(The Center Square) – Artificial intelligence analysis of data gathered by acoustic recording devices offers promise in monitoring the marbled murrelet and other difficult-to-study species, a research paper by Oregon State University and the U.S. Forest Service revealed.
“The threatened marbled murrelet is an iconic Pacific Northwest seabird that’s closely related to puffins and murres, but unlike those birds, murrelets raise their young as far as 60 miles inland in mature and old-growth forests,” a report about the study from Oregon State University said.
In other words, it’s a rare breed.
“There are very few species like it,” co-author Matt Betts of the OSU College of Forestry said in the report. “And there’s no other bird that feeds in the ocean and travels such long distances to inland nest sites. This behavior is super unusual and it makes studying this bird really challenging.”
Adam Duarte of the U.S. Forest Service’s Pacific Northwest Research Station led a research team that used data from acoustic recorders, initially placed to help monitor northern spotted owl populations at thousands of federally managed forest locations in the Oregon Coast Range and Washington’s Olympic Peninsula.
Researchers created a machine learning algorithm called a convolutional neural network to “mine the recordings for murrelet calls,” the report said.
The research, published in Ecological Indicators, was tested against known murrelet population data and found to be correct at a rate exceeding 90%. That means the recorders and AI can offer an accurate look at how many murrelets are calling in any given area, the report said.
“Next, we’re testing whether murrelet sounds can actually predict reproduction and occupancy in the species, but that is still a few steps off,” Betts said in the report.
The marbled murrelet is about the size of a dove. It spends most of its time in coastal waters searching for food. Examples of what it eats include krill, herring, anchovies, smelt, and capelin.
“Murrelets can only produce one offspring per year if the nest is successful, and their young require forage fish for proper growth and development,” the report said.
The birds usually lay a single egg high in a tree on a horizontal limb at least four inches in diameter. The main predators of murrelet nests include Steller’s jays, crows, and ravens.
On the West Coast, marbled murrelets are typically found from Santa Cruz, California, to the Aleutian Islands.
The species is considered threatened under the U.S. Endangered Species Act in California, Oregon, and Washington.
“The greatest number of detections in our study typically occurred where late-successional forest dominates and nearer to ocean habitats,” Duarte said in the report.
Late-successional means mature and old-growth forests.
“Our results offer considerable promise for species distribution modeling and long-term population monitoring for rare species,” Duarte said in the report. “Monitoring that’s far less labor intensive than nest searching via telemetry, ground-based nest searches or traditional audio/visual techniques.”
Joining Betts and Duarte in this study were Matthew Weldy of the College of Forestry; Zachary Ruff of the OSU College of Agricultural Sciences; Jonathon Valente, a former Oregon State postdoctoral researcher now at the U.S. Geological Survey; plus Damon Lesmeister and Julianna Jenkins of the Forest Service.
The Forest Service, the Bureau of Land Management, and the National Park Service funded this research.
