A report just released by the Audubon Society shows that a significant number of bird species seen in North America during the first weeks of winter have moved dramatically northward over the span of 40 years.
Also, a number of grassland species are not following this northward trend and for these species disappearing habitat from warming is taking an enormous toll, and leaving them with nowhere to go.
How did they determine this?
Tens of thousands of citizen scientists take part in the Audubon's annual Christmas bird count and report their findings to the society. Based on an analysis of 305 bird species across North America, the results indicate an average northward movement of 35 miles. Sixty bird species out of the 305 actually moved in excess of 100 miles during the four decades!
Here are some of the more common birds with the greatest northward movement over the forty- year period.....
--Purple Finch (433 miles)
--Wild Turkey (408 miles). I can usually hear the turkeys over on the hill early in the mornings, but they are tough to spot.
--Ring-Billed Gull (356 miles)
--Pine Siskin (288 miles). There was a front-page report in our local central Pennsylvania paper a couple weeks ago about the appearance of this bird in our region.
--Boreal Chickadee (279 miles)
--House Finch (270 miles). I can say we have plenty of these around my neighborhood!
According to the Audubon Society, the results of this study is evidence that global warming is having serious impact on natural systems.