Polar bears’ Valentine’s Day


This video is called Mother Polar Bear and Cubs Emerging from Den – BBC Planet Earth.

From eNature blog:

Three Guys For Every Girl— Why Male Polar Bears Have A Tough Time Getting A Date

Posted on Wednesday, February 05, 2014 by eNature

Valentine’s Day is coming up and love is in the Arctic air.

So what’s the best place for a male Polar Bear to meet a potential mate?

The experts recommend going to a prime seal-hunting spot. But finding such a spot is only the beginning of the challenge.

Nature Doesn’t Make It Easy

One reason a male Polar Bear must work overtime for a date is that females of the species don’t breed every year or even every other year. A female Polar Bear usually breeds only once every three years, which means that males outnumber eligible females three-to-one at the start of breeding season in the spring.

So competition for female attention is fierce, and males must fight one another, sometimes viciously, for the privilege of mating.

The Girls Can Play Hard To Get

Further complicating matters is the fact that female Polar Bears enjoy a good chase and will lead pursuing males across the ice for miles and miles.

In some cases, a chase can cover more than sixty miles—not for the timid or the weak of heart.

And we all thought it was tough to get a date to the Prom!

Without the vibrant color of a cardinal or the sweet song of a sparrow, how does a seabird go about attracting its mate? Here.

St Valentine’s Day is traditionally the time when birds start to choose their mates, with egg-laying for most resident species commencing in March or April. For a handful of birds, including Tawny Owl, Mistle Thrush and Dipper, nesting may already be under way in February, but numbers of these three early breeders are falling rapidly, according to the British Trust for Ornithology’s (BTO) BirdTrends report, published on-line today: here.

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Bears not hibernating in Nevada, USA


This video from the USA says about itself:

Awake for Winter: Tahoe Bears Not Hibernating

14 Jan 2014

Nevada wildlife officials say bears in the Tahoe Basin aren’t hibernating due to the mild winter weather, and that instead the animals are looking out looking for food, and getting closer to people. (Jan. 14).

In northern Europe winter weather so far may be mild, causing bears not to hibernate there as well etc; but elsewhere in North america, a “polar vortex” brings extremely cold weather.

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Swedish young Arctic foxes research


This video is called Arctic Fox Raids Polar Bear Kill.

From National Geographic:

In the winters of 2012 and 2013, National Geographic grantee Anders Angerbjörn and his Ph.D. student, Rasmus Erlandsson, studied an extremely threatened species, the Scandinavian arctic fox. The current population numbers fewer than 150 individuals in mainland Europe so many of the young foxes are having difficulty finding a non-related partner. Other threats to the species include competition from the red fox for the scarce small rodents they both depend upon for food. Angerbjörn and Erlandsson monitored the arctic fox population in Västerbotten and Norrbotten, Sweden, to identify the best territories for further conservation actions. This included tagging the baby foxes, which proved to be a challenge.

“When catching arctic foxes it is easy to believe that the smaller ones are the easiest to handle. In some aspects it is true. Their teeth are smaller and the jaws less powerful. Combined with a naïve lack of aggressive attitude it seems to make up for an easy piece of work to ear-tag a 700-gram cub. Well, sometimes it is, but just as human children have a hard time keeping still, the really small cubs do too.

“We handle the foxes in a bag while tagging, and the trick is to keep the animal still between your thighs while kneeling. And here comes the tricky part. How do you keep a small, wild fox still? You cannot apply too much force—it is barely a kilo of an endangered carnivore you are dealing with. You really do not want to hurt it. Just as with small children the best tool is patience, but at the same time you want the handling to be as short as possible.

“One particular cub had a technique I had never experienced before as it insistently tried to turn [onto] its back, for no obvious reason. I had to reach the ears, so I quickly turned the cub upright. The cub stayed still for a few seconds, and then began to roll onto its back again. The same maneuver, once again! And again! Finally, I got the tags in place, and after making measurements and taking some samples, I finally released the little fellow and it disappeared like lightning into the den.”

