Kogiidae – Small sperm whales

These “small sperm whales” inhabit a wide range of the world’s oceans, favoring temperate and tropical waters. Despite their global distribution, sightings at sea are exceptionally rare, leading to a scenario where much of what we know about these species comes from the study of stranded individuals or those encountered by accident. This scarcity of direct observation has made the Kogiidae family a subject of considerable intrigue and speculation among marine biologists.

Until 1998, the distinction between pygmy and dwarf sperm whales was not fully recognized, leading to a conflation of their behavioral and biological characteristics. Though similar in appearance and ecology, they are now understood to be distinct species, each with its own patterns of behavior and distribution.

Dietarily, both pygmy and dwarf sperm whales share a preference for squid, mirroring the dietary habits of their larger relative, the sperm whale (Physeter macrocephalus). However, the prey of Kogiidae members tends to be smaller, aligning with their reduced size. Their hunting strategy involves utilizing echolocation to locate prey in the deep ocean, a skill facilitated by the spermaceti organ found in their heads, much like the larger sperm whale. This organ plays a critical role in focusing and projecting sound waves, allowing these whales to navigate and hunt in the profound depths where light does not penetrate.

A fascinating aspect of Kogiidae biology is the presence of magnetic crystals within their brains. Research suggests these crystals could provide the whales with an internal compass, aiding in navigation across the vast and featureless oceanic landscapes they inhabit. This ability to sense Earth’s magnetic field would be particularly beneficial during migrations or in locating feeding grounds that change location over time.