Nature Watch: Mountain Connections

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

There are many places on our islands from which to view the breathtaking North Cascade and Olympic mountain ranges. More than scenic backdrops, they play an integral part in the life found on and around Whidbey and Camano Islands.

Perhaps the greatest mountain contributions come in the alteration of weather. Winds are blocked or concentrated and redirected. The amount of precipitation that falls on a spot largely depends on its orientation to the mountains.

Warm moist air entering from over the Pacific Ocean encounters the mountains. As the clouds rise to traverse the high ridges, they are cooled. Cold air cannot hold as much moisture as warm, so rain or snow is the result.

Large conifers such as those found on Hoypus Point at the northeast tip of Whidbey owe their existence to abundant rainfall. All the flora and fauna tied to old growth forests are also beneficiaries of this weather pattern.

Central Whidbey is situated to receive the opposite treatment from the Olympics. These mountains block prevailing storm patterns, creating the famous rain shadow effect. That, along with the glacial outwash gravels, produced the prairies that allow camas, lomatium and other dryland plants to flourish. It’s so dry that prickly pear cactus can be found growing on Ebey’s Bluff, a mere twenty miles from the rainforest of Hoypus Point.

It’s not just plant life that’s subject to these effects. The bird checklists of Camano and Whidbey would be much different if not for the mountain slopes. Starting in September, bird species begin to filter down to the lowlands. Species such as Ruby-crowned Kinglet, Fox Sparrow and Varied Thrush drop down to our islands to spend the winter in a more favorable climate.

Some bird species that winter elsewhere will tarry here awhile in spring as they wait for their mountain destinations to become hospitable. These include Townsend’s Solitaire, Mountain Bluebird and Calliope Hummingbird.

It may come as a surprise to learn that other animals also lead “up and down” lives. Some species of bats reverse the process, spending summers in the bug-rich lowlands and then flying up to hibernate in mountain caves.

California tortoiseshells, a butterfly species that is orangish with some black markings, flit downslope in September to hibernate. Their host plants, ceanothus, grow on the other side of the Pickets, a range of mountains along State Highway 20 near Newhalem. I don’t come across them here very often, so it’s always a treat to see one.

Not to be overlooked is the contribution of the rivers flowing out of the mountains. The Skagit and Snohomish Rivers move tons of silt scoured from slopes into the Salish Sea. Some of it is deposited by wave action around the islands, helping to create beaches and mudflats. Rivers also send nutrients downstream that are utilized by plankton and other aquatic life. In turn, salmon bring marine carbons back into the uplands on their spawning journeys.

Nearly every facet of nature in and around our islands has been affected by the majestic mountains. How different life would be here without them.

Coho salmon in spawning phase.

Fauna: Coho Salmon, a.k.a Silver Salmon (Oncorhynchus kisutch)

Coho salmon are important members of the Eastern Pacific salmonids, a group that includes the native salmon and trout species.

This species is anadromous, spending a portion of their lives in both salt and fresh water. They are found around our islands, first as 18-month-old smolts, sticking close to shore as they grow big enough to tackle the larger oceans. Cohos return as three- to four-year-old adults, having spent the time either in the Salish Sea or swimming off the outer coast from Oregon to British Columbia. They begin to return towards their spawning grounds in September. Coho passing by Whidbey and Camano are probably headed to the Skagit or Snohomish river systems.

As adults, they average six to twelve pounds, with a length of 20 to 30 inches. They have dark blue backs, silver sides and white bellies. The gums are white, as opposed to the black gums of the larger chinook salmon.

In the ocean, coho eat fish and squid. Favorite prey include Pacific herring, sand lance and sablefish.

Coho spawn in all sections of rivers and their tributaries. They are blocked by falls and stream gradients that are greater than 20 percent.

Anglers do catch a few coho from Whidbey and Camano beaches. You may see one jump as they pass by on their way to their spawning river. Various reasons have been put forth for this behavior: attempts to rid their bodies of sea lice; chasing after prey; escaping the attack of sharks or marine mammals; expressing vitality.

Sighting coho salmon is much easier along tributaries such as the Skykomish River.

Large woody debris defends against erosion by breaking the force of waves. Photo by Martha Ellis.

Flora: Large Woody Debris

Large woody debris (LWD) is driftwood made up of the logs and stumps found along rivers and ocean beaches.

The LWD found on the beaches of Whidbey and Camano Islands come either from trees fallen from bluffs or those washed down mountain rivers. Some of the latter have drifted across from the Olympic Peninsula.

Our island beaches are exposed to harsh wave action. LWD defends against erosion by breaking the force of waves, particularly during stormy weather.

LWD provides habitat for both flora and fauna. Northern alligator lizards find shelter under logs on the beach. Many invertebrates are drawn to the wood, which in turn attracts birds looking for a meal. Plants such as sand verbena and American sea rocket wouldn’t survive without the presence of these logs, keeping them from inundation by seawater. We once watched a dozen or more woodland skipper butterflies nectaring from sea rockets on a Camano Island beach protected by driftwood.

Nutrient cycling is also an important contribution of LWD. Gribbles – a species of isopod – and shipworms – a type of mollusk – digest wood; in the process organic material can then be accessed by other life forms.

It’s important to leave LWD in place. Removal of driftwood threatens the beach ecosystem. Each log you clamber over on the way to your favorite beach has a story to tell.

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