Q 01/05

How do resting spinner dolphins manage to keep swimming and surfacing for air while they sleep?

A) Podmates nudge them to the surface

B) Half the brain stays awake

C) Air sacs keep them afloat

D) Ocean currents carry them

Answer · why

B) Half the brain stays awake

Half the brain stays awake while the other half sleeps, so a resting spinner dolphin can still swim slowly and come up to breathe. A quiet school drif...

Q 02/05

Toxoplasmosis, a disease that has killed Hawaiian spinner dolphins, reaches the sea from which animal's droppings?

A) Cats

B) Rats

C) Pigs

D) Chickens

Answer · why

A) Cats

Cats shed the parasite's eggs in their droppings, and rain can wash them down to the coast. Fatal infections have been confirmed in spinner dolphins o...

Q 03/05

Which small shark leaves round crater scars on nearly every adult spinner dolphin off Hawaii?

A) Blacktip reef

B) Grey reef

C) Cookiecutter

D) Bonnethead

Answer · why

C) Cookiecutter

The cookiecutter shark gouges out round plugs of flesh, as if with a cookie cutter. Its bite marks have turned up on whales, big fish and even submari...

Q 04/05

Wartime sonar crews mistook the dense layer of sea life that spinner dolphins feed on for what?

A) A submarine

B) A shipwreck

C) A minefield

D) The seabed

Answer · why

D) The seabed

The seabed seemed to sit far too shallow and to rise after dark, so the layer became known as the false bottom. It is really millions of small animals...

Q 05/05

Off Oahu, how do night-hunting spinner dolphins bunch up their prey before pairs dart in to feed?

A) Circling it together

B) Blowing bubble nets

C) Slapping it with tails

D) Driving it onto beaches

Answer · why

A) Circling it together

Circling it together, the school packs its prey into a tight patch, and then a pair at a time swims through the middle to make a catch.