In late April we started to have occasional visits from Ruby-throated Hummingbirds, once every few days. Male hummers were first on the scene,

Male Ruby-throated Hummingbird

followed by visits from females about a week later.

Female Ruby-throated Hummingbird

Now things have settled in to more of a regular thing, with what seems like at least two different females visiting our two hummingbird feeders. They’re here for the summer.

Ruby-throated Hummingbirds are the only species of hummingbirds that are native to the eastern United States and Canada. These avian beauties spend the winter in Central America, returning each spring to their breeding grounds in the north.

Male and female hummingbirds don’t spend much time together. They mate, then quickly part ways, each establishing their own territory. (The avian equivalent of a one-night stand, with consequences.) The female builds the nest, and raises the kids as a single mom. She incubates the eggs herself, sitting on the nest for a large percentage of her day. This may explain why the hummers seem to disappear for a few weeks shortly after their arrival.

When building her nest, the female Ruby-throated Hummingbird uses natural materials she finds in the woods. She uses scales that were the protective covering for leaf and flower buds during the winter.

Emerging hickory leaves with bud scales at their base

Emerging Sassafras (Sassafras albidum) leaves with bud scales at their base, accompanied by an assasin bug, Zelus luridus

She adds lichen to the outside of the nest.

Lichen, Common Greenshield ( Flavoparmelia caperata)

Foliose lichen

Unfurling Cinnamon Fern

or the spore casings of the Cinnamon ferns,

Cinnamon Fern

as well as other plant sources.

She secures her materials together and to a tree branch using spider webs, which are extremely strong. Spider webs are also stretchy, which allows the nest to expand to accommodate her growing offspring.  (Sort of like the 5% spandex in your pants that is so accommodating after a big meal!)

Trashline Orbweaver

The perfect place to build this nest is on a branch that is already covered in lichen, since it is the perfect camouflage for a lichen-covered nest.

Lichen-covered maple branch, a good nesting site for a Ruby-throated Hummingbird

The finished product looks like this.

Ruby-throated Hummingbird on her nest.

When Ruby-throated Hummingbirds first arrive in their summer breeding territories, the flowers that provide them with an ample source of nectar in exchange for their pollination services are not likely to be blooming yet, at least in the northern parts of their range. So they rely on another source of food – sap from wells made by Yellow-bellied Sapsuckers.

Yellow-bellied Sapsucker

The Sapsuckers drill holes through the bark of a tree and into the tree’s phloem, or sapwood, a highly nutritious source of food. Sapsuckers are known to use hundreds of species of trees as food sources, although they have a preference for birches and maples because their sap is especially high in nutrients. Yellow-bellied Sapsuckers typically drill horizontal rows of sap wells.

Sap wells drilled by a Yellow-bellied Sapsucker

Ruby-throated Hummingbirds also feed at these sap wells. In addition to sap, these wells provide protein in the form of insects that also visit them for food. Even some species of butterflies may feed here, including Mourning Cloaks. Like many other birds, Sapsuckers and hummingbirds rely on insects as an important part of their diet, especially when they are raising their young.

During the blooming season, Ruby-throated Hummingbirds are attracted to brightly-colored tubular flowers as their source for nectar. Several species of plants have evolved their flowers in such a way as to be a perfect match for the hummingbird’s anatomy. The Ruby-throated Hummingbird is the only reliable pollinator for their flowers, so without this bird, we wouldn’t have these plants. (See Ruby-throated Hummingbirds and Cardinal-flower – A Perfect Partnership!) Some hummingbird-dependent plants are Wild Columbine (Aquilegia canadensis),

Wild Columbine (Aquilegia canadensis)

Trumpet Honeysuckle (Lonicera sempervirons),

Trumpet Honeysuckle (Lonicera sempervirons) flowers

which produces fruit (more food for birds!) if successfully pollinated by a Ruby-throated Hummingbird,

Trumpet Honeysuckle (Lonicera sempervirens) fruit

Beebalm (Monarda didyma),

Beebalm (Monarda didyma) with Hummingbird Clearwing Moth (Hemaris thysbe)

and Cardinal-flower (Lobelia cardinalis).

Ruby-throated Hummingbird with Cardinal-flower (Lobelia cardinalis)

Jewelweeds are an important source of nectar for Ruby-throated Hummingbirds in late summer. There are two native species in the Ruby-throat’s territory, one that is bright orange with dark dots and is sometimes called Spotted Touch-me-not (Impatiens capensis), the other has yellow flowers, and may be called Pale Touch-me-not (Impatiens pallida). Hummingbirds are one of many pollinators for these plants, along with several insect species.

Jewelweed, or Spotted Touch-me-not (Impatiens capensis) with Sweat Bee

Ruby-throated Hummingbirds also nectar on flowers for which they are not the primary pollinators.  I’ve seen them feeding on White Beardtongue (Penstemon digitalis),

Ruby-throated Hummingbird with White Beardtongue (Penstemon digitalis)

Tall Larkspur (Delphinium exaltatum),

Ruby-throated Hummingbird with Tall Larkspur (Delphinium exaltatum)

Great Blue Lobelia (Lobelia siphilitica), and Purple Giant Hyssop (Agastache scrofulariifolia), but they will use many others.

In September, the Ruby-throated Hummingbirds will be off again to their winter feeding grounds in Central America. The adult males depart first, followed in a few weeks by the females and juveniles. We’ll enjoy them until then.

Ruby-throated_Hummingbird

Ruby-throated Hummingbird

Resources

Bradley, Richard A.  Common Spiders of North America.  2013.

Eastman, John.  Birds of Forest, Yard, & Thicket.  1997.

Eastman, John.  The Book of Swamp and Bog.  1995

Harrison, Hal H.  Eastern Birds’ Nests.  1975

Stokes, Donald & Lillian.  A Guide to Bird Behavior Volume III.  1989

Walewski, Joe.  Lichens of the North Woods.  2007.