—Ph.D. student Rasmus Erlandsson, team member with Anders Angerbjörn, Global Exploration fund grantee

Young American kestrels survive bear attack


This video from the USA says about itself:

American Kestrels Feed Their Nestling in Aviary Nest Box 5/14/2009

Kestrels displaying excellent parenting skills in their aviary nestbox. The mated pair (Paco and Margarita) take turns ripping and tearing mouse parts for an eager nestling. The female Kestrel remained in the aviary on a diet of live sparrows (baggies) and “Rodent Pro” mice. She was released into the Baja wild at maturity and the mated pair are in their third breeding year. Six Kestrels raised/released to date.

From the Cornell Lab of Ornitology in the USA today:

It’s a heart-wrenching sight, finding a box on the ground in ruins. But with quick thinking, Alice Droske saved four American Kestrel nestlings that were thrown from their nest in the chaos of a bear attack.

Bear-ly A Scratch

by Alice Droske, a NestWatcher, FeederWatcher, Great Backyard Bird Count participant, and Cornell Lab member for 25 years

June 24, 2013, started out like any other American Kestrel nest box monitoring day. I, along with Joe Palzkill and Judy Schwarzmeier (federally licensed banders), monitor 27 kestrel nest boxes for Beaver Creek Reserve in Fall Creek, Wisconsin. Jill Barland, our silent auction winner, was with us.

It was a beautiful warm day, and upon our arrival at Box 20, we expected to find 4 juvenile kestrels inside the nest box, which we were prepared to band. We had quite a shock! As we drove up, there was no nest box on the 10-foot pole. Our truck went deadly silent inside. We looked at each other and said, “Oh no.”

We jumped out of the truck and began searching the area for the nest box. We found the nest box broken and scattered in pieces on the ground beneath the pole. Just then, the farmer who had given us permission to place the box on his farmland drove past. I ran to the farmer and asked, “Have you seen a bear on your property?” He replied, “Yes. A rather large bear has been seen in the area.” We were fairly certain that a bear had ransacked our kestrel nest box.

We quickly began surveying the area under the nest box. To our surprise, on the ground hidden in the tall grass were the four juvenile kestrels! We assessed they had been on the ground for several days due to the amount of fecal matter and pellets. They remained quiet until Joe pushed the tall grass away from where they were huddled together. Once they were spotted, they became very noisy.

Judy began the process of aging, sexing, and banding the juvenile kestrels with Jill aiding her. Joe and I used the two ladders we carry in the truck and began repairing the nest box. We used multiple bungee cords and used the old screws to reattach the nest box on the pole. We then placed the four juveniles into the nest box, while the adult female kestrel flew overhead. Later that evening, we returned to the nest box to check that our repair work was holding up. The adult pair was flying to the nest box and dropping prey into the entrance hole. The parents continued to feed the young, and the four juvenile kestrels fledged successfully. At the end of the season, the old box was taken down, and a new box was installed. It was a happy ending to an exciting adventure for us all and an important reminder why we monitor our kestrel nest boxes so diligently.

Prehistoric Spanish bears’ sex life discovery


This diagram compares the size the shape of the penis bones of the following bear species: A) sun bear, B) Asian black bear, C) Andean bear, D) American black bear, E) sloth bear, F) brown bear, G) polar bear and H) the extinct Indarctos arctoides. Credit: PLOS ONE, doi:10.1371/journal.pone.0073711.g001

From LiveScience:

Size Mattered to Ancient Bear, Penis Bones Suggest

By Megan Gannon, News Editor

September 24, 2013 11:56am ET

Scientists don’t have any footage to shed light on the sex lives of ancient bears, but fossil penis bones can tell all.

Researchers recently studied a collection of penis bones from an extinct species of bear in Spain. Compared with today’s bears, this ancient creature, named Indarctos arctoides, had a surprisingly large penis bone that suggests it had infrequent but long-lasting sex sessions, the study found. And the females may have used penis size to assess their mates.

