Photos top to bottom: Grizzly Bear; Clark’s Nutcrackers
What dietary preference do Grizzly Bears and Clark’s Nutcrackers have in common? Both consume large quantities of Whitebark Pine seeds. Clark’s Nutcrackers rely almost solely upon them, while grizzlies seek them as one of their most important fall foods, high in protein and fat. Red Squirrels and Black Bears also feed on them.
Grizzlies feed on White-bark Pine seeds from mid-August to late fall. Sometimes they dig up Red Squirrel caches of cones to obtain a larger supply – even when there is up to six feet of snow. Female grizzlies especially rely heavily upon the high energy seeds of the Whitebark Pine to build up their fat reserves prior to hibernation.
Unfortunately, these high-energy nuts are in decline, along with the tree that produces them. The ramifications of this tree’s decline are far reaching, including snowmelt volume, alpine plant and animal diversity in alpine areas and more grizzly/human encounters. White Bark Pines grow on windy ridges in mountainous areas. They act as snow fences, causing large accumulations of snow, which later results in delayed snow melting that leads to longer periods of ephemeral stream flows. They provide vegetative cover where otherwise there is little-none, and they provide nutritious seeds for birds and mammals.
Whitebark Pines are declining rapidly in the northern Rockies. The hardest hit areas are near Yellowstone and Glacier National Parks. Their decline is primarily due to warming temperatures which enable the Mountain Pine Beetle to survive through the winter and to exist at higher elevations. This spells disaster for the Whitebark Pines which showed in a 2009 over flight that 90% in the Greater Yellowstone Ecosystem had beetle activity. Grizzly expert and advocate Doug Peacock said in an interview by Yale Environment 360, that “82-83% of the Whitebark Pines in the GYE are either dead or dying.”
What can be done about this? Biologists are attaching packets of verbenone, a synthetic pheromone that deters beetles, to Whitebark trees with high cone production and resistance to disease. Seeds are also being collected from disease-free trees to test them for genetic resistance. A recent attempt to place the Whitebark Pine under protection under the Endangered Species act failed. The U.S. Fish and Wildlife Service said it will not immediately list the tree due to higher priorities and a lack of funding. It may or may not revisit this decision.
In the meantime, along with the tree’s demise, we will likely witness a decrease in the Clark’s Nutcracker population and an increase in human/grizzly encounters. When Doug Peacock was asked if the loss of pine nuts was going to result in more contacts between bears and humans, he replied “absolutely, absolutely.”
Several weeks ago while in Cooke City, Montana on the NE border of Yellowstone Park, there was evidence that this is already occurring. The town bakery we visited had a grizzly at its doorstep earlier the same morning. According to the store proprietor, another grizzly had taken several steps into the bakery on a previous visit before retreating. Ironically, this bakery served “Bear Claws.” Be prepared to meet more of your grizzly neighbors, those of you who live in the Greater Yellowstone Ecosystem.
Sources: Whitebark Pine Seeds, Red Squirrels, and Grizzly Bears: An Interconnected Relationship by Kim Sager, University of Idaho, 2009; Whitebark Pine in the Greater Yellowstone Ecosystem, Greater Yellowstone Network Brief, April 2012; A Fierce Advocate for Grizzlies Sees Warning Signs for the Bear, Yale Environment 360, 2010; Whitebark Pine, Grand Teton Resource Brief, 2011; Whitebark Pines Ailing, but Don’t Get Protections, by Matthew Brown, Seattle Times, 2012.
