Flank gland

The flank gland is one of several specialized posterolateral glands (a group of glands located along the sides and the rear) found predominately in certain species of rodents including voles, shrews, hamsters, and other members of the Cricetidae family.[1][2]

The flank gland is located laterally on each side of the abdomen. It is often present in both males and females, though this varies by species, and is usually larger in males.[1][3] In some species, self-scratching of the flank gland, typically with a hind foot, causes secretion of an oily substance that leaves the surrounding hair visibly matted and emits a chemical odor.[2] These chemicals vary in composition within the same species as well as within an individual as it progresses through sexual maturity.[4] Scent marking via secretions of the flank gland has been observed: for example, some male microtene rodents will perform “drum-marking,” in which they repeatedly scratch their flank gland with their foot and proceed to stomp the ground several times.[5]

In dominant individuals the matting of fur at the location of secretion is more conspicuous than in subordinate individuals, suggesting it serves as some visual signal.[2] There is also experimental evidence of male golden hamsters and of lab rats fighting, after which the victor will scent-mark more than the submitter: this suggests it is used by dominant individuals to establish territory.[6][7] There is evidence that rodents can remember odors of individuals and discriminate between those that are familiar and those that are not, even when the chemical qualities of the odors are very similar; however, they are not able to discriminate between non-familiar kin and non-kin.[8][9] Additionally, female golden hamsters show a sexual preference towards familiar non-kin odors.[10] Flank gland size varies between individuals, though studies concerning a correlation between size of flank gland and reproductive success in males give conflicting results.[11][12]

References

  1. ↑ 1.0 1.1 W. B. Quay, "The Specialized Posterolateral Sebaceous Glandular Regions in Microtine Rodents", Journal of Mammalogy, Vol. 49, No. 3 (Aug., 1968), pp. 427-445, accessed 29 October 2012
  2. ↑ 2.0 2.1 2.2 Jerry O. Wolff and Martha F. Johnson, "Scent Marking in Taiga Voles, Microtus xanthognathus" Journal of Mammalogy, Vol. 60, No. 2 (May, 1979), pp. 400-404, accessed 29 October 2012
  3. ↑ Cantoni et al., "Intra- and Interindividual Variation in Flank Gland Secretions of Free-ranging Shrews (Crocidura russula)". Journal of Chemical Ecology (1996) Vol. 22, No. 9, pp. 1669–88, accessed 29 October 2012
  4. ↑ A. S. Parkes and H. M. Bruce, "Olfactory Stimuli in Mammalian Reproduction" Science, New Series, Vol. 134, No. 3485 (Oct. 13, 1961), pp. 1049-1054, accessed 29 October 2012
  5. ↑ Frederick J. Jannett, Jr., "Drum-marking by Arvicola richardsoni and Its Taxonomic Significance", American Midland Naturalist, Vol. 92, No. 1 (Jul., 1974), pp. 230-234, accessed 29 October 2012
  6. ↑ Katherine Ralls, "Mammalian Scent Marking", Science, New Series, Vol. 171, No. 3970 (Feb. 5, 1971), pp. 443-449, accessed 29 October 2012
  7. ↑ Michael N. Lehman and David B. Adams, "A Statistical and Motivational Analysis of the Social Behaviors of the Male Laboratory Rat", Behaviour, Vol. 61, No. 3/4 (1977), pp. 238-275, accessed 29 October 2012
  8. ↑ Giora Heth, Josephine Todrank and Hynek Burda, "Individual Odor Similarities within Colonies and across Species of Cryptomys Mole Rats", Journal of Mammalogy, Vol. 83, No. 2 (May, 2002), pp. 569-575, accessed 29 October 2012
  9. ↑ Robert E. Johnston, "Chemical Communication in Rodents: From Pheromones to Individual Recognition", Journal of Mammalogy, Vol. 84, No. 4 (Nov., 2003), pp. 1141-1162, accessed 29 October 2012
  10. ↑ Jill M. Mateo and Robert E. Johnston, "Kin Recognition and the 'Armpit Effect': Evidence of Self-Referent Phenotype Matching", Proceedings: Biological Sciences, Vol. 267, No. 1444 (Apr. 7, 2000), pp. 695-700, accessed 29 October 2012
  11. ↑ Masakado Kawata, "Mating System and Reproductive Success in a Spring Population of the Red-Backed Vole, Clethrionomys Rufocanus Bedfordiae", Oikos, Vol. 45, No. 2 (Oct., 1985), pp. 181-190, accessed 29 October 2012
  12. ↑ Masakado Kawata, "Mating Success, Spatial Organization, and Male Characteristics in Experimental Field Populations of the Red-Backed Vole Clethrionomys rufocanus bedfordiae", Journal of Animal Ecology, Vol. 57, No. 1 (Feb., 1988), pp. 217-235, accessed 29 October 2012