Aggressive seal in Plymouth Sound.

[penfold]

Where's Wally?

 

[TiggerToo]

Where's Wally?

Not in Plymouth

 

[AntarcticPilot]

Polar Bear? I doubt there is any predator other than a human.

Polar bears would be prey-sized for a Killer Whale. Killer Whales are top predators; basically nothing eats them. I don't think they've even been targeted by a fishery; too small and not prolific enough. Of course there have been opportunistic catches, but no targeted hunt.

 

[grumpy_o_g]

I don't suppose it helps that most diver are basically about 6' long, dark-coloured and roughly Seal-shaped. If i was a SEAL mum or dad to be or with a new-born or two I think I'd be fairly aggressive towards a stranger like that hanging around outside my home. Would bright yellow wet suits help?

 

[grumpy_o_g]

Polar bears would be prey-sized for a Killer Whale. Killer Whales are top predators; basically nothing eats them. I don't think they've even been targeted by a fishery; too small and not prolific enough. Of course there have been opportunistic catches, but no targeted hunt.

I think Sea-World is the killer whale's biggest threat...

 

[mjcoon]

I don't suppose it helps that most diver are basically about 6' long, dark-coloured and roughly Seal-shaped. If i was a SEAL mum or dad to be or with a new-born or two I think I'd be fairly aggressive towards a stranger like that hanging around outside my home. Would bright yellow wet suits help?

Do seals have colour vision? Do they need it to ensure they are not eating poisonous fish (which may advertise their deterrent)?

 

[AntarcticPilot]

Do seals have colour vision? Do they need it to ensure they are not eating poisonous fish (which may advertise their deterrent)?

Good question! They're fairly closely related to dogs (they share some diseases in common, which is a good reason for keeping dogs away from seals), and dogs have colour vision, but not like ours - I'd have to look it up, but I think they see red and blue but not green. That's from memory, though, and I may have got mixed up. But I'm pretty sure they only have 2 types of cone cell, not three, so their colour perception isn't like ours.

I once looked up whales' vision, and it appears that's similar - two colours, not three - but the sensitivity ranges are not like ours, so their colour vision is very different from ours. But for most whales and dolphins, if not all, sight is secondary to sonar.

 

[capnsensible]

Roses are grey.

Violets are grey.

I'm a dog.

 

[AntarcticPilot]

Roses are grey.

Violets are grey.

I'm a dog.

It's a common fallacy that dogs have no colour vision. It isn't true, but they do have less effective colour vision than ours (2 types of colour receptor, rather than three)

 

[oldmanofthehills]

Good question! They're fairly closely related to dogs (they share some diseases in common, which is a good reason for keeping dogs away from seals), and dogs have colour vision, but not like ours - I'd have to look it up, but I think they see red and blue but not green. That's from memory, though, and I may have got mixed up. But I'm pretty sure they only have 2 types of cone cell, not three, so their colour perception isn't like ours.

I once looked up whales' vision, and it appears that's similar - two colours, not three - but the sensitivity ranges are not like ours, so their colour vision is very different from ours. But for most whales and dolphins, if not all, sight is secondary to sonar.

Pure carnivores only need to see their prey. Good light sensitivity for dusktime hunting needs rods and this limits space for cones. Omnivores such as ourselves must distinguish unripe or poisonous berries etc from good to eat berries and colour vision pretty essential. Dogs as scavengers are somewhere in between I guess, and if seals are related they will come out the same.

I am surprised whales have any colour vision as they are related to deer, but the split was long long ago

 

[AntarcticPilot]

Pure carnivores only need to see their prey. Good light sensitivity for dusktime hunting needs rods and this limits space for cones. Omnivores such as ourselves must distinguish unripe or poisonous berries etc from good to eat berries and colour vision pretty essential. Dogs as scavengers are somewhere in between I guess, and if seals are related they will come out the same.

I am surprised whales have any colour vision as they are related to deer, but the split was long long ago

I looked it up in response to a question about whether the colour of antifouling would have an effect on the likelihood of a whale attack - it's on here Pilot whale attacks! But the outcome was that yes, they can see colours, but not in any way we can relate to.

 

[Daydream believer]

I was windsurfing in the Blackwater one day & felloff in the fairway, whilst trying a carve gybe. I was getting my breath back by the board when I heard a shot of air. I looked round & 10 feet away was a large head sticking out of the water. I did one of the quickest water starts I have ever done & was off like a shot.

