The Gardens’ Talk Series (Dec 08) – Adventures in Collecting & Studying Beautiful Rhododendrons in South-East Asia

Norwegian Lemmings Threatened by Climate Change

Image credit: Balsamia on Flickr

Norwegian Lemmings Suffer from “Wrong Type of Snow”
Earlier today Michael reported that climate change is reaking havoc on the axolotl (aka the “Mexican walking fish”). But the freaky looking fish isn’t the only animal being driven to the brink of extinction. Given their reputation, it’s amazing any are alive at all, but according to the BBC the lemming is now in serious trouble too…

Jeremy actually touched on this issue last year when he wrote about threats to the Arctic predator population, but it seems that Norwegian lemmings have been having a tough time of late. Normally their numbers fluctuate in three to five year cycles. Some years would see populations so high that some lemmings would leap from cliffs into water – prompting the incorrect myth that the species practised collective suicide. But with snow cover decreasing, lemmings numbers are increasingly dwindling. The BBC explains why: 

“Rather than hibernating, lemmings spend the winter living in the space between the ground and a stable layer of snow above. […] But the peak years are not occurring anymore. The research team, composed of Norwegian and French scientists, believes the winters are now too humid, leading to the “wrong kind of snow”. This results in a less stable subnivean space (the space between the ground and the snow layer above), meaning substantially fewer animals survive until spring.”

BBC 

Bush Administration Proposes 48 New Endangered Species in Hawaii

Photo credit: Getty Images

Trust us, we’re as surprised as you are: In a bold, uncharacteristic, and long-overdue move, the federal government announced a proposal on Tuesday to add 48 species, found only on the island of Kaui in Hawaii, to the endangered species list. With 329 imperiled plants, animals, and insects, Hawaii has more endangered species than any other state.

Protecting these species would involve a “holistic approach,” according to Interior Secretary Dirk Kempthorne, who, lest we forget, dug in his heels every step of the way before finally reluctantly caving in to pressure to list the polar bear as threatened. If the 45 plants, two birds, and one insect are successfully added to the list, a process that involves a yearlong study, approximately 43 square miles would be designated as critical habitat for all 48 species. While this would depart from a 30-year-old practice of mapping out each species’ habitat individually, which does little to help the entire ecosystem, conservation groups remain wary.

“It is good news that the Fish and Wildlife Service has finally started to do their job, once again, of proposing protection under the Endangered Species Act for plants and animals on the brink of disappearing forever,” says Leda Huta, executive director of theEndangered Species Coalition (ESC). “Unfortunately, given this administration’s track record, we will have to go over the proposal with a fine-toothed comb to ensure that the protections are really being put into place.”

Although the ESC calls the action “an end to the drought,” it also points out that that administration has yet to act on the 23 other species it told Congress it would begin the listing process for this fiscal year.

“This Administration has the worst record of protection since the Endangered Species Act was created in 1973,” Huta says. “They have bent over backwards—and around ethics policies—to keep all but a handful of species unprotected and their record on providing adequate habitat for species to recover is even worse.”

The Center for Biological Diversity is equally skeptical. “While we welcome this action to protect these incredibly rare and imperiled species, in no way does it make up for the Administration’s abysmal track-record of listing and protecting endangered and threatened species,” says Mike Senatore, the Center’s Biodiversity Program director and senior counsel. “This action also does nothing for the hundreds of additional species that have languished for years awaiting protection under the Endangered Species Act. In fact, the proposal even falls short of the Interior Department’s announcement earlier this year that it would propose adding 71 species to the list of endangered and threatened species.”

At this point, though, we’ll take whatever we can get. ::Associated Press, ::Endangered Species Coalition, ::Center for Biological Diversity

More on the Endangered Species Act:
Bush Officials Launch Stealth Attack on U.S. Wildlife
AP Reports Proposal to Drastically Alter Endangered Species Act
Delaying Tactics Put U.S. Wildlife in Hot Water
Endangered Species List is Itself Endangered
America Celebrates Endangered Species Day
A Bush Administration Policy Adjustment

Source:

“Bush Administration Proposes 48 New Endangered Species in Hawaii”, treehugger.com, Travel & Nature, Jasmin Malik Chua, 1st Oct 2008

World’s Strangest Creature? Part Mammal, Part Reptile

The platypus sports fur like a mammal, paddles its duck feet like a bird and lays eggs in the manner of a reptile.

