Hi, Doug.
For the past 30+ years, my wife and I have been monitoring/managing nest boxes
for bluebirds and six other species of cavity-nesting birds (including
titmice). I would recommend any natural materials that biodegrade in a month
or less---the approximate nesting period for most songbirds (incubation period
and nestling period combined). Bluebird nests are made almost exclusively of
dried grasses or pine needles. Some of the other birds (titmice, Carolina
wrens) incorporate dead leaves into their nests. (And, titmice and
Great-Crested Flycatchers may put pieces of sloughed-off snake skin in their
nests, too.) Most birds are pretty efficient at finding the things they need
for nest building, but we can certainly help them by leaving dried grasses,
leaves, pine needles, etc. in some areas of our yards. (Sometimes, having a
pristine or "postcard" yard is not necessarily a good thing.) In my opinion,
all plasticized materials should be avoided. (Frankly, cotton string and other
"natural" fibers could pose a danger, too.) During our tenure, I can remember
finding at least three female bluebirds that became entangled in plastic twine
(i.e., the orange-colored twine used to hold hay bales together) or
monofilament fishing line the female birds had incorporated in their
nests...end result---the adult birds perished and their eggs did not hatch. In
other instances, I have removed monofilament fishing line from many, many nest
cups (particularly in Prothonotary Warbler nests) before the materials could
endanger the adult birds or their nestlings. (I can also recall an incident
where an entire nest cup in a bluebird nest consisted of a large, flattened wad
of monofilament line---if I had not intervened, I believe birds most certainly
would have perished in that nest box, too.)
I've probably mentioned things you already know...if so, please excuse the
repetition. Thanks for helping our feathered friends!
Cordially,Bob PeakTrigg County, KY
On Saturday, April 25, 2020, 9:23:42 AM CDT, DOUGLAS HENNIG
<hennig@xxxxxxxx> wrote:
Friends
Weeks ago I used a piece of a broken leather shoelace to tie some lightweight
garden fencing together. Since then I've noticed several birds harvesting the
fuzzy fibers from the end of the lace--presumably for their nests. Species
I've seen include Titmouse and a small grayish bird that I'll assume was a
vireo.
Do any of you provide materials for nesting birds to use? If yes, what have
you used successfully and are there any things that should be avoided?
Thanks and excuse me if this has been covered recently in other messages.
Doug Hennig
Magoffin/Morgan line near Caney
