The presence of crater-like wounds on cetaceans and other large marine vertebrates and
invertebrates has been attributed to various organisms. We review the evidence for the
identity of the biting agent responsible for crater wounds on large whales, using data collected
from sei (Balaenoptera borealis), fin (B. physalus), inshore and offshore Bryde’s (B.
brydeii sp) and sperm whales (Physeter macrocephalus) examined at the Donkergat whaling
station, Saldanha Bay, South Africa between March and October 1963. We then analyse
the intensity and trends in its predation on large whales. Despite the scarcity of local
records, we conclude that a cookie-cutter shark Isistius sp is the most likely candidate. We
make inferences about the trends in (1) total counts of unhealed bitemarks, and (2) the proportion
of unhealed bitemarks that were recent. We use day of the year; reproductive class,
social grouping or sex; depth interval and body length as candidate covariates. The models
with highest support for total counts of unhealed bitemarks involve the day of the year in all
species. Depth was an important predictor in all species except offshore Bryde’s whales.
Models for the proportion of recent bites were only informative for sei and fin whales. We
conclude that temporal scarring patterns support what is currently hypothesized about the
distribution and movements of these whale species, given that Isistius does not occur in the
Antarctic and has an oceanic habitat. The incidence of fresh bites confirms the presence of
Isistius in the region. The lower numbers of unhealed bites on medium-sized sperm whales
suggests that this group spends more time outside the area in which bites are incurred, providing
a clue to one of the biggest gaps in our understanding of the movements of mature
and maturing sperm males.