Duly Noted: Do Roe Deer Know North and South?

"Duly Noted" posts pass on information gathered from other sources.  This post was sparked by my reading Jason G. Goldman's summary of some research on the escape patterns of European roe deer that appeared in the October 2016 Scientific American.  I found his summary so interesting that I looked up and read the original article.

This research was funded by a grant from the Czech Republic and published as "Compass-controlled escape behavior in roe deer" by Petr Obleser, Vlastimil Hart, E. Pascal Malkemper, et al., in Behavioral Ecology and Sociobiology, 20: 1345 (August 2016). Roe deer graze in open fields and run away when they see humans, so these researchers deliberately spooked 188 groups of deer grazing in three different areas during April and August of 2014.  68 were males, 120 were females.  115 were singles; 45 were pairs; 19 were groups of three; 5 were groups of four; and 4 were groups of five. Rather than running directly away from the humans or toward the nearest cover, the roe deer preferred heading toward magnetic north or south.

This magnetic alignment was more pronounced in groups than in singles.  When an observer approached from the east or the west, the deer did not flee in the opposite direction, but northward or southward.  There are advantages in a herd fleeing in the same direction: individuals can escape without colliding with each other, and they can reassemble easily as a group once the perceived threat is over.  But that would be true for any direction the herd took--the question is, why did these deer so consistently escape to either the north or the south?  These researchers conclude that the deer might be able to detect the earth's magnetic field.

All kinds of questions immediately come to mind.  Is this behavior consistent in other seasons of the year?  In areas other than South Bohemia and West Moravia?  And if so, to what degree, if any, does it hold for other species of deer?

I confess I've never paid attention to the escape directions of the mule deer or whitetails that I've hunted, but I'm going to start.  If anyone else does the same and passes on the information, I'll be happy to post the results.  You can reach me at ghcox3@gmail.com.