Gray Whale Spotted on Wrong Side of World

I came up with reintroducing gray whales to the Atlantic a year or so ago, only to find someone else had also thought of it much more systematically. But maybe the whales will do it on their own.

Small correction: if one is traveling south keeping a continental shelf on one's left, one is following the west coast of a continent.

Coby,

Just to add a bit of logic and common sense to this.

The below Wiki link shows us that there were indeed Gray whales inhabiting this area way back in the 18th century until we killed them all. Maybe what we are seeing is the beginings of the return.

Of course if we are to blame climate change on this event due to the melting Arctic ice then it stands to reason that the ice was also melting back then as it is today how else would the whales swim off the coast of Israel?

http://en.wikipedia.org/wiki/Gray_whale

Yes, crakar, maybe one of their eggs, long buried in the ocean mud, finally hatched...

crakar: there were likely two separate species (Atlantic gray whales and Pacific gray whales). "[H]ow else would the whales swim off the coast of Israel?" Uh, probably they were distributed in the two oceans much the same way as North Atlantic and North Pacific right whales are:
http://en.wikipedia.org/wiki/Right_whale
Those lineages are thought to have become separated due to the closing of the Central American Seaway by the Panamanian Isthmus. Got it?

coby

This is a fascinating story, but I suggest it would be drawing a very long bow to attribute this in any way to climate change.

I would be very interested to know how genetically related the extinct Atlantic population was to the Pacific population. This would enable us to understand if there was much immigration/emigration between the two metapopulations, and may give us clues as to what has happened here.

If (as I suspect is a possibility) there was immigration, then it may well be that the Pacific population has now recovered to a sufficient level such that immature males leave the area in search of feeding grounds or mates. This whale may have followed a former immigration route, and ended up in an area that although once inhabited, is unfortunately no longer. It then followed what was once the normal southern breeding route towards the Mediterranean.
Of course, this assumes the Israel whale is an immature male, but I could find nothing in the story to confirm this one way or the other.

But if this is true, it is a good thing, not a bad thing as many appear to be suggesting. It is normal behaviour for immature males to immigrate between metapopulations, and if such behaviour is beginning to occur in grey whales, it means the metapopulation in the Pacific is reaching carrying capacity. (A LOT of assumption here, but it is at least a feasible explanation)

Coby,

Whales are mammals dont you know nuffin.

Steve L.

Missed my point obviously.....if we had 3 seperate pods/groups of Gray, one being in this area in the 18th century then the question is how did they get there?

If the only reason to explain why this lone whale got there is because of Arctic ice melt (as stated above) then obviously the only way the 18th century whales got there could be if the Arctic ice melted way back then.

So what caused the ice melt in the 18th century?

Crakar, this has already been explained to you once, but maybe repetition will drill through your superdense skull. The older, now extinct population of Atlantic gray whales did no have to somehow have a way of swimming there from the Pacific -- it was presumably established long ago, before the closing of the Isthmus of Panama. The Atlantic and Pacific populations may have been genetically very different, perhaps qualifying as different species. We will never know, of course. But then the Atlantic population was hunted to extinction.

Whales can no longer swim south of North America -- so we saw no Atlantic gray whales for 150 years. Now we suddenly see one. Probably because the ice is melting.

D'oh!

Perhaps the whale researchers should spend more time explaining to this animal that Global Warming is a hoax and by making it look like the ice is melting, the whale is unwittingly being used as a pawn by Al Gore/The New World Order to usher in communism - which will apply to whales too!

crakar, can you please confirm that you have understood that the population of atlantic grey whales that was hunted to extinction 150 yrs ago had been there for a very long time and was cut off from the pacific population some 3 million years ago when the Panamanian isthmus formed.

So nothing to do with arctic meltin 150 years ago.

I wrote a previous comment in response to mandas @6. Either my comment was deleted or I forgot to press "post". Anyway, I was trying to show that mandas is wrong. Mandas is right about needing genetic evidence of differences between Atlantic and Pacific gray whales; this is hard to do (though not necessarily impossible) because Atlantic gray whales are extinct. Is there other available evidence?

