Identifying birds by their bird’s nests
Have you ever noticed a bird’s nest and
wondered what type of bird built it? Hopefully, the following
information will help you in making that identification.
A bird’s primary consideration when
choosing a nesting site is security. Birds fall into two general nesting
categories: cavity nesters and non-cavity nesters. A cavity nester is a
bird that will build a nest in a hollowed tree, cactus or birdhouse
(nesting box); somewhere they can be enclosed and protected. Obviously
then, a non-cavity nester is a bird that will build a nest in a tree, in
a bush, or on the ground; in a place where they are in the open.
Protection from predators and proximity to
food is of vital importance to the success of a bird’s offspring.
Abundant and easily obtained sources of food allow for more time to be
devoted to better site selection and construction of higher quality
nests, along with more time and energy to be vigilant in defense of the
nesting territory from interlopers and predators.
Chickadees, as an example are cavity
nesters. They will excavate their own nest site in rotten or decaying
wood, use an old woodpecker hole, or use a nesting box. Mountain
chickadees may excavate a cavity as well in very loose wood. They will
also nest under rock crevices in a bank or in a hole in the ground. They
may add a cozy lining of fur or moss to the nest.
Another style nest is that of a bushtit.
The 1-foot-long hanging nest of a bushtit resembles an oriole’s nest and
is woven out of a variety of materials including mosses, lichens,
leaves, and spider’s webs.
The cactus wren builds an elaborate
gourd-shaped nest in about ten days, and may fuss with improvements for
another several weeks. A male house wren may lay claim to a nesting
cavity by filling it with more than 400 small twigs. If the female likes
what she sees, she will then take over, adding the nest cup and lining
it with grass, inner bark, hair, and feathers.
A robin usually returns to the same area
to nest each year and may occasionally use last year’s nest again after
some renovation. The American robin will use mud in its nest to give it
strength. You can put out a small pan of mud and nesting materials
(short strings, yarn, dry grasses) and watch the robins come collect
materials to make their nests.
Mourning doves’ nests are sticks woven
together by the female with materials which have been collected by the
male. Their nests are more platform than cup shaped.
Often the nest is so flimsy, it can blow apart easily in a slight breeze.
Both male and female house finches display
a strong tendency to return to the same area to breed, often occupying
the same nest site as the previous year. Ironically, house finches
rarely use bird houses to build their nest in; instead they seem to
prefer locations such as coniferous trees, cactus plants, ledges, street
lamps, ivy on building, and hanging planters.
Hummingbirds build their nests primarily
from spider webs due to their elasticity. That allows room in the nest
for the babies to grow. The web is also used as a glue to attach the
nest to a tree branch. The nest is about the size of a golf ball; around
1.5 inches in diameter.
The American goldfinch is one of the
latest breeding songbirds, waiting to nest until mid-to-late summer when
thistle seeds and down are readily available. They use the down to
build their nest. Goldfinches prefer to nest in habitats with trees and
shrubs and usually place their nest four to ten feet high, often near a
water source (such as a bird bath).
The oriole nest is an engineering
masterpiece. The female weaves a hanging-basket nest with plant fibers,
grasses, vine and tree bark and sometimes string or yarn placed out on
the small twigs of a branch 6-45 feet in the air. This keeps them safe
from most predators. It takes as many as 12 days for an oriole to weave
its nest. One Baltimore oriole was observed spending 40 hours building a
nest with about 10,000 stitches and the tying of thousands of knots,
all with its beak.
The white-breasted nuthatch is known to
bill-sweep a crushed insect around their nest cavity’s entrance hole.
Presumably to deter predators with the chemical-defense mechanisms from
the insect. The red-breasted nuthatch will line the entrance to its
nesting cavity with drops of sticky conifer resin. It is thought that
this may be a tactic to discourage predators or nest competitors from
entering. The nuthatches avoid the resin themselves by diving directly
into the cavity without ever touching the sides of the entry hole.
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