In Part 1 about Clark’s Nutcrackers (Interior News, July 18, 2024), I wrote about the important symbiosis between whitebark pine (Pinus albicaulis) trees and the nutcrackers.
By way of correction, in that first article, you may well have wondered what is so special about collecting 30 seeds? It was supposed to say they are known to collect up to 30,000 seeds, cache them and then find most of them over the next nine months."
The trees depend on the birds to harvest, cache (disperse) and ‘plant’ their seeds while the nutcrackers need the highly nutritious pine seed (said to be as nutritious as butter or chocolate) to survive winter months and feed their offspring.
However, this relationship is in jeopardy due to a pine blister rust fungus that was introduced to North America and is steadily attacking and killing whitebark pine (as well as four other five-needle pines) across its natural range from California north to the Bulkley Valley.
In addition, some whitebark pine growing at lower elevations in our area were unable to fend off attacks by mountain pine beetles, especially during the major beetle attacks of the 2000s. This happened even though the whitebark trees have some resistance to the beetle since they are both native to North America and have evolved together.
Loss of the whitebark pine ecosystem means not only the loss of food for nutcrackers, grizzly bears and other animals, but also shade that allows growth of subalpine fir and spruce trees and the associated plants and animals. The shade also slows the rate of snow melt at higher elevations.
Already, failure of pine stands to produce seed has caused the disappearance of Clark’s nutcracker populations in parts of their North American range. While the birds will eat less nutritious seeds of other trees such as Douglas fir, it often means they leave the area and travel great distances to find other food. Not enough is known about what they eat and how they cope.
Research is being carried out by many scientists throughout the range of the five-needle pines, especially the whitebark pine relationship with Clark’s nutcrackers, to try and find potential solutions to this dilemma and prevent extinction of the tree and loss of birds.
The Bulkley Valley is at the northern limit of the range of both whitebark pine and the nutcrackers, so it is not surprising there are researchers here working on different aspects of the problem.
Sybille Hauessler and Alana Clason, both Smithers biologists, have been working on trying to find whitebark pines that may naturally have some resistance to the blister rust. The cones of trees with few or no fungal blisters were harvested, and the seed grown to seedling stage. These were then planted out into forest clearings, recent fires or in treeline (subalpine) openings.
Interestingly, tree seedlings have been found in the understory of lodgepole pine forests burned by wildfire. It is assumed that the nutcrackers planted the seeds in these nutrient poor, dry sites that are much like the conditions the whitebark pines prefer to grow in at subalpine elevations.
Alana is also trying to figure out how the Clark’s nutcrackers cope when the whitebark pine seed crop fails. What other seeds the nutcrackers eat, how far away they go to find other food and whether the birds would come back if rust resistant seedlings of whitebark pine (as well as the four other pines) survive, are some of the questions that need to be answered.
