When the stewardship staff of the Jackson Hole Land Trust carries out our requisite annual summer monitoring of easement protected properties, we are always on the lookout for changes on the ground, anomalies, and interesting natural occurrences. Different years bring different trends related to overarching natural manifestations such as weather, disease outbreaks, and hydrological regimes; different seasons highlight the timing of plant flowering and movement of wildlife to and from seasonal habitats; different monitoring days expose us to interesting spectacles that leave us wondering about the former – why is this happening this season? Why is this trending this year? Often we just wonder, why?
As many residents of Jackson Hole are experiencing now, northwest Wyoming has been rather dry this year. It began with a lower snowpack and an earlier than usual peak runoff, followed by a spring and summer lacking rains. As reported by NOAA’s National Weather Service, we were at around 75% of normal precipitation for April and May, followed by 10 to 50% of normal for June. Warm spring temperatures prompted bears to emerge early from hibernation, and other wildlife to leave off early from winter habitats in pursuit of forage in transitional areas.
Across the West this year, traditional food sources for bears and ungulates have been lacking, and the lack of water translates into forage that is lower in nutritional value. This all spells bad news for wildlife and imposes stress on animals during a time of the year when caloric intake, in preparation for the mating season and the cold winter ahead, is vital.
A prominent observation that left us scratching our heads this summer was seeing bark that had been stripped from the base of mature spruce trees near the confluence of the Snake and Gros Ventres Rivers. This wasn’t porcupine gnawing activity or elk or deer thrashing small trees with their velvet antlers, nor was it a lightning strike that had blown the bark off of a tree trunk. What we witnessed was emblematic of something more systematic, more powerful, and more desperate.
Bears had stripped the bark off of dozens of mature spruce trees in an effort to get at the tree’s cambium and phloem underneath. Why? Green = Nutrition. With the dearth of other food source available elsewhere, the bears had surrendered to scraping their teeth (literally) on the green cambium for calories. (See photo).
What does this mean for bears? Desperation yields innovation in locating obtainable calories; time will tell what the consequences of the dry, poor forage summer of 2012 will have on survivorship and fecundity of the Valley’s bear population.
What does this mean for a mature spruce forest? Fully girdled bark may likely result in tree mortality as nutrients from the needles are not able to supply the root system. And with that, the Valley may lose an 80 year old stand of riverbottom spruce forest, and the structural diversity that it provides.
Time will tell.
-Steffan FreemanView All Posts from 'Notes From The Field' Previous Post | Next Post