A. Eastern and western Pacific gray whales are highly genetically distinct, despite their feeding grounds being quite close together (possibly overlapping).
http://www.iwcoffice.org/_documents/sci_com/sc61docs/SC-61-BRG30.pdf
Ignoring the genetics, note that the populations are demographically isolated (one is 'of least concern'; the other is 'critically endangered'). Therefore you can imagine that Atlantic and Pacific gray whales, whose feeding grounds were literally an ocean apart, would interbreed extremely rarely, if at all.

B. Eastern Pacific gray whales currently number about 20,000 (maybe 25,000 now). That's quite a bit less than their pre-historic population size as estimated by population genetics.
http://palumbi.stanford.edu/whales.html
Therefore you should probably de-emphasize your assumption of density-dependent dispersal (today's population is unlikely to be at carrying capacity).

C. See the right whale link I posted in #5. North Atlantic and North Pacific species -- no migration between the two oceans, no interbreeding.

D. Even bowhead whales may show some genetic differentiation between eastern and western Arctic populations (although it's clear they're not highly distinct.)
http://folk.uio.no/bachmann/Publications/Borge%20et%20al%20-%202007.pdf
If bowhead whales, which breed at high latitudes, demonstrate some genetic differentiation between eastern and western Arctic, you can imagine that genetic differentiation between Pacific and Atlantic gray whales (with low latitude breeding locations e.g. Baja) would be very great.

Steve L

Thanks for your comments. My post was really just a thought bubble rather than a detailed attempt to explain how the Pacific Gray Whale ended up in the Mediterranean, but I take your point on a number of the issues. However, before I accepted your views as correct, I think there would need to be further work done in a couple of areas.

Point A seems quite reasonable. If Western and Eastern Grey whales interbreed rarely, then it would seem reasonable that Pacific and Atlantic sub-species would be even less likely to interbreed. But I would suggest that both rarely and less likely does not mean never, and this could only be determined by genetic matching. Given the Atlantic sub-species is extinct we may never be able to do this, so I guess it is a moot point.

Point B. I don't necessarily agree with your assertion about density dependence. Just because the current population level is less than historic levels, does not mean that the population has not reached carrying capacity. The habitat has been significantly altered in the past century or so due to human influences, and it may well be that those changes have altered the available food supply etc, and the current carrying capacity may well be significantly less than it was in the past. This is normal in just about any ecosystem, so there is no reason to assume that the carrying capacity for whales is the same as it was a century or more ago. More work is needed in this area in any case.

Point C and D - It may well be the case that Right and Bowhead Whales show limited interbreeding, but such is not the case for Humpbacks, which are more closely related to Grays than Right Whales, and which do immigrate and interbreed (albeit to a relatively limited degree). Link to a study here if you are interested:
http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0007318

So just to summarise, you may well be right and my thought bubble may well be incorrect, and thank you for putting forward some thoughts. But I don't think we can say with certaintly what has occured in this particular situation, and I do suggest that this is not just a case of a whale taking a wrong turn somewhere and getting lost (what do you think DID happen?)

Hi mandas. Thought bubbles should be encouraged, but in the interest of making sure all the relevant factors are considered, sometimes these bubbles will get burst. For point A, depending on what you mean by rarely, you can include interbreeding among species. And considerable introgression of genetic variation from one group to another millions of years ago (Isthmus) may not have had time to drift to fixation or diverge. Basically you're going to find some genetic similarity between Pacific gray whales and Atlantic gray whales (if they can obtain enough samples from museum bones for example), and you'll have to figure out at what point that similarity is low enough that you can say "these groups don't exchange reproductive migrants". I did a project on fish above waterfalls in separate rivers, separated by hundreds of kilometers. They've been like that since the last ice age. They "never" exchange migrants, yet their Fst scores were less than 1.

