Biologist Mark Norman found octopuses (octopi?) off the coast of Indonesia that use split open coconut shells as hiding places. This is the first known tool use by an invertebrate animal:
An octopus would dig up the two halves of a coconut shell, then use them as protective shielding when stopping in exposed areas or when resting in sediment.
This, on its own, astonished the team. Then they noticed that the octopuses, after using the coconut shells, would arrange them neatly below the centers of their bodies and "walk" around with the shells—awkwardly.
It's uncertain whether these were African or European coconuts. Video at the link.
Link | Photo: Roger Steene
Comments (28)
The M is for Man-eating.
Lisa: But isn't that a bit short-sighted? What happens when we're
overrun by lizards?
Skinner: No problem. We simply release wave after wave of Chinese
needle snakes. They'll wipe out the lizards.
Lisa: But aren't the snakes even worse?
Skinner: Yes, but we're prepared for that. We've lined up a fabulous
type of gorilla that thrives on snake meat.
Lisa: But then we're stuck with gorillas!
Skinner: No, that's the beautiful part. When wintertime rolls around,
the gorillas simply freeze to death.
When a new species is introduced to an area, it can often make an easy living. Organisms that are not a problem in the area in which they evolved can overrun the natives when they find themselves in new locations. They have an easy time of it, squeeze out native species, and breed like crazy.
Eventually however, the presence of these invaders who become so plentiful becomes an opportunity for another species, one that preys on the invader. The predator might itself be an introduced species, or it might be an existing organism that has adapted and stepped up to the task/free lunch offered by the invasive species.
Yes, over time, these things have a way of working themselves out. But the span of time required can be longer that is convenient for human activities. And certainly much diversity is lost along the way.
Humans have been responsible for the introduction of so many organisms into new locations. Sometimes it is intentional, like the cane toads. Sometimes introductions are a by-product of other activities such as Eurasian plants brought to the Americas as seed in animal fodder or larval stages of marine organisms in ballast tanks.
In most cases, we've lost diversity, a lot of diversity. The case of the cane toads is a rare one in that people pay attention to it. They don't so much notice the difference in the assemblage of weeds in roadside ditches, or the loss of native bee species.
It's a pity. Sadly it is rather inevitable.