More difficult: before them was a pair of containers, one narrow, one broad. Sometimes the water level was the same, and with the stones to them, the birds could not get the worm in the narrow container. The winners of this test were entitled to the next, a cut above: the level was higher in the large bowl and only allowed to raise enough water. Excellent result. Of the four birds that have passed the first year, the following three succeeded.
Two pairs of U-tubes, with a similar to the previous image & nbsp ;: right device, the two are interdependent and therefore it is possible to raise the worm into the tube by dropping stones into the big one. The Plexiglas making visible mechanism, it is clear that the left, the worm will not be accessible. But for a corvid is too subtle reasoning. © 2014 Logan et al.
Two pairs of U-tubes, with a similar device to the previous image: right, both are integral and therefore it is possible to raise the worm into the tube by dropping stones into the big one. The Plexiglas making visible mechanism, it is clear that the left, the worm will not be accessible. enjoycoloring.com But for a corvid is too subtle reasoning. © 2014 Logan et al.
Two pairs of U-tubes, with a similar to the previous image & nbsp ;: right device, the two are interdependent and therefore it is possible to raise the worm into the tube by dropping stones into the big one. The Plexiglas making visible mechanism, it is clear that the left, the worm will not be accessible. But for a corvid is too subtle reasoning. © 2014 Logan et al.
Two pairs of U-tubes, with a similar device to the previous image: right, both are integral and therefore it is possible to raise the worm into the tube by dropping stones into the big one. The Plexiglas making visible mechanism, it is clear that the left, the worm will not be accessible. enjoycoloring.com But for a corvid is too subtle reasoning. © 2014 Logan et al.