So let's skip B for now and get to the humpback paper. The reason I made comparisons to right and bowhead whales is because their geography shares a lot in common with gray whales. That said, I don't see anything in the paper indicating any interbreeding of North Pacific and North Atlantic humpbacks. The following is from the introduction to the paper:
"In general, humpback whales within an ocean basin in the Northern Hemisphere (NH) mix on common sub-areas in breeding grounds but segregate and show maternal fidelity to particular sectors on their feeding areas [25], [27], [28]. This is reflected in the very high and significant fixation indices (FST~0.4) between feeding areas and breeding grounds in the North Pacific, and in significant indices (KST~0.04) between feeding areas in the North Atlantic [29], [30]."
The interesting bits here that humpback populations have overlapping breeding areas and separate feeding areas (opposite to grays), and that despite the great potential for interbreeding, *within* the North Pacific there is VERY strong population differentiation. Can you point me to the part that indicates interbreeding among North Pacific and North Atlantic populations? I wouldn't be entirely surprised if there was gene flow between the two via a southern route (an option the gray whales don't have), but I think it's unlikely.

Let's revisit point B. You're right: it's quite possible that carrying capacity has changed ... for the worse. My inclination is to blame bottom trawling. But if this scenario involves density-dependent dispersal, the male that is forced to go looking for mates elsewhere will be young (just becoming mature), correct? I don't know if that's consistent with the facts in this case.

As you can tell, I am interested in this topic. And if there is relevant stuff in the paper that I've missed, please point me to it.

You ask what I think did happen -- I think the animal got lost. It happens quite often in nature. Birds that colonize islands (Canada geese in Hawaii, for example) generally aren't out there trying to find need new habitat. It's the same with lizards and isolated islands -- it's not intentional. I work on sockeye now -- the salmon species demonstrating the greatest spawning site fidelity. We have seen several instances that we interpret as fish simply getting lost. It's not adaptive because these fish don't spawn successfully. So I think animals get lost fairly often. But they can only get lost to areas if they have access. That's what makes the gray whale in the Mediterranean so interesting.

Steve L,

Once again thanks for your comments. I work in wildlife management in a terrestrial environment, and migration between sub-population groups is one area where I have been concentrating lately with regard to a project to reintroduce a vulnerable species to part of its former range. I won't go into all the detail because it is too long and complex for this forum (and you appear to have a grasp of the concepts anyway).

The paper on humpbacks that I linked to is interesting for a couple of reasons, because it suggests that gene flow between the sub-populations does not necessarily follow what would be logically assumed. It suggests that there is a high degree of population structure, and hence isolation, between groups within an ocean basic (particularly the Indian Ocean), but there was evidence for gene flow between groups in different ocean basins - especially the Indian and Atlantic basins.

Of course, these two sub-populations do share adjacent (possibly overlapping??) feeding grounds in the Antarctic, but the rates of gene flow appear to quite low (but existing nonetheless). If two sub-populations of a closely related species shared a common feeding ground, I would expect substantial gene flow between the two groups, such there would be little genetic diversity between the two - but this is obviously not the case. So just what triggers whales to immigrate would make a very interesting study, and may provide clues as to what has happened in the case of our 'lost' gray.

It would be interesting to know just how extensive the gray's range was in the Chukchi Sea. If the range extends a significant distance along the northern coast of Alaska/Canada then it may well be that, in the past, the two oceanic basin groups ranges overlapped (or were very close at least). If this is true, then it would be possible that migration and geneflow did occur, and it would be only by studying the DNA of both species that we could determine how much and how recently this last occurred. If there is evidence that there was relatively recent mixing (say in the last few hundred years before the Atlantic population went extinct), then it would confirm that migration did occur, despite the view that the species were geographically isolated millions of years ago by the closing of Panama.

With regard to the point about the age/sex of the lost whale, I agree that it would have to be an adolescent or recently mature male for my hypothesis to be correct - but I did point that out in my original post - and I have no information either way to confirm or deny that.

