The flank gland is one of several specialized posterolateral

glands In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). Structure D ...

(a group of glands located along the sides and the rear) found predominately in certain species of

rodents Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are roden ...

including voles, shrews, hamsters, and other members of the family

Cricetidae The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At almost 608 species, it is the second-largest family of mammals, and has me ...

.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 2012Jerry 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 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. 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. These chemicals vary in composition within the same species as well as within an individual as it progresses through sexual maturity. 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. 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. 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 A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or an ...

. 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. Additionally, female golden hamsters show a sexual preference towards familiar non-kin odors. Flank gland size varies between individuals, though studies concerning a correlation between size of flank gland and

reproductive success Reproductive success is an individual's production of offspring per breeding event or lifetime. This is not limited by the number of offspring produced by one individual, but also the reproductive success of these offspring themselves. Reproduct ...

in males give conflicting results.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

References

{{reflist Rodent anatomy Glands