Dolpin (12) Flashcards
(30 cards)
What is the largest dolphin species?
The orca, also known as the killer whale.
What is the maximum weight of an adult orca?
5,400 kilograms
- What is the smallest porpoise species?
- What other accolade does it hold?
- The vaquita, an incredibly stupid looking animal.
- It’s also one of the most endangered marine mammals on Earth.
What physical feature helps distinguish dolphins from porpoises?
Dolphins have prominent beaks; porpoises have rounded heads.
What shape are dolphins’ dorsal fins?
Curved and hook-shaped.
What shape are porpoises’ dorsal fins?
Triangular.
How do the teeth of dolphins differ from those of porpoises?
Dolphins’ teeth are pointed and cone-shaped; porpoises have spade-shaped teeth.
Are dolphins or porpoises generally longer and leaner?
Dolphins are generally longer and leaner than porpoises.
Which group of animals is thought to be less social, dolphins or porpoises?
Porpoises are thought to be less social than dolphins.
Do porpoises engage in blowhole whistling communication?
Scientists believe porpoises do not engage in this behaviour.
What is a possible reason porpoises do not whistle?
Structural differences in their blowholes.
Which species is more likely to approach boats, dolphins or porpoises?
Dolphins are more likely to approach boats.
What is the typical depth range for bottlenose dolphins when they’re inshore?
Less than 50m deep
What factors can segregate different bottlebose dolphin populations in the English Channel (2 Points)?
Genetic and social factors
Bottlenose dolphins tend to have strikingly limited _______.
Ranges
What can the four English Channel bottlenose dolphin ecotype groups be separated into?
Pelagic ecotype (found in shelf waters) and coastal ecotype
What type of populations do coastal ecotype bottlenose dolphins typically form?
The coastal ecotype forms small, discrete, and separate coastal populations.
True or False: The pelagic ecotype of bottlenose dolphins is found in small, discrete populations.
False - the pelagic ecotype occurs in large numbers, unlike the coastal ecotype.
What significant change in ambient noise levels did Ross estimate between 1950 and 1975?
An increase of 10 dB in areas where shipping noise dominates
The more powerful the engine of a vessel, the greater the amount of _______ it will produce.
sound (at least at low frequencies)
Are dolphins nice to each other when they’re ill?
Yes - if one dolphin is ill, then others will be nice to it :)
How do dolphins sleep?
Dolphins sleep with one eye open and one side of their brain active, allowing them to remain vigilant while resting.
How fast can bottlenose dolphins swim?
Up to 20mph!
What is the preferred habitat of humpbacks?
Waters over and along the edges of continental shelves and around some oceanic islands
