Monday, 28 July 2014

Perils of the English countryside

27 July 2014 Last updated at 04:15


By David McKenna
BBC News

Most people would be wary of crossing a large snorting bull in a field but, every year, scores of people are injured or even killed by other animals in the English countryside.

Many are creatures that may not instantly spring to mind - and have caused injury or terrified people who were otherwise enjoying a rural idyll.

But which animals are dangerous and why do they attack?

Frogs with vivid colour markings to ward off predators can also appear invisible - via Herp Digest

June 23rd, 2014 (Phys.org) —Frogs that rely on their vivid colour markings to ward off predators can also appear invisible, Deakin University scientists have discovered.
Researchers from Deakin University's Centre for Integrated Ecology found the anomaly among a species of frog in which some individuals use their rainbow hues to warn they are poisonous or toxic while others rely on their colourings to make them difficult to detect.
Centre for Integrated Ecology evolutionary biologist Professor John Endler and his Ph.D. student and co-author studied poison dart frogs in the wild and identified the reason behind the paradoxical observation that the amphibian's colourful markings varied between each animal.
Studying the vibrant blue and yellow poison dart frogs (Dendrobates tinctorius) in their natural habitat in French Guiana, Deakin researcher Bibiana Rojas found that one group of frogs exhibited bold or elongated patterns, the other demonstrated mottled and more variable markings.
The paradox was that the more variable the frog's markings, the less likely were predators to learn to recognise the danger. But if different colour patterns accompanied different behaviour, then pattern variation can be an advantage instead of a disadvantage.
"We found that some frogs move frequently in the same direction while others moved randomly, and that this movement behaviour variation corresponded to the colour patterns," Professor Endler said.
"The frogs with elongated patterns moved continuously in the same direction to create an illusion of static pattern, or a pattern travelling at a slower speed, to thwart predators attempting to track their trajectory.
"But frogs which moved randomly and changed directions frequently, rely on interrupted colour patterns that appear visually disruptive and hard to see at a distance, giving them an advantage in predator detection rather than tracking.
"These findings are quite exciting as we believe they might have application in the human world for defence camouflage," Professor Endler said.
"Alternatively, taxis, police cars, and ambulances could be painted with horizontal stripes to make them more easily seen when they are going past."
Professor Endler has been studying aposematic animals for many years - species that use colour in the wild to either attract a mate or ward off predation.
In Australia, Blue-ringed octopus and redback spiders, and the introduced Monarch Butterfly are among a variety of animal species instantly recognised for their chromatic colours that warn of their danger to would-be predators.
Black, red, yellow and white are among the bold colour schemes employed in nature to warn of danger.
The researcher's report, "Paradox lost: variable colour-pattern geometry is associated with differences in movement of aposematic frogs", has been published in the latest copy of the prestigious Royal Society Journal Biology Letters.
More information: Bibiana Rojas, Jennifer Devillechabrolle, and John A. Endler. "Paradox lost: variable colour-pattern geometry is associated with differences in movement in aposematic frogs." Biol. Lett.. 2014 10 6 20140193; DOI: 10.1098/rsbl.2014.0193 (published 18 June 2014) 1744-957X

Provided by Deakin University

Green turtle links Costa Rica's Cocos Island with Ecuador's Galapagos - via Herp Digest


Lindsay Fendt, 6/23/14, Tico Times
One normal migration for turtles, one giant discovery for humankind.
With his 14-day journey from the waters of Costa Rica’s Cocos Island National Park to the Galapagos Marine Reserve in Ecuador, “Sanjay,” an endangered green sea turtle, established the first direct migration link between the two protected areas.
Sanjay was one of three green sea turtles tagged by scientists from the marine conservation groups Turtle Island Restoration Network and PRETOMA during a 10-day research expedition. Using a $4,000 satellite tag, biologists from the organizations were able to map Sanjay’s exact migration.
“It’s truly remarkable. Sanjay knew where he was headed, and made a beeline from one marine protected area to the next,” said Alex Hearn, conservation science director for Turtle Island Restoration Network. “These protected areas of ocean are hot spots for endangered green sea turtles, but we also need to think about their migratory corridors between protected areas.”
Though the two organizations have tagged hundreds of sea turtles over the years, Sanjay is the first to show movement between the two protected areas. Sanjay’s migration is the latest piece of evidence linking the green turtles of the Galapagos and Cocos Island, a link that biologists have long suspected due to the populations’ genetic similarities.
The project’s researchers hope that the new evidence will help encourage the development of conservation programs between protected areas.
“These species are protected while they are in the reserves, but as soon as they swim beyond the no-fishing zone, they are being hammered by industrial fishing vessels that set millions of hooks in the region,” said Todd Steiner, executive director of Turtle Island Restoration Network. “Our goal is to collect the necessary scientific data to understand the migratory routes and advocate for ‘protected swimways’ to protect these endangered species though out their migration.”

Do butterfly wing patterns really mimic predator eyes?

23 July 2014 Last updated at 05:32

By Ella Davies
Science writer

A bumper crop of spikey black caterpillars have appeared on the nation's nettles this summer.

Clad in velvet coats peppered with white dots, the creatures have been sunning themselves and munching through the weeds in remarkable numbers prompting a flurry of enquiries and reports to the charity Butterfly Conservation.

They might not be so familiar in this form but the insects will grow up to be arguably Britain's most colourful and recognisable butterfly - the peacock.

As they prepare for their annual Big Butterfly Count, experts at the charity are predicting a bonanza of the butterflies.

Last year, the species surged to third position in the survey which asks the public to record how many butterflies they see in 15 minutes of sunny weather.

Following on from this success, peacocks emerged in good numbers after their winter hibernation according to Butterfly Conservation's Surveys Manager Richard Fox. The warm, dry weather since the spring has provided ideal conditions for breeding, egg-laying and the development of caterpillars.

Humans share fairness concerns with other species

Date:
July 24, 2014

Source:
American Psychological Association (APA)

Summary:
Humans aren’t the only species to react strongly to actions they consider unfair. A similar drive for fairness in monkeys and some dogs may offer insight into people’s desire for equity, according to experts.


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