Be warned – spiders can hear you

❝ While jumping spiders are known to have great vision, a new Cornell University study proves for the first time that spiders can hear at a distance.

The discovery runs counter to standard textbook wisdom that claimed spiders could only detect nearby sounds.

❝ A study describes how researchers used metal microelectrodes in a jumping spider’s poppy-seed-sized brain to show that auditory neurons can sense far-field sounds, at distances up to 3 meters, or about 600 spider body lengths.

In further tests, researchers stimulated sensitive long hairs on the spider’s legs and body – previously known to pick up near-field airflow and vibrations – which generated a response in the same neurons that fired after hearing distant sounds, providing evidence the hairs are likely detecting nanoscale air particles that become excited from a sound wave…

❝ The techniques open up studies that link neurology with behavior in all spiders, Ron Hoy said. Gil Menda has since found evidence of hearing in five different spider species: jumping spiders, fishing spiders, wolf spiders, netcasting spiders and house spiders.

Future work by Hoy’s lab will investigate audio perception from lyriform organs and will better investigate audio neurons in the brain. The findings could have applications for using hairlike structures for extremely sensitive microphones, such as in hearing aids.

I wonder if they’ll investigate Google spiders? Har.

Meanwhile, RTFA. A delightful tale of accidental discoveries and cross-discipline cooperation.

Hidden housemates in Oz

golden huntsman
Click to enlargeBeregama aurea, Golden HuntsmanLinda Rayor

You’re driving along and you open the sun visor. You’re cleaning at home and bump a painting hanging on the wall. Suddenly, out runs a huge, hairy spider. Australia’s huntsman spiders are the stuff of myths and nightmares.

But these are also the most interesting of their family, and deserve their place in the pantheon of Australian wildlife…

First, let’s talk numbers: there are currently 1,207 species of huntsman spider in the Family Sparassidae, out of the total 45,881 described spider species worldwide. It is estimated that there are 155 huntsman spider species found throughout Australia.

Of those, approximately 95 species are found only in Australia. All of these are probably descended from a single common ancestor that immigrated from Papua New Guinea or elsewhere in Southeast Asia.

Huntsmen are big spiders…many of the endemics are sizeable animals that can weigh 1-2 grams and may be as big as the palm of your hand.

The world’s second largest species, the massive Golden Huntsman (Beregama aurea) from tropical Queensland, weighs over 5.5 grams. An adult’s forelegs may stretch 15 cm, and they lay egg sacs the size of golf balls…

All huntsman spiders are active at night, emerging from their retreats to forage for insects and other invertebrates, and occasionally small vertebrates. They are ambush predators, generally sitting and waiting for prey to come close before running and leaping on it…

During the day, most huntsman prefer to rest in retreats under bark, crevices, or other protected areas. This is why so many people encounter the spiders under the sun visors of their cars or behind curtains in their homes, because those are perfect tight spaces for a sleepy spider…

What should you do if you do find a big spider in your car or living room? First, get a grip! She isn’t going to hurt you.

Second, find a take-away container, scoop the spider into the container and release it outside. Huntsman spiders almost never bite humans since they rely on speed to escape most predators. When they do bite, most bites are quick defensive nips without injecting venom…

Treasure your huntsman spiders. They deserve a place alongside koalas and kangaroos as iconic Australian wildlife.

Really nice article and this is only a small portion. Click the link up top in this post and read the whole thing. Interesting, entertaining, stuff worth learning.

We get Golden Orb Weaver spiders here in New Mexico that think they’re as big as a Huntsman – but, they really aren’t. They are just as pretty. You really should get to know all your housemates.

Thanks, Honeyman

Spiders casting webs as lifeboats in Australia’s floodwaters


 

Thousands of spiders have cast eerie webs over vast areas of flood-hit Australia after being forced to seek shelter by the rising waters.

Experts said the spiders may be spinning the sticky webs to help them survive the deluge, which has forced thousands of people to leave their homes over the past week.

“What we’ve seen here is a type of wolf spider,” Owen Seeman, arachnid expert at Queensland Museum, told Reuters. “They are trying to hide away from the waters.”