Human males today don’t have a penis bone, formally called a bacula, but it is found in many other mammals, including chimpanzees and gorillas. Whereas humans depend on blood pressure to stiffen up their sexual member, a penis bone helps animals keep their penis reliably erect for intercourse. [7 Wild Facts About the Penis]

Penis bones are rare in the fossil record, but researchers found five of them in the Madrid Basin in Spain that belonged to this large primitive bear, Indarctos arctoides. The bear roamed Europe during the Late Miocene (around 12 million to 5 million years ago), and the male of the species would have grown to around 584 pounds (265 kilograms), similar in size to the European brown bear.

Its bacula was, on average, 9.1 inches (23.3 centimeters) long — significantly larger than the penis bones of much bigger bears. Male polar bears, the biggest bears on Earth today, typically weigh 1,100 lbs. (500 kg), but their penis bone averages about 7.3 inches (18.6 cm) long, the researchers say.

The length of the penis bone could reveal details not only about the sexual behavior of Indarctos arctoides, but also the species’ ecological habits and mating system.

Based on the size of baculum, the researchers think the bear likely had fewer but longer periods of intercourse than other mammals. A long baculum, the study researchers say, could have served as a physical support during mating, helping to keep the female’s reproductive tract open and in an optimal position for fertilization during these sporadic dalliances.

Indarctos arctoides may have also had relatively large individual ranges and possibly a lower population density, giving rise to fewer sexual encounters, the researchers say.

The fossil record shows that the male Indarctos arctoides would have been much larger than the female. Previous research has suggested bear species with strong sex differences tend to have shorter penis bones and mating systems where males take multiple mates and fiercely compete for females. The fact that Indarctos arctoides had a relatively long bacula suggests it was a sexually selected trait that females used to assess mate quality.

The study was led by paleobiologist Juan Abella, of the Autonomous University of Barcelona. It was detailed Sept. 18 in the journal PLOS ONE.

Good American grizzly bear news


This video from the USA is called Grizzly Bears V the Wolves Survival Documentary HQ.

From Associated Press:

1st grizzly seen at Elk Refuge in nearly 20 years

August 27, 2013 4:00 pm

JACKSON, Wyo. — A grizzly has been spotted at the National Elk Refuge for the first time in nearly 20 years.

A sow, with three cubs, was seen on Aug. 20 feeding on a gut pile from the annual bison hunt. It’s believed to have been a bear well-known to visitors of Grand Teton National Park, No. 399. That bear had triplets this year and had been seen in the southeast edge of the national park days before the refuge sighting.

A grizzly, also with three cubs, was last seen at the refuge in 1994.

Refuge biologist Eric Cole said that hunters have been warned to carry bear spray because of the possibility of grizzlies being drawn to the hunt.

And not so good news: November 2013: Trophy hunting is putting British Columbia’s population of grizzly bears at risk scientists from the Raincoast Conservation Foundation, the University of Victoria and Simon Fraser University have found. For despite supposedly strict regulations the report shows trophy hunters regularly kill more bears than allowed under the province’s own management policy, and passes doubt on the BC government’s claim that ‘sound science’ is used to manage the trophy hunting: here.

Fast Fact Attack: Endangered Species No. 80 – The Malayan Sun Bear: here.

Yellowstone wolves helping grizzly bears


This video from the USA is called Grizzly vs. Polar Bear.

From Wildlife Extra:

The return of wolves to Yellowstone has helped grizzly bears

Wolves provide a boost to bears, birds and butterflies

July 2013. A new study suggests that the return of wolves to Yellowstone National Park is beginning to bring back a key part of the diet of grizzly bears that has been missing for much of the past century – berries that help bears put on fat before going into hibernation. It’s one of the first reports to identify the interactions between these large, important predators, based on complex ecological processes.

Wolves proving huge value to wildlife

The researchers found that the level of berries consumed by Yellowstone grizzlies is significantly higher now that shrubs are starting to recover following the re-introduction of wolves, which have reduced over-browsing by elk herds. The berry bushes also produce flowers of value to pollinators like butterflies, insects and hummingbirds; food for other small and large mammals; and special benefits to birds.

