A dark, round-headed small whale that forms large groups in tropical seas.
It has no obvious beak, a relatively large dorsal fin and flippers that taper to pointed tips.
Three melon-headed whales tagged around Hawaiʻi changed how deeply they dived between day and night. In West and colleagues’ study, the whales used shallower water by day; at night, median maximum dive depths were about 220–248 m. Each of the three tagged animals averaged dives more than four times deeper at night, and the two Kohala residents increased dive rates at dusk.
Stomach samples, examined separately, contained a diverse range of squid and fish, including lanternfishes. The pattern suggests that whales shift through the water column as deep-water prey move upward after dark. Yet the tag result comes from only three whales, and researchers did not observe prey capture on every dive. A small Hawaiian sample cannot define the behavior of melon-headed whales worldwide.
IUCN Red List · Least Concern (LC) · Global species-level assessment
The 2019 global IUCN assessment lists the Melon-headed Whale as Least Concern (LC), assessed on 14 February 2019. Its broad tropical and subtropical distribution and the absence of evidence for major threats causing a global decline supported that category; the global population trend is recorded as Unknown. Least Concern is not evidence that the species is increasing.