Alaskan Brown Bears, Part III — Motherhood
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Brown Bears are solitary animals. They don’t rely on each other for companionship. The adults don’t willingly associate with each other although they will sometimes gather at a food source. That aside, the adults’ interactions are confined to breeding and occasional fights between boars competing for territory and mates.
The exception to this rule is the bond between cubs and mother bears. Sows are devoted mothers, caring closely for their offspring until they are about three years of age. Mother bears and their cubs travel, eat and sleep together, and even when the cubs are more than two years old, they don’t wander too far away from their mothers.
Brown Bears frequently produce twins and occasionally triplets. We saw several pairs of twins and one set of triplets. The yearling cubs in this first picture belong to a sow nicknamed “Agro.” We would encounter this family often over the four days that we photographed at Lake Clark.
All of the cubs that we saw, including Agro’s cubs, were well-nourished. It was obvious that the mothers were doing an excellent job caring for them.
The cubs learn by emulating their mothers. The mothers took them along as they foraged. On several occasions we watched sows and their cubs digging for clams.
One evening we watched a sow take her third-year twins for a swim.
The cubs nurse until they are more than two years old. They continue to nurse occasionally even after they’ve begun foraging for food. The youngest cubs, cubs born this year, are known as “spring cubs” or “cubs of the year” (“coys”). They are far more dependent on mother’s milk than are older cubs. One evening we watched a sow known as “Crimp Ear” (she has a deformed left ear) nurse her first year cubs. She lay down, exposed her breasts, and allowed her cubs to suckle. For a couple of minutes she appeared to be the picture of maternal contentment.
However, once she decided that the cubs had had enough, Crimp Ear simply rolled over and brushed the still-nursing cubs away with her forepaw.
She then watched, seemingly indulgently, as her cubs complained bitterly about having their feeding terminated.
Tomorrow, I’ll post some images that reveal another aspect of these bears’ behavior, their foraging.
Images made with a Canon 5Div, 100-400mm f4.5-5.6 ISII zoom lens, aperture priority setting. The first image shot at ISO 400, f8 @ 1/1000. The second shot at ISO 640, f8 @ 1/1250. The third shot at ISO 640, f6.3 @ 1/800. The fourth through sixth images shot at ISO 800, f7.2 @ 1/500.