by Unknown
In response to such sperm competition, males of some species developed sperm that formed into a hard plug, blocking the way for the sperm of any other males. In other species, males produced a lot of sperm, so that these outnumbered and swamped the opposition. However, keeping up a high level of sperm production can be a problem. If successive copulations followed on too quickly from one another, this could result in the number of sperm in the ejaculate dropping sharply. By alternating their penises, lizards of A. carolinensis may overcome this problem. Torkaz and Slowinski found that males alternated the use of their right and left penises only if one copulation followed less than 24 hours after another. If the interval between copulations was longer, then they used the same penis.
The biologists carried out an experiment in which they prevented penis alternation. They did this by taping over one half of a male’s cloacal vent, through which the penis protrudes when aroused. This stopped the animal from using the penis on that side. The biologists found that males which were forced to reuse the same penis within 24 hours transferred fewer sperm in the later copulations. However, the researchers found no such drop in the numbers of sperm when successive copulations were as long as 72 hours apart. In this situation, they said, the sperm duct had time to be restocked with sperm.
According to Torkaz and Slowinski, their research demonstrated that the lizards adjusted their behaviour in response to sperm competition, using their penises alternately to ensure that maximum sperm transfer was kept up, even if the gap between copulations was short.
Big attraction
Few birds have penises, but the Argentine lake duck Oxyura vittata is one sizeable exception. Its corkscrew-shaped member was thought to be about 20 centimetres long—half the duck’s body length. But in 2001, Kevin McCracken of the University of Alaska found one aroused specimen whose penis was hanging out of the body sac where it usually resided. It measured a whopping 42.5 centimetres.
‘This is the first record of the penis “hanging out” in its natural form,’ said McCracken. He suggested that this highly promiscuous bird displayed its penis to attract females, which might explain why evolution has favoured length.
And, after apologising for going to such lengths, we move on to the next, more genteel, chapter.
7 Animals and their ilk
‘If we could talk to the animals, learn their languages, maybe take an animal degree…’ Dr Doolittle, in the eponymous hit musical, mused what it would be like if we could speak to those with which humans share the planet. Sadly, we are not much further down the road to deciphering the language of intelligent dolphins or chimps, let alone actually figuring out if dogs bark in order to converse or simply to irritate the neighbours.
In fact, some may feel that science has had a patchy relationship with the animal kingdom, but New Scientist has long campaigned for an end to the sight of mammals with cosmetics rubbed in their eyes and smoking beagles. Indeed, often it’s the proverbial Mother Nature rather than humans who can be the wickedest of mistresses. What personality disorder led her to decree that herrings should communicate via farts? More intriguingly, what on earth led researcher Ben Wilson and his colleagues to uncover this fact? And why did Mother Nature decide that male rats should sing an ultrasonic song shortly after ejaculating? Just so biologists Ronald Barfield and Lynette Geyer could discover it and find their way into this chapter?
From classical-music-loving carp to urban myths about toppling penguins, little has escaped the notice of scientists down the years, although sadly we had to leave out the story of the Kenyan MP who suggested allowing hyenas into the nation’s hospitals to consume the unclaimed bodies of deceased humans. He thought it would save money on storage and burials (and who could argue with such logic?). Unfortunately (for us, not the relatives of the cadavers), he doesn’t qualify for this chapter because a) his suggestion was inexplicably rejected and b) he was a politician, not a scientist, which really disqualifies him from any knowledge of what’s good for any of us, let alone an appearance in this book.
And we admit it, this chapter is just as much about animals pushing the boundaries of what is believable or acceptable as it is about scientists. But we all share a common ancestor, so what the heck? French poet Jean Marcenac almost wrote ‘The more I learn about humans, the more I like animals’. We’d only agree up to a point, especially when faced with a farting herring…
While most of the experiments on animals that follow are based on passive research, we are surprised but pleased to include this report that shows spiders are quite chilled when it comes to heavy drug consumption. Elephants on LSD was a particularly nasty idea (see Chapter 5), but, it seems, spiders are rather more groovy.
Spiders on speed get weaving
Spiders on marijuana are so laid back that they weave just so much of their webs and then…well, it just doesn’t seem to matter anymore. On the soporific drug chloral hydrate, they drop off before they even get started.
A spider’s skill at spinning its web is so obviously affected by the ups and downs of different drugs that in 1995 scientists at NASA’s Marshall Space Flight Center in Alabama thought spiders could replace other animals in testing the toxicity of chemicals.
Different drugs had varying effects on the average arachnid addict. On benzedrine, a well-known upper, house spiders spun their webs with great gusto, but apparently without much planning, leaving large holes. On caffeine they seemed unable to do more than string a few threads together at random.
The more toxic the chemical, the more deformed the web. NASA researchers had hoped that with help from a computer program they would be able to quantify this effect to produce an accurate test for toxicity.
But, being terribly right-on, we can’t really say we are happy with dosing spiders or any animal with drugs already tried and tested in humans. Far better, we feel, to give them something we can presume in advance they might enjoy.
