Next on Jonathan Bird's Blue World: Sharks that east something disgusting!
Ahh, Hawaii.
With its beautiful beaches and warm weather, few would argue that Hawaii is one of the
nicest places in the world to visit.
But you know me, I won't be sitting on the beach getting a tan.
I have come to Hawaii to investigate a marine mystery involving a whale and a shark.
Hi I'm Jonathan Bird and welcome to my world!
Pods of Pilot whales live in the waters around the Big Island of Hawaii.
And sometimes they have Oceanic white tip sharks following behind them.
Nobody knows why the sharks follow the whales, but I'd like to see if I can get to the bottom
of this mystery.
My journey begins with my friend Drew Bradley who has a 25 foot boat and knows how to find
the whales.
We load the boat at 7 AM and set out in search of whales.
Pilot whales are not large.
They only reach about 20 feet long.
To find them, we cruise around in the waters about a mile offshore and look for their dorsal
fins.
Sometimes this can take a few hours before we find the whales.
What's that about 1 o'clock?
We have found some whales, so now we have to see if we can get close to them without
spooking them away.
Pilot whales like to keep to themselves.
They aren't particularly curious about people, so they often take off when we try to move
in.
This small pod seems to be moving along slowly.
I'll try to get into the water with them and see if they have a shark following them.
As I slip into the water, all I can see is blue.
I wait patiently to see if they will come to me.
They pass by me, never coming too close.
Getting any decent shots of the whales underwater is tough.
After the whales pass, I keep looking for a shark, but there isn't one.
Apparently not every pod of pilot whales has a shark following behind.
So, it's off to find another pod of pilot whales.
We don't find one immediately, but we do come across a large pod of melon-headed whales.
These small whales look a lot more like dolphins than whales, except they have a funny flat
face.
They love to play in the bow wave of the boat just like dolphins.
After the melon-headed whales get bored and swim away, we finally find another pod of
pilot whales.
This is a big pod and I hope they will have a shark or two swimming with them.
I get into the water again and slowly swim towards the whales.
They seem to be relaxing in the water, just floating.
Pilot whales feed in the deep, far below, and they often rest for a while between dives.
This pair is spy-hopping—a behavior where the whales float vertically and stick their
heads out of the water to take a look above the surface.
They might be curious about our boat.
Suddenly I can hear squeaking and clicking.
The big pod of melon-headed whales has come over to play with the pilot whales!
I had no idea that pilot whales and melon-headed whales like to hang out together.
It looks like the melon-headed whales like to buzz the pilot whales and taunt them, as
if they are asking them to join the fun.
For the most part, only the juvenile pilot whales join in the action.
The adults just float and watch, keeping an eye out for trouble.
But the younger pilot whales chase and play with the melon-headed whales.
Then, in the middle of the action, a female Oceanic White tip shark cruises through the
middle, not interested in the fun and games.
The shark is all business.
But, what business?
The Oceanic White tip is supposedly one of the most aggressive sharks in the world.
Divers are urged to be very careful when an Oceanic White tip is in the area.
The shark is accompanied by a pilotfish.
This striped fish gets its name from the fact that people used to think the shark would
follow the fish to food as if the fish was piloting the shark.
Now we know this isn't true.
The fish is just a moocher that gets a free meal from the shark's messy eating habits.
The shark also has an old fishing hook stuck in her mouth.
This shark was lucky.
The fisherman cut the line and released her.
She takes a few close passes by me, then turns and rushes up to my camera.
This seems like aggressive behavior, but I don't think it is.
Oceanic White tip sharks live in the open ocean where there is very little food.
Sharks can sense electrical currents in the water generated by the muscles of fish.
This is one of the ways they find food.
Video cameras make electrical currents too, just like fish.
Coming close and bumping the camera is the only way the shark can figure out that the
camera is not food.
Once she realizes that the camera isn't food, she is no longer aggressive.
In fact, she is pretty mellow.
Oceanic White tips are supposed to be really dangerous, but look: this shark lets me pet
her.
Soon she starts to lose interest in me because she is hungry and I'm not food.
To get her to stick around, Drew throws some pieces of fish in the water as a snack.
This is a clue that tells me a lot about the relationship between the shark and the whales.
If the shark will leave the whales for food, that means that the shark probably stays with
the whales for food.
Since the whales are much too large for the shark to eat, they must somehow provide the
shark with food.
But how?
One theory suggests that the shark mooches food from the whales, just like the pilot
fish mooches it from the shark.
Another theory suggests that the shark uses the whales as moving camouflage to hide behind,
so it can sneak up on fish.
But I saw something that gives me another idea what the sharks are doing.
This is a new theory that I have never heard before.
I saw a shark eat the fecal material of a whale.
Yes, you heard me right, the shark ate whale poop.
It's very possible that a shark follows a pod of whales surviving on whale poop until
the shark comes across something better, like Drew throwing chunks of bait off the back
of his boat.
It's also possible that the shark uses a combination of these techniques to survive.
One thing is for sure, the shark is happy to leave the whales if something yummy comes
along, so the shark is clearly opportunistic—looking for a meal and open to options.
My incredible few days swimming with the pilot whales and the sharks was the experience of
a lifetime, something I will never forget.
And once again it showed me that sharks are amazing animals with all kinds of mysterious
behavior, not just eating machines.
It leaves me with many more questions than answers about the relationship between the
shark and the whales, but I learned one thing about Oceanic white tip sharks.
If they are hungry enough, even whale poop is better food than nothing!