Seabird research creates opportunities for ecosystem understanding

A marbled murrelet, an Oregon seabird, emerges from the water. OSU researchers in the College of Forestry study the murrelet to better understand human environmental impacts on maritime and coastal forest habitats.

Melinda Myers, News Contributor

The Institute for Working Forest Landscapes in the College of Forestry at Oregon State University have funded a little more than one million dollars annually for a new study aimed at conserving marbled murrelet populations in Oregon, said James Rivers, a professor of animal ecology in the College of Forestry and lead researcher on the project.

The marbled murrelet is a medium-sized seabird that belongs to the same family as puffins and murres. This bird has amazed scientists and stakeholders alike with its uniquely-demanding life cycle, according to Rivers.

Rivers explained that researchers can use seabird populations to gauge the health and stability of their habitat.

“The neat thing about the marbled murrelet is that it is a canary in a coalmine for not just one, but two different ecosystems: the coastal forest and the marine environment,” Rivers said.

Collecting more data on murrelets would give clues about both the coastal and marine ecosystems, and this information is used by stakeholders and scientists when creating policy, fine-tuning land management and interpreting environmental health, according to Rivers.

“The big question is to understand how activities such as harvesting timber affect murrelet populations,” Rivers said. “A big challenge is working with how little data we have about these birds. One of our long-term goals is to collect and provide more data on these species for future reference.”

The marbled murrelet has incredibly unique breeding strategies said Kim Nelson, an avian ecologist at OSU who found the first marbled murrelet nest in Oregon.

In the mid-1980s, I was on Marys Peak—near Corvallis and 30 miles inland—when I heard seabirds flying through the forest at dawn while conducting forest-bird surveys.  The seabirds turned out to be marbled murrelets,” Nelson said in an email.  “Because of these observations, I began conducting research on this unique species.”

The marbled murrelet is one of three species in its genus, but is the only one to live on the North American continent.

“They are cryptic, camouflaged and crepuscular—active primarily at dawn and dusk,” Nelson said via email. “I was excited to find a seabird in the forest so far from the coast—and fascinated to find out (what) little was known about its ecology despite being first described in the late 1700s.”

The significant lack of data that researchers have to track marbled murrelet populations presents a challenge.

Remarkably, Rivers said, this project has received broad support. Rivers and his fellow researchers have the support of the Dean of the College of Forestry, the state forest industry, conservation groups, the state legislature and local timber stakeholders

“People recognized that researching this bird and collecting information on it was beneficial to all in the long run,” Rivers said.

Ecosystem Impact

Tracking the marbled murrelet creates an opportunity for advocates and consumers alike to obtain important information to help create policy or conservation strategies.

Seabird ecology can show scientists clues about the environment the birds live in, and seabird patterns can show where the environment is thriving, if there is enough food, which prey type is most abundant and relative ocean pollution levels, according to Rob Suryan, a marine ornithologist associated with OSU but not with the project.

“We know this from many years of seabird field studies around the world. Some of the most important studies are those that have occurred for many decades and can evaluate changes over time,” Suryan said in an email.

Nesting success is directly linked to prey abundance, Suryan said. If there is a poor breeding season, it could be an indication that there is low food availability for the populations.

“This year was terrible for seabird nesting—and not just for murrelets: puffins, terns and murre colonies experienced collapses this spring. The key question is ‘what are they trying to tell us?’” Rivers said.

The alcid seabird family contains recognizable seabirds such as murres, guillemots, puffins, auklets and murrelets.

Rivers and his crew were able to tag and follow 61 murrelets during the 2017 season; however, none were detected nesting inland.

“Obviously, ocean conditions were not good enough for the birds to think they could support a new nest,” Rivers said. “Unlike the smaller birds I’ve worked with—chickadees, sparrows—seabirds don’t have to breed every year and can wait until there are enough food resources to raise their young.”

This follows the historical decline of marbled murrelet populations that researchers such as Rivers and Nelson have been observing.

“Murrelet populations are declining primarily because of habitat loss and habitat fragmentation.  Optimal nest sites are limiting,” Nelson said via email. “On top of limitations in their nesting habitat, they are affected by changes in prey availability and ever-increasing changes in the physical properties of the ocean due primarily to climate change.”

The more fragmented a forest habitat is, the less healthy the ecosystem becomes. This, in turn, results in the decline of optimal murrelet nesting habitat, Nelson said in an email. Habitat fragmentation occurs when large swaths of habitat are diminished to smaller isolated patches. This decays the natural ecosystem and isolates populations.

“Nests are subjected to predation from bird species such as corvids, ravens and jays, which raises the nest failure rate up to 60 to 70 percent,” Nelson said via email.

Research Procedures

Tagging and tracking murrelets requires researchers to follow populations as they breed, nest and migrate. This presents a number of logistical and circumstantial challenges to overcome.

“Our challenge this past field season was to show that we can successfully capture murrelets on the ocean, attach VHF radios and track their movements. The greatest challenge was the weather,” Nelson said via email.

In the spring season around April, researchers venture out into open ocean waters at night to collect and radio tag murrelets that indicate they are about to nest.

“They roost on top of the water and, if we are lucky, we can sneak up on them and scoop them up safely out of the water with a large net,” Rivers said.

After birds are tagged and released, they can be tracked using radio telemetry. The radio tags emit a high-frequency signal that can be detected by a special receiver, and researchers can hone in on the location of each tag. However, this requires researchers to fly above known murrelet nesting areas due to the limited range of the devices, according to Rivers.

“Sometimes it’s hard to find that signal being sent up, so we’ve also been using unmanned aerial vehicles (UAVs) to track thermal signatures and locate nests In theory, that should make it a little easier for us,” Rivers said.

“We hope to get a global positioning system (GPS) incorporated into the tracking tags.That’d be helpful because we’d be able to track the birds in real time,” said Matt Betts, a landscape ecologist also associated with the project. “We’d be able to create a better map of important behaviors such as foraging and nesting.”

After marbled murrelet pairs settle into their nests, researchers wait in anticipation for a photo of the adults, the nest or the hopeful egg. Researchers must be prepared to be patient and wait.

This is one of the behaviors that makes the marbled murrelet so difficult to study in the field, according to Rivers.

“If our opportunity to observe an adult visiting a nest in the early morning hours is missed, it creates a sort of bottleneck on our research because we have to continue returning to the nest site until we find the nest,” Rivers said.

If the nest is successful, the juvenile will fly to the coast in late September and join the adult birds on the water. There, the cycle begins again.

“Right now we are finishing up the last bits of fieldwork. The fall will be dedicated for data analysis and trying to make sense of the results we got from this season and gearing up for field work for 2018,” Rivers said in an email.