Counter-marking

Wilcox R. and Johnson R.E. (1995). Scent counter-marks specialised mechanisms of perception and response to odors in hamsters. J Comp Psychol 109, 349-356. 

Fig. 8.2 Mean response frequency or duration by (a-c) female, F, and (d-f) male, M, L. catta to conspecific glandular secretions, (a) F sniffing all odorants as a function of her reproductive state (breed > non F 3 =28.57, P =0.013 ). (b) F licking labial odorant as a function of the donors reproductive state (breed > non t =3.00, P= 0.58, n.s.). (c) F frequency and site-specificity of scent marking as a function of odorant type Fs counter marked the unscented dowel in response to scrotal scent, but over-marked scented dowels in response to labial scent (ti = 3.87, P =0.030 ). (d) M response as a function of odorant type (antebrachial was sniffed least = 6.75, P = 0.011 brachial was wrist marked most Fs = 7.16, P = 0.009 ). (e) M...

Johnston, R.E., Sorokin, E.S. and Ferkin, M.H. (1997b) Scent counter-marking by male meadow voles females prefer the top-scent male. Ethology 103, 443 53. 

Daumae, M. and Kimura, T. (1986). Analysis of urination pattern of male-male counter marking in mice. Zoological Society of Japan Tokyo), 3,1103. 

Johnston, R. E., Sorokin, E. S., and Ferkin, M. R, 1997, Scent counter-marking female meadow voles discriminate individual s marks and prefer top-scent males, Anim. Behav. 54 679-690. 

Johnston, R.E., Munver, R. Tung, C. 1995. Scent counter marks Selective memory for the top scent by golden hamsters. Anim. Behav., 49, 1435-1442. 

COMPETING COUNTER-MARKS AS SIGNALS OF COMPETITIVE QUALITY... 

According to our Competing Counter-marks hypothesis, both competitors and potential mates can assess the competitive ability of a territory owner, or an individual advertising its dominance, from the presence of competing counter-marks in a scent-marked area,... 

Animals who defend territories or dominate an area scent-marked exclusively by themselves should be preferred as mates over those whose territories contain counter-marks from competitors. 

Animals should prefer mates who have counter-marked any competitor scent marks over those whose scent marks are counter-marked by competitors. 

Territory owners or dominant individuals should scent mark their defended area to advertise their dominance and identity, and should counter-mark rapidly if they encounter any competing marks in their scent-marked area, or remove such marks. 

Attempts to remove a competitor s marks have been reported much less frequently (e.g. male oribi. Gosling 1972, 1985). This may be because a dominant individual is likely to gain an advantage from leaving a competitor s mark available for investigation and counter-marking it to show that it has overcome a challenge for dominance successfully, if potential mates are able to discriminate which individual s marks were deposited most recently (see below). 

Figure 2. Paired choices of male scent-marked territories presented to female house mice in estrous (see Rich Hurst 1998 for full details). Wild-caught adult male mice, housed in pairs of neighbouring enclosures separated by a mesh-capped tunnel, were each allowed to counter-mark floor tiles bearing scent marks from a non-neighbour male. Males were removed and floor tiles rearranged to create one territory marked exclusively by the owner and another containing some floor tiles (shown as hatched squares) marked by the owner and counter-marked by another male. In experiment 1 (a) the territories were otherwise identical. In experiment 2 (b and c), the physical protection surrounding the males nestbox was also varied. Protected nest sites were surrounded by the enclosure walls and house bricks and were partially covered with a lid. After opening the tunnel between territories, females were allowed to explore for 2h, then removed and given a choice between the body odors of the two territory owners, and finally interacted with each male within his territory.

Preference for Mates that Counter-Mark Competitors... 

Male hamsters discriminate between female vaginal secretions deposited 24h apart (Johnston Schmidt 1979) and meadow voles respond more strongly to fresh compared to one day old anogenital scents (Ferkin, Burda, O Connor Lee 1995), but age differences are not necessary for either hamsters (Johnston et al 1995) or meadow voles (Johnston et al. 1997b) to discriminate between scent marks and counter-marks if these physically overlap, at least in part. However, our preliminary experiments with wild house mice suggest that an age difference in scents is necessary for female mice to discriminate between the urinary scent marks and counter-marks of competing males. We found that females discriminated in... 

Animals might discriminate which mark physically overlies another, and thus must have been deposited more recently. Johnston (1995) suggests that they might either detect interruptions in the track of one animal s scent mark but not in the scent mark of the other animal, or perceive which scent is stronger in the area of overlap. For this mechanism to work, animals must deposit counter-marks so that they partially overlie those of their competitor. 

Johnston, R.E. 1995. Responses to individual signatures in scent counter-marks a striking new phenomenon. In Chemical Signals in Vertebrates 7 (Ed. by R. Apfelbach, D. Muller-Schwarze, K. Reutter E. Weiler), pp. 361—369. Oxford Elsevier Press. 

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