Alaskan Brown Bears, Part IV — Foraging

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What do Coastal Brown Bears eat?  A short and not entirely flippant answer is: anything that they want to. Although these bears can capture and kill prey, they are omnivores, eating both plant and animal material.

The bears that we observed foraged on two types of food consisting of beach grasses and clams.  The area we visited included a sea of grass extending inland from the shoreline for a substantial distance.  For the bears these grasslands were one gigantic salad bar.

We watched as the bears grazed almost nonstop.  According to our guide an adult bear may consume 30 pounds of grass or more each day.

Grass is of poor nutritional value and, although the bears can digest it to a certain extent, it does not provide them with necessary fat and protein.  To obtain that, the bears must eat animal material.  At Lake Clark, clams supply the bears with vital nutrition.

The tides along the Cook Inlet are big, rising and falling several feet each day.  Low tide exposes enormous mud flats that  cover  an expanse of hundreds of yards in depth from the high tide mark to the waterline.  Millions of Razor Clams bury themselves in this mud, sometimes as much as two feet beneath the surface.  The bears have learned to dig these clams from their muddy homes.  Each day at low tide bears walk out onto the mud flats and dig for clams.  Mother bears always are accompanied by their cubs.  Older cubs eagerly dig for clams along with their mothers.

Here, two third-year cubs begin digging.  Notice that although these cubs are twins, one of them is much larger than the other.  That is not uncommon among bear cubs.

The mud on the flats is thick and gooey.  It adheres to everything.  The cubs become covered with the stuff as they dig.

They not only don’t seem to mind, but like young children everywhere, they seem to revel in their muddiness.

Digging for clams sometimes requires a long reach.  This cub has its foreleg buried in mud up to his or her elbow.

As the cub reaches for the prize it looks around suspiciously, wanting to make certain that a sibling doesn’t sneak up and grab the clam.

With the prize attained, the cub reacts to an approaching bear.  No worries in this case, the other bear expressed no interest and the cub was able to eat in peace (the clam is visible by the cub’s left fore foot).

The bears harvest clams by the bushel.  These animals’ prodigious appetites enable them to pack away huge amounts of food when the opportunity exists.  As the summer progresses native fruits and berries ripen and the bears shift their focus to eating those plants.  In early autumn they will fish for salmon as they spawn.  Salmon are the grand prize for the bears.  They are rich in fat and protein and eating them enables a bear to pack on quite a bit of weight in preparation for winter dormancy.

The first image made with a Sony RX100-3, aperture priority setting, ISO 320, f7.1 @ 1/160.  All other images made with a Canon 5Div, 100-400mm f4.5-5.6 ISII zoom lens, aperture priority setting.  The second image shot at ISO 400, f8 @ 1/640.  Remaining images shot at ISO 500, f6.3 @ 1/800.

3 responses to “Alaskan Brown Bears, Part IV — Foraging”

  1. Tom Munson says :

    Terrific series, Steve.

  2. Sue says :

    The third photo, the one of the twins, is incredibly beautiful and sculptural.

  3. tkiiatmindspringcom says :

    The photograph of the twins is great!

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