What Murrelets Need

What tree surgeon Hoyt Foster discovered in 1974--a Marbled Murrelet chick hunkered down on a branch 148 up a Douglas-fir--provided critical clues to the nesting habitat of this federally threatened little seabird. 

Marbled Murrelets need a wide branch, preferably covered in moss, at least 50 feet up a tree that is >150 years old and no more than 55 miles from salt water. This kind of habitat was once amply available along the Pacific Northwest coast. Now, that habitat has been reduced to patches and fragments and the murrelet population has been steadily crashing.

In Washington state, the population has dropped 44% between 2001 and 2015 and continues to decline at the rate of 4% a year. This means, based on the 2016 population in our state, that we will losing 284 murrelets a year. The primary cause is the historic and ongoing logging of our old-growth and mature coastal forests.

On September 7, 2018, the Department of Natural Resources released a long-term conservation strategy that will help determine the fate the of the Marbled Murrelet on the 576,000 acres of land it manages for these birds and other wildlife. Much this acreage is habitat, but not all of it. An estimated 154,000 acres consist of murecelt nesting habitat. As you might imagine, the management of this habitat is hotly contested. The mature and old-growth forests provide both valuable revenue to our state when horizontal; they provide critical habitat to murrelets for nesting when left vertical. 

What Marbled Murrelets do not need is Jaime Herrera Beutler, the U.S. Congressperson representing Washington's 3rd district in southwest Washington. Though she believes she is doing the right thing to protect family-wage jobs in her district, her efforts in the murrelet arena are misguided (which is to say guided by the timber industry and misinformation) and will surely backfire if she continues to refuse to understand the basic habitat needs of the murrelet. Her constituents have more to lose than gain by supporting her position on managing our state forest lands.

Rep. Herrera Beutler introduced an amendment to the House Appropriations Bill for Interior & Environment that would essentially result in the logging of everything but the bare essentials for nesting murrelets. Here is the text of her short-sighted bill.

This stingy bill should not be supported. It proposes to protect only the highest-quality forest stands. It will create silos of habitat for the murrelet and other species that benefit from contiguous blocks of forest. It will not contribute to the recovery of this imperiled species. It will not meet the U.S. Fish & Wildlife Services criteria required of the Department of Natural Resources to continue legally harvesting their state trust lands.  

Jaime Herrera Beutler's amendment offers a bulldozer at a time when we need are well-honed axes, sharpened pencils, and sharp minds.

In its recently revised Draft Environmental Impact Statement, the Department of Natural Resources has offered several options for protecting forest lands that will eventually grow into murrelet nesting habitat. While it may irk some to set aside younger forests for future murrelet habitat, this is what is needed to give this bird a fighting chance. 

Murrelet chick ready to fledge. (Photo courtesy Hamer Environmental).

What is Old-Growth?

When we talk about old-growth trees our minds may generate an image of a tree like this western red-cedar (above) or one of the mighty drive-thru California redwoods. The definition of old-growth varies depending on such factors as the species of the tree, the latitude at which it grows, geographical region, plant associations, soil productivity, elevation, and which federal or state agency you ask. 

If you ask, as I did one morning, a slightly hung-over college student to guess how big an old-growth tree is, you might get an answer like this: "Big. Really big. As big as my brain is right now."

In Rare Bird, I spent a lot of time in the old-growth coastal forests of the Pacific Northwest tagging along with biologists who were studying the marbled murrelet, a seabird that nests in these forests. It was a constant challenge to avoid saying "big," "really big," and "wow."  Which is understandable because an old-growth tree is awesome and we are appropriately left speechless or nearly so. But this does not help the marbled murrelet whose survival depends on our understanding of its habitat--the forests we describe in shorthand as "old-growth." Few of us--slightly hungover or not--are not likely to provide any details.

Until the 1980s, scientists were hard-pressed to come up with a solid definition of an old-growth forest. During the controversy over the protection of the northern spotted owl and the logging of its habitat (old growth? second growth?), a seven-page definition emerged and was then distilled into this working definition: a forest that "has been largely unmodified by timber harvesting, and whose larger trees average over 200 years old or greater than 31 inches (80 cm) in diameter at breast height."  This gets distilled down even further to 80 cm dbh. 

