Capybara Scent Glands and Scent-Marking Behavior

Abstract

Scent marking in mammals can convey a wide range of information (e.g., Brown 1979; Muller-Schwarze 1983; Brown and Macdonald 1985a, b; Arakawa et al. 2008), sometimes linked to agonistic behavior in ritualized contests over resources (e.g., Gosling 1990). Scent marks are used by some mammals to delineate territorial boundaries, as in Ethiopian wolves (Sillero-Zubiri and Macdonald 1998). They can also indicate group membership, as in matrilines of cats, Felis sylvestris catus(Passanisi and Macdonald 1990), individual identity, as in dwarf mongooses, Helogale undulate(Rasa 1973) or spotted hyenas, Crocuta crocuta(Drea et al. 2002) or social and sexual status as in giant otters, Pteronura brasiliensis(Leuchtenberger and Mourao 2008). Frequently, scent-marking behavior and the chemistry of the secretion are related to social dominance (e.g., Huck and Banks 1982; Novotny et al. 1990; Ryon and Brown 1990). The latter is especially true in rodents, where status signaling appears to be the most common function of scent marking (Roberts 2007). Scent glands are commonly sexually dimorphic. Capybaras are unusual among caviomorph rodents in having not only anal glands but also a nasal gland, both of which are sexually dimorphic (Macdonald et al. 1984; Macdonald 1985).