The Outcome of a Previous Social Interaction with a Same‐sex Conspecific Affects the Behavior of Meadow Voles, Microtus pennsylvanicus

Abstract

In species where conspecifics compete for resources such as territories, remembering where a neighbor was previously encountered and the outcome of that interaction may give individuals advantages over nearby conspecifics. We used a two‐phase experiment to test the hypothesis that female meadow voles, Microtus pennsylvanicus, who during the breeding season are territorial and agonistic toward one another, can use details of an encounter with another female in one location to later navigate nearby areas. During the encounter phase, pairs of females interacted for two minutes in one isolated section of a Y‐maze; control females were placed in alone. Females were scored as either winners or losers. Winners displayed twice as many agonistic acts against their opponent. The test phase took place after a retention interval of one hour, 1 d, or 1 wk. Single females were returned to a clean and empty Y‐maze and allowed to explore the entire apparatus for 15 min. We recorded the amount of time spent in each section of the maze. After retention intervals of one hour and 7 d winners, losers, and controls spent similar amounts of time in each section. However, after 24 h, winners spent more time in the encounter section; losers and control females spent similar amounts of time in each section. The results suggest that meadow voles' memory of the details of a single encounter is influenced by the emotional valence attached to that event. The duration of memory may be associated with the establishment of territories by female meadow voles.

The response of rodents to scent marks: Four broad hypotheses

“…Taken together, these observations support Hypothesis 3. The particular response should represent a balance of the costs and benefits associated with that choice (Hobbs et al, 2012;Pierce et al, 2005;Vlautin and Ferkin, 2013;Zala et al, 2004), which supports Hypothesis 4. The response in question would have been modified over time through evolutionary pressures placed on individuals in that species (Roberts, 2007).…”

“…The findings also suggest that the response to the scent mark is influenced by the emotional valence attached to that event or scent donor by the receiver. Thus, the response to scent mark is not fixed and will also depend on the internal and external context that the receiver finds itself Vlautin and Ferkin, 2013). Roberts (2007) and Ferkin (2011) posited the view that the information contained or conveyed by a sender's scent marks should affect the responses of receivers in such a way as to optimize the survival and fitness of both the sender and the receiver.…”

“…This information also allows receivers to recollect the outcome of previous encounters with particular senders (Vlautin and Ferkin, 2012), which would affect their response when they encounter those scent marks again (Apfelback et al, 1991;Ferkin et al, 2008;Franklin and Ferkin et al, 2005). This flexible response to scent marks allows receivers to adjust their responses accordingly, depending on the identity of the sender, past associations and context (Hurst and Beynon, 2004;Kaur et al, 2014;Vlautin and Ferkin, 2013). Thus, the response chosen will be modulated by the receiver's ability and capacity for discrimination, categorization, judgments of relative numerousness, and recollection of the emotional valence attached to the event (Ferkin and Hobbs, 2014;Ferkin, 2006, 2008;.…”

Female meadow voles, Microtus pennsylvanicus, do not alter their over-marking in response to female conspecifics that were food deprived

“…Possession of a territory increases the fitness and survival of female voles and other small female mammals (Wolff 1993). By over-marking the scent marks of other females at relatively high and similar rates, FD and AL females could signal their residency in a territory and thereby reduce intrusions by neighboring females and costly encounters with wandering female conspecifics (Ferkin and Seamon 1987; Vlautin and Ferkin 2013). Another interpretation is that by over-marking the scent marks of other females, the top-scent FD and AL females may be more likely to indicate to nearby conspecifics that this territory is occupied (Johnston 2003; Hurst and Beynon 2004; Ferkin et al 2004), In this way, both FD and AL female voles may also benefit from having similar rates of scent marking and over-marking to attract nearby males as mates.…”