The Alaskan nutrient cycle

Paul Klaver has an absolutely breathtaking short film revealing the nutrient cycle spawned (rimshot) by the salmon in Alaska. It’s gorgeous and I just don’t understand how he managed to get some of the shots. Watch it in fullscreen mode.

I have a fond (?) memory of growing up in Portland, Oregon and heading out to “Outdoor School” for a few days, where they attempted to inculcate a love of the outdoors in us city kids. We visited right after spawning season which meant the stream that ran through the camp was surrounded with decaying salmon carcasses, resulting in the entire place smelling of old fish. Lovely, no?

via Explore

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Superorganisms = organism

People like to talk about ants as ‘superorganisms’. Of course, we’re all kind of superorganisms, built out of a structure of captured cells and using home-grown bacteria to function. But when we talk about ants, wasps, and termites, we mean something else. Each insect on its own seems to be an independent organism – though they can’t all survive away from the colony – but in reality, the colony is the organism.

In PNAS, Hou et al. apply the metabolic scaling law to eusocial insect colonies. Individual organisms have a metabolic rate that scales as the 3/4 power of body mass. Along with this are laws scaling reproductive organ mass, total biomass, and organism (colony) growth with metabolism. Individual ants do not follow this law: worker ants have almost no reproductive organs while the queen has tons of ’em.

The figure above shows the body mass vs. metabolic rate for some (non-ant/wasp/termite) insects and for various colonies as a whole. And the curves are the same! If you look at the other predictions, they all turn up exactly on the curve, too. So it is only when you consider the colony as a whole that eusocial insect act as a proper organism. Iain Couzin once mentioned to me that ants in a colony act analogously to neurons in a brain, though I can’t for the life of me remember how that was. But see, the individual ant is just like a lonely neuron: meaningless.

The cycle of the city of ants

E.O. Wilson has a story in the New Yorker! About ants! It’s not great as literature, per se, but it is quite interesting. Imagine ant fanfic: that’s basically what this is. Like a preening middle schooler, he tries to show off all the fun little things he knows about how ants live. That’s not meant as too much of a knock, because maybe that’s the point: the story’s not about immersing yourself in the characters so much as about conveying knowledge about the characters. Read it and learn.

[picture from]

Ecology of the canine subway

Here’s an interesting Financial Times article on the ecology of stray dogs in Moscow:

The dogs divide into four types, he says, which are determined by their character, how they forage for food, their level of socialisation to people and the ecological niche they inhabit.

Those that remain most comfortable with people Poyarkov calls “guard dogs”. Their territories tend to be garages, warehouses, hospitals and other fenced-in institutions, and they develop ties to the security guards from whom they receive food and whom they regard as masters. I’ve seen them in my neighbourhood near the front gate to the Central Clinical Hospital for Civil Aviation. When I pass on the other side with my dog they cross the street towards us, barking loudly.

“The second stage of becoming wild is where the dog is socialised to people in general, but not personally,” says Poyarkov. “These are the beggars and they are excellent psychologists.” He gives as an example a dog that appears to be dozing as throngs of people walk past, but who rears his head when an easy target comes into view: “The dog will come to a little old lady, start smiling and wagging his tail, and sure enough, he’ll get food.” These dogs not only smell who is carrying something tasty, but sense who will stop and feed them.

The beggars live in relatively small packs and are subordinate to leaders. If a dog is intelligent but occupies a low rank and does not get enough to eat, he will separate from the pack frequently to look for food. If he sees other dogs begging, he will watch and learn.

The third group comprises dogs that are somewhat socialised to people, but whose social interaction is directed almost exclusively towards other strays. Their main strategy for acquiring food is gathering scraps from the streets and the many open rubbish bins. During the Soviet period, the pickings were slim, which limited their population (as did a government policy of catching and killing them). But as Russia began to prosper in the post-Soviet years, official efforts to cull them fell away and, at the same time, many more choice offerings appeared in the bins. The strays flourished.

The last of Poyarkov’s groups are the wild dogs. “There are dogs living in the city that are not socialised to people. They know people, but view them as dangerous. Their range is extremely broad, and they are ­predators. They catch mice, rats and the occasional cat. They live in the city, but as a rule near industrial complexes, or in wooded parks. They are nocturnal and walk about when there are fewer people on the streets.”

It’s an interesting story of what happens when a domesticated animal is, in a sense, redomesticated, or undomesticated. These dogs have also learned how to use the subway system to get from place to place. Surely that is a novel behavior you wouldn’t expect from animal psychology? What’s interesting is that not all the dogs have learned how to do this but, presumably, are able to pass on the ability to other dogs who follow them. Do we have a little animal culture here?

Why old people shrink

Here’s why I’ll end up 5’2″ by the time I die:

Degeneration with age interferes with the normal process of regaining height, and by 60 a loss of two inches is not uncommon.

There are 23 jellylike intervertebral disks that act as shock absorbers between the spinal vertebrae, Dr. Härtl said. The disks, which are as much as 88 percent water, are compressed during the day as standing, moving and vibration squeeze out fluid. Then at night, when the body is flat and at rest, the disks reabsorb fluid like sponges.

As we get older, degenerative processes interfere with reabsorption, Dr. Härtl said. Blood supply and circulation diminish, and the disk material stiffens.

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My brother the Dauphin

Dolphins are pretty smart. Their brain-to-body ratio is in fact second only to humans, and the cerebral folds that allow a more dense collection of grey matter are probably more wrinkly than a humans. It shouldn’t come as a particular surprise that dolphins even pass things on culturally (something that’s been discussed here before) –

In one recent case, a dolphin rescued from the wild was taught to tail-walk while recuperating for three weeks in a dolphinarium in Australia…After she was released, scientists were astonished to see the trick spreading among wild dolphins who had learnt it from the former captive…There are many similar examples, such as the way dolphins living off Western Australia learnt to hold sponges over their snouts to protect themselves when searching for spiny fish on the ocean floor.

Behavior is not just culturally expressed, it is both novel and conscious:

A dolphin’s ability to invent novel behaviours was put to the test in a famous experiment by the renowned dolphin expert Karen Pryor. Two rough-toothed dolphins were rewarded whenever they came up with a new behaviour. It took just a few trials for both dolphins to realise what was required. A similar trial was set up with humans. The humans took about as long to realise what they were being trained to do as did the dolphins. For both the dolphins and the humans, there was a period of frustration (even anger, in the humans) before they “caught on”. Once they figured it out, the humans expressed great relief, whereas the dolphins raced around the tank excitedly, displaying more and more novel behaviours.

Go watch some videos of them doing awesome things. Because awesome dolphins are awesome.

[Photo source]