animal behaviour
edyong | November 9, 2009The female case-bearing leaf beetle Neochlamisus platani tries to give her children a head-start in life, but most mothers might not be keen on how she does it - encasing her young in an armoured shell made of her own faeces. After she lays her eggs, she seals each one in a bell-shaped case. When the larva hatches, it performs some renovations, cutting a hole in the roof and enlarge the structure with their own poo. By sticking its head and legs out, it converts its excremental maisonette into a mobile home, one that it carries around with them until adulthood.
All leaf beetles do this, but…
edyong | November 2, 2009In 1898, railway workers in Tsavo, Kenya were terrorised by a pair of man-eating lions, who killed at least 28 people during a 10-month reign of terror. It ended in December when a British officer called Lt. Col. John H. Patterson killed both beasts. The man-eaters' notorious exploits have been immortalised in no less than three Hollywood films, including most recently The Ghost and the Darkness. But despite their fame, no one is quite sure how many people they killed. The Ugandan Railway Company said 28; Patterson claimed it was 135.
Both parties had reasons to lie, either playing down or…
edyong | November 1, 2009We had numerous elephant sightings on our South Africa trip including a few family groups and a couple of lone males. Seeing them in documentaries or in zoos never quite captures just how big and impressive they are in the flesh, especially when they do things like beat up a tree. Note how this male uses his tusks and trunks to break off branches.
Also note how quiet it is except for the breaking of branches. Elephants may look like lumbering beasts, but their footfalls are dainty and quiet. They are 'digitigrade', meaning that they walk on their toes like a cat or a dog. Their heels rest on…
edyong | October 31, 2009This article is reposted from the old Wordpress incarnation of Not Exactly Rocket Science.
When it comes to sex, it makes sense to stick to your own species. Even putting aside our own innate revulsion, inter-species liaisons are a bad idea because they mostly fail to produce any young. In the few instances they do, the hybrid progeny aren't exactly racing ahead in the survival stakes and are often sterile (think mules).
But having poor unfit young is still better than having no young at all and if an animal's options are limited, siring a generation of hybrids may be a last resort. Karin…
edyong | October 27, 2009Many humans whinge about not getting oral sex often enough, but for most animals, it's completely non-existent. In fact, we know of only animal apart from humans to regularly engage in fellatio - the short-nosed fruit bat (Cynopterus sphinx).
The bat's sexual antics have only just been recorded by Min Tan of China's Guangdong Entomological Institute (who are either branching out, or are confused about entomology). Tan captured 60 wild bats from a nearby park, housed them in pairs of the opposite sex and voyeuristically filmed their liaisons using a night-time camera. Twenty of the bats got…
edyong | October 27, 2009In East Africa lives a species of spider that drinks mammalian blood. But fear not - Evarcha culicivora is an indirect vampire - it sates its thirst by preying on female mosquitoes that have previously fed on blood themselves.
Even though its habitat is full of non-biting midges called "lake flies", it can tell the difference between these insects and the blood-carrying mozzies it carries. Robert Jackson from the University of Canterbury discovered this behaviour a few years ago and one of his colleagues, Fiona Cross, has now found that the blood isn't just a meal for the spiders, it's an…
edyong | October 25, 2009The most incredible eyes in the animal world can be found under the sea, on the head of the mantis shrimps. Each eye can move independently and can focus on object with three different areas, giving the mantis shrimp "trinocular vision". While we see in three colours, they see in twelve, and they can tune individual light-sensitive cells depending on local light levels. They can even see a special type of light - 'circularly polarised light' - that no other animal can.
But Nicholas Roberts from the University of Bristol has found a new twist to the mantis shrimp's eye. It contains a…
edyong | October 24, 2009
Nature is rife with charlatans. Hundreds of animals have evolved to look like other species in order to fool predators into thinking they're more of a threat, or to sneak up on unsuspecting prey. In the Indo-Pacific lives a fish that does both and has the rare ability to switch between different disguises - the bluestriped fangblenny.
Common though it is, mimicry is usually restrictive and most fakers are stuck with one disguise. Until a few years ago, the only known animal that could switch between different acts was the amazing mimic octopus, which contorts its flexible body to look…
edyong | October 23, 2009There is a deep hole in a tree trunk and within is a tasty dollop of sweet, nutritious honey. It's a worthwhile prize for any animal skilled or clever enough to reach it, and chimpanzees certainly have both of these qualities. But the solutions they find aren't always the same - they depend on cultural traditions.
Chimps from the Sonso community in Uganda are skilled at the use of sticks and unsurprisingly, they manufacture stick-based tools to reach the honey. Chimps from the Kanyawara community in a different part of Uganda have never been seen to use sticks in the wild. Instead, they…
edyong | October 22, 2009By directing the evolution of a worm, scientists have confirmed answers to the age-old question: "What is the point of having sex with someone else?" For most people, that would hardly be a tricky query but it's no reflection on the lives of evolutionary scientists that sex has been one of biology's oldest puzzles.
