Experimental Evidence of Spatial Memory and Home Range Affinity in White-tailed Deer (Odocoileus virginianus)

Introduction The role of spatial memory in how animals move through landscapes remains elusive and its quantification challenging (Moorcroft 2012; Spencer 2012; Fagan et al. 2013). Memory effects in the spatial ecology of animals were postulated in the earliest observations of the movements of individual animals and were eventually confirmed with the development of radio-tracking technology (M]oorcroft 2012). With parallel advances in cognitive sciences and statistical analyses of animal movements, the influence of spatial memory is increasingly being recognized and incorporated into mathematical models of animal movement (Gautestad and Mysterud 2005; Borger et al. 2008; Gautestad 2011; Moorcroft 2012; Spencer 2012; Gautestad et al. 2013). Because spatial memory is an internal cognitive pro cess, movements based on memory may be directed toward space beyond an animal’s current field of perception (Gautestad and Mysterud 2005; Moorcroft 2012; Fagan et al. 2013). Thus, to distinguish memorybased movements from movements elicited by the im mediate external environment requires experimental manipulation (Moorcroft 2012). However, the spatial memory that animals possess before experimentation begins is unknown to researchers. Fagen et al. (2013) suggest one solution to this problem is tracking the spatial dynamics of juveniles throughout ontogeny to obtain complete movement histories before experimentation. They further suggest translocating these animals to novel environments, which may help identify movements influenced by previous spatial memories. The movements of adult female White-tailed Deer (Odocoileus virginianus) and their fawns in northeastern Minnesota indicated that spatial memories developed by fawns following their mothers was a primary influence on their adult home-range locations, seasonal migrations, and landscape distribution (Nelson and Mech 1981, 1987, 1999, 2006; Nelson 1994, 1998). Further evidence of spatial memory was inferred from a pilot study in which adult females and fawns were translocated to unfamiliar areas (Nelson 1994). Some deer returned to their home ranges and resumed their previous movement patterns, while others did not return, but mimicked their pre-translocation movements near their release sites. Traditional movements and home-range affinity not only suggest the capacity for spatial memory, but also imply a fitness advantage of the propensity to occupy familiar space. To collect experimental evidence of this capacity and propensity, I delineated the home ranges Experimental Evidence of Spatial Memory and Home Range Affinity in White-tailed Deer (Odocoileus virginianus)