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Home , Atlantic spotted dolphin, Bottlenose dolphin, Oceanic dolphin, Porpoise, River dolphin

WHO IS WHO? DIFFERENCES BETWEEN & MONDAY

This week you’ll be looking at the traits that make dolphins different from porpoises (both of which are classified as cetaceans and toothed ).

Picture #1 shows a cetacean with an elongated face, or “beak”, and cone-shaped teeth. Picture #2 shows a cetacean with a blunt (flatter) face and spade-shaped teeth.

Who is who? Inspect the close-up photos below to determine who the is and who the is!

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Answer: These two traits (face shape and teeth shape) are the best ways to determine the difference between a dolphin and a porpoise. Photo #1 is an Atlantic . Photo #2 is a Harbor Porpoise. Dolphins tend to have cone-shaped teeth and a more elongated face, though there are some exceptions. Porpoise tend to have spade-shaped, or flatter teeth and blunter, rounded faces. WHO IS WHO? DIFFERENCES BETWEEN DOLPHINS & PORPOISES TUESDAY

Picture #1 shows a cetacean with triangular . Picture #2 shows a cetacean with a hooked, or curved, dorsal fin.

Who is who? Inspect the close-up photos below to determine who the dolphin is and who the porpoise is!

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PHOTO: AMANDA COLBERT PHOTO: ERIN GLESS

Answer: Picture #1 is a porpoise. Porpoises tend to have a triangular shape to their dorsal fins, though there are a few that don’t follow this particular rule. Picture #2 is a dolphin. Dolphins tend to have hooked, or curved dorsal fins, and some of them can grow quite large depending on the species! Since the dorsal fin is something that is commonly seen when these cetaceans come to the surface to breathe, these “field markers” (body parts) can help when trying to figure out if the you’re seeing is a dolphin or a porpoise. WHO IS WHO? DIFFERENCES BETWEEN DOLPHINS & PORPOISES WEDNESDAY

Picture #1 shows a cetacean with a stout, boxy body shape. Picture #2 shows a cetacean with a sleek, streamlined body shape.

Who is who? Inspect the close-up photos below to determine who the dolphin is and who the porpoise is!

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PHOTOS: NOAA FISHERIES

Answer: Picture #1 is a porpoise. Porpoises tend to be stouter than dolphins and have a boxier tendency to their spine/body shape. Picture #2 is a dolphin. Dolphins tend to be sleeker and more streamlined than porpoises. Body shape traits are not always visible or easy to figure out when seeing either kind of animal on the water, which is why considering beak/blunt face, teeth type, and dorsal fin shape and size will help more. For a fun way to search for information and photos of individual dolphin or porpoise species, use NOAA Fisheries “find a species” option, here: https://www.fisheries.noaa.gov/find-species WHO IS WHO? DIFFERENCES BETWEEN DOLPHINS & PORPOISES THURSDAY

Who is who?: There are 6 species of this type of cetacean. There are 38 oceanic species and 4 river species of this type of cetacean. The photos below show Harbor Porpoises and Common Dolphins “porpoising”. This behavior is commonly seen when these are chasing prey near the surface. In pursuit of their food, the animal breaks the surface in a forward-motion jump, moving quickly. The water is disturbed in a way that columns of spray come off the sides, or the tail, of the animal. Some species of porpoise and dolphins also enjoy “bow-riding” boats and tankers as they create a “wake”, or waves that come off the front of the boat.

PHOTO: RENEE BEITZEL

PHOTO: ERIN GLESS

Answer: The most up-to-date counts by scientists show that there are 6 species of porpoises, 38 species (which includes the orca), and 4 species of . However, classifying any animal is not an exact science. As scientists continue to study dolphins and porpoises, new information and discoveries will continue to be made. This sometimes causes one species to be split into two or more species. For more information and fun dolphin and porpoise facts check out WDC’s website: https://us.whales.org/whales-dolphins/how-many-species-of- dolphins-are-there/ WHO IS WHO? DIFFERENCES BETWEEN DOLPHINS & PORPOISES FRIDAY

Who is who? Most of my species make vocalizations that can be detected by the ear. Most of my species make vocalizations that cannot be detected by the human ear without slowing down or adjusting the “range” of the original recordings.

*To help the guesser choose who you think is who, click on the link to the sound files as clues (but don’t let them see the infographic or the name, just yet). One is a vocalization from a dolphin, the other is from a porpoise. Once you listen to both, determine who makes each sounds.

Dall’s porpoise (Phocoenoides dalli)

WEIGHT LIFESPAN Up to 440 pounds 15 to 20 LENGTH REGION 7 to 8 feet Alaska, West Coast

THREATS Entanglement in fishing gear, Hunting, Habitat alteration, Contaminants, noise.

INFOGRAPHIC: INTERNATIONAL COMMISSION INFOGRAPHIC: CREATED USING INFO & GRAPHICS FROM NOAA FISHERIES http://cetus.ucsd.edu/voicesinthesea_org/species/dolp http://cetus.ucsd.edu/voicesinthesea_org/species/porpoises/ hins/atlanticSpotted.html dalls.html

Answer: The clips that were played were from an Atlantic and a Dall’s Porpoise. The Dall’s recording was slowed down to 1/20th the original speed so that the gentle “clinking” sounds could be heard. This is because most porpoises’ vocalizations either happen so rapidly that we can’t hear them, or they make vocalizations in a higher or lower range than human ears are capable of hearing.

There are MANY more recordings of both whales and (seals, lions) for those who are interested in what vocalizations and noises these marine species can make! Check them out here: http://cetus.ucsd.edu/voicesinthesea_org/index.html