Strange discoveries: cow magnetism and magpie self-identity

Humans have observed other animals for hundreds of thousands of years. Yet research with some of our familiar fellow creatures continues to reveal unsuspected talents. Two such discoveries reported last month make the point. They also highlight the fact that evolution has developed a variety of common traits in a wide range of species.

A German-Czech team has shown that cattle and deer have an unsuspected magnetic sense that lets them line up with the north-south direction of Earth’s magnetic field. The scientists note that it’s amazing that “this ubiquitous phenomenon does not seem to have been noticed by herdsmen, ranchers, or hunters.”

Another German research team has made the equally surprising discovery that magpies have a sense of self-recognition when looking in a mirror. Until now, this characteristic “human” capability has been seen clearly only in apes, though also, as the team notes, “at least suggestively in dolphins and elephants.” It also notes that the magpie findings “suggest that essential components of human self-recognition have evolved independently in different vertebrate classes with a separate evolutionary history.”

Helmut Prior at Germany’s Goethe University in Frankfurt and colleagues described the magpie experiments in the August issue of PLoS Biology. The birds were given distinctive marks they could not see directly but could see in the mirror. The way a bird dealt with the spot or other marking by scratching or removing it showed it saw the mirror image as reflecting itself and not simply as being another bird.

While the scientists conclude that their finding shows “that elaborate cognitive skills arose independently” in birds and mammals, they warn against reading too much into that implication.

“We do not claim that the findings demonstrate a level of self-consciousness or self-reflection typical of humans,” they say.

Discovery of a magnetic “sixth sense” in deer and cattle has a different broad implication. Many life forms as diverse as birds and bacteria have it. They use it primarily for navigation. But it is surprising to find it in pastoral cattle and foraging deer who do not appear to need such a navigational aid, as Sabine Begall at Germany’s University of Duisburg-Essen and colleagues note in their report last month in the Proceedings of the (US) National Academy of Sciences.

Yet the animals regularly align their bodies in roughly a magnetic north-south direction when grazing or resting.

Why they do it is a mystery. They scientists note that “our findings open horizons for the study of magneto-reception in general and are of potential significance” for animal husbandry and welfare.

They add that the findings challenge neuroscientists and biophysicists to explain how this magnetic “sixth sense” works.

The findings are based on field observations of 2,974 deer in 241 locations in the Czech Republic and satellite images of 8,510 cattle in 308 pastures and plains around the world seen through the computer program Google Earth.

The scientists ruled out the direction of wind and sunlight as reasons for the animals’ consistent north-south orientation because these varied widely in the different locations. That left magnetic alignment as what the scientists call “the most parsimonious explanation.”

Our animal companions probably have more undiscovered talents. Some of them may give insight into humanity’s own evolution as part of life on Earth.