Finally, I am not all that convinced about the 'just getting lost' idea. As I said, I work in a terrestrial environment, and in my experience the animals that people think are 'lost' or somewhere they didn't expect are there because they have been 'kicked out' of their original sub-population group and are actually looking for a new habitat - in effect, migrating. But of course, migration is not always successful (it often fails), and the animal doesn't find a new habitat and dies, which is probably going to happen to this gray whale. But that is what makes the study of animals so interesting.

If i understand correctly IF we could compare the Alantic whales DNA with the Pacific DNA then we could estimate how long they have been seperated, seeing how we have killed all the ones in the Atlantic then this is impossible (how long does DNA exist in whale bone, I see we recently discovered 4% Neanderthal DNA in Humans).

All that aside without DNA evidence we do not know how/why the whale is there so we naturally blame AGW, and why not it causes all the other wordly ills at present.

By the way if you where in a boat on the Pacific ocean and wanted to go to the Atlantic ocean but the Arctic was full of ice can you get there some other way?

crakar -- The recent lack of ice in the Arctic in the summer (when gray whales are up there feeding) provides a pretty strong mechanistic explanation. It's not just a matter of blaming AGW for no good reason. Boats can get from the Pacific to the Atlantic without going through the Arctic; gray whales can't because they don't go down as far as Panama never mind south of the equator.

Thats exactly right Steve, in post 3 i tried to force the alarmists to show their hand by saying that the Atlantic gray whales or for that matter the Pacific gray whales migrated from one ocean to the other.

This must have happened before the 18th century, as the only way they could have done this was if the Arctic ice had melted i wanted to know what caused the ice to melt way back then.

This attempt was cunningly thwarted by saying (post 8, 10) that the Atlantic whales got there 3 million years ago via the Isthmus of Panama therefore the Arctic has never melted for 3 million years and only is now to allow a whale to sneak through, lets blame AGW.

Do you know for a fact that the Arctic has not melted in a similar way 2, 3, 4, 500 years or even 1 or 2 thousand years ago to allow such a migration? Then refroze trapping the Atlantic group?

I just hate the way you lot jump on any little thing and twist it to suit your own needs, it is very unbecoming.

It's much more fulfilling to have this conversation with someone who might actually derive some practical benefit from the discussion and is actually interested than with someone who is just being contradictory. So thanks also for your comments.

Let's get some basic and specific stuff out of the way. First, one thing you might consider investigating is old whaling records. Where in the Arctic gray whales were 'sampled' could go a long way to supporting the notion that transArctic migration occurred historically. Unfortunately, these weren't structured surveys in the northwest passage or northeast passage, so absence of evidence can't at all be used as evidence of absence.

Second, you're interested in migration as well as effective migration. Although dispersal might get a whale into the Atlantic under your explanation for our 'lost' whale, such dispersers would need to reproduce to be detected a generation later. Thus, even good genetic data wouldn't be as powerful as we would wish.

Third, I don't think that you'd be able to distinguish recent effective migrants from allelic variation that is just hanging on. I mean, this is really quite tough to do without very large samples both of the genome and of the populations. You couldn't do parentage analysis, for example, so you'd be stuck with trying to assess linkage disequilibrium from just a few Atlantic samples. I don't think you could do it.

In conclusion of the basic stuff, then, a lot more work has the potential of confirming your hypothesis, but very little chance of rejecting it.

More generally, though, there are islands of habitat in terrestrial environs, too, and I think island biogeography is the correct context for interpreting what's going on here. You write "migration" when really you mean "dispersal". (I may have been similar imprecise in my language.) There is a lot of theory with respect to natural selection and dispersal, and it has a lot of history behind it (e.g., r- and K-selection). To my knowledge, gray whales are not the kinds of organisms that you would expect to disperse so radically (as in island biogeography, in which the vast majority of dispersers do not find the island). It gets into arm-waving territory here, but genes for radical dispersal would be weeded out of the population unless those genes were successful in alternate habitats -- successful enough to produce more dispersers that brought the genes back into the original population. I'm not saying it didn't happen. But, given the distinction between Pacific and Atlantic whales that are more likely to disperse past the Arctic barrier, I am saying that believing it did happen requires some faith. And I think it requires more faith still to believe that the melting away of heaps of sea ice, over the last few years, had no effect on this gray whale being able to disperse through the Arctic.

