Animal of the Week -- July 30, 2007

So, I'm thinking, I need to do animal of the fortnight, and in the UK at the moment it's all great white sharks off Cornwall. Are the maneating leviathans really there? Possibly, probably not, the sharks seen are more likely to be basking sharks (bigger than great whites but filter feeders), porbeagle sharks (smaller than great whites, but large and fast, though nothing to worry about), or mako sharks (larger than a porbeagle, smaller than a great white, but large, fast and fierce, although not a maneater). And I am looking up information about these sharks, and then I spy the name of an animal of which I had not heard before, Alepisaurus ferox (longnose lancetfish)

Now, lancetfish are large predatory fish that eat smaller fish and small swimming crustaceans. They are considered pests by tuna fisheries where they take the bait from hooks and their watery flesh is not considered worth eating.

Quite unremarkable really, however, I was tickled by the name because it includes my former employers, The Lancet, a medical journal. Appropriately for a fish that shares its name with the august medical organ renowned for its "stand on several important medical issues - recent examples include criticism of the World Health Organization, rejecting the efficacy of homeopathy as a therapeutic option and its disapproval of Reed Elsevier's links with the arms industry [Source Wikipedia]", lancetfish have sharp teeth, hunt by ambush, and have a big mouth.

Their insipid watery flesh is, I would like to stress, less like the contents of The Lancet. And as for their purported aphrodisiac powers, well, I would be too abashed to comment.

Please forgive me this minor indulgence, it's a bit of a rubbish AOTW I know. But there you go. Also, I am going to take the next few weeks off. A small matter of a dissertation and shabby work ethic mean that I am likely to need all the minutes I can find. But AOTW will return per week and reinvigorated in September. I wish you all a lovely summer.

Animal of the Week -- July 16, 2007

Well, it's that time of year again, when an afternoon outside becomes a constant battle against foe whose endless onslaught is like nothing seen outside a Lord of the Rings battle scene. No sooner have you shaken one from your hair than another lands in your cleavage, and when you've picked that out, you find three have landed in your drink/on your ice cream/in your mouth. And what is this haphazard winged plague of summer? Lasius niger (black garden ants), that's what.

You may wonder what triggers this aerial onslaught, when generally ants aren't that noted for their flying, and are most annoying for dying in your sugarbowl. Our insect tormentors are either queens, the most prominent fat ones, or males, the little ones that you see but don't really mind about because they're much less custardy. This is the only time that the ants will fly, hence their lack of proficiency.

On this, their nuptial flight, the males and females will mate, and with the juices of the male safely apportioned, he will die, the queen will lose her wings and tunnel underground and begin to lay eggs. The fertilised eggs hatch and the larvae become female workers. Throughout the rest of the year the colony swells as more and more workers hatch out of the never ending supply of eggs from the distended and immobile queen. The colony spreads further and further looking for food, getting into your cupboards dying in the threads of your jam-jar lids, wandering off with the contents of picnic baskets, and getting in your pants. What else do ants do?

As summer approaches, the workers decide it's time for the success of the colony to be spread even further, and they select some eggs (still fertilised by the product of the nuptial flight) to raise as dispersing queens, and the queen lays some unfertilised eggs that will become males. Triggered by cues of daylength, temperature, and humidity with astounding and fearsome synchronicity colonies all over an area crack open and the winged horde takes flight. The mass eruption means that queens of one colony might mate with males of another rather than with their own brothers.

The flying menace some years reaches such proportions that they clog air-conditioning and trigger mass congregations of sea gulls and swallows, which come to feast on the glut. Humans deal with the event by flapping, moaning, squashing and beating them from the sky with badminton racquets. I say let them be, they'll be gone as soon and as suddenly as they came.

One downside of black ant for the gardeners among you is that they farm aphids, protecting them from predators while harvesting a sticky secretion called honeydew (the nasty smut that gathers on a car parked under a lime tree). In the picture, a black ant is carrying an aphid in its jaws.

Animalof the Week -- July 9, 2007

I worry that I am starting to sound a bit like a countryside diary of late, what with my tales of cockchafers, pigeons, swifts, and other things that I see as I pootle around London, such as piranhas and golden moles. So this week I am going to resist the temptation to regale you with the tale of peregrine falcons spotted over Clapham on Sunday morning.

