Q: We have bluebirds nesting in a box in our field, and hear weak chirping emanating from the "nursery." Is there a set number of baby birds that they have at one time?
A: I can definitely say that there is no set number, but there is a range. And even the range has a range. I often refer to "A Guide to The Nests, Eggs, and Nestlings of North American Birds" by Paul J. Baicich and Colin J.O. Harrison. From what I read in this volume, "Eggs: Usually 4-5, sometimes 3-7." That does not mean, that those numbers will hatch and fledge. I just checked the downy youngsters in our nest and find three. We will be more able to determine, when they leave the nest, just how many eggs were laid. Last year, we had two eggs laid, and I was not persistent enough to check on how many fledged. Earlier in that nesting season, the competitive English sparrows killed one adult female at the nest.
It is interesting that when the young leave the nest (fledge), the male will look after them while his mate re-nests! And this nesting twice, along with an increase in nesting boxes, is reason for their come-back from the brink of near extirpation (eradication). Drive back roads, especially in farm country and you will most likely see bluebird nesting boxes along the way. And bluebirds don't need extensive fields or meadows, being content nesting in gardens and at edge of lawns.
Hikes, paddles and events
Here are a few outings that have caught my attention:
May 29, 10 a.m. to 4 p.m. Mount Greylock.
June 1, dusk to 11 p.m. Notchview Reservation, Windsor. Join members of Arunah Hill Natural Science Center as they focus their telescopes on the heavens: Stars, galaxies, planets, meteors, and more. Information and to pre-register: Trustees of Reservations, 413-532-1631, ext.10, or firstname.lastname@example.org.
June 16, Father's Day Canoe Trip, 8:30 to 11:30 a.m., Bartholomew's Cobble, Ashley Falls. Pre-registration required. Paddle the winding Housatonic to view the beauty of this meandering river as it passes through agricultural fields and floodplain forests. Watch for bald eagles flying over Bartholomew's Cobble. With your guide, learn about the river's history and what is happening to restore some of its most precious habitats. Information and to register:email@example.com or phone 413-229-8600
Questions and comments for Thom Smith: Email Naturewatch@live.com