The report said that berries may be sufficiently important to grizzly bear diet and health that they could be considered in legal disputes – as is white pine nut availability now – about whether or not to change the “threatened” status of grizzly bears under the Endangered Species Act.

Wild fruit important part of grizzly diet

“Wild fruit is typically an important part of grizzly bear diet, especially in late summer when they are trying to gain weight as rapidly as possible before winter hibernation,” said William Ripple, a professor in the OSU Department of Forest Ecosystems and Society, and lead author on the article. “Berries are one part of a diverse food source that aids bear survival and reproduction, and at certain times of the year can be more than half their diet in many places in North America.”

When wolves were removed from Yellowstone early in the 1900s, increased browsing by elk herds caused the demise of young aspen and willow trees – a favourite food – along with many berry-producing shrubs and tall, herbaceous plants. The recovery of those trees and other food sources since the re-introduction of wolves in the 1990s has had a profound impact on the Yellowstone ecosystem, researchers say, even though it’s still in the very early stages.

Need for an ‘ecologically effective number of wolves’

“Studies like this also point to the need for an ecologically effective number of wolves,” said co-author Robert Beschta, an OSU professor emeritus. “As we learn more about the cascading effects they have on ecosystems, the issue may be more than having just enough individual wolves so they can survive as a species. In some situations, we may wish to consider the numbers necessary to help control over browsing, allow tree and shrub recovery, and restore ecosystem health.”

As wolves help reduce elk numbers in Yellowstone and allow tree and shrub recovery, researchers said, this improves the diet and health of grizzly bears. In turn, a healthy grizzly bear population provides a second avenue of control on wild ungulates, especially on new-borns in the spring time.

Percentage of fruit in grizzly bear diet doubled during August

Yellowstone has a wide variety of nutritious berries – serviceberry, chokecherry, buffaloberry, twinberry, huckleberry and others – that are highly palatable to bears. These shrubs are also eaten by elk and thus likely declined as elk populations grew over time. With the return of wolves, the new study found the percentage of fruit in grizzly bear scat in recent years almost doubled during August.

Because the abundant elk have been an important food for Yellowstone grizzly bears for the past half-century, the increased supply of berries may help offset the reduced availability of elk in the bears’ diet in recent years. More research is needed regarding the effects of wolves on plants and animals consumed by grizzly bears.

Overgrazing led to livestock depredation

There is precedent for high levels of ungulate herbivory causing problems for grizzly bears, who are omnivores that eat both plants and animals. Before going extinct in the American Southwest by the early 1900s, grizzly bear diets shifted toward livestock depredation, the report noted, because of lack of plant-based food caused by livestock overgrazing. And, in the absence of wolves, black bears went extinct on Anticosti Island in Canada after over-browsing of berry shrubs by introduced while-tailed deer.

Increases in berry production in Yellowstone may also provide a buffer against other ecosystem shifts, the researchers noted – whitebark pine nut production, a favoured bear food, may be facing pressure from climate change. Grizzly bear survival declined during years of low nut production.

Livestock grazing in grizzly bear habitat adjacent to the national park, and bison herbivory in the park, probably also contribute to high foraging pressure on shrubs and forbs, the report said. In addition to eliminating wolf-livestock conflicts, retiring livestock allotments in the grizzly bear recovery zone adjacent to Yellowstone could benefit bears through increases in plant foods.

The report was published by scientists from Oregon State University and Washington State University in the Journal of Animal Ecology.

Climate change is killing these wolves. Should the government save them? Here.

All across the Greater Yellowstone Ecosystem, a 28,000-square-mile area covering parts of Montana, Wyoming and Idaho, a devastating beetle infestation has been killing whitebark pines. The consequences may stretch far beyond the fate of a single species of tree, however. The whitebark pine has been called the linchpin of the high-altitude ecosystem. The trees produce cones that contain pine seeds that feed red squirrels, a bird known as the Clark’s nutcracker and, most significantly, grizzly bears — a symbol of the American West and the current focus of a high-profile conservation battle: here.

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