Tag Archives: Department of Zoology

Jun 7 2011

Spiders: To decorate or not decorate the web, that is the question?

But when it comes to ensnaring their prey?

A decorated or not decorated web, for spiders, works just the same.

So why do it at all?

Scientists have cracked the secret code in the decorations of web-making spiders…

Oh, good cause you know I was worried.

*shakes head sadly*

[via Physorg] The team, led by Dr. Andre Walter and Professor Mark Elgar from the University of Melbourne’s Department of Zoology, found that orb-weaving respond to severe damage to their webs by building bigger silk crosses, but if the damage is mild they don’t bother adding extra decoration.

Professor Mark Elgar said web damage is costly for spiders as a lot of nutritional resources are required to rebuild a web. “So they evolved this ingenious way to minimize unwanted damage,” he said.

“It’s much like we mark glass windows with tape to prevent people walking into them,” he said.

The team collected a group of orb-weaving spiders and left them to build their webs in the laboratory. Some of the completed webs were severely damaged, others lightly damaged and the remainder left alone. The response of the spiders was then observed.

“The fact that spiders increased their decorating activity in response to severe damage but didn’t increase their decorating following light suggests that the conspicuous building of silk crosses serves to make webs more visible to animals that might accidentally walk or fly into them,” Professor Elgar said.

Adding decorations to spiders’ orb-webs was first reported over a century ago but why these spiders decorate their webs has been the topic of controversial debate for decades.

“Our study helps unravel this mystery,” Professor Elgar said. The study was published in Behavioral Ecology and Sociobiology. [Read More]

Or, for spiders?

It could be that they just have a twisted, sinister sense of humor and these decorations are in truth nothing more than a warped case of ‘X’ marks the spot…

A mark to aspire to when entangling their prey.

Loom tells the story of a successful catch.

Year: 2010
Length: 5’20″
Directors: Jan Bitzer, Ilija Brunck, Csaba Letay
Technical director: Fabian Pross
Production company: Filmakademie BW
Producer: Regina Welker
Sound: Joel Corelitz / waveplant
Artists:Felix Mertikat, Jin-Ho Jeon, Roman Kälin, Tom Weber, Christian Hertwig, Silke Finger, Jacob Frey, Leszek Plichta, Georg Schneider, Anja Wacker, Andreas ‘Felix’ Gebhardt, Falko Paeper, Sarah Eim
5.1 Mix: David Axelbaum / Airstream Audio

Me?

I’m guessing the latter.

Cause, yeah…

Spiders are kind of evil bastards that way.

May 10 2011

Shocking study: Animals have personalities too!

So…

Humans aren’t the only species on the planet who has a personality, huh?

No…

Really?

I love it how science is so quick to catch up in figuring this out…

ScienceDaily (Apr. 28, 2011) — An individual’s personality can have a big effect on their life. Some people are outgoing and gregarious while others find novel situations stressful which can be detrimental to their health and wellbeing. Increasingly, scientists are discovering that animals are no different.

A new study led by Dr Kathryn Arnold, of the Environment Department at the University of York has added important experimental evidence showing that animal personalities are reflected in their oxidative stress profiles. The research is published in the Journal of Experimental Biology.

Dr Arnold teamed up with graduate student Katherine Herborn, at the Institute of Biodiversity, Animal Health and Comparative Medicine at the University of Glasgow, to classify the personalities of 22 greenfinches.

They tested each bird’s reactions to a novel situation by adding a brightly coloured cookie-cutter to each greenfinch’s food bowl, and timing how long it took for the birds to pluck up courage to approach the food. The researchers found that the boldest birds took only a few seconds to overcome their fear while more timid birds took up to 30 minutes to approach their meal.

Dr Arnold and Katherine Herborn also measured the greenfinches’ motivation to explore by attaching an intriguing object to the birds’ perches and timing how long it took them to land next to it. However, there was no correlation between the birds’ courage and curiosity.

The researchers then measured the birds’ damaging reactive oxygen metabolite levels and their defences against them. Comparing the bird’s blood oxidative profiles with their personalities, the team found that the most timid birds had the highest levels of damaging oxygen toxins and the weakest defences, so they suffered more oxidative stress than braver individuals. Also, the scientists found that the most curious birds (those that approached objects fastest) had better defences against oxidative damage than less curious greenfinches.

Dr Arnold wants to extend the work to establish how personality traits affects birds in the wild. She says, “Neophobic birds — those that are afraid of new things — may suffer high costs of oxidative stress and die early because they paid these physiological costs, but they might also be less likely to be eaten by a predator because they are more wary than bolder birds .”

The research also involved scientists at The Edward Grey Institute, Department of Zoology at Oxford and the WALTHAM Centre for Pet Nutrition at Melton Mowbray, Leicestershire. The research was part-funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and the Royal Society. [Read More]

But since THEY(scientists)  are saying it now, as opposed to all the non-scientific idiots who claimed it earlier and were scoffed ay BY scientists…

Now of course it MUST be true.

[Source]

But only NOW because they say so.

Aug 15 2010

Some cats and dogs can be friends. It is possible and how.

Some animals are capable of amazing, committed lifelong friendships…

While others? Not so much.

Thinking about adopting a perky little puppy as a friend for your fluffy cat, but worried that they’ll fight – well, like cats and dogs?

Think again. New research at Tel Aviv University, the first of its kind in the world, has found a new recipe for success. According to the study, if the cat is adopted before the dog and if they are introduced when still young (less than 6 months for kittens, a year for dogs), there is a high probability that your two pets will get along swimmingly.

Results from the research were recently reported in the journal Applied Animal Behaviour Science.

“This is the first time anyone has done scientific research on pets living in the same home,” says Prof. Joseph Terkel, from the Department of Zoology at Tel Aviv University.  “It’s especially relevant to the one-third of Americans who own a pet and are thinking about adopting a second one of the opposite species.”

Talk Like a Dog

After interviewing almost 200 pet owners who own both a cat and a dog, then videotaping and analyzing the animals’ behavior, TAU researchers concluded that cats and dogs can cohabitate happily if certain conditions are met. Prof. Terkel and his graduate student Neta-li Feuerstein found that two-thirds of the homes they surveyed reported a positive relationship between their cat and dog.

But it wasn’t all sweetness and light (or, for that matter, bones and catnip). There was a reported indifference between the cat and dog in 25% of the homes, while aggression and fighting were observed in 10% of the homes.

One reason for the fighting might have been crossed inter-species signals. Cats and dogs may not have been able to read each other’s body cues. For instance, cats tend to lash their tails about when mad, while dogs growl and arch their backs. A cat purrs when happy, while a dog wags its tail. A cat’s averted head signals aggression, while in a dog the same head position signals submission.

In homes where cat/dog détente existed, Prof. Terkel observed a surprising behavior. “We found that cats and dogs are learning how to talk each other’s language. It was a surprise that cats can learn how to talk ‘Dog’ and vice versa.”

What’s especially interesting, Prof. Terkel remarks, is that both cats and dogs have appeared to evolve beyond their instincts. They can learn to read each other’s body signals, suggesting that the two species may have more in common than was previously suspected.