To complicate matters, for the purposes of a major scientific study on marbled murrelet nesting habitat on Washington state trust lands, marbled murrelet nesting trees were defined as being >48 cm dbh ( >19 inches dbh (2008 Science Team Report). Scientists have discovered that marbled murrelets will nest in trees younger than old-growth--trees described as "mature"--if these trees have the right size nesting platforms. The right size is 4 inches or greater and that size may occur in younger trees where nest branches are deformed/enlarged by mistletoe.

For the generalist-naturalist, 80 cm dbh is a good rule of thumb.

What does 80 cm dbh even look like? Does 32 inches dbh make it any easier? Sure--imagining a tree with a trunk 4 inches shy of a wooden yardstick creates a visual impression--but not one as huge as I expected. Was the Douglas-fir in my backyard old-growth? How was I going to measure the diameter of this living tree? For that matter, why do scientists measure a tree's diameter instead of its circumference?  I wasn't going to wait for an answer. Nor was I going to wait for a blow-down and a chainsaw.

Seems like a lot of work to get an accurate measurement of a tree's diameter.

I converted 80 cm dbh to 251 cm circumference and then cut a piece of yellow flagging tape to measure that girth. FYI: 251 cm=98.9 inches, and, because we are friends, let's call it 100 inches. I went outside and wrapped by 100-inch tape around my Douglas-fir.  A juvie! It was only 75 inches around. I put the yellow tape into my coat pocket and whipped it out last week during a snow-shoe foray in the foothills of the Cascade Range at White Pass (southeast of Mt. Rainier).

Tie a yellow ribbon 'round the old-growth tree--it's been 200 long years, will you still hug me? This hemlock's 100-inch circumference qualifies it as an old-growth tree--but is this tree habitat?     Photo by N.D. Ruth

This magnificent hemlock meets the old-growth standard of 80 cm dbh--or 100 inches in girth. This tree is in a lovely but it is not in an old-growth forest. To be an old-growth forest, this tree would need to be accompanied by other similarly big living trees, big dead standing trees (snags), fallen trees (nurse logs), a multi-level canopy, and an understory of younger trees and shrubs. This tree above is in a stand of younger trees and is bordered by Hwy 12 and a cross-country ski trail on side and a lake on the other. Because this stand is in an area used for recreation, the forest here has been managed for public access and safety--not as wildlife habitat. This tree is 100 miles from salt water and too far inland to be marbled murrelet habitat (they will nest as far as 50 miles inland).

The forest below is within the 50-mile breeding range of the marbled murrelet but is it marbled murrelet habitat?

This is an old-growth stand of western red-cedar, western hemlock Douglas-fir, and Sitka spruce in Rainbow Falls State Park, in the Chehalis River Valley southwest of Olympia, Washington.   ( Photo my MM Ruth)

This is Rainbow Rock State Park--a 139 acre park along the Chehalis River. Once surrounded by thousands of acres of old-growth forest, this is the remnant gem. The cedars, hemlocks, firs, and spruces all meet the 100-inch standard and the other qualifications in terms of snags, nurse logs, multi-level canopy, etc. But is this nesting habitat for a marbled murrelet?  Unless scientific surveys of this forest document certain marbled murrelet behaviors (such as flying below the canopy height, landing on branches), this forest cannot be declared "occupied" habitat. But based on other factors, this forest could be declared "potential" habitat--a place where marbled murrelets could nest. Marbled murrelet surveys are expensive, time consuming, and labor intensive. And, they make people grouchy because surveys start well before dawn, which is really really early in the summer.

Because I am interested in getting to know the forests where I live, I have started taking my yellow ribbon with me when I go on a walk or hike. When I remember to also take my camera, I will start posting photographs here on my blog and and here.

Meanwhile, recommended reading: Old Growth in a New World" A Pacific Northwest Icon Reexamined, Thomas A. Spies and Sally L. Duncan, eds. Island Press, 2009.

Not recommended viewing unless you have 3'06" to fritter away on Tony Orlando and Dawn: This stunning "live" performance from the 1970s--the taste-free decade.