February 19, 2014

Cone Crop of the Century, Part II – How it Happens and Who's Cashing In

In September, we wrote about the huge cone crop in evergreen trees in the Rockies in 2013, especially in spruce and fir trees. We wanted to follow up.

A forester friend of ours sent us a scientific paper on synchronous crops of cones or nuts across entire forests. Cone crops can be synchronous among many species of trees for as much as 2500 km! This can add up to millions of square kilometres in which trees are all doing the same thing!

The jury is still out on how the trees all do the same thing, but the leading theory is the “Moran Effect.” (Have you noticed that theories sound more impressive when you give them a name that ends in “Effect”?)  Patrick Moran, an Australian bloke, showed that some external factor – for example, above average temperatures in May – could stimulate the some kind of identical effect in millions of organisms spread across huge distances.

Male white-winged crossbill
Does anything benefit from a jumbo cone crop here in the Rockies? Well, the trees probably do, as there are more seeds that can potentially sprout into future trees. But the other obvious winners are any animals that eat the seeds in evergreen cones. Squirrels had a banner year.  We saw lots of youngsters, including a litter of four, which we'd never seen before.  And, in the last few weeks in Lake Louise, another species has been cashing in: white-winged crossbills.

These little finches are super charming, and have the most amazing beaks: they look like curved pliers with the tongs out of alignment. So, no good for a carpentry project, but great for opening cones and eating the seeds. You've got to see it to believe it.

Crossbills can gobble up as many as 3000 per day, and when the food is abundant, it will stimulate breeding, even in the middle of winter! Last week, we started to hear the cheerful songs of courting male crossbills, just in time for Valentine's Day. This is a little sample of their love song.