Nature’s instruction manual for this oddball, it turns out, is just as much of a mishmash.

Researchers just mapped the genome of a female platypus from Australia. The genetic sequence of this Aussie monotreme (a type of mammal) is detailed in the May 8 issue of the journal Nature.

“The platypus is a very ancient offshoot of the mammal tree, so it was 166 million years ago that we last shared a common ancestor with platypuses,” said study team member Jenny Graves, head of the Comparative Genomics Group at the Australian National University. “And that puts them somewhere between mammals and reptiles, because they still maintain quite a lot of reptilian characteristics that we’ve lost, for instance they still lay eggs.”

She added, “So we can use them to trace the changes that have occurred as we went from being a reptile, to having fur to making milk to having live-born young.”

The primitive mammal lives in burrows in Eastern Australia dug along the banks of streams and rivers that it relies on for food. Its flat, streamlined body extends just 20 inches (50 centimeters), tipped with a tail that resembles a ping-pong paddle and four webbed feet. The platypus (Ornithorhynchus anatinus) is one of only two mammals — the other is the echidna (spiny anteater) — that lays eggs. And unlike other mammals, the male platypus can deliver venom from a tiny spur on each hind limb.

To sort out the evolutionary relationships among platypuses and other animals, the team compared the genome of a female platypus nicknamed Glennie with those of humans, mice, dogs, opossums and chickens. (Chickens were included to represent egg-laying animals, such as extinct reptiles, that passed on much of their DNA to the platypus and other mammals in the course of evolution.)

At roughly 2.2 billion base pairs, the platypus genome is about two-thirds the size of the human genome, the researchers found. It shares more than 80 percent of its genes with other mammals. 

Like humans, platypuses carry an X and a Y chromosome. But unlike humans, the X and Y are not sex chromosomes. “That means we can go right back to the time when our sex chromosomes were just ordinary chromosomes minding their own business and ask well what happened, what made them into sex chromosomes,” Graves said.

The researchers revealed the animal has 52 chromosomes, including 10 sex chromosomes.

The genome also included sections of DNA linked to egg-laying and others for lactation. Since the platypus lacks nipples, the pups suckle milk from the mother’s abdominal skin.

Another oddity: When paddling through the water, a platypus keeps its eyes, ears and nostrils closed, and its duck-bill serves as an antenna, sensing the faint electric fields surrounding prey. Even so, the platypus genome reveals the animal held onto genes for odor-detection.

The study, which included more than 100 scientists from across the globe, was funded by the National Human Genome Research Institute (NHGRI).

 

By Jeanna Bryner, Senior Writer for www.livescience.com

Posted: 070508 01:00 pm ET

Illustration Credit: Zina Deretsky, National Science Foundation

Sex Strategies Come in Small, Medium, Large

 

In the beetle world, it’s the big guys who often win in the mating game, chomping their larger jaws down on the competition to fend them off.

But biggest is not always best. All sizes of male sap beetles — large, medium and small — can get lucky.
Each size adopts a different tactic in finding a mate, evolutionary ecologist Takahisa Miyatake at Okayama University in Japan and his colleagues found.

These beetles are found all throughout Japan. They live off the sap exuding from oak trees.

The largest male beetles wait for females at feeding areas — in the case of experiments, thin banana slices — and then fight for the right to mate. In those cases, the males with the biggest jaws stand the best chance of winning.

The medium-sized beetles — too small to beat the bigger males — have developed wings relatively larger than those of their larger counterparts. So the middleweights use their wings to search for feeding sites that are unoccupied by large males and woo with females there.

The smallest males adopt yet another completely different tactic — they rely on their relatively larger testicles. They stay at feeding sites with big males and then sneakily attempt to have sex with females behind the backs of the other males. They can then produce sperm that is more competitive than that of the bigger males.

While scientists had known that small and large male sap beetles (Librodor japonicus) employed different strategies, they had not known of the unique tactic of the medium-sized males. Miyatake said researchers should reexamine other beetles for such strategies as well.

The findings are detailed in the April issue of the journal Ecological Entomology.

 

 

Source:

 

Sex Strategies Come in Small, Medium, Large, Charles Q. Choi, LiveScience 07 April 2008 ET