Hi All,

At one time confirmation codes were placed into a hierarchy of  quality of 
evidence. The Maryland atlas discounts the hierarchy in favor of avoiding 
any harassment of nesting birds by well-meaning, but overzealous, atlas 
workers. In the old hierarchy the "NB" code was at the bottom because lone 
females, on rare occasion, build "play" nests (for want of a better term). 
Indeed nest building by wrens and woodpeckers was excluded as a confirmation 
and given the probable code "N" (still used by the MD/DC atlas) because of 
woodpecker's making breeding season roost holes and the dummy nests built by 
male wrens. At least one North American atlas project (New York) went so far 
as to remove nest building as a confirmation for any bird. I always felt the 
latter was throwing the baby out with the bath water. If observers pay close 
attention to the behavior of suspect females they will often see her mate 
guarding her from the advances of other males and see her go repeatedly to 
the nest site. The few completed "play" nests that observers encounter 
during an atlas project is more than repaid by having the "NB" code 
available to atlasers so we don't harass our nesting birds into failed 
breeding by looking for "better" active nests.

It seems to me, based on Gail's description, that these Black-throated Green 
Warblers' behavior is not strong enough evidence to pull the trigger on the 
"NB" code. In the North Country Black-throated Green Warblers usually don't 
have nests built until late May at the earliest. We had a Black-throated 
Green nest-building at the 2002 MOS Conference on Keyser's Ridge on 8 June, 
so the first week of May is also awfully early for serious nest building.

Good Atlasing,

Walter Ellison
MD-DC Atlas Coordinator - MOS
23460 Clarissa Road
Chestertown, MD 21620
phone: 410-778-9568
e-mail: 

"A person who is looking for something doesn't travel very fast" - E. B. 
White (in "Stuart Little")

"Are there *ever* enough birds?" - Connie Hagar as quoted by Edwin Way Teale 
in "Wandering through Winter"

----- Original Message ----- 
From: "Gail B. Mackiernan <>" <>
To: <>
Sent: Tuesday, May 09, 2006 1:12 PM
Subject: [MDOSPREY] B-T Greens gathering nesting material in DC


> Actually we have seen two female B-T Gs so far this spring gathering 
> nesting material -- picking up bits of fluff and fine fibers and flying 
> off with them into the woods. Whether they are really building a nest or 
> it is just that their hormones are totally pumped and they are 
> "practicing" I am not sure. According to the Atlas criteria do these 
> actions constitute nest-building?  (Not sure how to interpret this 
> activity...)
>
> We also saw a B&W female apparently *really* nest-building a couple of 
> years ago at Military Field -- she was making repeated trips to fluffy 
> (willow?) catkins and carrying the fibers off -- so seemed to be actively 
> constructing. These do nest in Little Bennett so maybe not so unexpected.
>
> Gail
>
> -------------- Original message ----------------------
> From: "Frederick W. Fallon" <>
>> Black-thr Green gathering nest material! Either that throws out
>> "gathering nest material" as a surrogate for "Nest Building" as an Atlas
>> "confirmed" code, or they're expanding their range something
>> considerable! Something to think about.
>>
>
>