The spider webs were seen near the inland city of Wagga Wagga in New South Wales, where 8,000 people were forced from their homes before the flood waters receded on Wednesday.

The Australian Museum’s entomology collections manager Graham Milledge said the spiders’ behavior was known as ballooning, and was typical after spiders are forced to flee from floods.

Better the spiders instead of the snakes. 🙂

Spiders pour from cargo hold – ship ordered to leave Guam

A South Korean cargo ship had to be turned away…after an infestation of spiders was discovered in the cargo hold.

Customs officials discovered the infestation in the MV Altavia’s cargo after the South Korean ship docked in Guam, one of the Mariana Islands in the western Pacific Ocean.

Thousands of spiders, some with bodies as big as 10 pence pieces, started pouring out of the ship’s crates as Guam’s Port Authority workers began moving the containers off the boat onto the dock, last Wednesday.

The shipment had been destined for a US military base construction site on the island for 8,000 US Marines.

The ship was told to leave the port and moor off shore while officials investigated if the species was venomous or posed any danger, Guam’s agriculture officials said.

It was then turned away completely two days later and told to return home with the spiders still on board.

“It was because of the quantity,” Joseph Torres, director of Guam’s Department of Agriculture told US military newspaper Stars and Stripes…

It is unclear what happened to the ship or spiders after the ship left Guam.

The spider species remains unidentified.

Probably on their way to Okinawa. Har!

Spider-smuggler stopped in Germany

big-spider-lives-here

German customs officials have detained a man who was trying to smuggle more than 160 large trapdoor spiders into the country from Switzerland.

The Swiss driver was also carrying 45 boxes of cockroaches as food for his eight-legged cargo, they said.

The spiders, most of which were “as big as a fist“, were found wriggling around in boxes and plastic bags in his car.

The same man was stopped at the same place two years ago trying to bring some 1,000 spiders for sale at a fair.

“Of course, the officers didn’t open anything. They knew immediately what was going on,” a spokesman for the customs office told the AFP news agency.

Gives me an excuse to use one of my own photos. That’s the front door to a critter something like these – living in my back meadow.

Spiders get their space legs — all eight of them

Two plucky spiders on the international space station have bounced back from a tangled false start to weave amazing new webs in zero gravity.

The orb-weaving spiders were transported to the station aboard NASA’s shuttle Endeavour earlier this week, but initially wove an aimless concoction in their lab enclosure during their first days in weightlessness. But now they’ve taken another stab at weightless web construction.

“We noticed the spiders’ made a symmetrical web,” the space station’s current skipper Michael Fincke radioed to Mission Control today. “It looks beautiful.”

Fincke said he was amazed at how fast the two eight-legged creatures appear to have adapted to living in space.

The spiders are part of an experiment aimed at sparking interest in science among students on Earth. The arachnids are the same kind of spider as “Charlotte” in the children’s book “Charlotte’s Web” by E.B. White.

I’m certain the spiders don’t even worry too much about budget constraints, space station traffic management or [maybe] what flavor their food may be.

It is pretty cool they figured out how to deal with zero-gravity, though.

Spiders who prey together, stay together — and form enormous colonies

Click photo for example of huge nest

The ability to work together and capture larger prey has allowed social spiders to stretch the laws of nature and reach enormous colony sizes, UBC zoologists have found. The findings may also explain why social spiders thrive in tropical areas but dwindle with increasing latitude and elevation.

“The size of organisms tends to be constrained by a scaling principle scientists call ‘surface to volume ratio,’” says Leticia Avilés, lead author. While organisms typically have energetic needs proportional to their volume, they must acquire nutrients through their surface.

“As the organism grows, this surface to volume ratio declines. In a way, this is how nature keeps the sizes of various species in check.”

The same principle may apply to social groups. The surface area of the three-dimensional webs social spiders use to capture prey does not grow as fast as the number of spiders contained in the nests; so number of incoming prey per spider declines with colony size. But Anelosimus eximius, a species of social spider notable for its enormous colony size – some total more than 20,000 individuals – have gained the ability to stretch that law by cooperating and thus capturing increasingly large insects as their colonies grow.

I wonder if this applies to Facebook?