[obol] Lies, damned lies and White-throated Sparrows

[Craig Miller]

Mike,

The sparrow graphs are indeed interesting!

Another hypothesis that might be brought up are the increasingly warm 
winters that Oregon has been experiencing since 1990. This has been 
particularly noticeable on the east side of the cascades, where a small 
change in average temperatures can make the difference for some species 
ability to survive. This is likely to have an effect on multiple species.

My guess is that better observer coverage and an actual increase in 
numbers are both influencing the statistics.

Craig Miller



Mike Patterson wrote:
> I've have spent a bit a time with Christmas Bird Count sparrow
> data and put in my two cents at:
>
> http://www.surfbirds.com/blogs/mbalame/
>
> Be forewarned, it's chock full of numbers and graphs and all
> manner of quasi-sciency stuff.  If you're not interested do go 
> there.
>
>