Animal pleasure
In 1995, primate pornography was the entertainment on offer for bored gorillas at Longleat House near Warminster, UK. Samba and Nico romped over a quarter of a hectare of private island during the day and enjoyed all the comforts of home at night.
Their house was equipped with satellite TV, to which they were glued throughout the long winter evenings. Longleat’s press officer Claire Keener told New Scientist that Samba and Nico preferred jungle movies and became especially excited when gorillas appeared on the screen. At the consenting age of 30 years old, both were allowed to watch blue movies of primates mating in the wild, in the hope that they would be aroused into mating.
Not a bad life: first-class room service, a wholesome and varied diet of fruit, vegetables and beech leaves, and a visit from a personal vet once a week. Lights out at bedtime ensured a comfortable night’s sleep but despite the movies, there was no monkeying around.
Success, sadly, was not forthcoming, which is bad news for all those zoological institutions that have trouble getting the likes of pandas and polar bears to mate. Still, panda porn and its ilk give us an excuse to report any amount of research into the sexual behaviour of animals.
Exhibitionist spiny anteater reveals bizarre penis
In 2007, the bizarre sex life of the spiny anteater was exposed when it was discovered that the male ejaculates using only one half of its penis. These findings about the creature’s sex life may seem salacious but they could help shed light on an evolutionary mystery.
It seems that the way the mammal ejaculates is similar to the way reptiles do—by shutting down one side of its penis before secreting semen from the other side. Reptiles have a pair of male members called hemipenes for sex, and they use only one of the two during each act of copulation (see Chapter 6).
The spiny anteater (Tachyglossus aculeatus), also known as the short-beaked echidna, is a primitive mammal found in Australia and New Guinea. Like the platypus, it is a monotreme, laying eggs instead of bearing live young. Monotremes have many features in common with reptiles, and the hope is t
hat by studying them, scientists may find clues as to how mammals evolved. The spiny anteater, however, is notoriously difficult to observe in the wild and shows little enthusiasm for breeding in captivity, so, prior to 2007, nobody had managed to observe them ejaculate.
Fortunately, Steve Johnston of the University of Queensland in Gatton, Australia, and his colleagues inherited a male spiny anteater that was not so shy. The creature had been ‘retired’ from a zoo because it produced an erection when being handled at public viewing sessions, bemusing its visitors. By filming this animal, the researchers were able to describe the unique spiny anteater erection and ejaculation behaviour for the first time.
The spiny anteater’s four-headed phallus had been puzzling scientists. ‘When we tried to collect semen by electrically stimulated ejaculation before, not only did we not get a single drop, but the whole penis swelled up to a four-headed monster that wouldn’t fit the female reproductive tract, which has only two branches,’ said Johnston. ‘Now we know that during a normal erection, two heads get shut down and the other two fit.’ The heads used are swapped each time the mammal has sex.
The evolutionary significance of one-sided ejaculation was unknown, but may play a role in sperm competition—where sperm from many males may compete to fertilise an egg. Indeed, in the spiny anteater, up to 11 males may form a queue behind one female to copulate with her. The researchers also observed that hundreds of sperm team up to form bundles that swim much faster than individual sperm in the spiny anteater’s semen—another possible adaptation for sperm competition.
‘We can now study echidna sperm much better, which should offer fascinating insights into the evolution of mammals,’ said Russell Jones from the University of Newcastle in New South Wales, who first dissected sperm bundles from dead echidna in the 1980s.
Why a big horn gives beetles a tiny organ
Rapid metamorphosis may explain why beetle species are numerous enough to overwhelm almost any other creature on Earth. The superfast evolution of the male dung beetle’s penis to wildly differing sizes in the same species could mean that new species appear within a few years rather than over millennia.
In 2008, Armin Moczek from Indiana University, Bloomington, and colleagues studied four populations of one species of horned beetles in Eastern and Western Australia, Italy and the US. The most striking difference was between beetles in Western Australia, which had small horns and big genitals, and those in the US, which had the complete opposite. The variation in genital size between these two populations was as pronounced as that between ten other species in countries across Asia, Europe, and South America.
Organs developing within the pupa must compete for a limited supply of nutrients. So if one organ grows bigger, another is stunted. Thus, males with large horns tend to have smaller genitals, and vice versa.
Strong male beetles use their horns to fight for females, but weaker males prefer to sneak off to mate while competitors are fighting. Which strategy works best depends on the size of the population. In those with more females, fighting is most successful, and big-horned beetles win most mates. But when there are not enough females, fighting is often fruitless, so evolution favours beetles with smaller horns but cunning tactics.
Because beetles with genitals of different sizes cannot mate, Moczek thought the four populations might soon split into distinct species. ‘It’s unprecedented that 50 years would be long enough to generate variation normally only found in species which have been separated for millions of years,’ he said.
Of course, mating practices vary greatly between species, but it’s safe to assume the medaka fish in this following article from 1994 weren’t expecting to breed in zero gravity.
