Over‐marking and Adjacent Marking are Influenced by Sibship in Male Prairie Voles, Microtus ochrogaster

Abstract

Ferkin. M. H 1999 Over-marking and adjacent marking are influenced by sibship in male prairie voles, Microfus ochrogusfer. Ethology 105, 1-1 1. AbstractScent over-marking occurs when an animal deposits its scent mark on top of the scent mark of a conspecific. Over-marking may provide advantages in the transfer of information to the individual whose scent is on top but not to the individual whose scent is on the bottom. We tested the hypothesis that over-marking is a competitive form of olfactory communication and that male prairie voles would over-mark the scent marks of same-sex conspecifics more than those of same-sex siblings. Two agematched male voles (first male and second male) were placed successively into an arena in which they were allowed to explore freely and scent mark for 15 min at age 12.20, 28, 36,44, and 52 d. The first male was placed into a clean arena, whereas the second male was placed into an arena containing either the scent marks of an age-matched male sibling or nonsibling. Age affected the total number of scent marks deposited by the voles; 12-20-d-old voles deposited fewer scent marks, over-marks and adjacent marks than did 28-52-d-old voles. Sibship did not affect the total number of scent marks deposited by the first and second voles but did affect the number of over-marks and adjacent marks deposited by the second vole. Siblings received significantly fewer over-marks and adjacent marks than did nonsiblings; this effect was most dramatic after the voles reached 28d of age, a time coincident with the onset of puberty. Males separated from siblings and housed singly at 44-d-old and tested at 52-d-old, deposited significantly more over-marks and adjacent marks in arenas if the first vole was a nonsibling than if it was a sibling. This differential scent-marking supports the hypothesis that over-marking and adjacent marking are used as competitive forms of olfactory communication by male prairie voles.

Meadow voles and prairie voles differ in the percentage of conspecific marks they over-mark

“…They found that male and female prairie voles avoid over-marking the scent marks of male conspecifics (Thomas and Kaczmarek 2002;Thomas and Wolff 2002;Wolff et al 2002). Interestingly, other studies on prairie voles, and those on meadow voles and golden hamsters indicate that they do not avoid over-marking the scent marks of same-sex and opposite-sex conspecifics (this study; Johnston et al 1997a;Ferkin 1999a;Kohli and Ferkin 1999;Johnston 2001;Ferkin et al 2004). Differences in the results between those studies and those of Thomas and co-workers may be traced to differences in methods.…”

“…Our data suggest that for male voles over-marking may be an incidental by-product of scent marking in areas marked by unfamiliar and unrelated male conspecifics. Interestingly, male prairie voles over-mark a greater percentage of the scent marks of unfamiliar male conspecifics than they do those of their male siblings (Kohli and Ferkin 1999). This observation suggests that male prairie voles can identify the scent marks of their brother siblings and avoid over-marking them.…”

“…This observation suggests that male prairie voles can identify the scent marks of their brother siblings and avoid over-marking them. In that female voles prefer the mark of the top-scent male to that of the bottom-scent male (Johnston et al 1997a,b;Ferkin et al 1999;Woodward et al 1999), male prairie voles may reduce competition with their brothers by not over-marking their scent marks (Kohli and Ferkin 1999). Over-marking appears to be involved in same-sex competition among male Mongolian gerbils, Meriones unguiculatus (Biben 1980), golden hamsters (Johnston et al 1995;Johnston 2001), house mice, Mus domesticus (Hurst 1990a;Rich and Hurst 1999), and canids (Macdonald 1980).…”

“…Carnivores (Macdonald 1980), ungulates (Gosling 1985), primates (Heymann 1998), and captive rodents (Biben 1980;Rozenfeld et al 1987;Johnston et al 1994Johnston et al , 1997aKohli and Ferkin 1999) over-mark the scent marks of conspecifics. Most of the research on over-marking, however, has been directed at the responses of individuals to over-marks of conspecifics.…”

Perspectives on over-marking: is it good to be on top?

“…Another prediction is that individuals over-mark the scent marks of same-sex competitors more than those of other same-sex conspecifics. For example, they may over-mark a greater proportion of scent marks of unfamiliar same-sex conspecifics than those of familiar siblings (Kohli and Ferkin 1999). Direct and indirect support for the competition hypothesis comes from studies on meadow voles, prairie voles, tree shrews, sifakas, golden hamsters, house mice, dogs, Mongolian gerbils, moustached tamarins, deer, bilbies, grey wolves, honey badgers, ring-tailed lemurs, bank voles, and African antelopes (Johnson and Johnson 1983;Mertl-Millhollen et al 1986;Rozenfeld et al 1987;Hurst 1990a, b;Smith and Abbott 1999;Ferkin et al 2004a;Palagi et al 2004;Lewis 2005).…”