Study
Killer whale predation on sperm whales: observations and implications
Pitman, Robert L.; Ballance, Lisa T.; Mesnick, Sarah I.; Chivers, Susan J.
Marine Mammal Science, 2001
Direct observation and review of recorded encounters in which killer whales attacked sperm whales, documenting group sizes, attack structure and the defensive formations the sperm whales adopted.
- Studied in
- Orcinus orca, Physeter macrocephalus
- Sample size
- documented predation events and encounter records
Killer whales attacked in coordinated groups, and sperm whales responded with a defensive rosette — heads inward, tails outward — that appeared effective. Successful kills were rare and required sustained group effort.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Killer whale predation on large whales is real but costly, and shapes the defensive behaviour of the prey species.
How NatureHQ reads it
Useful because it corrects two things at once. Killer whales are not casually killing large whales — the events are rare and hard-won — and the prey are not passive, but running an organised counter-strategy. The popular framing of orcas as effortless apex predators does not survive the actual encounter records.
- Opportunistic observation of rare events; encounter rates are not a measure of frequency.
- Outcomes of many observed attacks were not seen through to a conclusion.
- Concentrated in regions with high observer effort.
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Published by: Wiley journalsPublished in a Wiley journal.
doi.org/10.1111/j.1748-7692.2001.tb01000.x
This reference was resolved automatically against Crossref and OpenAlex on 2026-08-11.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-09.