Hello, tweets.

I don't know how many of you have used the Breeding Bird Survey website to learn about our North American birds. Presumably all who run such surveys in our area know about it. If not, check it out.

http://137.227.242.23/bbs/bbs.html

You can find much information here on distribution, relative abundance, and population trends of breeding birds. Look at a wide selection of maps on population trends (http://137.227.242.23/bbs/htm03/trend2003_v2.html), and it's quite educational to see how some species have increased and others decreased in the last four decades. Even more interesting, there are increases in some parts of the range, decreases in other parts, and there seem to be some commonalities in these phenomena.

For example, quite a few species seem to have increased at the periphery of their ranges, presumably indicating an increase in range size. Quite a few species seem to have increased more in the northern parts of their ranges. A sign of changes brought about by global warming? Also, there are often differences in population trends in the East and West. Some are surprising. It's interesting to predict in your mind what the trends might look like in a species, then click on it to see its map.

You can also look at quantitative data on population trends (http://137.227.242.23/bbs/specl07.html) by species over their entire range or by region (http://137.227.242.23/bbs/reglist07.html). Note that statistically significant declines are shown in red, increases in blue. Make sure you understand the symbols that are used to indicate the value of the data for each species and region.

And check out other features on the home page. This is our government at work for us in a very constructive way!
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Dennis Paulson
1724 NE 98 St.
Seattle, WA 98115
206-528-1382
dennispaulson at comcast.net