OREGON STATE UNIVERSITY

Marbled Murrelet becomes a flagship species for environmental change

Oregon State professor Jim Rivers calls the marbled murrelet — a small seabird native to the North Pacific — a flagship species for healthy ecosystems because it is one of the only birds in the world that gets all of its food from the marine environment but nests well inland in forested areas, sometimes as far as 50 miles from the nearest ocean.

Murrelets are listed as threatened under the U.S. Endangered Species Act in Oregon, Washington and California, yet little is known about the nesting habits of this curious, short-beaked seabird in Oregon.

Rivers and a team of scientists from the Oregon State College of Forestry including Matt Betts, Kim Nelson, and Dan Roby, as well as the Oregon State Department of Fisheries and Wildlife and the U.S. Geological Survey, want to learn more about the habitat of choice for nesting, as well as the factors that contribute to successful raising their young.

A better understanding of murrelet nesting habitat is critical for informing tough policy decisions on conservation and active management of coastal forests. Therefore, with funding from the Oregon State Forest Research Lab, the team has begun an important study of this species.

Nesting near the coast makes murrelets unique from their relatives like puffins or guillemots, species that often nest on rock outcroppings along the coast. It also makes them exceptionally challenging to study, and researchers go to great lengths to locate nests.

“We start by capturing the bird at sea during the night when they can be netted from a small boat close to shore,” Rivers says. “We then attach tracking tags, release the birds and use fixed-wing aircraft to traverse coastal forests to find the tracking tags. If all goes well, we narrow the bird’s location to a stand where can locate the nest.

Rivers admits this is a lot of work.

“But it’s the only way we can get a sample of reasonable size that allows us to best understand the breeding habitat that this species needs,” he says.

The goal of studying marbled murrelets is to provide information for management policies and practices in forests where the birds nest.

“In particular, we want to know where they nest on the landscape, what influences their ability to nest successfully, and ultimately how timber harvest near nest stands may influence their ability to breed successfully,” Nelson began studying the birds in the 1980s, and her existing research is an integral part of the project.

“We found the first nest of this species in Oregon in 1990,” she says. “Since then my work has focused on finding nest sites, studying breeding ecology, using modeling to describe optimal habitat, assessing the impacts of fragmentation and predation, mapping forgaging hot spots and more.”

Nelson calls murrelets cryptic and secretive. “They’ve foiled biologists for centuries,” she says.

Now the team is adopting a new approach to finding murrelet nests by building upon knowledge and techniques gained from other murrelet research and adapting it to conditions specific to Oregon.

To help find the birds’ cryptic nests, the research team is also working with researchers with the National Oceanic and Atmospheric Administration and a private NGO, Oceans Unmanned, to fly unmanned aerial vehicles (UAVs) with thermal infrared cameras in coastal forests to help locate active nests.

“Using UAVs to conduct this kind of research is cutting edge,” Rivers says. “No one has used them to locate cryptic nests within complex terrestrial habitats, in part because of logistical challenges and because of extensive regulations. Nevertheless, we really need to find murrelets nests and monitor them to better understand their breeding habits, and UAVs offer us a promising opportunity in this regard.”

After a successful pilot season in 2016, the research is ongoing and ever expanding.

“The ocean conditions are expected to provide good foraging opportunities for birds during future breeding seasons,” Rivers says. “Our goal is to capture and tag a large sample of the murrelets on the ocean with tracking tags, and continue that approach to obtain data in multiple years. This project requires us to capture a large number of birds because an unknown proportion of adults forgo breeding, so some tagged birds may not nest within the timeframe that the tracking tags are functional.”

If the project goes well and enough data are collected, the research team will be able to make recommendations to land managers about how murrelet habitat should be managed to sustain murrelet populations.

“This study should be able to say something about their habitat needs and requirements in Oregon in particular,” Rivers says. “Ultimately, we want to learn how forest management practices may influence this threatened species so we can provide information for adaptive management to reach both economic and ecological goals.”