The problem is this: many creatures can reproduce by fertilising themselves instead of getting someone else to do it, and at first glance they should do much better individuals that cross-fertilise. For a start, they'd ensure that all of their genes reach the next generation,…
edyong | October 20, 2009In the forests of South Africa lurks an arachnophobe's nightmare - Nephila kowaci, the largest web-spinning spider in the world. The females of this newly discovered species have bodies that are 3-4 centimetres in length (1.5 inches) and legs that are each around 7.5cm long (3 inches).
This new species is the largest of an already massive family. There are 15 species of Nephila - the golden orb weavers - and at least 10 of them have bodies that are over an inch long. Many spin webs that are over a metre in diameter.
The first of these giants was discovered by Linnaeus himself in 1767 and…
edyong | October 17, 2009This article is reposted from the old Wordpress incarnation of Not Exactly Rocket Science.
Imagine you get a bad cold, but you decide to put on a brave face and go into work anyway. Instead of jokingly covering their mouths and making jibes about staying away from you, your colleagues act perfectly normally and some even and start rubbing up against you. It's a weird scenario, but not if you were an ant.
With their large colonies and intense co-operation, ants are some of the most successful animals on the planet. But like all social insects and animals, their large group sizes make them…
edyong | October 13, 2009In the movie industry, special effects and computer-generated imagery are becoming better and more realistic. As they'd improve, you'd expect moviegoers to more readily accept virtual worlds and characters, but that's not always the case. It turns out that people are incredibly put off by images or animations of humans that strive for realism, but aren't quite there yet.
A character like Wall-E is lovable because he's clearly not human but has many human-like qualities and expressions. In contrast, the more realistic CG-characters of Beowulf or The Polar Express are far closer to reality but…
edyong | October 12, 2009In Latin America, there lives a unique spider called Bagheera kiplingi. It's a jumping spider and it shares the group's large, acute eyes and prodigious leaping ability. But it also has a trait that singles it out among all 40,000 species of spider - it's mostly vegetarian.
Virtually all spiders are predators. They may hunt using different methods but they all end up sucking the liquidised innards of their prey. If they consume plants, they do so rarely, even accidentally. Some take the odd sip of nectar to supplement their diet of flesh. Others accidentally swallow pollen while recycling…
edyong | October 3, 2009This article is reposted from the old Wordpress incarnation of Not Exactly Rocket Science. The blog is on holiday until the start of October, when I'll return with fresh material.
Every month, at the full moon, tourists and students gather on the beach at Koh Phangan, Thailand for a night of booze, dancing, and debauchery. But the moon-themed antics of these party-goers look positively tepid when compared to those of the Great Barrier Reef's corals. With the help of two genes and a spot of moonlight, the corals synchronise one of the greatest spectacles of the natural world - a mass annual…
neurophilosophy | October 2, 2009SEVERAL hundred species of fish have evolved the ability to generate electric fields, which they use to navigate, communicate and home in on prey. But this ability comes at a cost - the electric field is generated continuously throughout life, so consumes a great deal of energy, and it can also attract predators which are sensitive to it. Electrogenic fish species therefore utilize various strategies to save energy and to minimize the likelihood of being detected. Some generate irregular pulses of electrical discharges whose rate can be modulated; others can also modulate the strength of the…
edyong | September 30, 2009This article is reposted from the old Wordpress incarnation of Not Exactly Rocket Science. The blog is on holiday until the start of October, when I'll return with fresh material.
Sex is, on the whole, a good thing. I know it, you know it, and natural selection knows it. But try telling it to bdelloid rotifers. These small invertebrates have survived without sex for some 80 million years.
While many animals, from aphids to Komodo dragons, can reproduce asexually from time to time, it's incredibly rare to find a group that have abandoned sex altogether. The bdelloid rotifers (pronounced…
edyong | September 27, 2009This article is reposted from the old Wordpress incarnation of Not Exactly Rocket Science. The blog is on holiday until the start of October, when I'll return with fresh material.
It's tempting to think that elephants have their own PR agency. Just last week, their mighty reputation was damaged by the revelation that they are scared away by bees but they have bounced back with a new study that cements their standing among the most intelligent of animals.
Lucy Bates and colleagues from the University of St Andrews have found that African elephants (Loxodonta africana) can tell the…
edyong | September 26, 2009This article is reposted from the old Wordpress incarnation of Not Exactly Rocket Science. The blog is on holiday until the start of October, when I'll return with fresh material.
In your garden, there's a fair chance that a farmer is currently tranquilising her livestock with a chemical cocktail she secretes from her feet. Don't believe me? Look closer...
Humans aren't the only species that farms other animals for food - ants do it too and their herds consist of aphids. They feed on plant sap and excrete a sweet and nutritious liquid called honeydew, which the ants drink.
In…
edyong | September 25, 2009This article is reposted from the old Wordpress incarnation of Not Exactly Rocket Science. The blog is on holiday until the start of October, when I'll return with fresh material.
It's a myth that elephants are afraid of mice, but new research shows that they're not too keen on bees. Even though they fearlessly stand up to lions, the mere buzzing of bees is enough to send a herd of elephants running off. Armed with this knowledge, African farmers may soon be able to use strategically placed hives or recordings to minimise conflicts with elephants.
Iain Douglas-Hamilton and Fritz Vollrath…