Novel ways elephants communicate

photo courtesy of  Greg George

It is believed that elephants use low frequency signals transmitted through the ground as a means of communication.  A current theory is that elephants are able to sense the vibrations through pressure-sensitive nerve endings, Pacinian corpuscles, in their feet and —Meissner’s corpuscles that detect infrasonic vibrations - in the tip of their trunks.

 Scientists Katy Payne, Joyce Poole and their colleagues discovered that elephants emit a variety of infrasounds—calls too low in pitch to be heard by most humans. In 1989, Payne and her colleagues conducted a landmark experiment at a waterhole in Etosha demonstrating that these powerful infrasonic rumbles contain specific messages that can be heard and understood by other elephants more than 2 miles away.

This article contains information on the progression of seismic communication research in elephants and evidence supporting the idea that elephants use low frequency signals to communicate a variety of information from predator warnings to reproductive cues.

Okay to hunt elephants?

photo coutesy of Brian Snelson  

Successful conservation efforts are resulting in new problems as the swelling number of elephants may exceed what parks can support.  The South African government recently lifted the ban on killing elephants as a last resort in controlling the population.  According to an article in the Guardian

Amid words of protest and expressions of relief environment minister Martinus van Schalkwyk announced the elephant had been a victim of its own success with numbers growing from 8,000 to nearly 20,000 in national parks and private reserves in just over a decade.

 Supporters of culling point to growing difficulties in managing elephants in the country’s biggest and most famous game reserve, Kruger National Park. It has more than 12,500 elephants, 5,000 more than is sustainable, according to park officials. Ecologists say the animals’ huge appetites and fondness for “habitat re-engineering” - reducing forests to flatland by uprooting trees and trampling plants as they feed and roam - threaten the park’s biodiversity. 

However, elephants endear a lot of support from South Africans and the rest of the world because of their perceived gentle nature and the strength of their social bonds.  Some conservation groups, and animal rights advocates oppose lifting the restriction and approaching the situation as a numbers game.

Michele Pickover of Animal Rights Africa, which has threatened to urge a tourist boycott if culling goes ahead, said there was no scientific proof that the killing of elephants was necessary or even effective in controlling the population.

“This is a sad day for the country. Elephants are being treated as commodities by the government and game managers,” she said.

This article from National Geographic in 2004 gives more background on the debate, which has been going on for years and has included the voices of many different groups:  parks managers, game rangers, academics, community leaders, and the representatives of animal rights groups.  

Wolf population management

After the gray wolf is delisted, responsibility for population management transfers from the U.S government to individual states like Wyoming, Montana and Idaho.

An excerpt from the Idaho Wolf Conservation and Management Plan:

IDFG is charged by statute with the management of Idaho’s wildlife (Idaho Code §36-103(a): “All wildlife, including all wild animals, wild birds, and fish, within the state of Idaho, is hereby declared to be the property of the state of Idaho. It shall be preserved, protected, perpetuated, and managed. It shall be only captured or taken at such times or places, under such conditions, or by such means, or in such manner, as will preserve, protect and perpetuate such wildlife, and provide for the citizens of this state and, as by law permitted to others, continued supplies of such wildlife for hunting, fishing and trapping.”). This plan will enable the transition of the management of the gray wolf back to the IDFG as either a big game animal, furbearer, or special classification of predator that provides for controlled take after delisting. This classification will enable IDFG to provide protection for wolves as well as consider the impacts of wolves on other big game species, those sectors of the economy dependent upon sport hunting, livestock, domestic animals, and humans.

Amazing sea creatures

Click here to watch a visually stunning video about bioluminescent fish and cephalopods (squids, octopus) hosted by oceanographer David Gallo.

Certain underwater animals can respond to changes or threats in their environment by changing their appearance, a behavior that is useful for camouflaging, warding off predators or attracting a mate.

One of the most fascinating examples are deep-sea animals who live an environment with minimal light yet have adapted behaviors that capitalize on their ability to mimic different wavelengths of light.

An article, “Bioluminescent and Red-Fluorescent Lures in a Deep-Sea Siphonophore,” in the journal Science discusses the biology of bioluminescence and research that can provide a better understanding of how light (or lack there of) affects marine ecology.

Some great background information about bioluminescence can be found on this Web site

Bioluminescence has evolved many times in the sea as evidenced by the several distinct chemical mechanisms by which light is emitted, and the large number of only distantly related taxonomic groups that have many bioluminescent memberss.

Experts on polar bears

I found some interesting commentary and numbers that really get to the heart of the looming threat of global warming and its impact on polar bears.  Full article can be found on BBC News Web site.

• Scientists say Arctic sea ice is melting at a rate of up to 9% per decade
• Arctic summers could be ice-free by mid-century
• Dr Andrew Derocher, of the University of Alberta, Edmonton, has used the data to assess the impact on the Arctic’s top predator - he believes the polar bear could disappear in the wild by the end of the century unless the pace of global warming slows.
• British polar expert Dr Peter Wadhams of the University of Cambridge says the bear faces a gloomy future unless it is able to change its habits: “It could be that a polar bear could adapt to a new habitat and adopt habits like the brown bear in Alaska which hunts salmon in streams and other small animals on land,” he said.
• Lynn Rosentrater, climate scientist in the WWF International Arctic Programme, thinks that is unlikely to happen.
• Polar bears are currently found in Arctic regions of Alaska, Canada, Russia, Greenland and Norway.
• Populations in southern limits such as Hudson Bay are at most risk of dying out.

