Australian Crocs: Home or Death!

[frigidmagi]

BBC

Three homesick crocodiles in Australia have shocked experts by returning hundreds of kilometres back to their homes after being relocated.

The discovery was made after tracking devices were attached to the reptiles.

Saltwater crocodiles caught near popular Australian beaches and rivers are often shipped to more remote areas.

But the policy of relocating rogue crocodiles will now be questioned - since it seems the animals have a well-developed homing instinct.

Researchers said the results of their study were "staggering".

"We often thought crocodiles tired very quickly but here we show very clearly that they are capable of moving long distances for days on end," added Professor Craig Franklin, from the University of Queensland.

One large croc was trapped on the west coast of Queensland's rugged Cape York Peninsula.

It was flown by helicopter to the east coast. Within three weeks it was back home, after a journey of more than 400km (250 miles).

The other crocodiles in the experiment did exactly the same. They were, according to one scientist, just like boomerangs.

Croc (Craig Franklin)
The homing capabilities of the crocs staggered the team
It is unclear, though, what enables the reptiles to navigate so skilfully.

Professor Franklin said crocodiles probably used many factors such as their position to the Sun, magnetic fields, sight, and smell to navigate.

"Crocodiles are more closely related to birds than they are any other reptile so they are possibly using navigation systems similar to birds," he added.

The Queensland professor paid tribute to the late naturalist Steve Irwin who was a major driving force behind the study. Irwin, famous for his appearances on TV with crocodiles, was killed in September 2006 when a stingray barb pierced his heart as he was filming an underwater documentary.

The long-distance estuarine crocs (Crocodylus porosus) are featured in a paper in the (Public Library of Science) PLoS ONE journal.

The project was a collaboration between the University of Queensland, Australia Zoo and Queensland Parks and Wildlife Service.

Some species seem to want to be made into luxury goods (CT explosion in 5...4...3)

[Cpl Kendall]

That's amazing.

[Mayabird]

Lots of animals have homing instincts. Sea turtles are able to return to the beaches where they were born to lay their eggs, and then swim back to their normal feeding waters thousands of miles away. Many seabirds fly around the world outside the breeding season and then return within yards of their usual nesting place during the breeding season. Heck, hummingbirds have been found to return to the exact same garden year after year after their migrations.

And for a most extreme example, there's a reason why the kanji symbol for "frog" is "home." I have a good friend who lives in a house with an atrium in the center, open to the sky. The atrium has a pond where two bullfrogs live. She tried to catch them and release them outside to a stream near her house, but only caught and relocated one. A few days later, she found a bullfrog waiting on her front step. She thought it was the one that she had not caught (and had decided to keep) which had somehow gotten out; she did keep the door open a lot. So she propped the door open and let it in, and it returned to the atrium. That's when she learned that it was the frog she had relocated in the first place. It came home.

[Comrade Tortoise]

This doesnt surprise me in the least. partially because there are a lot of studies that show that relocated animals basically find a way back home or die. The thing is, these animals have a home range that during their life time they dont leave. They know where everything is, hiding places, good places to wait for prey, sunny spots, shady spots, etc. More important, that spot is theirs. When they are relocated they have to fight for territory, and usually lose (there is a home court advantage in territorial fights). It only makes sense that they would evolve homing abilities.

[Batman]

Of course lots of animals have homing instincts. I take it from the article however that until those incidents, crocodiles were not assumed to be among them.

[Comrade Tortoise]

Of course lots of animals have homing instincts. I take it from the article however that until those incidents, crocodiles were not assumed to be among them.

I assumed they were...

[Batman]

Of course lots of animals have homing instincts. I take it from the article however that until those incidents, crocodiles were not assumed to be among them.

I assumed they were...

Then you're smarter than the people who did?

[Comrade Tortoise]

Of course lots of animals have homing instincts. I take it from the article however that until those incidents, crocodiles were not assumed to be among them.

I assumed they were...

Then you're smarter than the people who did?

No. I just know that the animals are territorial. It is a reasonable
inference that such animals can find their way back when relocated, especially when most other animals which have territories or small home ranges can do so. Relocation doesnt work, and that is evident to just about anyone who keeps up with the literature