Maybe if we see right whale species on the wrong side of the Arctic within the next 50 years (and if you and I are still around), then you'll agree that something is going on that probably didn't happen before.

I'll end my time on this thread by referring back to the fish-above-waterfalls example (because it may be interesting to you). The ones that fall down may reproduce below the falls. But because they can't migrate up the waterfall, an initially migratory group of animals will stop being migratory (because all the genes for migrating downstream are lost from the population). We can still find individuals immediately below the waterfalls that have fallen down. It's accidental. They may have been displaced downstream by better competitors, but for all intents and purposes, they got lost.

Steve L

One other interesting thing that I didn't consider till I looked at a map of the Arctic from above (and this shows such two dimensional thinking that I am embaressed by it) is that, although the migration route across the north of Alaska and Canada is one possibility, the other route across the north of Russia is a much more likely migration routhe. The Russian route generally is ice free a lot more, and the distances are not all that signficantly different.
It could add weight to the 'getting lost' hypothesis, because the landmass would remain on the animal's left - but I have no idea if that is how whales navigate and it seems a very anthropomorphic perspective to me.

I am still going to stick with my migration hypothesis for now - but am more inclined to believe the migration route was across Russia, rather than across Canada.

Any thoughts?

Steve

And yes, you are correct about dispersal vs migration - I was using incorrect terminology. Hope it didn't cause too much confusion. I probably shouldn't call it a hypothesis either, because it is completely lacking in any real evidence and is just an idea that I think is worth exploring, and which lends at least a (potentially) credible explanation to the event.

crakar, you forgot my cunning response in #5!
I don't understand what are you complaining about. There was a very interesting observation, unprecedented in 150 years of modern observation. We know something about how this animal migrates and its requirements for dispersal ... and we know that reduced sea ice would have enhanced the chances of this whale getting to the Atlantic. Are you complaining about that? Which part do you find unbecoming?

You know what I find unbecoming? I'm not going to generalize; this is just about you. Someone provides you a very good reason for thinking that Atlantic and Pacific whales haven't had much opportunity to disperse through the Arctic (see links and writing above about right whales), and you don't bother to read it. Instead you densely and hypocritically accuse other people of twisting things. I think that's unbecoming.

You're so eager to accuse people of things that you couldn't effectively ask your question. You should have asked, right at the beginning, "When was the last time Arctic sea ice retreated as much as in the last few years, such that whale dispersal could occur?" There has been some research done on this -- why don't you look it up?
http://www.wunderground.com/climate/NorthernPassages.asp Were you too busy accusing others of ignoring questions you find interesting?

You're so eager to accuse people of things that, in addition, you couldn't evaluate the value of your question for this discussion. Let's say 6,000 to 8,500 years ago (when orbital variations increased insolation of the Arctic) is the last time it happened? What difference would that make? What if it was 120,000 years ago? Would it change the fact that Arctic sea ice has retreated a lot recently or that the retreat is promoted by AGW? By the way, you're the first one to mention AGW in this thread. Read it through again -- you're the one who has been blindly obsessed. So try to be calm and think about your question. Ask yourself, "What difference does it make?" And if it makes a difference, then cobble evidence together to try and make a cogent point. Accusing others accomplishes nothing.

Others here are asking questions like, "If North Atlantic and North Pacific whales could easily disperse through the Arctic, then how come right whales in each ocean are so distinct?" Pondering that and then thinking about how often gray whales transit the Arctic has led to some discussion of the rarity of this event. Some people come to the conclusion that it's very rare. Don't blame them for twisting any little thing. Blame Occam for the fact that that they drew simple conclusions. Believe that whales transit the Arctic all the time if you want. But don't blame anybody else for your lack of effort in finding evidence for it. Blame yourself. And blame yourself for contributing so poorly to this discussion.

mandas, this is the last bit that Coby has in this blog post:
"all the way through the Canadian Archipelago and west of Greenland (or, perhaps more likely, westward, above Russia and Europe, via the Northeast Passage) until instinct instructed it to turn south and ultimately hang a left."

