As the United States experiences a snow shortage, researchers have released a study showing that declining snowfall in the mountainous regions of Arizona are causing a cascading series of effects that are proving devastating to songbirds .
The massive cold wave of the 1890's devastated bluebird and robin populations. Then again the cold winters in North America in the 1920's, 1940's and early 1960's pretty well wiped out the Eastern Bluebirds across the northeastern states. By the early 1970's Eastern Bluebirds were making a come back across the northeast USA. Another massive die off in the mid 1970's was really the driving force to create The North American Bluebird Society in the late 1970's in order to save the Eastern Bluebirds mostly. Since the 1980's there have been regional disasters with the bluebird and robin populations but no REALLY cold weather that griped the nation all the way down through the main wintering grounds of the Eastern Bluebirds. It only takes about one week of ice and snow in late January or early February that covers the middle states from Missouri to the Carolinas and then on down into the northern halves of the gulf coast states and we can lose a huge percentage of the Eastern Bluebird population again