The hummingbirds are back! Who among us has not joyfully exclaimed when the first Ruby-throated Hummingbird of the year appears at our flowers or feeder? It’s hard to think of a Maine migratory breeding bird whose spring arrival is more eagerly anticipated.
The hummingbird family is restricted to the New World with most of the 328 species occurring in Central America and South America. Unsurprisingly, south Texas and southeastern Arizona have the highest hummingbird diversity in the U.S. with almost 20 species in each area. For us New Englanders, we have to be content with a single species.
But, our Ruby-throated Hummingbirds have a broad nesting distribution, occurring in the United States east of 100 degrees latitude everywhere except the southern tip of the Florida peninsula. In Canada, ruby-throats occur from the Maritime Provinces westward into Saskatchewan. No other species of hummingbird in North America has a broader geographic range.
The delights of watching Ruby-throated Hummingbirds are many. The red throat feathers (called a gorget) of a male Ruby-throated Hummingbird may seem to sparkle in the right light. Their throat feathers refract light, giving the bird an iridescence that makes the feathers seem to shimmer as the bird moves its head.
Who isn’t amazed by a hummingbird’s ability to fly backwards? Unlike other birds that extend their wings down and forward during a powerful downstroke and then fold the wings to raise them back for the next downstroke, hummingbirds generate lift and thrust on both the downstroke and upstroke. Their wings in motion describe a figure-8 when viewed from the side. At the end of the downstroke, the wing is moved backwards and power is created by the upstroke moving forward to the head.
Don’t expect to see these amazing wing movements with your naked eye. Hummingbird wings are a blur in motion; the wings beat up to 70 times a second. Slow-motion video is needed to see the figure-8 wing movements.
Ruby-throated Hummingbirds have a mating system called promiscuity. Each male tries to mate with as many females as possible. No long-lasting pair bonds are forged.
A male will court a female through complicated flight displays. When a female flies into his territory, he begins with a dive display, flying U-shaped loops starting from as high as 30 feet above the female. If the female perches, he switches to very fast, side-to-side flights, with his gorget extended, within two feet of the female. If the male is acceptable as a mate, the female will cock her tail feathers to one side and lower her wings, inviting the male to mate with her. Mating lasts only about 2-3 seconds and that is the end of the male’s contribution to the offspring. Keep an eye out for these behaviors. I find them fascinating.
As a single mom, the female builds the nest by herself. The base is made of the down from dandelions and thistles and is attached to the upper side of a branch, much like a saddle over the back of a horse. The sides of the nest are made of plant down, bud scales and spider webs. The plant material is woven into the nest with the spider silk.
The eggs are usually two in number and, as you might imagine, are tiny. An average egg is half an inch long. That’s barely larger than an English pea.
Incubation takes 12-14 days and the young hatch as naked, blind chicks. Feeding usually begins soon after hatching and the young fledge about 20 days after hatching.
We think of Ruby-throated Hummingbirds as depending on nectar for their nutrition. However, these birds also take spiders and insects (mosquitoes, gnats, fruit flies and small bees). Sometimes hummingbirds steal insects caught in spider webs and may take insects attracted to oozing sap from Yellow-bellied Sapsucker wells.
[First published on June 18, 2017]