Instead, this week's AOTW is something a slightly larger and much rarer bird of prey. Rarer to the extent of being extinct, for about 6 million years. This week's Animal of the Week is Argentavis magificens (giant teratorn). This relative of the living condors was the largest flying bird ever to have lived. With a wingspan of up to 8 m (28 feet) and weighing possibly as much as 100 kg (220 lb). For reference, a wandering albatross has a wingspan of 3.83 m, modern day Andean condors have a wingspan of 3 m and weigh up to 12 kg, and the heaviest flying birds, European (AOTW, April 11, 2005) and Kori bustards weigh no more than 20 kg.

The teratorns were large birds of North and South America that lived from the Miocene to the Pleistocene (15 million to 11 thousand years ago), and this species survived in Argentina from 8–6 million years ago. Other teratorns were not much larger than the modern-day condors, but Argentavis magnificens was truly a monster. People have speculated whether and how such an enormous bird could fly, but the imprints of feather attachments on the birds wing bones (an upper-arm bone would have been the same length as a whole human arm) show that they had flight feathers. Fortunately, the lack of the Andes in South America at the time these birds lived meant that strong westerly winds whipped across the continent, which would have helped the bird take to the sky with a little running around and flapping.

Whether these birds scavenged or hunted is also a bone of contention. Other teratorns almost certainly hunted, because they resembled eagles, which hunt, much more than they did their close relatives condors, which scavenge. But could a bird this size be an active hunter? Perhaps it did a little of both, driving the marsupial lions away from their kills of giant sloths or weird camels with trunks (South America was different then) when the opportunity arose, and when it didn't, swooping down on animals up to the size of hares and small dogs, picking them off the ground, and swallowing them whole.

This week's image may not be entirely accurate. Certainly Argentavis magnificens would never have soared over the heads of Japanese cartoon characters, or any humanoids for that matter. Furthermore, the head may not have been bald. But there you go, needs must when you need to steal a picture.

What a bird!

Animal of the Week -- July 2, 2007

What a week for news!

On the plus side Tony Blair has gone, and although ballots were absent in the selection of his successor, and East Timor have held their first public democratic vote, and although the count is slow, the process looks good. On the downside, floods have ravaged the north of England and various US states, Wimbledon has barely started, the UK is on the highest state of terror alert after some deluded fanatics tried to car bomb London and Glasgow, and perhaps worst of all, to compound all the misery in the world that I have not been able to summarise in my brief introduction so far, the Spice Girls have reformed.

Thank god that news about animals tends to be more neutral, like that about this week's animal Pygocentrus nattereri (red-bellied piranha), in fact, this news is just about the best and most complete image overhaul sine Paris Hilton vowed to invest her time, money, and, er, intellect for good on her release from jail. For researchers now claim that piranhas are not the frenzied, blood thirsty, pack predators capable of stripping a cow carcass in minutes, but rather their shoaling behaviour is driven by cowardice in an attempt to avoid predation by river dolphins (AOTW, Feb 21, 2005: http://animal-of-the-week.blogspot.com/2005_02_01_archive.html), caimans, and the enormous fish that live in the amazon.

Now, I can't find out the exact species of piranha studies, but at red-bellied piranhas are some of the most aggressive, and certainly not the sort of fish immortalised in the "One, two, three, four, five, once I caught a fish alive" nursery rhyme, which would no doubt have a different ending if it were.* Most piranhas are vegetarian anyway, and the most aggressive ones, such as this and its close relatives, are likely to have been the subject of the study, if not, why bother?! Apparently even these typically only hang around in small shoals and prey on small fish, carrion, or bits of larger fish. According to the researchers, they only form large shoals when the waters recede and they are more prone to predation, and not for the purposes of hunting large animals and stripping the flesh from captured secret agents at the behest of Ernst Bloefeld.

Of course, you may have seen demonstrations of these voracious fish stripping a chicken carcass to bare bones in seconds, and they will do that, but only when kept in small tanks and deprived of food. Despite this image makeover for the piranhas, you still can't keep them in aquaria with smaller fish, they'd eat them.

*One two three four five
Once I caught a fish alive
Six seven eight nine ten
Then I let it go again
Why did you let it go?
Because it bit all my fingers off and I didn't have a choice.

Tak tak,