Nature Watch: Dirty Fences

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

The poet Robert Frost included the line “Good fences make good neighbors,” in his poem Mending Wall. Dirty fences, also known as hedgerows, make good places for our wildlife neighbors.

Hedgerows originated in Europe, where they served to separate fields and delineate property boundaries. The hedgerows existing here often got their start from neglected fence lines. No matter the story of their origins, hedgerows are beneficial to wildlife.

There are many food resources associated with dirty fences. These include seeds, fruits, invertebrates and small mammals.

Birds are the main beneficiaries of hedgerows. At least 22 species use our local examples for sustenance or cover, including several sparrows, House Finch, American Goldfinch, Orange-crowned Warbler and Cedar Waxwing.

Hedgerows are especially useful to those birds that balk at flying long distances in the open. Species such as chickadees will travel from one woodlot to another by following the brushy “highway.”  Should a predator appear, the small birds quickly take cover among the shrubs.

Other wildlife use hedgerows for cover and foraging. Voles, deer mice, rabbits, shrews, raccoons, and even snakes and northern alligator lizards may be found in and around these dirty fences.

Many pollinators and other beneficial insects are residents of hedgerows, such as bumblebees, hoverflies, lacewings and ladybeetles.

The best hedgerows are a mix of deciduous and evergreen shrubs, with a scattering of trees down their length. Optimally, a quarter of the hedge’s composition should be evergreen shrubs and trees. Typical woody evergreens are Douglas-fir, shore pine and Oregon grape. Deciduous representatives include Nootka rose, hardhack, snowberry, red-flowering currant, osoberry, Scouler’s willow and Pacific crabapple.

Hedgerows reseed themselves but they are augmented by seeds blown in by the wind and those that are planted through bird droppings.

Non-traditional hedgerows are found where people have left a buffer of native flora between their lawn and the road fronting their property. Hedges also start along neglected road rights of way.

It takes several years for a hedgerow to achieve maximum wildlife value. They should be started by planting shrubs about 3 feet apart. For good habitat, a hedge should be a minimum of 6 feet wide.

If you contemplate establishing a hedgerow, consider using red alder, salal, red elderberry and serviceberry in addition to those already mentioned. All grow without much help.

Dirty fences have many values beyond wildlife habitat. They are scenic, control water runoff and moderate winds that dry soils prematurely.

There are many hedgerows to be seen on Camano and Whidbey Islands. Do not trespass in fields. There are trails and roads that allow you the access to appreciate one of our more unusual local habitats.

Common snowberry in bloom by Martha Ellis.

Flora: Common Snowberry (Symphoricarpos albus)

Common snowberry is a mainstay of local hedgerows.

This successful shrub grows 2 to 10 feet in height. It has oval to egg-shaped leaves measuring ¾ to 2 inches long.

Blooming in this species starts in May and continues through August. The blossoms are tiny pink or white bells that grow in clusters. The blossoms are pollinated by hummingbirds and bumblebees. It’s always amusing to see a large bumblebee gathering nectar from such tiny blooms. Clusters of white, waxy berries then ripen in the fall.

Snowberry rarely grows from seeds but depends on sprouting from rhizomes. Large thickets of snowberry may derive from only one or two individual shrubs. This ability allows them to be the first woody plant to rise phoenix-like after wildfires or other surface disturbance.

Rabbits eat snowberry stems and deer browse the leaves.

Several moth species use the shrub as a host plant, including western sheep moth and snowberry clearwing moth. I was once privileged to see an individual of the latter at Deception Pass State Park. These unusual moths have transparent wings.

Few birds eat the berries themselves and then only if other food resources are unavailable. I’ve observed Spotted Towhees eating the berries and thrushes are said to feed on them as well. Perhaps the reason snowberry bushes rarely grow from seed is because few of the berries go through the digestive system of birds which scarify seeds.

Birds do benefit from snowberries as locations for nesting. White-crowned Sparrows, Brewer’s Blackbirds and other small birds nest deep in the thickets.

Snowberry does best in partial sun locales but can tolerate everything from shade to full sun. It can be seen in many locations and offers something in each season: green leaves and delicate blooms in spring through summer, and the round snowball-like fruits in fall and winter.

Male Brewer’s Blackbird by Craig Johnson.

Fauna: Brewer’s Blackbird (Euphagus cyanocephalus)

Watch any large parking lot in the spring and the chances are you’ll witness a male Brewer’s Blackbird trying to impress a female.

Brewer’s Blackbirds are 8 to 9 inches long, with a wingspan of up to 15 inches. Males are all dark with a purple sheen on the head and a greenish sheen on the back, wings and tail. The pale yellow eyes contrast sharply with the dark face. Females are dull grayish-brown and have dark eyes.

A distinctive characteristic is the Brewer’s Blackbird strut. The birds walk with the head held erect and nodding sharply forward with each step. During courtship, the male will fan his tail while strutting in an attempt to impress a female.

Brewer’s Blackbirds feed on the ground out in the open. Their main diet in summer is insects and then a switch is made to the seeds of weeds and grasses in the fall and winter. Large numbers will flock with Red-winged Blackbirds in fields to eat grain spilled after harvest time is finished.

They’ve learned to exploit an unusual food source: insects stuck in the grills of parked cars. They also eat insect pests from the backs of livestock.

Brewer’s Blackbirds breed in loose colonies, often placing their nests in hedgerows. Males become very territorial in June and will utter harsh “Tschup” notes when predators appear. They swoop down on hawks and housecats and may even hit them if the threats get too close.

The birds are careful to guard the whereabouts of their nests. They gather insects in tall grass to feed their young and will enter a hedgerow a few feet away from the nest in order to make a stealthy approach.

Watch for these birds perched on powerlines near fields. They’re such common nesters in hedgerows that we’ve taken to calling Coupeville’s dirty fences “blackbird factories”!

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