It has been a week since any Cerulean Warblers have been heard or seen 
here on the southern end of Snake Mountain.  There is no expectation of 
locating them here again until next May, though I keep looking and 
listening.  July is not a month when Ceruleans have any expectation to 
be located in Vermont, so finding them well into July was much of a 
surprise.  Because the site is so close to my home, I'm able to check on 
the birds daily.  Overall, Cerulean observations in Vermont are very 
uncommon and usually limited to a single day.

At the end of these comments is a copy of an overview I posted a couple 
of weeks ago.   This note finishes the story for this year, which has 
been remarkable in the early arrival and much later departure dates:

2010  May 11 to June 26 [47 days]
2011  May 13 to June 25 [44 days]
2012  May  7  to July 7     [62 days]

Thus, this year the birds were observationally present for 15-18 days 
longer than the preceding two years.  A length of time that is 
consistent with a second nesting following the June 2nd storm which 
appears to have terminated an initial nesting (see previous overview 
below).

Behaviors in July also appear consistent with a second nesting. After 
the early territorial selection by males in May of this year, until July 
2nd I only observed one individual (a singing male) each day at the 
southernmost territory, which I visited virtually daily.

On July 2nd there were seen two birds, moving about in the lower 
mid-canopy (not the very high upper canopy typical since their 
arrival).  One was a singing male.  The other was either a female or 
fledgling.

On July 3rd there was heard one singing bird, whose song was incomplete 
at times.

On July 7th, the last observation day when birds were seen or heard, in 
the lower mid-canopy there were two birds counter-singing with 
occasional overlaps of songs.  One song was the full, common song of a 
male.  The second song was clearly that of a Cerulean, but with a 
variant tone and timber.  Moreover, it was not fully complete, as the 
distinctive Cerulean final rising buzz note was poorly formed and 
incomplete.  That bird seemed to me likely to be a juvenile.

To the duet there was then added a third Cerulean song.  It too had very 
subtle differences.  After some work I confirmed it to be an extremely 
deceptive mimic song of a Redstart ... which if heard alone at a bit of 
a distance would have been easily mistaken for a Cerulean.

Thus ends the 2012 Cerulean story at this site.

Ian
================================
Comments previously posted on 7/2/2012 ---------------

Cerulean Warblers have inhabited a 0.6 mile section of a forested lower 
ridge of the southern end of Snake Mountain in Bridport just above our 
house and pasture since at least 2008.  Ten males were located on June 
4th in 2010, 5 on May 31st in 2011, and 5 on May 21st this year.  More 
may be present, but I've not done follow-up surveys along the ridge each 
year.  Females are extraordinarily difficult to find; they do not sing.  
A morning dog walk takes me to the territory of one of the males every 
morning.

Recent first arrival dates are May 11, 2010, May 13, 2011, and a very 
early May 7th this year.   Corresponding last dates observed were June 
26, 2010 and June 25, 2011, which is consistent with the meager previous 
Vermont records.  However, remarkably they are still present this year 
now into July.  This morning, at the location I monitor daily, there 
were two foraging birds, a male and a female. Last year the day before 
the day I recorded the last bird of the year there were a male and a 
female together in the canopy.  That was my only certain observation of 
a female since I had been following the population, prior to today's 
sighting.

The behavior of the males appears consistent with this pattern:
2nd week of May ..... arrival; beginning to define territory
3rd week of May ...... much loud singing from high canopy in discrete 
territory
4th week of May ..... much less singing; a "quiet time" perhaps 
identifying incubation in process
1st week of June ..... continued "quiet time"
2nd and 3rd weeks of June ..... Male moving around and slightly off the 
territory, intermittent singing;
       foraging; perhaps feeding young
4th week of June ..... departure from territory to unknown location; 
perhaps likely southward.  Ceruleans are not
       known for having multiple broods.

This year on June 2nd, right in the middle of the "quiet time" we had a 
stationary, localized large thunderstorm with extremely heavy rain and 
wind.  Local gauges measured from 3-5 inches of rain in just a couple of 
hours.  Immediately thereafter, for the next several days, the male 
seemed quite agitated, giving alarm-like, loud songs ... typically not 
repeated in one spot (unusual for a Cerulean).  Cerulean nests are in 
forks of tiny branches in the high canopy of trees, often the tallest 
trees in an area.  I don't know the tolerance of a Cerulean nest, but 
the violence of this storm would certainly have tested its resiliency.

Subsequently there appears to have been a new territory established, 
about 500 feet distant and in the opposite direction from other known 
Ceruleans (when surveying all the singing males in the Snake Mountain 
population I found them to be generally 700 feet apart). I don't know 
the capacity for the species to nest a second time so soon, but the 
behavior since the storm is not inconsistent with such a possibility.  
And as of now, the birds have been here already a week longer than in 
previous years.