There’s a classic demonstration of the way the human brain works known as the Selective Attention Test. Here’s one example from YouTube. Having been told to count the number of passes of the ball, very few people even notice the gorilla walk slowly through the scene. I had that sort of experience when I caught the end of a TV programme earlier this week.
It was a BBC wildlife programme called ‘Johnny Kingdom and the Bears of Alaska’. I’ll confess I was put off watching it because my listing magazine called Mr Kingdom an amateur photographer. For me, the idea that someone who has made a number of wildlife documentaries and was filming wildlife for many years before being discovered should still be called an amateur was stretching the language a bit far.
Switching channels, however, I did come across
it close to the climax of Mr Kingdom’s one hour quest to see
bears in their natural environment catching salmon with their
bare ‘hands’ in the way Johnny did at home when a young man. His
search ended, successfully, on Kodiak Island in the far north of
the Pacific Ocean and now part of the US state of Alaska. The
viewer was supposed to be watching in awe as a female bear
caught a fish and then went, with her cub, up the side of the
lake to feed. My selective attention, however, could only focus
on all the
Heracleum mantegazzianum, giant hogweed, growing on
the banks. (See
January 2014 update.)
I took this screengrab and, in spite of the low quality, you should be able to see just how much of this plant is visible.
I’m neither surprised not disappointed that no mention was made of the plant but, for me, it just showed how unnatural this supposedly natural environment was. I checked online and confirmed that Alaska considers it to be an invasive plant and has programmes to try and control it though I assume these have to be focussed on land close to centres of population.
There is, of course, no risk to the bears from this plant because their thick fur will prevent the furocoumarins in the plant from reaching their skin but, to me at least, it demonstrated that even supposedly remote, wilderness areas are being impacted by the unknowing actions of our Victorian ancestors. Perhaps their focus on having an impressive garden plant and not considering the consequences of moving it from its home territory can be seen as a form of selective attention.
Two other points resonated with me as I watched selected parts of the programme and researched what Alaska is doing about giant hogweed. I came across this pdf of a slide presentation from the Alaska Department of Natural Resources. The eighth slide is about Alaska's ‘Weed Free’ forage/straw programme. It seems that Alaska has a scheme for checking that no harmful weeds are getting into animal feed with tags being affixed to bales to confirm the quality.
I’m sure such a scheme adds to the cost of feed but it seems to me to be an excellent idea and one which, if implemented in the UK, might prevent horses being harmed by the inclusion of Jacobaea vulgaris (syn. Senecio jacobaea), common ragwort, in feed.
The other thing that interested me was that the filming took place on Kodiak Island. This is one of the islands in the northern Pacific Ocean where, a very long time ago, the native people used poison extracted from plants in the Aconitum genus in order to kill whales.
Here’s what I say about this in ‘Is That Cat Dead? – and other questions about poison plants’;
Its use to poison the tip of a projectile is best seen when applied to harpoons used in whale hunting. The aboriginal peoples of the Kamchatka peninsula, Kurile, Kodiak and Aleutian islands in the far North Pacific Ocean, used lances coated with aconite poison to hunt whales. The lance heads were of stone and were intended to break off from the shaft so as to remain in place in the whale’s blubber. The whale would be lanced and left to die in the hope that the dead whale would wash up on one of the islands. Each whaler had his own lance head design so that people finding a dead whale would know who had killed it. Cultural rules dictated that the whale belonged to the killer but he would share it with the finders.
The first thing that would be done when a dead whale was found was that the flesh around the wound would be cut out, whether to remove the poisoned area or as a means of retrieving the point of the lance is unsure. Not all whales would beach in the hunters’ islands and some were found by the Nootka people further to the east. It is reported that the Nootka would not eat these whales though whether that was due to the presence of the aconite poison or because, the whale having taken much longer to come to shore, the meat had in any event become rotten cannot be determined.
Because not all whales would end up beached it is not possible to know how successful the poisoning was though some whales would have an old set of healed wounds indicating that they had survived a previous poison lance attack.
The effect of the poison is, also, unknown. It may that a big enough dose entered the bloodstream to poison the animal’s central nervous system or it may be that it caused only a local irritation which was enough to cause the animal to thrash around and, finally, die of exhaustion. There are some reports of villagers falling ill after eating whale meat though it seems unlikely that this would be the result of the poison as this is metabolised by the victim, in this case the whale.
Part of the lack of detailed information is that the use of poison was kept secret in favour of imbuing whaling with magic properties. Thus the fat from the corpse of a dead whaler would be made into grease and applied to the lance head to transfer the skill of the dead whaler to his successor.
I received an email from the Alaska Department of Natural Resources in the Division of Agriculture explaining that the plants I had seen were Heracleum lanatum (confusingly known as cow parsnip in the USA whereas in the UK Heracleum sphondylium bears that common name) a plant that grows to up to 3 metres tall and so is easily confused with the mantegazzianum, giant hogweed.
The giant hogweed has only ever been found in the south-east of the state (hence its inclusion in the presentation I linked to) and has been eradicated.
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