Astronauts aim to catch fish in the act
Voyeurism will reach new heights this week as astronauts aboard the space shuttle Columbia video the mating behaviour of two pairs of Japanese medaka fish. If the fish succeed in mating in orbit, and produce eggs and offspring, scientists will have a unique chance to study the role gravity plays in the development of the embryo. Successful mating could also pave the way for further experiments aimed at providing astronauts on long missions with a renewable source of food.
The experiment is one of about 80 set up by an international team of scientists to fly in a microgravity laboratory aboard Columbia. In the absence of gravity, many species of fish lose their balance and swim in loops rather than straight lines. This makes mating unlikely, says Victor Schneider, one of the NASA scientists overseeing the programme. Japan’s national space agency, NASDA, took a number of species up in aircraft flying a parabolic course that reproduces weightless conditions for a few seconds. The small, orange-coloured medakas did best in the flight tests, hence their spaceflight. The species also has other advantages. Medakas’ eggs take only eight days to hatch, so the astronauts should see results before the end of the 14-day mission. In addition, fish, eggs and offspring are all transparent, so the astronauts will be able to record the development of the body and internal organs on film. After behaving strangely at first, the fish recovered, but mating was a tentative affair.
None of us is surprised that animals enjoy sex, of course. What is more perturbing is that, like humans, they might have hang-ups about it.
The cat’s whiskers
Many inventors claim that their latest idea is ‘the dog’s bollocks’. But in 1996, CTI Corporation of Buckner, Missouri could claim that theirs really was. The company had developed a line in polypropylene canine testicles.
Artificial testicles, according to Chemical and Engineering News, were selling like hot cakes in the US and Canada. Trade-named Neuticles, they were installed in the dog’s scrotum in a two-minute procedure immediately following removal of the original articles. The idea was to be able to neuter dogs without causing psychological trauma.
Gregg Miller, CTI’s president, suggested that Neuticles would encourage owners to have their dogs seen to: ‘With these, the dog looks the same. He feels the same. He doesn’t even know he’s been neutered.’
Although Miller admitted that some people thought the product was silly, he claimed that Neuticles were ‘big news in the veterinary industry’. He had even produced ‘I love Neuticles’ bumper stickers for the proud owners of dogs with ersatz balls. Veterinarians, however, were sceptical of the idea that Neuticles could do much for a dog’s self-esteem.
And so are we. Even so, could this Suffolk punch stallion have benefited from a pair? Probably not. Still, we are impressed by this example of school science in action.
Soft solution
Childhood memories of a school science experiment helped a vet to save a patient’s professional career in 1992. The unfortunate victim of an accident at work was a Suffolk punch stallion, kicked in the genitals by a mare he was supposed to service. A painful swelling developed on the stallion’s penis.
The next day, vet Philip Ryder-Davis was called in. ‘Despite all manner of treatment, the oedematous swelling got worse and worse over the next three days,’ he said. With disaster looming, a long-forgotten science lesson came to mind, he explained.
Ryder-Davis remembered an experiment to demonstrate osmosis. The shell was removed from a raw egg, and the egg with its inner membrane still intact was put in a strong solution of sugar. Osmotic pressure forced the water from the egg, as it attempted to dilute the sugar solution and produce equilibrium on both sides of the membrane, and the egg gradually began to shrink. Ryder-Davis suspended a canister of syrup from belts around the animal’s abdomen and placed the damaged organ inside. Within 24 hours the swelling had disappeared, he reported, and the stallion recovered.
A specialist in the biology of membranes confirmed that the treatment was feasible. ‘Putting a swollen organ in a highly concentrated solution of salt or sugar would certainly pull the water out. It raises the question of what happens to the penises of swimmers in the Dead Sea,’ he added.
Animals tend to avoid the Dead Sea—the hint is in the name. But, then again,
you’d also expect animals to avoid falling into vessels from which they cannot escape. But they don’t, which leads us nicely on to a very eccentric invention.
Spidey’s escape
It is an old adage of the patents profession that the oddest ideas are the easiest to patent, simply because nobody has ever tried before. Although the examiners searched a wide range of previous patents, they were not able to come up with anything that anticipated the application filed by Edward Doughney of Bedfordshire, UK, in 1994.
Spiders are often trapped inside a bath because they cannot climb up the slippery curved slope. So the bather either has to flush them away down the plughole or give them a helping hand. A more humane answer, Doughney suggested, was a spider ladder.
A strip of flexible plastic had a suction pad on one end which anchored it to the top of the bath. The strip had a rough surface, so an athletic spider could climb to safety unaided.
Of course, there’s a whole raft of inventions designed to improve the lot of the animal kingdom. We’ve already encountered Neuticles and spider ladders, now how about these:
Wonder baas
English Nature decided that old methods were the best when in 1995 the rural heritage authority wanted to clear a thorny patch of ground to encourage the growth of sea-wort, a favourite food of the endangered reddish buff moth’s larvae. So a herd of milking goats was brought in to do the job on the Isle of Wight.