CURATED READING PATHS
Dolphins and porpoises
Compare familiar and less familiar dolphins and porpoises through visible markings, teeth, feeding, social behavior and location-specific evidence.
Compare familiar and less familiar dolphins and porpoises through visible markings, teeth, feeding, social behavior and location-specific evidence.
Animal profiles
Bottlenose dolphins: echolocation, social groups and distinct populations ↗
Common bottlenose dolphins use sound, flexible social groups, and locally varied feeding tactics across coastal and offshore habitats. Their familiar shape does not reveal a single population or behavior, and global species labels cannot substitute for local stock evidence.
Animal profiles
Orcas: why different populations eat different prey ↗
Orcas are oceanic dolphins whose prey choices vary among populations and regions. Residents, Bigg’s, and offshore forms illustrate the pattern in the North Pacific, while local specialization, learned calls, and evolving taxonomy caution against treating every orca as ecologically identical.
Animal profiles
Common dolphins: recognizing patterns and interpreting large groups ↗
Common dolphins are identified most reliably by the hourglass contrast along the flank, though age, viewing angle and long-beaked forms complicate recognition. Their large groups gather around prey-rich waters, but a surface view alone cannot establish group size or behavior.
Animal profiles
Spinner dolphins: spinning displays and daytime resting habitat ↗
Spinner dolphins are slender, long-rostrumed cetaceans known for leaps that may include several rotations. In Hawaiian island-associated populations, nighttime feeding and sheltered daytime rest are linked to prey movement and visual predator detection, though this routine is not universal.
Animal profiles
Risso’s dolphins: scars, teeth and a squid-focused diet ↗
Risso’s dolphins have a blunt, creased forehead, a tall curved dorsal fin and a distinctive shift from dark, lightly marked calves to often pale, scarred adults. Squid dominate reported diets, while scars and color remain imperfect clues to age or cause.
Animal profiles
Pacific white-sided dolphins: markings, movement and the North Pacific ↗
Pacific white-sided dolphins combine a robust body, short rostrum, conspicuous dorsal fin and pale flank stripes with a range spanning both sides of the temperate North Pacific. Their schooling-fish and squid diet, group behavior and identification limits help explain what a sighting can—and cannot—show.
Animal profiles
Hector’s dolphins: a small coastal dolphin with a rounded fin ↗
Hector’s dolphins are small New Zealand dolphins recognized by a rounded dorsal fin, short snout and gray, black and white markings. Geography helps distinguish the Hector’s and Māui subspecies, but appearance alone cannot reliably separate them; location, reporting details and, when needed, genetic evidence matter.
Animal profiles
Harbor porpoises: how porpoises differ from dolphins ↗
Harbor porpoises are small members of the porpoise family, with a blunt face, compact body and small triangular dorsal fin. Teeth, sound-producing anatomy, habitat and surfacing behavior help explain their differences from dolphins, while each field clue has limits and a brief sighting can undercount animals.