Crocodiles are not necessarily considered to be intellectual overflows. For hours on the banks of the river, motionless, dive between them, and occasionally snap an imprudent Beutenier - they do not appear to be in stock at first sight.
"Most people think crocodiles are lethargic, stupid and dull," says Vladimir Dinets from the University of Tennessee in Knoxville. The zoologist, however, has gained quite a different impression in his research. He recently found out that at least two crocodile species rely on a sophisticated hunting technique, using their sticks to spoil their victims.
"Most people think crocodiles are lethargic, stupid and dull," says Vladimir Dinets from the University of Tennessee in Knoxville. The zoologist, however, has gained quite a different impression in his research. He recently found out that at least two crocodile species rely on a sophisticated hunting technique, using their sticks to spoil their victims.
Thus, the Panzerschsen belong to the rather small and exclusive circle of animals using tools - an ability which was considered typical humanly a few decades ago. And they are not the only reptiles with unimagined talents. Turtles and tigers have also been underestimated for a long time.
This is probably due to the fact that most behavioral researchers have traditionally concentrated on mammals or birds. When it came to spiritual talents, it seemed to be simply much more promising candidates.
Common intellectual heritage?
How that might look exactly, however, is difficult to say. Because for a comprehensive talent comparison, the capabilities of reptiles are simply not yet sufficiently investigated. There are countless studies on the use of mammals and birds. The spectrum ranges from chimps, which crack nuts with nuts, to crows poking with forks.
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Until recently, however, there was not a single reptile that would make everyday life easier with any kind of aid. Until Vladimir Dinets and his colleagues came across the falling crocodiles.
For the first time, the researcher observed the strange behavior of swamp crocodiles in India. For hours, the animals lay motionless in the shallow water of a pond and balanced small branches on their muzzle.
Only when a heron landed and stretched the beak after such a branch, life came into the scenery: Suddenly the crocodile snapped. An accident? Or had the reptile placed the branches deliberately on the snout to lure a feathered prey?
Stick as an effective bait
Vladimir Dinets decided to systematically get to the bottom of the matter. For a year he has supervised alligators who lived in different waters of Louisiana - sometimes with and without herons colonies in the neighborhood.
But do these animals actually play in a league other than crocodiles and co. After all, all reptiles, birds and mammals go back to a common ancestor who lived about 280 million years ago. There could be a common spiritual heritage.
How that might look exactly, however, is difficult to say. Because for a comprehensive talent comparison, the capabilities of reptiles are simply not yet sufficiently investigated. There are countless studies on the use of mammals and birds. The spectrum ranges from chimps, which crack nuts with nuts, to crows poking with forks.
display
Until recently, however, there was not a single reptile that would make everyday life easier with any kind of aid. Until Vladimir Dinets and his colleagues came across the falling crocodiles.
For the first time, the researcher observed the strange behavior of swamp crocodiles in India. For hours, the animals lay motionless in the shallow water of a pond and balanced small branches on their muzzle.
Only when a heron landed and stretched the beak after such a branch, life came into the scenery: Suddenly the crocodile snapped. An accident? Or had the reptile placed the branches deliberately on the snout to lure a feathered prey?
Nesting material is often scarce in heron colonies, so that a stick could be a very effective bait for such birds. This was also reflected in the experiences of long-term employees of a crocodile farm in Florida. The Mississippi alligators there also showed a soft spot for branches - and they also had success in the heron hunting.
Vladimir Dinets decided to systematically get to the bottom of the matter. For a year he has supervised alligators who lived in different waters of Louisiana - sometimes with and without herons colonies in the neighborhood.
The results were unambiguous: to carry sticks on their noses is apparently announced in alligator circles only to the heron brutzeit - especially in the nest building phase between March and April.
And the inhabitants of the bird colonies showed this behavior much more frequently than their colleagues in other sections of the body of water. The animals therefore seem to use not only tools, but their tuning even to the hunting season.
And the inhabitants of the bird colonies showed this behavior much more frequently than their colleagues in other sections of the body of water. The animals therefore seem to use not only tools, but their tuning even to the hunting season.
Congenital or learned behavior?
However, the researchers do not yet know whether it is an innate or learned behavior, a strategy developed individually by each animal, or a tradition passed down from generation to generation. "In any case, the results show how easily one can underestimate the intelligence even of well-known animals," says Vladimir Dinets.
Other behavioral researchers have also made this experience. For example, a popular animal intelligence test is to show them photos. Do the candidates understand what is to be seen? And do they recognize the difference between the image and the real object? A number of birds and mammals meet this challenging mental challenge.
But how would reptiles beat? A team from the University of Lincoln in the UK and the University of Vienna has tested this at South American charcoal turtles.
The researchers have given the reptiles the choice between a greasy and a non-greasy object. If they decided to eat it, they were allowed to eat it. As soon as the animals understood this connection, the scientists replaced the real objects with color photographs.
Turtles follow the companions
But this had little effect on the decision of the animals - they knew quite well, on which photo a tasty piece of fruit was to be seen and not.
The turtles came to their limits, however, when they were to decide between the picture and the real object. In these cases, they chose only the random principle. So you could not tell whether it was a real or a virtual treat.
In other tests, however, the animals have surprisingly performed well. So they willingly follow the eye of a fellow-fellow. If the light spot fixes on top of the wall, which they can not see themselves, they also look upwards in most cases.
This does not sound particularly spectacular. It can be very useful, however, to see where the companions look. Perhaps they have discovered an enemy or a food source. Many primates, but also goats and raven birds, are acting exactly according to this motto. Only in the wild they lead a much more sociable life than charcoal turtles.
Social learning works even in the case of singles
Why should these loners have a lot of interest in the direction of their peers? The researchers suspect that this behavior could be an heirloom of the common ancestor of reptiles, mammals and birds. It is possible that the loner turtles have kept it simple without much use.
However, the armored South Americans also proved in other attempts, that despite a tendency to self-sacrificing, one can successfully orientate oneself to his peers.
For example, when it is necessary to run an obstacle around to a feeding place. When they were on their own, all the animals tested failed on this task. If, on the other hand, they had observed a colleague who already knew the diversion, they reached the goal without problems - some even on the first attempt.
And they could even transfer their knowledge to new situations in which the obstacle, for example, had a different form. This is the first time that the researchers have shown that social learning works without a social and complex life