Fernando Alvarez and Eduardo Aguilera
Fernando Alvarez and Ignacio Winfield
José Villalobos and Fernando Alvarez
Luis Mejía-Ortíz and Fernando Alvarez
Francisco Braza, Fernando Alvarez and Alberto Norzagaray
The rump patch of the Fallow Deer shows different visual patterns according to the activities performed by the animals. While in calm conditions the black tail sways over the white anal field; if in alarm, the tail hangs still, dividing the white field into two parts ; in higher stress the tail tends to be raised to a horizontal position, leaving the white anal field unbroken and outlined by the two lateral black stripes; if danger is impeding the tail gets erect, showing the white underside, now seen as an extension of the white anal field, or may even go up and down, the white brush of the tail appearing and disappearing On the basis of our results on the use of the rump patch and on the frequency of defecation (high in conditions of stress) and considering that the posture of the tail during defecation is one of the most frequently observed in alarm, we hypothesize that when defecation turned to function as a communicative signal of danger, a new selective force came into play, increasing the amplitude of the movements and originating the visual pattern of the rump patch that makes them more evident.