While not up on the behavior of NOMO, I can attest on the behavior of Sage
Thrashers. A very similar behavior in Sage Thrashers is quite common, I have
personally monitored about 100 SATH nests and know from other people of the
details of another 150 or so. I have only rarely heard of an observer
finding a nest via feeding, while other shrub-steppe birds such as Sage
Sparrow and Brewer's Sparrow readily feed in the presence of an observer. A
silent bird sitting with food (or even without food) and approachable (i.e.
wanting to be in that area) is a very good clue of nesting activity within
the immediate vicinity. The few occassions I have witnessed feeding in Sage
Thrashers I have been about 100-130m away from the nest. I have read that
this is a behavior found to be fairly common in North American Mimids.

Scott Downes
downess at charter.net
Yakima WA

> Message: 12
> Date: Thu, 30 Jun 2005 07:06:25 -0700
> From: "Jeff Kozma" <jkozma at charter.net>
> Subject: Re: [Tweeters] Eurasian Collared-Dove today
> To: "Tweeters" <Tweeters at u.washington.edu>, "Denny Granstrand"
> <dgranstrand at charter.net>
> Message-ID: <002301c57d7c$ebb8ca20$51d8bd42 at oemcomputer>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Hi Denny,
>
> The behavior you observed is very common for NOMO, holding food in the
bill
> and not going to nest. I studied NOMO in New Mexico and monitored around
> 125 nests over three years. I never once saw them feed the chicks. The
> behavior you described is classic and indicates that you were probably in
> the general vicinity of the nest. This standing still and silent behavior
> is a cue that I used to start my nest searches. More often than not, I
was
> able to locate a nest in an area using this silent still behavior. Often,
> the birds would keep flying around a general pattern throughout the area,
> moving from bush top to bush top, being silent and simply watching me.
This
> was my clue that a nest was near. Thus, the birds at Horn Rapids are most
> likely nesting.
>
> Interestingly, I only once encountered the aggressive intruder behavior
that
> is common occurrence with backyard NOMO in the east while studying the
birds
> in NM.
>
> Jeff Kozma
> Yakima