Birds
prefer familiar, native plants for nest material. The fields and forests where they used to get
it are disappearing, however.
A related problem is our tendency to “clean up” yards. Humans tend to put most natural nest material
in a plastic bag, destined for a landfill.
Recently
a friend brought me some old nests (a strange but welcome gift) and I
analyzed their contents. About 80% of it was small twigs and bits of leaves.
Another 15% (approximately) was lichens, bits of cobwebs, or stalks of native
grasses. Only a very small part was artificial things like string or yarn. (of course, this is species-specific)
These
particular nests came from an area with lots of trees. Nests in meadows,
conversely, will probably have a much higher percentage of native grasses. So,
the local environment of the nest-builder is important, but unnatural materials
(like old candy wrappers) play a very small part. Plus, used drier sheets are a
no-no for nests due to the chemicals remaining in them.
When
available, birds seem to like fur/hair (whether from a coyote or your pet
lab – it doesn’t matter). Nor do they seem to care much about the origin of
the cavity, box or platform they build their nests on. Swallows may seek out an
exterior beam of your house, and a few “cavity-dwelling” birds actually prefer
artificial boxes.
The
nests themselves, however, are largely natural materials – probably because
wild birds genetically recognize them.
The typical mowed lawn is a very unattractive and sterile habitat for
most birds, and offers little if any nesting material. A lawn isn’t found
naturally anywhere on earth.
Some favorite native grasses for nests are bluestem, muhly, threeawn and
gramma (left standing through the winter). These are not lawn grasses ! Also, birds often use thin strips of
bark from many types of trees native to the north Texas area.
Thin bark stripped from young trees (like
eve’s necklace, Mexican plum, redbud, red cedar, roughleaf dogwood or cedar
elm) are sought by birds. Also, small chips of bark (oaks are a favorite) are
used to cushion the bottom of nests.
Dangerous flight! During
a long migration flight small birds can actually die from exhausted fat and protein
reserves. Larger birds often succumb to dehydration, due to heat generation
from all that activity, which leads to evaporation of the body’s essential
water.
OWEN YOST, in addition
to being a blogger, is a licensed Landscape Architect emeritus who has lived
and worked in north Texas for over 30 years. He is the recipient of a Lifetime
Achievement Award of the Native Plant Society of Texas, and is a member of the
American Society of Landscape Architects (ASLA), International Federation of
Landscape Architects, National Wildlife Federation and the Audubon Society. His
office is at Yost87@charter.net in Denton.
