The overall temperament of an animal-or, more broadly, of the species-can play a role in navigation too. There’s work showing that cattle, deer and voles tend to orient in a north-south direction.” “That may cue them into the magnetic direction in the ground. “There are some studies that show that the ears of most mammals contain iron,” Beaver says. That might point it to a circle that contains a familiar person or tree or restaurant trash can, and so on.Ĭats, like other animals, might rely more on magnetic fields-a faculty that could turn out to be quite common in mammals. A dog that wanders out of its own immediate range might pick up the scent of, say, a familiar dog in the next circle. “If the dog had walked both from and back to his home he’d be following his own scent trail.” In this case, the dog was instead probably following an equally compelling smell: that of its owner, a type of navigation that is entirely possible over long distances as long as the wind is right.ĭogs extend their scent range by moving among overlapping circles of familiar scents-much the way cell phone coverage relies on interconnected footprints from different cell towers. “An eleven-mile distance is actually not terribly long for a dog,” says Bonnie Beaver, the executive director of the American College of Veterinary Behaviorists and a professor at Texas A&M University. Dogs, no surprise, are very big on scent, and that can take them a very long way. Mammals-and particularly two of the species of mammals that humans love best: dogs and cats-have a range of ways to get around.
Later studies, however, found that those cells were related to the immune system, not navigation. Pigeons were thought to navigate the same way, especially since they have cells in their beaks that are heavy in iron. In one study of baby sea sea turtles, which typically migrate east after hatching, changing the orientation of magnetic generators around a swimming pool changed the direction in which the hatchlings swam too. Many more animals navigate via magnetism-orienting themselves along the north-south lines of Earth’s magnetic fields. Throw the switch and change the stars, however, and the little critter was completely flummoxed. As long as the artificial Milky Way was in view, the beetle and its dung ball rolled right along. While naturalists have not extensively tracked the species’ perambulations in the wild, they’ve studied them in-yes-planetariums. The same is true of the unglamorous dung beetle. As TIME has reported, seabirds are believed to steer mostly by the sun and the stars, since if the animals are ever going to get lost, it tends to happen when the skies are overcast. The kind of natural map any animal follows depends largely on the species.
0 kommentar(er)
