Influence of mustelid scent-gland compounds on suppression of feeding by snowshoe hares (Lepus americanus)

This study investigated the influence of mustelid anal-gland compounds in suppressing feeding by snowshoe hares on coniferous tree seedlings. Pen and field bioassays indicated that 3-propyl-1,2-dithiolane from the stoat (Mustela erminea), and secondarily, 2,2-dimethylthietane from the mink (M. vison) had a very negative effect on feeding behavior of hares. The major component of stoat anal gland secretions, 2-propylthietane, and the related compounds, thietane and 2-methylthietane, were not effective. 3,3-Dimethyl-1,2-dithiolane from the least weasel (M. nivalis) and ferret (M. putorius) and di-n-propyldisulfide (acyclic analog of 3-propyl-1,2-dithiolane) similarly did not affect hare feeding. 3-Propyl-1,2-dithiolane and 2,2-dimethylthietane (also found inM. erminea) may act as interspecific chemical signals which induce a fear or avoidance response in hares. Such compounds have outstanding potential as area repellents to reduce crop and livestock depredations. Our study reports one of the first practical utilizations of mammalian semiochemicals in crop protection and wildlife management.     

Anaerobic microflora of the anal sac of the red fox (Vulpes vulpes)

Anal sac fluid from the red fox (Vulpes vulpes) was cultured for anaerobic bacteria by two techniques. The more strictly anaerobic technique yielded a wider range of species. Considerable biochemical differences were noted within named species, but no correlation could be found between the foxes and the organisms of their anal sac fluids.     

Influence of the plant antifeedant,pinosylvin, on suppression of feeding by snowshoe hares

This study investigated the influence of the plant antifeedants, pinosylvin and pinosylvin methyl ether (PME), on suppression of feeding by snowshoe hares (Lepus americanus). Screening bioassays showed clearly that pinosylvin suppressed feeding by hares when sprayed directly on coniferous tree seedlings. Pinosylvin odor, when associated with food (but not mixed with it), also significantly reduced consumption of rabbit chow by hares. Large pen bioassays indicated that both pinosylvin and PME significantly reduced feeding on tree seedlings by hares when the antifeedants were sprayed directly on trees. In field bioassays near Prince George, British Columbia, Canada, pinosylvin sprayed on trees and encapsulated in controlled-release devices of PVC plastic, with an internal wire as a twist-tie for attachment to tree, significantly reduced feeding by hares. Thus, pinosylvin will generate an avoidance response in terms of feeding by snowshoe hares. This response is likely triggered by an olfactory pathway based on positive results with controlledrelease devices attached to seedlings. Our study reports the first practical utilization of plant antifeedants for forest crop protection and wildlife management.     

Induction of marking behavior in wild red foxes (Vulpes vulpes L.) by synthetic urinary constituents

A control aqueous solution containing alcohol and polyethylene glycol, and a test solution with the addition of a mixture of eight volatile synthetic compounds identified in red fox urine, Were alternately placed on man-made mounds of fresh snow during January and February, the foxes' courtship season. The foxes preferentially marked those mounds treated with the test solution in the two experimental areas (P < 0.05 and <0.0001). It is concluded that one or more of the volatile substances induces mound marking in this species.     

Anal sac secretion of the red fox,Vulpes vulpes; volatile fatty acids and diamines: Implications for a fermentation hypothesis of chemical recognition

Putrescine (1,4-diaminobutane) and cadaverine (1,5-di-aminopentane) were identified in the anal sac secretions of the red fox,Vulpes vulpes, and of the lion, Panthera leo. Anal sac secretion samples obtained over a period of 10 weeks by sampling from within each sac of each of 6 captive foxes were analyzed and putrescine, cadaverine, and volatile fatty acid compositions and secretion pH values recorded. A significant (P < 0.001) negative correlation of pH (range 6.5–9.4) with total volatile fatty acid concentration was observed. Secretion compositions are discussed in the context of a fermentation hypothesis of chemical recognition. Secretion samples could not be unambiguously assigned to particular foxes on the basis of simple comparisons of volatile fatty acid profiles alone. Composition differences were noted between secretions obtained at a given time from corresponding right and left sacs.     

Use of predator odors as repellents to reduce feeding damage by herbivores

This study investigated the influence of the major anal-gland compounds from the stoat (Mustela erminea) and fecal and urine compounds from the red fox (Vulpes vulpes) in generating an avoidance response by montane voles (Microtus montanus), as well as suppressing feeding by montane and meadow (M. pennsylvanicus) voles on apple trees in orchards. In trap bioassays, a 11 mixture of 2-propylthietane and 3-propyl-1,2-dithiolane significantly reduced vole captures. Other mixtures of stoat compounds reduced the number of new voles captured but not total individuals. 2,5-Dihydro-2,4,5-trimethylthiazoline, a component of fox feces, significantly reduced vole captures in one of two bioassays. Deer mice (Peromyscus maniculatus) did not show a negative response to any predator odor. In overwinter field bioassays, mixtures of 2-propylthietane and 3-propyl-1,2-dithiolane clearly reduced vole feeding on apple trees in four test blocks. 2,5-Dihydro-2,4,5-trimethylthiazoline and a synthetic fox urine mixture also significantly reduced vole attack in respective orchard blocks. Similarly, the intensity of vole feeding, in terms of amount of bark and vascular tissues removed from trees, was reduced by 60% to 97% in predator odor treatments compared with the control. Our study reports the first long-term (four to five months) use of synthetic semiochemicals as area repellents for crop protection from vole feeding damage.     

Some chemical constituents of the scent of the striped skunk (Mephitis mephitis)

The malodorous, volatile portion of the scent or musk of the striped skunk (Mephitis mephitis) containstrans-2-butene-1-thiol, 3-methyl-1-butanethiol, andtrans-2-butenyl methyl disulfide but no 1- butanethiol.This work is taken from the M.S. thesis of D.T.B., University of New Hampshire, 1974.