On behalf of my co-authors, I'm pleased to announce publication of our paper in* Marine Mammal Science*, entitled, *Quantifying spatial and temporal variation of North Pacific fin whale (Balaenoptera physalus) acoustic behavior* Frederick I. Archer, Shannon Rankin, Kathleen M. Stafford, Manuel Castellote, Julien Delarue https://doi.org/10.1111/mms.12640 *Abstract* In order to help develop hypotheses of connectivity among North Pacific fin whales, we examine recordings from 10 regions collected in the spring and fall. We develop a Random Forest model to classify fin whale note types that avoids manual note classification errors. We also present a method that objectively quantifies the note and pattern composition of recordings. We find that fin whale recordings near Hawaii have distinctive patterns, similar to those found in other regions in the central North Pacific, suggesting potential migration pathways. Our results are consistent with previous studies that suggest there may be two different populations utilizing the Chukchi Sea and central Aleutians in the fall and mix to some degree in the southern Bering Sea. Conversely, we found little difference between spring and fall recordings in the eastern Gulf of Alaska, suggesting some residency of whales in this region. This is likely due to fine scale similarities of calls among the inshore regions of British Columbia, while offshore areas are being utilized by whales traveling from various distant areas. This study shows how our novel approach to characterize recordings is an objective and informative way to standardize spatial and temporal comparisons of fin whale recordings. -- *Eric Archer, Ph.D.* Southwest Fisheries Science Center (NMFS/NOAA) 8901 La Jolla Shores Drive La Jolla, CA 92037 USA 858-546-7121 (work) 858-546-7003 (FAX) Marine Mammal Genetics Group: swfsc.noaa.gov/mmtd-mmgenetics GitHub: github.com/ericarcher Adjunct Professor, Marine Biology Scripps Institution of Oceanography University of California, San Diego http://profiles.ucsd.edu/frederick.archer " *The universe doesn't care what you believe. The wonderful thing about science is that it doesn't ask for your faith, it just asks for your eyes.*" - Randall Munroe "*Lighthouses are more helpful than churches.*" - Benjamin Franklin "*...but I'll take a GPS over either one.*" - John C. "Craig" George