Mark Sloan – “What can stable isotopes tell us about the decline of Marbled Murrelets?”

Adult Marbled Murrelet in winter plumage - R & N Bowers/Vireo

Mark Sloan – “What can stable isotopes tell us about the decline of Marbled Murrelets?”
by Andrew Bryant, 25 Jan 2018.

Mark Sloan now works as  a “First Nations Relations Advisor” for the BC Government, but once upon a time he spent his days (and nights) capturing Marbled Murrelets at sea – for science!

These delightful robin-sized seabirds are noteworthy for a bunch or reasons.  Most of their population is found in B.C. (although they range from Californa to Alaska), where they’re considered “threatened” or “endangered”.  Most unusually, these seabirds nest in trees – specifically in big, tall trees typically associated with coastal old-growth forests.

Here in Powell River, we typically see murrelets in winter plumage, and rarely see them in their far more drab, brown breeding plumage.  Indeed, for decades their breeding habits remained unknown – the first nest was only discovered in 1974 – by a maintenance worker!

Mark’s was definitely a science talk, with hypotheses, statistical tests, graphs and definitions (what is “stable isotope analysisanyway?)
In a nutshell, what Mark’s team was trying to learn was whether breeding success of murrelets could be attributed to “how high on the food chain they were feeding”.  Their full paper is available here, but be forwarned…it’s hefty reading.

What I enjoy most about such talks is that science is indeed very much like a detective story.
Sometimes the data fit one’s hypothesis, the conclusions are straightforward, and all the loose ends get neatly tied up…

…and sometimes, as in this case, they don’t!