Scent marking beaver

Beaver scent marking. Top Beaver approaches, then sniffs the experimental scent mound. Middle Beaver scratches experimental scent mound with forepaws, then straddles and marks it. Bottom Beaver leaves the scent mound and swims away... 

Recently, Rosell and Sundsdal [78] tentatively identified 21 of the 43 constituents present in 96 scent marks deposited directly on snow or ice mounds by the Eurasian beaver, C. fiber. In this study, a higher final oven temperature was employed and several steroids were eluted from the capillary column. Because the main focus of this study was to determine whether the beaver uses castoreum and/or anal gland secretion for scent marking and not the full chem-... 

The anal gland secretion of beaver, C. canadensis, differs between the sexes (Gr0nneberg, 1978-79). The male grey duiker, Sylvicapra grimmia, has more 2-heptanone and 2-nonadecanone in its preorbital secretion than the female. Two thiazoles (2-isobutyl-1,3-thiazole and 2-isobutyl-4,5-dihydro-l,3-thiazole) and an epoxy ketone (3,4-epoxy-2-dodecanone) are also more abundant in the male s secretion. Correlated with these chemical differences is the fact that only males scent mark with the preorbital gland (Burger etal., 1990). 

Beaver Castor canadensis Differential response to scent marks of relatives and strangers, phenotype matching Sun and Miiller-Schwarze, 1997... 

Unlike most terrestrial mammals, beavers maintain territories along a line following watercourses. Both species, the Eurasian beaver, C. fiber, and the North American beaver, C. canadensis, dredge up mud from the bottom of their home pond, carry it on land, deposit it, and apply a scent mark on top of this mud... 

FIGURE 6.12 Correlation between population density and scent marking intensity in the beaver. Castor canadensis. (From Houlihan, 1989.)... 

If artificial castoreum scent marks are placed on the banks of a pond, beavers, C. canadensis, are more likely to visit, destroy, and re-mark the sites as the complexity of the artificial odor composition increases (Fig. 6.14). While some single phenolics from castoreum such as 4-ethylphenol trigger marking (Miiller-Schwarze and Houlihan, 1991), the response increases as the mixture grows to 4, 6,10,13, and finally 15 compounds. A mixture of 14 phenolics and 12 neutrals (mostly oxygenated monoterpenes) released responses almost as strong as whole castoreum (Schulte etal., 1995). 

Bollinger, K. S. (1980). Scent marking behavior of beaver (Castor canadensis) M. Sc. Thesis, University of Massachusetts, Amherst. 

Rosell, F., Bergan, F., and Parker, H. (1998). Scent marking in the Eurasian beaver [Castor fiber) as a means of territory defense. Journal of Chemical Ecology 24, 207-219. 

Scent Marking in Free-Ranging Mammals. Examples Beaver or Badger... 

In the following we focus on scent marking in beavers. Since this species happens to be primarily nocturnal, we study the results of marking, rather than the behavior itself. Many of the questions can also be asked for badgers, for instance. This exercise is particularly suited for field courses in or near wooded areas where beavers occur. 

To study beaver responses to defined scent stimuli we place an artificial scent mark near an active beaver lodge and record the animals responses. 

Discuss the function of scent marking in the context of the beavers extensive investment in habitat modification. 

Resell F, Nolet BA (1997) Factors affecting scent-marking behavior in Eurasian beaver (Castor fiber). J Chem Ecol 23 673-689... 

Rosell, F. 2002, The function of scent marking in beaver (Castor fiber) territorial defence, PhD thesis, Norwegian University of Science and Technology, Trondheim, Norway. 

Schulte, B. A., 1998, Scent marking and responses to male castor fluid by beavers, J. Mammal. 79 191-203. 

Within the chemical modality, conspicuousness of a signal increases by an expanding the active space or by placing it in the path of, and/or at the level of the sniffing animal, as in the hippopotamus. In contrast to the previous examples, no specially evolved visual or auditory components need be involved. For instance, beavers increase the active space of their scent marks by elevating them on mounds they construct from mud dug up from the bottom of their pond. Muskrats and river otter place their fecal marks at prominent spots along trails where encounters with conspecifics are likely. 

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