by Sydney Smith and Sally Lindfors
Brazilians call hummingbirds "beija-flôr," which means
"kiss-flower" in Portuguese. It is an apt name for the delicate
but controlled acrobatics that these beautiful birds display
while feeding. These flying jewels are spectacular for many
reasons—their flying techniques, their surprising hardiness,
their dazzling plumage, and countless other
characteristics.
You will not find hummingbirds in Asia, Africa, or Europe.
The more than 320 known species of the hummingbird family
(Trochilidae) are confined to the Western Hemisphere, and
mostly in the American tropics, from Mexico to Peru and Brazil.
The species that appear in North America only come to visit and
breed; they migrate north in the spring, nest, and then return
south in late summer or early fall. These visiting hummingbirds
are the smallest of migratory birds, with the most common
visitors to the United States weighing only three to four
grams.
About 26 hummingbird species have been seen north of Mexico.
In the East, you are likely to see only one species, the
ruby-throated hummingbird, who makes an appearance only after
wintering in Central America and migrating northward in spring
across the Gulf of Mexico, covering at least five hundred miles
without stopping. If you live in the West, you will see more
species—the black-chinned, broad-tailed, calliope, and rufous
hummingbirds in the mountains, and Allen's, Anna's, and Costa's
as common varieties on the coast. You will find most of these,
along with the blue-throated and magnificent hummingbirds, in
the Southwest, the region of the United States that enjoys the
greatest diversity of hummingbird species.
Jewel-like Plumage
No other bird possesses such varied and spectacularly
colored plumage as the hummingbird. Its coloring does not come
from pigmentation, as with other species, but from prism-like
cells within the top layers of the feathers. When light hits
these cells, it is broken apart into wavelengths that reflect
back to the viewer in varying degrees of intensity. The result
is that, merely by shifting position, a muted-looking bird will
suddenly become fiery red or vivid green.
Metabolic Extremes
The hummingbird is one of only a few bird species that can
become "torpid," experiencing an overnight metabolic change
that consists of a drop in body temperature—sometimes 20° to
30° Fahrenheit—and a slowing of the heart rate. The coma-like
state that results allows for a drastic reduction in their
energy consumption while they rest. This helps to
counterbalance the extreme amounts of energy hummingbirds
expend while awake, an expenditure that requires them to eat
half their body weight or more in insects and nectar each
day.
Virtuoso Flight
Hummingbirds are capable of flying at speeds of up to 30
miles per hour, and they are the only species capable of true
hovering and backward flight. Unlike other birds, hummingbirds
must depend completely on their wings for movement, as most
appear unable to walk or hop. If hummingbird wings were
compared to their human counterparts, the wings would be
virtually all "hand." This allows for a broader range of
movement and control. The muscles that move the wings—which
account for about a quarter of the bird's weight—enable them to
hover, move sideways, fly backward, and pivot around an axis
point. They can even fly upside down for very brief periods.
Hummingbirds never fly in flocks and are known to be
territorial, giving chase to every other bird who approaches
their flowers or feeders. Flying Courtships
Each species has a unique courtship behavior that may vary
by location and incorporate different songs or flight patterns.
Northernmost species depend less on vocalization; instead, they
use their wing or tail feathers to make sounds while conducting
wide-ranging aerial displays. Anna's, Allen's, and Costa's
hummingbirds display dramatic courtship behaviors, looping back
and forth in spectacular U-shaped dives up to 100 feet long,
while the more subdued ruby-throated flies in a lower, broader
arc.
After this flying courtship, only the females settle down to
raise a family. Females associate with males only long enough
to fertilize the eggs, and males generally have no role in
constructing the nest or rearing the young. Nests are about two
inches in diameter and are composed of seed, down, lichens,
small feathers, green moss, grass, and leaf fragments. These
materials are bound together and attached to a twig or branch
with spider webs. The nest may be perched high or low, in a
tree or a shrub, and will invariably contain two tiny white
eggs. The incubation period generally last 15 to 19 days. When
the nestlings hatch, the mother regurgitates food to feed them.
They fledge at about 22 days.
Feeding in Flight
Flowers that have evolved with hummingbirds and depend on
the birds for pollination are often trumpet-shaped or tubular
and lack a landing platform that would attract other
pollinators such as bees or insects. The hummingbird's bill and
tongue are specially adapted to suck up the nectar from these
blooms, which comprises most of their diet. Hummingbirds feed
on small insects as well, and can catch them on the wing. When
you see "hummers" hovering near the bark of a tree or the wall
of a house, they could be hunting tiny insects and spiders or
collecting spider webs for a nest.
How to Attract Hummingbirds
Keep the following points in mind when planning a
hummingbird garden.
- Plant tubular flowers in the hummingbird's favorite
colors, red or orange.
- Mix plant heights and flowering times, clumping
individual plant species together and placing taller plants
toward the back.
- Use native plants whenever possible.
- Plant flowers near a tree that can offer protection from
weather and predators.
- Do not use pesticides or herbicides.
- Add a birdbath with a mister or a dripper.
While hummingbirds are not social with each other, their
natural boldness and curiosity can give the impression that
they may be social with humans. They are so swift on the wing
that perhaps they can afford to be bold. With some
patience—maybe while holding a red tubular flower—you might be
lucky enough to experience the invisible whir of wings on your
face as this bold little fairy comes in for a closer look.
