U.S., I organized “Raptors Ocean to Ocean,” a effort to count as many as possible of the birds that were passing through the Isthmus, which is about 50 miles wide here. We set up 9 watch sites in a string streching from the Atlantic to the Pacific, from which we can count most of the migrating flocks. In the first three weeks we have counted 1.6 million raptors, and I hope to crack 3 million by the end of the watch period on November 14. Our biggest one-day count from a single site has been 238,000 birds, of which 150,000 passed in just one hour.