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Orca kills? (1 Viewer)

GeorgeMac

Sutherland
For the last two years, large numbers of dead seagulls are being washed up on Brora beach. The tides tend to bring stuff down the coast, so I'm guessing a lot of them come from perhaps the Helmsdale area.

The thing is, these are not the usual dead birds that wash up whole and then get pecked to bits. These are coming ashore fresh but completely sucked dry of all flesh.

I know orcas take birds from the surface, but I'm beginning to suspect they suck them dry and spit out the feathers. Could these be orca kills? I've never seen an orca off Brora, but they could be coming closer if these are indeed orca kills.
 

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RafaelMatias

Unknown member
Portugal
I wouldn't think anything mammalian could be responsible for the killing/eating. There's no visible evidence of chewing or broken bones, all meat seems to have been removed quite delicately. I'd suspect more of some kind of fish or crustacean (crabs, etc). Death might have been independent (disease?) from the creature that has eaten those gulls.
 

jurek

Well-known member
May be interesting to investigate, because it seems pretty one-off thing. Maybe just one individual seal learned to feed this way?
 

RafaelMatias

Unknown member
Portugal
How would a seal remove the meat without chewing through the rib bones and sternum? Those are really fragile bones, easily broken; and they are also soft, they surely would have been eaten as well. This looks like a bird that is (relatively) long dead and the meat is starting to detach from the bone (as can seen on the legs muscles). This, unless seals learnt how to use a scalpel.
 

GeorgeMac

Sutherland
There are dozens of these turning up on the beach. There are 2 or 3 fresh ones just about every week. This particular bird came ashore with the tide as I was walking by. As Rafael says, fragile bones are not broken and there are no signs of chewing. This bird is quite fresh, it hasn't been dead very long, and its eyes have not even been pecked out. To me it looks as if it has been sucked out of its juices, like all the others. In this photo you can see that the bird's eyes are moist and fresh, as is the flesh on the rib cage, and that's its tongue sticking out which doesn't suggest death by natural causes. In my opinion, the bird has only been dead a day or two. I'll take a few piccies in more detail next time I come across one.
 

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RafaelMatias

Unknown member
Portugal
There are dozens of these turning up on the beach. There are 2 or 3 fresh ones just about every day. As Rafael says, fragile bones are not broken and there are no signs of chewing. The birds are also fresh, they haven't been dead very long, and their eyes have not even been pecked out. To me they look as if they have been sucked out of their juices. In this photo you can see that the bird's eyes are moist and fresh, as is the flesh on the rib cage, and that's its tongue sticking out. In my opinion, the bird has only been dead a few hours. I'll take a few piccies in more detail next time I come across one.
That's interesting, and I'd say it clears crustaceans/crabs. Don't know what to think really.

10 years ago or so, when I was working on the Falklands, there was a bull Southern Sea Lion that had the somewhat unusual habit of hunting Gentoo Penguins, a species whose skeleton is much more robust than that of a gull and the victims would become actually quite bashed (especially on the rib cage); the sea lion would grab the penguin by the lose skin of the neck and would throw it around until it managed to skin it; this same sea lion appears on film in one of the BBC documentaries (Life in the Freezer? Frozen Planet? Blue Planet? in one of these, Frozen Planet maybe), the production of which I had the privilege to witness.
 

Andrea Collins

Beside the Duddon, Cumbria
Supporter
England
Great Skuas perhaps? They are certainly capable of killing large gulls and would likely tear the carcass open and feed on it out on the water, leaving the remains to drift away on the tide. Perhaps one individual pair have taken a liking to large gulls.
 

RafaelMatias

Unknown member
Portugal
Great Skuas perhaps? They are certainly capable of killing large gulls and would likely tear the carcass open and feed on it out on the water, leaving the remains to drift away on the tide. Perhaps one individual pair have taken a liking to large gulls.

This makes sense to me.
 

GeorgeMac

Sutherland
I like that suggestion Andrea. I was thinking perhaps sea eagles, but discarded that idea as I would have thought they would take their prey to land to scoff. What we can safely assume is the birds are being taken at sea, so either from the surface or from the air. Sea Eagles I've ruled out as I'm convinced they would take their prey to shore. I don't think we have any predatory fish around here. In fresh water, pike could certainly do this. If we don't have any predatory fish, then orca was the only thing I could think of. I know great skuas prey on young, but didn't know they could take adult birds. There are Great skuas here as I see them out at sea regularly. If they can take adult birds and feed on them out on the water, that would certainly account for the clean fresh carcases being washed up.

I envy you your time in the Falklands Rafeal. That's quite a life experience to savour.
 
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GeorgeMac

Sutherland
I'm just back from another walk along the beach and I think we can clear this one up, as well as another little mystery that's puzzled me for some time.

I've been here since the 1970s off and on, and I've never seen crows on Brora beach. Well, not until 2 years ago. Why would crows show up 2 years ago? Never understood that.

This morning I realised that the crows showed up about the same time as these carcasses began washing up on the beach. My guess is this small crow colony owes its existence to a pair of Great Skuas who have acquired a taste for herring gull. The way nature balances itself is amazing. Here's a hoodie (or a hybrid) feasting this morning on Great Skua leftovers.
 

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GeorgeMac

Sutherland
There is a good way to test this theory. If after the breeding season and the Great Skuas are gone, if the carcasses disappear and return next year, that will pretty much confirm it.
 

GeorgeMac

Sutherland
Quick update. I found a photo I'd not worked on, a fresh corpse I'd seen on 30th May. I've not seen any fresh kills since that last one. This bird is a northern fulmar. I'll keep my eyes open and report if and when they start turning up again.
 

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Andrea Collins

Beside the Duddon, Cumbria
Supporter
England
I'll be happy to be proved wrong but I'm even more inclined to think Great Skua on the basis of that photo. The Fulmar's wings would surely be mangled if it was a marine mammal, and other birds that might target Fulmars, such as Peregrines or White-tailed Eagles would carry their prey away rather than leaving the remains on the water.
 

GeorgeMac

Sutherland
I'm pretty sure it isn't the seals scoffing them. By the way, I spotted 2 adult shelducks yesterday with 3 ducklings. Nice to see them here!
 

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