maritimus

The taxonomic name for polar bears is Ursus maritimus, which means sea bear, a fitting name for these champion swimmers. They have been known to swim more than 60 miles (about 100 kilometers) without rest in search of food, using their broad front feet for paddling and their back legs like rudders to steer. Unfortunately, due to loss of ice, the bears are now having to swim longer distances, as much as a few hundred miles, which takes a toll on their energy and fat storage.

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It’s that time of year again! Mammal March Madness has arrived! 

This is the annual tournament of simulated combat between mammal species organized by four biologists. 65 species enter … and only one is crowned the champion. Here’s how it works:

Scientific literature is cited to substantiate likely outcomes as a probabilistic function of the two species’ attributes within the battle environment. Attributes considered in calculating battle outcome include temperament, weaponry, armor, body mass, running speed, fight style, physiology, and motivation.

Through the scientific information embedded in the bout descriptions, participants are educated about inter-species interactions, the importance of ecological context, how natural selection has shaped adaptations, and conservation management of endangered species.

The first bout - a wildcard match between the Thor Hero Shrew and the King Midas Bat has already finished (winner: HERO SHREW) - but you still have time to fill out your bracket before the first round of regular match-ups (the “chill mammal” division) begins tonight. Download your bracket here and fill it out!

You can follow the matches on twitter via the #2016MMM hashtag. Tournament schedule:

Week One
3/8    Chill
3/9    Mascots
3/10  Mighty Giants
3/11  Nouns                 

Week Two
3/14  MG & C
3/16  M&N
3/17  Sweet 16

Week Three
3/21  Elite Trait
3/22  Final Roar
3/24  Championship

My favorite to win? Ursus maritimus.

Here’s my terrible, punny sports-radio style send-up of last year’s competition:

The illustrations in the poster up top were created by Charon Henning - check out more of her artwork here.

nature.com
Polar bear metabolism cannot cope with ice loss
The Arctic mammals may not survive the ongoing loss of their hunting grounds.

Polar bears’ metabolism does not slow very much during the summer months when sea ice melts and food becomes scarce, according to a study1 published today (16 July) in Science. With the Arctic warming faster than the global average, the finding does not bode well  for the bears (Ursus maritimus), who use the ice as a hunting ground.

No safe haven for polar bears in warming Arctic

Not a single polar-bear haven in the rapidly warming Arctic is safe from the effects of climate change, researchers have found.

Polar bears (Ursus maritimus) rely on sea ice for roaming, breeding, and as a platform from which to hunt seals. When the ice melts in the summer, the bears spend several months on land, largely fasting, until the freeze-up allows them to resume hunting. So if they are to survive, they need pockets of ice to persist almost year-round.

Some climate models suggest that most of the Arctic may be ice-free in summer by mid-century[1]. But icy refuges near the North Pole currently support 19 populations of polar bears, totalling some 25,000 individuals.  Scientists weren’t sure about the exact rate of ice retreat in these habitats, or whether some refuges might not yet be dwindling.

All of the Arctic refuges are in fact on the decline, a detailed examination of satellite data now suggests. Mathematician Harry Stern and biologist Kristin Laidre at the University of Washington in Seattle used a 35-year satellite record to examine each of the 19 population areas, which range from 53,000 to 281,000 square kilometres in size. For each, they calculated the dates on which sea ice retreated in the Arctic spring and advanced in the autumn, as well as the average summer sea-ice concentration and number of ice-covered days.

Polar bears’ sea-ice habitat is dwindling as the Arctic warms. Theo Allofs/Minden Pictures/FLPA