Nature Watch: Under Construction

About the author: Steve Ellis is a naturalist and Land Trust member who enjoys sharing his love of the natural world. His blog series, “Nature Watch,” will appear each month in “Habitchat,” chronicling native plants and wildlife you can expect to see during that particular time of year. We thank Steve for sharing his passion, illustrating the importance of island conservation.

Overview

No permits have been issued, yet building is occurring at hundreds of sites in Island County. May is prime nesting time for songbirds (passerines).

Cup-style nests are the norm for most passerines. In many species, it’s the female that constructs the nest. Using only her beak and talons, she weaves twigs and other materials together to create the cup.

After the nest is constructed, the female brings softer materials for the structure’s interior. She forms this material to fit her size and shape by entering the nest and slowly rotating her body while pressing down on the rim with her chin and the underside of her tail. She may have to push backwards with her feet to enlarge the space.

American Robins take two to six days to build a nest, with the males helping to deliver mud and other materials. A White-crowned Sparrow female needs a week or more for completion. The female Wilson’s Warbler sites her cup in a depression under a log or beneath low-growing plants.

There are some exceptions to the passerine cup nest. A male Marsh Wren may spend a week creating the dome-shaped nest he hopes will be attractive to a female. He builds the nest 2 to 5 feet up in cattails or bulrushes. The dome is 7 inches tall and 5 inches wide, with an entrance hole on the side near the top. Multiple nests may be required before one strikes the female’s fancy, and once she’s made her choice, she’ll finish the inside with grass, cattail down and feathers.

Bushtit nest by Martha Ellis.

Perhaps the most intricate nests are those of Bushtits, a small, gray-colored species related to chickadees. A finished Bushtit nest resembles a hanging gym sock, with an entrance hole near the enclosed top.  The “sock” is built in a tree or shrub, with many located in oceanspray bushes. Materials include dry leaves, moss, twigs, lichens and grass. Spider silk is continually added to give the structure elasticity. A Bushtit pair may take up to six weeks to weave a nest. During construction, the pair will spend the nights in the nest. Material will be added even after eggs have been laid.

You can assist nest-building by providing such raw materials as lengths of string no longer than 3 inches, long fur combed from a dog and dried grasses. If you have a low spot in your yard, keep it muddy by adding water. White chicken feathers are irresistible to Tree and Violet-green Swallows. Balls of commercial cotton material can be purchased from stores that specialize in bird feeding supplies – hummingbirds and goldfinches are especially attracted to this material. Place these various items in the open and, if possible, out of reach of housecats.

Diligent observation in a variety of habitats should reveal several species hard at work, carrying items to hidden locations. Admire their dedication from afar, so as not to interfere with nesting and the creation of the next generation of birds.

Rufous Hummingbird by Jennifer Holmes.

Rufous Hummingbird nest by Martha Ellis.

Fauna: Rufous Hummingbird (Selasphorus rufus)

The spunky little Rufous Hummingbird is a fairly common nesting species on our islands.

Rufous Hummingbirds are 3.5 to 4 inches in length. Males are mostly rufous, with some green on the wings and white on the breast. The gorget, the brightly-colored throat patch, is orange-red. Females are green above and white below, with dull rufous sides.

Migrating males arrive from western Mexico in late February and early March. Females trail the males by a couple of weeks. Sometimes a dip in their numbers is noticed; these are birds that tarried here a while as they waited for spring to arrive in British Columbia and southeast Alaska.

The Rufous Hummingbird diet consists of nectar taken from salmonberry, red-flowering currant and other bloomers. They also eat insects and have been seen drinking from tree trunk “wells” created by Red-breasted Sapsuckers.

After mating, the female selects a site from 2 to 50 feet high in a bush or tree in which to build her nest.  Early nesters build in locations deep in sheltering branches. Later nesters may choose more open sites such as Pacific rhododendrons.

Nest materials include moss, plant down and bark shreds. The outside is decorated with lichens for camouflage and the structure is wrapped with spider silk. The cup is the size of half a golf ball, with a rim that may be an inch in thickness. The inside will have soft plant material to cushion her two pea-sized eggs.

Males leave our area in early summer, choosing to head upslope into the North Cascades. Females and juveniles follow a bit later. Males tend to ascend to higher elevations before migrating south.

Aside from the standard hummingbird feeder, there are other ways to attract these flying jewels. Add salmonberry and red-flowering currant to your yard. Western hemlocks and salal provide shelter and possible nest sites. Leave spider webs that are attached to the outside of your buildings. Consider hanging up a ball of nest materials.

You can find Rufous Hummingbirds in open forests, along hedgerows and thickets, and in suburbs.

Pacific Rhododendron by Martha Ellis.

Pacific Rhododendron blossom by Martha Ellis.

Flora: Pacific Rhododendron (Rhododendron macrophyllum)

Washington’s state flower grows as either a spreading bush or as a leggy, tree-like shrub reaching over 20 feet in height.

Pacific rhodies have 4- to 8-inch leaves that are oblong and leathery. They are dark green above and paler below. The leaves will curl to preserve heat in cold temperatures or to retain moisture during arid conditions.

“Showy” is the best description of the large blossoms. Clusters of bell-shaped flowers grow from the ends of the twigs. The pink to rose-purple (rarely whitish) blooms have five petals that reach 1.5 inches in length.

Flowering reaches its peak in May. The fragrance emanating from the blooms attracts bumblebees and western tiger swallowtail butterflies. Anna’s and Rufous Hummingbirds also nectar from the blossoms, which in turn aids in pollination.

Woody capsules follow the flowers. These capsules split open while still attached to the shrub and release tiny seeds that are dispersed by gravity and wind.

Pacific rhodies have the ability to sprout from their root systems following wildfires or clearcutting.  Their roots help anchor soils in steep areas, especially after a disturbance.

Deer occasionally browse the leaves in winter when better food isn’t available, and a few bird species – most notably Rufous Hummingbirds – nest among the branches.

Moderately acidic soils in open or shady forests are handled well by Pacific rhododendrons.  If you contemplate adding this beautiful shrub to your yard, note that plenty of direct sunlight can be harmful to the leaves. Several local plant nurseries sell this species.

There are many places to see the beauty of native rhodie blooms on our islands. The display in Rhododendron Park near Coupeville lasts well into June and is worth a visit.

Read more Habitchat blog posts