I think I've exhausted most of my thoughts on this topic. I don't know if I'd interpret things very differently if I new the whale used the northeast versus the northwest passage. I'll probably come back once tomorrow to see if crakar has anything at all intelligent to add and then that will be it for me. Have a good one.

Steve
Yeah - I can be a bity dense sometimes and must have glossed over the bit about the route across Russia until I worked it out for myself! Doh!

Still, the whole issue is very interesting and raises a lot of questions that are worth exploring further. But I would caution you about looking for intelligent comments from our friend - it will be a very long wait.

Thanks for that Steve, so in the end we have a lone whale swimming in the Atlantic, if you want to claim this is caused by AGW then go right ahead.

crakar24 at #24 said, "if you want to claim this is caused by AGW then go right ahead."
Really? You got upset when we just talked about an article that mentioned the association of the two things. It's a big flip-flop to now give your blessing.

#24 also said, "so in the end we have a lone whale swimming in the Atlantic."
Jeez, what did you think we had? That's also what we had in the beginning. Coby, can you replace crakar24 with v.25? This one can't read.

I gave up trying to talk sense into you lot so yes you have my blessing. You can blame Skip for the fact that i cannot read, he mentioned drinking red wine which reminded me i had a bottle or two in the cupboard.

New version has been uploaded.

On a more serious note Mandas mentioned "how do whales navigate", so how do they navigate? Magnetic fields, the sun or land marks. He also said this one may have gotten lost. I always thought those that repeatedly beached them selves are the ones who have gotten lost.

I once watched a show about pigeons and how they navigate and it would appear that they use landmarks and maybe the sun during the daytime but how do they do it at night? They thought it must be magnetic fields maybe it is the same for whales.

"I always thought those that repeatedly beached them selves are the ones who have gotten lost." - Crakar v.25

Depends, that whale might have been on it's way to Whalemart and took a wrong turn at the Arctic.

DW

Or (lets see how old you are here) - 'it shouldn't have taken that left turn at Albuquerque'.

I must admit I find this topic interesting for a couple of reasons. Firstly because of the dispersal mechanisms which is applicable to my current work, and secondly because I spent a long time over the water trying to navigate. So I did some more research on the issue of how whales navigate and if they can get lost.

We humans tend to get lost if we wander off our 'map'; whether it be a hard copy map or the internal map in our brains. We also tend to navigate by reference to landmarks and by the position of the sun (ie visual cues), so we often anthropomorphise and expect that other animals will operate the same way. This is pretty silly if you think about it, because other animals have a very different perspective on the world, and have different sensor capabilities.

No-one knows for sure how whales navigate, but it is almost certainly not the case that they navigate by visual means. The most likely explanations put forward are they use echo-location or 'sound mapping' for short range navigation, and magnetic mapping for long range navigation. Both of these are suitable underwater where visual cues are lacking, and we know that whales possess excellent auditory capabilities and probably possess a magnetic sense as well.

Both of these would require internal maps in the whales brain that it use to find its way around. Sonar maps would most likely be learnt from experience (becoming familiar with the sonar characteristics of its environment), but there is evidence to suggest that magnetic maps are somehow hard wired into the brain from birth, enabling whales to follow migration pathways that they have never seen before.

What this all means is that the concept of a whale getting lost in the Arctic, and accidently following the coast of northern Russia and western Europe rather than the west coast of America makes no sense at all. Whales simply don't navigate that way. Of course, a whale may accidently wander off it's internal map and be completely unaware of it's surroundings (and hence lost), but if the magnetic map for migration is hard wired into the brain, this is unlikely. Whales can also communicate with each other across vast distances in deep sound channels, so it makes intuitive sense that a whale that found itself 'off the map' might attempt to locate the pod and get back into familiar territory.

