Food Deprivation Suppresses a Preference for the Top‐Scent Mark of an Over‐Mark in Meadow Voles (Microtus pennsylvanicus)

Abstract

Food availability affects whether mammals communicate their interest in interacting with opposite‐sex conspecifics. This study examined the responses of voles to over‐marks, and factors that influence the formation and maintenance of a preference for the top‐scent in an over‐mark. Specifically, we investigated how food deprivation affected the amount of time male and female voles exposed to an over‐mark, later responded to the marks of the top‐ and bottom‐scent donors when subsequently presented with the two scents side by side. Males and females that were not food deprived and males that were food deprived 6 h before exposure to an over‐mark later maintained a preference for the donor of the top‐scent mark compared with the donor of the bottom‐scent mark of the over‐mark. Females that were food deprived for 6 h before or after exposure of the over‐mark and males food deprived 6 h after the exposure to the over‐mark showed no preference for the top‐scent mark donor. Re‐feeding females that were food deprived for 6 h before exposure to an over‐mark was sufficient to restore their preference for the mark of the top‐scent male over that of the bottom‐scent male. The different responses of food‐deprived male and female voles to over‐marks of opposite‐sex conspecifics may be associated with differences in their tactics for interacting with potential mates and the higher energetic costs of reproduction in female voles than in male voles.

Dietary protein content affects the response of meadow voles, Microtus pennsylvanicus, to over-marks

“…One possible explanation for this finding is that voles fed a 9% and 13% protein diet are no longer able to discriminate between the top-and bottomscent marks of a same-sex over-mark. Meadow voles that were exposed to an over-mark and then food-deprived for 6 h could not discriminate between the top-and bottomscent marks of a same-sex over-mark (Pierce et al 2007b). Likewise, rats fed a ketogenic diet, a high-fat, lowcarbohydrate, and low-protein diet, suffered severe impairments in discriminations involving visual-spatial memory (Zhao et al 2004).…”

“…Our testing methods were similar to those detailed in other studies of over-marking in voles (Ferkin et al 1999Woodward et al 2000;Leonard et al 2001;Pierce et al 2007b). Our design involved two phases, the exposure phase and testing phase, both of which took place in the subjects' home cages.…”

“…Thus, the diet and subsequent quality of the receiver affect how it responds to the signals of opposite-sex conspecifics (Ferkin et al 1997;Fisher and Rosenthal 2006;Hobbs et al 2008). In addition, the diet and subsequent quality of the sender affect how opposite-sex conspecifics respond to its signals (Wade and Schneider 1992;Ferkin et al 1997;Gill and Rissman 1997;Jones and Wade 2002;Pierce et al 2007b;Hobbs et al 2008). In many species, traits used by males to attract or indicate interest in females are influenced by dietary components such as dietary protein (Ferkin et al 1997;Droney 1998;McGlothlin et al 2007;Hobbs et al 2008), calcium (McGraw 2007), vitamin D (Martin and Lopez 2006), and carotenoids (Kodric-Brown 1985;Hill 1991Hill , 1992, with females responding preferentially to males fed diets high in these substances.…”

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

“…There is no direct support for this speculation. However, female voles that were food derived for 6 hours no longer displayed a preference for the top-scent mark donor of a male-male over-mark -a preference that was displayed by females that were not food deprived (Pierce et al 2007). A second possibility is that female meadow voles cannot detect differences or choose not to respond to scent marks of female conspecifics that differ in their nutritional status.…”

The importance of chemical communication studies to mammalian conservation biology: A review

“…Scent can provide an indication of both infection 16 and the activation of the immune system , therefore individuals may refuse to settle in areas where odours of conspecifics indicate poor health or a lack of resources. Meadow voles (M. pennsylvanicus) discriminate between food deprived conspecifics through odour cues (Pierce et al, 2007). Female rodents can discriminate between infected and non-infected males, finding infected male scent less attractive (e.g.…”