Common Redpolls and Pine Grosbeaks
These two irruptive species are common throughout central Ontario this winter. To some, these movements may seem erratic but they're not. The so-called "irruptions" of northern bird species are caused by failures of staple food crops in the boreal forest and beyond. Ron Pittaway has acquired some expertise in predicting the movements of "northern birds". His 2007-2008 Winter Finch Forecast is spot-on.