Marbled murrelets live between two worlds. They feed in the ocean but fly dozens of miles inland to nest on broad branches of old-growth trees in the Pacific Northwest.
That means chicks hidden high in the forest depend on fish their parents carry from the coast. When ocean conditions limit that food supply, the consequences reach the nest. Parents deliver fewer fish, and chicks take longer to leave the nest, giving predators more time to find them.
Oregon State University researchers are studying that connection. But first, they have to find the nests.
“Finding their nests is a bit of a needle in a haystack because they may be very far from the marine environment where we would typically see them,” said Jim Rivers, an associate professor and director of OSU’s Forest Animal Ecology Lab.
Researchers capture murrelets at sea at night and attach tracking tags. They use aircraft to follow the signals and locate nests inland, then climb nearby trees to install cameras.
The footage reveals what parents bring their chicks to eat and how often they deliver it. Pacific sand lance and fish in the smelt family accounted for more than 90% of the prey researchers identified in the study.
During years with poor ocean conditions, chicks received fewer fish each day and remained in their nests longer. This extended their exposure to predators such as common ravens and red-tailed hawks.
“The danger is a predator that might find it, come along and take it off of that nest,” Rivers said.
In particularly poor years, food shortages can keep murrelets from nesting at all, he said.
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- James Rivers, associate professor and director of the Forest Animal Ecology Lab, Oregon State University
