[MARMAM] New Publication

Chloe K chloe.kotik at gmail.com
Sat Aug 13 09:00:01 PDT 2022

Hello all,

My coauthors and I are pleased to announce the publication of our new

Kotik, C.,  Durban, J. W.,  Fearnbach, H., &  Barrett-Lennard, L. G. (2022).
  Morphometrics of mammal-eating killer whales from drone photogrammetry,
with comparison to sympatric fish-eating killer whales in the eastern North
Pacific. *Marine Mammal Science*,  1– 17. https://doi.org/10.1111/mms.12965

Aerial photogrammetry has provided increased power for monitoring the
health of individuals in the endangered population of Southern Resident
killer whales (SRKW, Orcinus orca) in the eastern North Pacific. These data
have shown evidence of nutritional stress, with individual growth and body
condition correlating with the availability of their primary prey, Chinook
salmon (Oncorhynchus tshawytscha). We used drones to derive similar but
novel photogrammetry measurements from a sympatric population of
mammal-eating Bigg's killer whales (BKWs) that has been increasing in
abundance in recent decades. From 2014 to 2019 we photographed 95
individual BKWs in Canadian waters off Vancouver Island and US waters in
the Salish Sea; we estimated asymptotic lengths of 6.4 m for adult females
and 7.3 m for adult males, both longer than corresponding length estimates
for SRKWs. As a proxy for body condition, we measured head width at a
standardized distance behind the blowhole, expressed as proportion of the
length between the blowhole and dorsal fin, and estimated that on average,
all age/sex classes of BKWs were more robust than corresponding classes of
SRKWs. These differences likely reflect divergent adaptive selection in
these prey-specialist ecotypes, but may also partially indicate recent
impacts of differential prey availability.

Please feel free to contact chloe.kotik at gmail.com for a PDF or any



Chloe Kotik, M.Sci
chloe.kotik at gmail.com
617 840 8184
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