Door to Nature

Hummingbird at a fully opened Mexican sunflower.

The Ruby-throated Hummingbird possibly captures the hearts of more people each summer than any other bird in Door County, and each year we learn more about these dazzling little winged jewels. We number ourselves among the many who firmly believe that, ounce for ounce, there’s not another bird that comes even close to equaling the hummingbird in its incredible feats.

The roughly 339 species of hummingbirds of the world all live in either North, Central or South America. Ours, the Ruby-throated, has the largest breeding range of the 16 species in North America. The plumage of few other birds of the world can match the brilliant iridescent colors of these tiny winged dynamos. The bird’s pointed bill, tubular at the tip and also brush-tipped, is wonderfully adapted to probing flowers for nectar and insects. Its unique ability to hover helicopter-like at blossoms eliminates nearly all competition from other birds.

A male hummer showing its ruby red gorget.

Even though the hummingbird does have a tiny crop in which it can store food for sustenance overnight, its metabolism is so high that in order to endure very cold nights this amazing little bird becomes dormant. It’s been determined that around 75% of a hummingbird’s food consists of insects with the remainder being flower nectar or sugar water from feeders. People frequently see their hummingbirds sipping sugar water but seldom get to see the hummers hunting for insects. Those Rubythroats wintering in, for example, Costa Rica, eat almost entirely insects in the absence of flowers.

Believe me, the fact that hummingbirds “hum” is not because they don’t know the words! Their wings are a virtual blur as they hover at flowers, their wings beating somewhere between 50 and 55 times per second and producing that humming sound. They do have vocalizations in addition to their wing sounds consisting of very high-pitched musical squeaks and twittering.

This hummer at a hosta flower sticks out its tongue.

It was during my pre-field artillery days with the U.S. Army, when my hearing was still very acute, that I had the good fortune several times to observe the male’s astounding pendulum flight. This phenomenon is produced during courtship with the females and also to display anger and to threaten other hummers from entering their feeding territories. It’s during this unusual aerial display that the male sings very excitedly.

Hummingbirds’ pointed wings that are swept back at their sides and have a high-speed shape enable these birds to be very swift in flight. They also can hover, fly backward, shift sideways, and fly straight up and down. There are relatively few instances of these tiny elusive masters of flight being caught by predators

A female hummingbird in a cedar tree.

It is invariably during the late summer season that people thrill to the sight of a hummingbird-like insect hovering at flowers, long coiled tongue extended into the nectar tubes of the blossoms and appearing for all the world like a very strange little hummingbird of unknown identity. It’s the antennae on the heads of the strange “hummers” that confuse the observers.

Two different clear-wing moths are what the people are most likely observing at their flowers. The most commonly seen species of this region is the Snowberry Clearwing Moth whose body is a light yellowish-tan having a darker band near its rear end. The other fairly common and slightly larger species is the Hummingbird Moth whose body is a dark reddish-brown, also containing a darker band toward the rear. Both have perfectly transparent wing areas and also the antennae, or “feelers,” found on all moths and many other insects.

Hummer at a partially opened Mexican sunflower.

Ruby-throated hummingbirds nest in every county in Wisconsin and, for the most part, are double-brooded. The young, which fledge after being in the nest from 18 to 22 days, are then fed by the female for around four to seven more days before she lays her second clutch of two eggs. Observations of fledgling hummingbirds being fed by the female, and never the male, run from June 10 to September 15, indicating quite clearly that the female raises two broods.

Banding studies indicate that if a female Rubythroat survives the winter she tends to return to the same woods in which she nested the previous summer. Realizing that this tiny creature very likely migrated to, for example southern Louisiana, rested and fed for several days and then flew non-stop around 500 miles across the Gulf of Mexico, wintered in Central America and found her own way back the following May to your woods and yard surely is just short of miraculous.

Naturally the male Rubythroat’s brilliant iridescent throat gorget (GOR-jet) makes for easy identification. His tail is slightly forked and has no white tail spots whatsoever. The adult female lacks the red throat gorget, has no fork in her tail and does have white spots near the tips of each of the three outer tail feathers. Both young males and females have the white tail-feather spots. The young males will not attain the red gorget until their winter feather molts. Some of the young males will show faint red throat spots before they leave for the South. Adult males will leave here first, usually by late August or early September, followed by the adult females a week or two later and, lastly, by the young of the year.

It’s important to keep your hummingbird feeders up until at least a week or two after your last sighting of the hummers, which may be into late September or early October. A late migrating hummer may need the sugar water to help it continue its trip south. Take good care of your hummingbirds, the crown jewels of the bird world.