So what does this all mean? Of course, this whale MAY have become lost due to illness or some sort of sensory deficit, but I suggest that if that were the case, it probably wouldn't survive a long ocean migration either. It does tend to support the view that the whale deliberately took the path that it did, but why this would be the case we can only speculate (as I have done in earlier posts). As Steve L has suggested, there are alternate views to mine, and we probably will never know the truth, but we may be able to explore them further if we can recover the body when this whale dies, as it almost certainly will.

We dont have a whalemart here but we do have a K mart which is of course whale speak for a Krill Mart maybe he went looking for that?

(sorry thats the best i could come up with)

Mandas,

So if the whale wasnt stupid and did not get lost then the only solution left is that it followed its instincts and turned left at Albuquerque just like the rabbit should have done.

You said

"but there is evidence to suggest that magnetic maps are somehow hard wired into the brain from birth, enabling whales to follow migration pathways that they have never seen before."

If we imagine a time before AGW when the Arctic ice was a lot less it would be possible for the gray whales to migrate from Atlantic to Pacific via the Arctic.

Do you think this whale simply got lost and finding it self in never before seen territory (to it at least) some instinctive part of the brain kicked in and said "swim south young man".

If so then what makes you think it will surely die? Whales occupied this piece of water before or will it simply get picked off by killer whales etc?

If this whale got separated from the group in it's summer feeding ground in the Bering or Chukchi Sea, it didn't follow some instinctive call and start swimming south - it went on a very long migration either east or (more likely) west before turning south. And if you are the sort of animal that navigates by magnetic means, that makes no sense at all - east and west are completely different magnetically to south. It smacks of a deliberate migration to me (but I know others such as Steve L disagree - with equal claims to being correct).

And while the opening of the sea passages around the land masses surrounding the Arctic are essential for this to occur, the northern sea route across Russia does open fairly regularly, so AGW may not have a played any part in this event (although it may have assisted). I certainly wouldn't attribute it to AGW unless I had signficantly more data (but once again, others disagree and have equal claim to being correct).

Gray Whales also feed by scooping tiny crustaceans from the ocean floor and filtering them - and I suspect the Mediterranean will offer pretty slim picking of this food supply. Mind you, Fin Whales (also baleen whales) survive in the Mediterranean so maybe there is some hope for the Gray - but given the differences in the way they feed I still have my doubts unless it can return north.

If this whale does navigate by magnetic field, wouldn't it be quite easy to get lost venturing too close to the magnetic north pole? After all, once there, every direction is south...

coby

What you say sounds reasonable in theory, but magnetic flux lines are a little more complex than that. But in any case the magnetic north pole is currently located just off the northwest coast of Greenland, so it would be virtually impossible for the whale to have strayed anywhere near it.

Arghh, now you guys are talking about more stuff that it is nearly impossible to figure out. We don't even have migration mechanisms well worked out for salmon. You can imagine this would be harder with whales. You need a map and a compass. Once you're off the map, the compass doesn't do you much good. Gray whales are relatively solitary and the Arctic is relatively shallow -- I don't think sound would help the whale navigate long distances very well, especially with all the noise from ice cracking, colliding, etc. When they are on the feeding grounds, they are concerned with looking for food. The males do this for longer than the females before migrating south. It's entirely possible that they aren't navigating at all during that time. They could simply be hitting the best food sources until something clicks in (day length or another clock) that says, "time to go breed". Depending on where the animal is at that point, many things could have happen. Maybe it can't orient properly (because it's off the map) or maybe ice has closed behind it and it has no choice but to follow another route or be trapped. This kind of speculation may be of interest among experts, but it's rather meaningless coming from me.

On another topic I found this: http://www.pnas.org/content/104/52/E2.full
This suggests a lack of trans-Arctic gene flow in Gray whales for the last 100,000 years. It's just an assumption, but it's an expert assumption which should be considered more valuable than the very non-parsimonious discussion of homing and straying in gray whales above ... in my opinion. [Note: this is a comment on another paper in which the 100,000 year assumption is made; these authors aren't criticizing that assumption -- they're criticizing the original paper for not considering the possibility that a southern population of gray whales existed.]