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
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
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
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. Any ideas?
It definitely was a delight to see both a male in good voice and a
foraging female this morning. And in July, no less!