Members
and friends of Downeast Audubon have been monitoring nest boxes on the
DEA Bluebird Trail for 17 years now. The little project that started
with just 20 boxes in two locations in 2009 has become a county-wide
citizen science undertaking, with 475 boxes in 137 locations in ’25!
More than 100 people spent time in the field last year checking on their
boxes and collecting data so that we are able to keep records of how
three of our cavity-nesting species are doing. Eastern Bluebirds, Tree
Swallows and Black-capped Chickadees readily use wooden bird boxes built
to certain specifications and placed in appropriate habitats.
Most data received at the end of the season gets uploaded by Blaise
deSibour, James Longo and Leda Beth Gray to Cornell Lab of Ornithology’s
NestWatch (www.nestwatch.org),
a database used to study the current conditions of breeding bird
populations and how they may change over time. In order to contribute to
NestWatch, all boxes must have GPS coordinates and completed data
sheets. One or two trips to check on the bird box over the course of the
nesting season is not enough! Weekly visits from April to August are
recommended. If we don’t have GPS coordinates for your box, please
contact us and we’ll guide you how to do it. Once we have the
coordinates, your boxes will be added to the DEA Bluebird Trail Map
which is located on our website at the bottom of the Conservation tab.
Check it out, it’s impressive!
2025 went along fairly smoothly as far as nesting seasons go.
Luckily there were no catastrophic weather events which caused
overwhelming mortality. The number of both bluebirds and swallows that
fledged was down by about 100 for each species but happily, the number
of chickadees fledged was up by more than 125. Part of the reason for
the decline in the two species was likely due to the fact that 18 boxes
were removed from the project last year that were in prime habitat for
bluebirds and swallows AND we didn’t get any data or data was incomplete
from 69 boxes. If you have bird houses, please be a responsible
landlord and monitor them. Even if they go unused or fail, that is
important to know.
Nesting results from the 406 boxes that we received useable data from:
•A total of 1,307 chicks successfully fledged! (77 fewer than last year)
•111 nest boxes went unused. A nest may have been started or abandoned but if no
eggs were laid, it is considered “unused.” If a box is vacant for more than 2-3
years, we recommend moving it.
•67 houses were used for more than one brood, often by different species;
65 were used twice—2 batches of eggs were laid but did not necessarily fledge;
2 boxes had three nesting attempts!
•72 nesting attempts failed. Eggs were laid but no chicks fledged. Failure can happen
at any stage. Nests with eggs/chicks can be abandoned, predated or succumb to
parasites, lack of food or bad weather. (Heat doesn’t seem to be an issue here.)
Thanks
to each and every one of the volunteers for giving time and care to the
birds last year AND for sending in your nesting data!
Please, if
you have bird houses, monitor them! It definitely increases the chances
of nesting success. The North American Bluebird Society says that a house that
is not monitored may do more harm to birds than good. Putting up a house is a
commitment to provide as safe a place as possible for birds to raise their
young. Clean them out in early spring, check them weekly for activity, keep
tabs on what happens, and send us your data! If you need pointers how to
do this, don’t hesitate to ask: deaudubon@gmail.com.
2025 data
sheets are now available. Thank you to all the volunteers who take time out
of their busy day to help the birds!
Our data
continues to be uploaded to NestWatch, a program at Cornell Lab of Ornithology,
thanks to James Longo, Blaise deSibour and other volunteers. To view our
Bluebird Trail Map, go to the bottom of the Conservation tab on our website- www.downeastaudubon.org.
You too can
share in the joy of having birds nest on your property by purchasing a
DEA-built bird house next spring for $45, ready to install. Or if you
have existing bird houses on your property, why not monitor them weekly and
submit your findings? Be a part of our expanding Bluebird Trail—it’s a
great conservation project to get involved with!
More
often than not, bluebirds go unnoticed because at a distance their beautiful
blue and orange colors aren’t that noticeable to the naked eye. Found in open
countryside and meadows, bluebirds primarily feed on insects throughout the
spring and summer, but eat mostly berries in fall and winter. They nest in
cavities, yet lack the ability to create a cavity, relying on old woodpecker
holes and nest boxes.
In
the middle of the 1900’s bluebirds were in decline, even raising fears of
extinction due to habitat loss, pesticides and competition from non native
birds like starlings and house sparrows, two aggressive species that will evict
bluebirds from a nest hole. A big component of habitat loss was the tendency
for humans to cut the old dead snags where woodpecker holes were the main homes
for bluebirds. Fortunately, volunteer nest box programs have helped bluebirds
to recover, particularly where correct hole sizes helped eliminate aggressive
competitors and predators. Their ongoing recovery depends on nest boxes.
Instructional video by James Longo
Because bluebirds are dependent on
nest box programs, Downeast Audubon plans to increase the number of houses each
year on properties with public access. In order to do this we need your help as
volunteers to help monitor them. It is a very rewarding project and lots of
fun! From mid-May to early August the houses need to be checked in the morning
once every week or so and data recorded. To see baby bluebirds and swallows
about to fledge is a real treat! Downeast Audubon can train interested
volunteers—please call or e-mail us today to let us know if you are interested.
Locations and quantity of Audubon bluebird boxes.
Nestbox plans are available on the North American Bluebird Society (NABS) web page Bluebird Nestbox Plans. It is important to have a 1.5 inch opening for the door, and a way to open the box and monitor the nest. Also there should be no perch on the box-- bluebirds do not need perches and perches just make it easier for predators!
Downeast Audubon assembles boxes from reasonably priced kits available from FEDCO seeds in Waterville. We mount them on poles into the ground with a stake driver and a sledge hammer.
Boxes should be put up as early as possible in the spring, or preferably in the fall. Migrating birds may use the houses for roosting and take note of their locations for the upcoming breeding season!
For information on where to place boxes, how to mount them, and protection from House Sparrows and predators, please see the excellent fact sheet on the NABS web site.
