[TN-Bird] Re: thoughts on Bill Pulliam's BBS data graphs of Wood Duck and Black-throated Green Warbler

  • From: Bill Pulliam <littlezz@xxxxxxxxx>
  • To: TN-birds <tn-bird@xxxxxxxxxxxxx>
  • Date: Thu, 13 Oct 2011 08:05:45 -0500

It's interesting to me that the discussion here has been entirely about declining species, and especially about a species whose decline is already well-known. Of course the species that are in trouble are a major concern. But the biggest message I got from the BBS data in total was about the increases. Raptors have skyrocketed. The non- neotropical migrant forest birds have increased dramatically as well. The median for all 104 species that had enough data to give meaningful statewide trends was an increase of 66%. Let's not forget the good news!


About the declines -- I found some surprises in the list of species that had dropped sharply. Four of the top five are well known: Bewick's Wren (-100%), Loggerhead Shrike (-90%), Golden-winged Warbler (-89%), and Northern Bobwhite (-78%). But nestled among these is also Yellow Warbler at -87%. Nine more species showed drops of greater than 50%: Common Nighthawk (-78%), Gray Catbird (-71%), House Sparrow (-70%), American Redstart (-65%), Eastern Meadowlark (-61%), Northern Flicker (-58%), Common Grackle (-58%), Whip-poor- will (-52%), and Orchard Oriole (-52%).

And again to keep the context, while 14 species showed drops of greater than 50%, 37 species showed increases of more than 100% (i.e. double). One native species was almost entirely extirpated (Bewick's Wren), one native species became a widespread new member of our breeding avifauna (Tree Swallow).

Bill Pulliam
Hohenwald TN

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