Tropical birds living in Chicago

photo courtesy of Eloise Mason

Trudging along the snow-covered streets of Hyde Park, you hear chirping and screeching resembling the sound of Styrofoam pieces rubbing together.  You look up and see a bright green and blue parakeet.  You may think that all the cold and snow has finally made you go mad, but there really are tropical birds that have colonized on the South Side of Chicago. They are called monk parakeets.

These birds have been living in Hyde Park for more than 30 years. No one knows exactly how the wild parakeets arrived in Chicago, but it seems they are here to stay.

Mark Spreyer, a biologist who directs the Stillman Nature Center in South Barrington, has written about the monk parakeet and led tours for people interested in seeing the exotic birds.  He told Parrot Chronicles the monk parakeets ”chose the right place to put up a colony. Everyone there really likes them. It’s a really diverse neighborhood and I think there’s a kind of multiculturalism connection between the people and the birds. They fascinate people,” he said.

Stephen Pruett-Jones, associate professor of ecology and evolution at the University of Chicago, will give a lecture on the exotic birds who have settled in Hyde Park.  The impact of these non-native birds on other bird species, the environment and the community is the topic of Pruett-Jones’ lecture at noon on Feb. 20. 

Roughly one foot long, the monk parakeet is a very social and gregarious bird. The plume of green feathers on the bird’s head and neck inspired its scientific name, myiopsitta monachus, because its hood of feathers resembles a monk’s hood, according to the Houston Audubon Society. 

Pruett-Jones has been observing these birds for more than 15 years, and is generating a map of monk parakeet nests in Chicago and the surrounding areas including northwest Indiana and southern Wisconsin, with help from undergraduate students and local inhabitants’ sightings.

Experiments conducted in aviaries with captive birds have found the large nests provide a four-degree advantage over outside temperatures, so it is slightly warmer in the nests.  However, “if that was the only thing they had going for them, they could not survive the winters.  They only survive the winters because they have access to a large good-quality food source,” in birdfeeders, said Pruett-Jones. 

“I think this winter will probably slow them up,” said Spreyer.  The thick snow cover could make it harder to find food, and may “knock their numbers back a bit,” he said. Pruett-Jones estimates the number in Hyde Park at about 200.

The birds are of some concern for utility companies in Illinois.  Monk parakeets occasionally build their nests on utility poles and power transformers, which can ignite fires and cause power outages. 

The lecture will be in the Swift common room at the University of Chicago in Hyde Park.  Admission is $5 at the door, and includes a vegetarian meal. Reserve a place before Tuesday at noon by contacting divinitylunch@gmail.com

Polar Bear Info

One of the most interesting things about the polar bears is that although they appear white, their fur is actually translucent and the skin below is black to absorb heat from the sun.

Polar bears eat seals, walruses, narwhals, fish, birds, berries, and many other foods.  They are carnivorous and need to eat about 4 lbs of meat daily to maintain their weight.

Mothers nurse their cubs for a long time, sometimes more than two years.

They have partially webbed front paws making them better swimmers capable of swimming long distances

Only female polar bears hibernate, and unlike other hibernators, polar bears give birth during hibernating, usually to two cubs.

These facts and more can be found on SeaWorld’s Web site.

Polar Bear = Endangered Species?

The U.S Fish and Wildlife Service is expected to make a decision soon on whether the polar bear should be listed as threatened under the Endangered Species Act.  The proposal was initiated over a year ago due to concerns that melting ice is threatening polar bear habitat and their ability to hunt for food.

 ”A species can be listed under the Endangered Species Act under one of two categories, endangered or threatened. An endangered species is likely to go extinct within all or a significant portion of its range in the foreseeable future. The polar bear was petitioned to be listed as a threatened species, defined as a species likely to become endangered in the foreseeable future,” according to F&WS - Alaska

A day in the life of a polar bear

The Polar Bear International Web site allows you to track polar bears that have been collared, including around the Chuckchi Sea.  It is an awesome tool!

Data is provided to the site by the the U.S. Geological Survey Alaska Science Center.

Polar Bear International has teamed with more than 35 Zoos to organize the “Year of the polar bear,” which began January 1, 2008.  “PBI’s two-pronged mission is to support conservation measures through scientific research and to educate the public about issues relating to the polar bear and its habitat.”

Alaska’s protected areas

For most of Bush’s presidency, there has been some debate over what should be done with protected forests in Alaska.  Conservationists would like to protect these areas to maintain wildlife habitats and keep roads from being built for loggers.  Other interest groups would like to see increased opportunities for logging and for oil drilling to help these industries and some say, support communities whose economy relies on these jobs.

 According to a Natural Resources Defense Council press release, “The Bush administration’s just-released management plan for the Tongass National Forest in Alaska puts millions of pristine acres in this ancient rainforest on the auction block to the timber industry, yet will raise no revenue for the U.S. government, as the U.S. taxpayers themselves will have to pay to build the roads the timber companies need to access the forest. The Tongass is the largest national forest in the country.”

 According to an article in the L.A. Times, “At 17 million acres, roughly the size of West Virginia, the Tongass National Forest in southeastern Alaska is the country’s largest national forest and the world’s largest intact coastal temperate rain forest. It contains grizzly and black bears, wolves, eagles and five species of wild Alaskan salmon.

Under the new plan, about 3.4 million acres of the forest would be open to logging and development. Of this acreage, about 2.4 million is in roadless areas, and about 663,000 acres is considered to have trees valuable for timber production.”

This post is to provide a little background on a complex issue, that I will continue to address in future posts.