Use of anal gland secretion to distinguish the two beaver species Castor canadensis and C. fiber

Nolet

et al. 2005

Behav Ecol Sociobiol

Self Cite

118

According to current theories of territoriality, an animal is expected to defend the smallest area that can provide resources for maximisation of reproduction, known as the 'economically defendable' area. In group territorial species however, the strategies behind resource defence are likely to be more complex with corporate territoriality, cooperative breeding, delayed dispersal and intra-group competition all potentially playing a role. Here we examined group territoriality in a social herbivorous rodent, the Eurasian beaver Castor fiber. Beavers in our study do not inhabit economically defendable territories. Instead the sequence of arrival of pairs into unoccupied areas seems to play a more important role in determining the size of the territory, whereas group size is determined by past reproductive success. We argue that the settlement pattern and reproductive history have a lasting impact in the territorial system of beavers due to a combination of the low adult mortality, high dispersal costs, and avoidance of resource depletion.

Section: Telemarkmentioning

confidence: 99%

Territory and group sizes in Eurasian beavers (Castor fiber): echoes of settlement and reproduction?

Campbell

Nolet

et al. 2005

Behav Ecol Sociobiol

Self Cite

118

“…For the Eurasian beaver, the AGS is a thick paste of a greyish color in females, and is an oily fluid with a whitish or pale straw color in males. For the North American beaver (C. canadensis), the AGS of the two sexes show also a consistent difference regardless of age: it is brown and viscous in males, but it is whitish or light yellow and runny in females (see Rosell and Sun, 1999). Obviously, the viscous secretion of the Eurasian female and the North American males would make the pelage sticky and would lessen water repellency of the pelage.…”

Section: Resultsmentioning

confidence: 99%

Untitled

Journal of Chemical Ecology

2002

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Abstract-The scent-matching hypothesis postulates that scent marks provide an olfactory link between a resident owner and his territory, and that this enables intruding animals to recognize the chance of escalated conflicts. However, it is unclear if Eurasian beavers (Castor fiber) mark their own pelage with castoreum from their castor sacs (i.e., the same material used in territorial marking); and/or if beavers mark their pelage with anal gland secretion (AGS) from the anal glands to waterproof the pelage and to act as a "living-scent mark". Chemical analysis (gas chromatography and mass spectrometry) of hair samples from 22 live-trapped beavers revealed that castoreum compounds were not present in any samples, AGS compounds were found from 3 animals (13.6%) around the cloaca, and the compound squalene was found in all the samples. Beavers may release castoreum directly into the water when it meets an intruder. Thereby, the "scent mark" in the water can provide an olfactory link between a resident owner and his territory. Squalene, in contrast to AGS, may be essential for keeping beaver pelts water-repellant.

“…We opened the castor sacs with a surgical blade and scraped the castoreum from the inside surface with a metal scapula. AGS was collected from the glands by cutting off the last 2-3 mm of the papillae and squeezing out the secretion (Rosell and Sun, 1999;. Sun and Müller-Schwarze (1998a) found no significant variation in the chemical compounds from the right and left gland of the North American beaver, and we, therefore, collected all secretion in the same glass vial.…”

Section: Methodsmentioning

confidence: 98%

Untitled

Journal of Chemical Ecology

Sundsdal

2001

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Abstract-Mammals use urine, feces, or the secretion of specialized skin glands to mark their territories. These sources can carry different information and, thus, have different functions. Presently it is not known if beavers (Castor spp.) deposit castoreum (primarily a mixture of secondary metabolites from urine) from the castor sacs and secretion from the anal glands (AGS) together or alone when scent marking their territories. We hypothesized that castoreum would be the main scent signal used in the defense of beaver territories during winter and predicted that castoreum would be deposited more often than AGS. A total of 96 scent marks on snow were collected from January 1 to March 31, 1997-1999 in the Bø River, Telemark County, Norway. In order to obtain control material, we chemically analyzed AGS and castoreum from 60 dead beavers collected during January-May 1997-1999. We compared the compounds found in the dead beavers with compounds found in the scent marks on snow. Samples were analyzed by using gas chromatography-mass spectrometry (GC-MS). All 96 scent marks contained compounds from castoreum, whereas compounds from AGS were found in only four scent marks. This suggests that beavers do not specifically deposit AGS on scent mounds as they do with castoreum and that the AGS compounds we found probably were remnants of AGS from the feet or fur following pelt lubrication or coprophagy behavior. We conclude that castoreum is the main scent signal used in the defense of beaver territories during winter.