 

[johnalison]

One of my most memorable evenings in Hamford Water was when we were anchored there overnight. I looked out at about 9pm in September and saw a seal drifting past. I went into the cockpit to get a better view and saw another seal on the other side. Before long I could see maybe eight seals forming a semicircle based on the northern shore. I watched them for twenty minutes as they drifted in with the flood tide, obviously enclosing an area based on the shore. As the light faded I assumed the a shoal of mullet was doomed but the light went before the denouement. What fascinates me is how they managed to organise the hunt. With no speech, how did they say “ left a bit Fred. A bit faster Gladys”? I have tried to Google cooperative behaviour in seals but found nothing.

 

[AntarcticPilot]

One of my most memorable evenings in Hamford Water was when we were anchored there overnight. I looked out at about 9pm in September and saw a seal drifting past. I went into the cockpit to get a better view and saw another seal on the other side. Before long I could see maybe eight seals forming a semicircle based on the northern shore. I watched them for twenty minutes as they drifted in with the flood tide, obviously enclosing an area based on the shore. As the light faded I assumed the a shoal of mullet was doomed but the light went before the denouement. What fascinates me is how they managed to organise the hunt. With no speech, how did they say “ left a bit Fred. A bit faster Gladys”? I have tried to Google cooperative behaviour in seals but found nothing.

That's interesting. I've never heard of anyone observing or mentioning cooperative hunting in seals, especially in such a coordinated fashion, but I'm no marine mammalogist. Whales and dolphins certainly hunt cooperatively, but they have much larger brains and communication capabilities. Seals are in a par with dogs intellectually; dogs hunt in packs. Can I suggest that you contact SMRU | Sea Mammal Research Unit They'll either know all about it, or possibly thank you for reporting previously unreported behaviour!

 

[mjcoon]

What fascinates me is how they managed to organise the hunt. With no speech, how did they say “ left a bit Fred. A bit faster Gladys”? I have tried to Google cooperative behaviour in seals but found nothing.

Perhaps it's a bit like a shepherd whistling to a sheepdog, but more symmetrical!

 

[bikedaft]

I have often, indeed usually had a seal follow a boat length behind when rowing (Leven/Clyde). Wee 5m rowing dinghy. Never felt threatened by that behaviour.

My folks listened to Margaret Thatcher on R4 in the 80's at about 9pm one summer's evening in L Sween at anchor. About 10mins into her speech we noticed about 15-20 seals all around the stern in a semicircle - all v curious, listening to her distinctive voice. Never had anything like that again.

 

[grumpy_o_g]

I have often, indeed usually had a seal follow a boat length behind when rowing (Leven/Clyde). Wee 5m rowing dinghy. Never felt threatened by that behaviour.

My folks listened to Margaret Thatcher on R4 in the 80's at about 9pm one summer's evening in L Sween at anchor. About 10mins into her speech we noticed about 15-20 seals all around the stern in a semicircle - all v curious, listening to her distinctive voice. Never had anything like that again.

Seals are well known for being very right-wing. Otters on the other hand are definitely socialists at heart, though the Sea Otter is a little more neutral. Beavers are the worst, born preppers the lot of 'em.

 

[Frogmogman]

What do you get to eat the killer whale?

Simple. Japanese. ??

As in “キラークジラを殺すことができた”

(“I could murder a killer whale” in Japanese)

 

[Frogmogman]

Seals are well known for being very right-wing. Otters on the other hand are definitely socialists at heart, though the Sea Otter is a little more neutral. Beavers are the worst, born preppers the lot of 'em.

Presumably whales support Plaid Cymru………

 

[johnalison]

That's interesting. I've never heard of anyone observing or mentioning cooperative hunting in seals, especially in such a coordinated fashion, but I'm no marine mammalogist. Whales and dolphins certainly hunt cooperatively, but they have much larger brains and communication capabilities. Seals are in a par with dogs intellectually; dogs hunt in packs. Can I suggest that you contact SMRU | Sea Mammal Research Unit They'll either know all about it, or possibly thank you for reporting previously unreported behaviour!

That’s a good idea. I have met a number of people concerned with wildlife and mentioned it but none of them seemed to know about it.