Hyperphagia Black Bears of Grand Teton National Park - October 2017
Hyperphagia Survival Strategy
As autumn turns to winter and temperatures plummet, bears enter into a feeding frenzy called hyperphagia. Hyperphagia is from the Greek words phagia (to eat) and hyper (obsessively) and thus means 'to be obsessed with feeding”. Incessant feeding is exactly the behavior I observed in the Black Bears inhabiting the southern Hawthorn abundant region of Grand Teton National Park. Each River Hawthorn tree produces a windfall of nutrition at a time when other food sources are becoming scarce. For ravenous pre-hibernation bears that must enter hibernation with maximum fat stores, Hawthorn berries may provide life or death sustenance for winter survival.
black bearursus americanuswildliferiver hawthorncrataegus rivularishyperphagiaautumngrand teton national parkwyoming
Hyperphagic Black Bear
The bears that I observed literally consumed berries all day long and I am sure that they were eating all night as well. It was interesting to observe the delicacy and precision in which the bears were able to remove berries from around Hawthorn briers. Highly developed tongue and lips sensory and motor nerves allow the bears the great tactility and dexterity necessary to efficiently harvest berries and avoid injury from stout hawthorns.
black bearursus americanuswildliferiver hawthorncrataegus rivularishyperphagiaautumngrand teton national parkwyoming
Hyperphagic Black Bear
A hyperphagic black bear pursuing autumn hawthorn berries.
black bearursus americanuswildliferiver hawthorncrataegus rivularishyperphagiaautumngrand teton national parkwyoming
Hawthorn Berries
A hyperphagic bear spends 20 to 24 hours a day eating and consumes up to 25,000 calories; if each berry contains 5 calories then a bear would have to ingest a monumental 5000 berries each day.
I tasted the berries and they were sweet and delicious; vine ripened and frozen to absolute perfection. Late harvest wines and ice wines are sweet and incredibly flavorful. Harvesting grapes during late autumn maximizes sweetness and flavor and in terms of ice wine, the grapes are allowed to freeze on the vine which concentrates the aroma and sugar content. The bears must have been immensely enjoying these sweet nutrient dense treats.black bearursus americanuswildliferiver hawthorncrataegus rivularisberrieshyperphagiaautumngrand teton national parkwyoming
Hyperphagic Black Bear
Six inches of snow failed to deter the bears from devouring berries and as we would expect, the cold front and snow seemed to intensify their appetites. This sow had two cubs that she kept in the safety of a nearby tree while she sat beneath a Hawthorn and consumed berries the better part of the morning.
black bearursus americanuswildliferiver hawthorncrataegus rivularisberrieshyperphagiaautumngrand teton national parkwyoming
Silent Encounter
Situated under a Hawthorn tree, a Black Bear shakes to remove accumulated snow from her fur.
black bearursus americanuswildliferiver hawthorncrataegus rivularisberrieshyperphagiaautumngrand teton national parkwyoming
Hawthorn Montage
I observed several bears as they foraged around in the trees
meticulously nibbling their way through hundreds of berries. The scattered litter generated by the feeding frenzy created a beautiful montage of leaves and berries.black bearursus americanuswildliferiver hawthorncrataegus rivularisberrieshyperphagiaautumngrand teton national parkwyoming
Hawthorn Laden Scat
The scat depicted is laden with Hawthorn berries and seeds; it was deposited by a female black bear with two cubs. There were literally thousands of Hawthorn berry saturated droppings in her territory, clearly indicating her predominate food source. The examination of scat shape, size and content often reveals a treasure trove of information in terms of health, diet and species identification.
black bearursus americanuswildliferiver hawthorncrataegus rivularishyperphagiascatautumngrand teton national parkwyoming
Hawthorn Berry Scat
This is a closeup image of a typical Hawthorn berry scat from a Black Bear. The scat contains skins and seeds and it is not unpleasant; it has an aroma of spice and fruit. Bear scat that consists of digested animal protein may have a foul odor, and contain traces of hair and bone. In the spring,Black Bears consume a tremendous amount of plant matter including grass, flowers, seeds, and dried berries from the previous year. I have observed that the spring droppings are typically black with a grassy spicy aroma.
black bearursus americanuswildliferiver hawthorncrataegus rivularishyperphagiascatautumngrand teton national parkwyoming
Beary Shenanigans
Watching Black Bears feeding in Hawthorn trees was quite captivating; witnessing them feed while oblivious of their surroundings afforded me several sessions of uninterrupted observation of their unique ursid berry eating behavior. Occasionally, the bears would nearly fall out of the trees, hang upside down, stand, and basically just entertain me with their constant antics.
black bearursus americanuswildliferiver hawthorncrataegus rivularishyperphagiaautumngrand teton national parkwyoming
Lateral View Mandible and Molar Teeth of a Kodiak Brown Bear
Did you know that generally greater than 90% of a bears diet comes from plants. Based on skull anatomy and phylogenetic history, bears are classified as carnivores but in terms of diet, bears are truly omnivorous (diverse diet of both plant and animal materials). Note that the molars of a bear are similar to human teeth in form and function and indeed man and bear have similar diets.
Seasonal Turn
Snowfall and browsing bears put the beautiful Hawthorn and it's berries to sleep for the winter. It's a bitter sweet time of year as the seasons change but everything turns with a purpose and next spring the Hawthorn trees will bloom and their autumn berries will once again nourish a new generation of bears.
black bearursus americanuswildliferiver hawthorncrataegus rivularisberrieshyperphagiaautumngrand teton national parkwyoming