Bear Cubs at Birth

It looks like one of nature’s follies that bears are born during the worst of winter. No other mammal living in the North gives birth at this time. And no other mammals except the marsupials have such immature offspring. Bears have the smallest young in relation to the mother’s body size of any higher mammal. Typically bear cubs weigh between one three-hundredth and one five-hundredth as much as their mother. On average a newborn black bear cub weighs little more than 10.5 ounces (300 g) and is 9 inches (23 cm) long. Brown bear and polar bear cubs are marginally larger, about 17.5 to 28 ounces (500-800 g) in weight and 12 inches (30 cm) in length. If a newborn human infant were that small in comparison, it would weigh between 3.6 and 6 ounces (100-170 g), the weight of a 14 to 16 week old fetus. Even in the most advanced neonatal intensive care unit, a baby born at such an early developmental stage could not be saved. For bears, on the other hand, the birth of premature cubs is normal – indeed, inevitable.

Taken from Matthias Breiter’s book on bears.

The Humpback Whale

humpback whale breachingForty tons of meat and blubber erupt out of the calm waters along Lynn Canal. The entire body of an adult humpback whale emerges from the sea, twists around its core and falls back into the ocean. Icy Strait and Lynn Canal are known for their high concentrations of humpback whales during the summer months. Why the animals breach is the source of much speculation. Some feel that it may help the animal to dislodge barnacles from their skin. It also could be dominance behavior, or it may simply be an expression of joy.

Point Adolphus along Ice Strait, opposite the entrance to Glacier Bay, is possibly the single best known place to observe humpback whales. The strong current swirling around the promontory concentrates small feed fish, and whales hang around this stretch of water all summer long, never moving far. At slack tide, when the current is at its weakest, the animals seem to indulge themselves with play such as tail-slapping and lob-tailing. The animals are known to repeat this performance over and over. At times the same behavior is used to warn other whales, as when the fluke hits the water, the loud resonant sound can be heard for miles.

As whale populations grow, the number of whale carcasses that are discovered along the beaches is increasing too. Some animals die in collisions with ships. There are cases when whales get entangled in nets. Most fatalities, however, are likely due to natural causes. For scavenging birds and land-dwelling carnivores, a beached whale is a food bonanza that can last for several months, as long as the tide doesn’t take back its gift. The rich resource will attract grizzlies from far away. Mostly, it is the large boars that feed on the carcass. Sows with cubs stay their distance for sake of safety, and only come in when the males have had their fill and retreated for a siesta.

This is an excerpt from Matthias Breiter’s award-winning book, Inside Passage.

 

Book Signing 2011

Book Signing Poster

A big thank you to everyone who made it out to the book signing in Juneau, Alaska! You were lots of fun to meet and produced a great turn-out. Matthias is currently doing another signing in Denali National Park until Wednesday (July 13th).

Book Signing Schedule for Summer 2011:

July 11- 13: Denali National Park
July 17th: Alaska Sealife Center
July 20-22: Mendenhall Visitor Center in Juneau, Alaska

 

Dates to be announced:

Sitka
Ketchikan
Vancouver

Black Bear Cubs – Who’s Your Daddy?

Black bear cub in tree

DID YOU KNOW?
When a mama bear gives birth to two or more cubs, each cub can have a different father? Litters of bear cubs (2 cubs or more), are fraternal rather than identical multiple births.

THE SCIENCE:
Each ovulation in a female bear produces but one ovum, several copulations are required to stimulate the release of the eggs and fertilize them. Ovulation in mammals either occurs spontaneously (without any external trigger), as in humans, or is induced by the male, as in bears.

This information is from Breiter’s book on black bears, brown bears or grizzlies, and polar bears – Bears: A Year in the Life

Chowmane’s Cubs

Grizzly sow and triplet cubs
“…Chowmane’s cubs fit this description perfectly. They are lively fellows, studying attentively the surrounding area from between her legs. Still wet from the downpour a little earlier, they look like they have just fallen out of a washing machine. Their dark fur is completely tousled. Chowmane awards me a short glance and then sits down at the water’s edge. A few minutes later she rises again and wades out into the river. Meanwhile, the cubs have become deeply involved in a wrestling match and are oblivious to the fact that their mother is leaving their side. With obvious delight, they throw punches and bite each other’s neck and shoulders. Then, all of a sudden, the fighting ends. The surroundings regain shape and with it the realization that an important element of their world is amiss. Although their mother is only thirty yards away, they start to display signs of distress. Fidgety, they stand up, look in all directions and utter a short, hoarse bark. Without hesitation, Chowmane heads back to shore. It is apparent that the cubs have difficulty identifying their mother visually, as Chowmane’s approach does not arouse the expected enthusiastic response. Instead, a hint of panic descends upon her offspring. Frightened, they run into the tall grass, seeking shelter there. Seconds later their heads pop up above the green blades a few yards away. They peer toward Chowmane, still uncertain whether she represents danger or protection. Not until she huffs and pops her jaw are they certain of her identity, and finally they relax and return to the shore. Another crisis in their young lives is over.

Animals that raise their offspring in relative isolation often display a limited ability to identify their own progeny. The same is also obviously true for the capability of bear cubs to recognize their mother. Cases of cub swapping have been observed repeatedly along salmon streams. Primarily this happens when several family groups with young of equal age fish the same part of the river, and the cubs mingle. With many bears around, the cubs are agitated, nervous and occasionally get confused to the extent that they follow the wrong female upon her departure from the river. Most often the young bears are reunited with their biological mother within a few hours. Occasionally, however, they remain permanently with the foster family. In one instance, a sow was observed with cubs of different ages, one of which was most certainly not her own. In general, the foster mother appears to have little problem with the new addition to her family or the swapping of family members as long as the strange cub keeps calm. Should the adoptee become nervous, timidly bellowing for its true mother, acceptance on the part of the foster parent may turn into lethal intolerance. Upon observing bears for a long time, one truth emerges clearly: there are no absolutes in the realm of animal behavior.

Chowmane’s visit to the river was of short duration. Reunited, the family disappears shortly afterward into the nearby forest. In the absence of fish, there is no point in staying. I have not taken a single picture. But Chowmane will return. In the days ahead, I will get plenty of opportunity to capture her on film. To raise her progeny, as well as to put on a layer of fat for the winter ahead, a sow with cubs has to consume twenty thousand kilocalories per day. Thus, a female can ill afford to ignore a rich resource such as Brooks River during the salmon migration. For me, just seeing an old acquaintance again was worth my wait in the rain. I only hope her attempt to raise offspring will be crowned with success this time…”

An excerpt from Breiter’s book – Bears of Katmai