Galea musteloides - Common Yellow-Toothed Cavy​

Physical Description:

The common yellow-toothed cavy (Galea musteloides) is a wild guinea pig found in streamsides, savannas, bushland, and farmlands (Rood 1972, Redford and Eisenberg 1992, Sachser et. al. 1999).  Its name is derived from the yellowish enamel color on the short incisors (Walker 1975).  Pelage is typically a darker agouti with a white belly.  They have elongated hind feet with 4 toes and 3-toed front feet that are strong and flat (Lacher Jr. 1999).  Members of this genus weigh 300-600 grams with non-pregnant females weighing on average 15% more than males.  The reason for this phenomenon is still unclear due to the lack of research on wild populations of G. musteloides (Sachser et. al. 1999).  Redford and Eisenberg (1992) have provided several mean morphological measurements.  TL = 204.3, HF = 38.3, E = 18.6, Wta = 225.7.  Galea has a dental formula of 1/1, 0/0, 1/1, 3/3 = 20.  The large submandibular gland sets Galea apart from other members of Caviidae.  Females have 4 mammae (Rood 1972).

Distribution:

Galea has a widespread distribution and is common throughout its range.  It can be found from southern Peru to northern Chile and north central Argentina (Neris 2002).  In Paraguay, it is mostly restricted to the western region throughout the Chaco (Fig. 1).

Figure 1: Paraguayan distribution of Galea musteloides (Neris 2002).

Ontogeny and Reproduction:

G. musteloides has a promiscuous mating system and will mate throughout the year (Sachser et. al. 1999).  They reach sexual maturity by the age of 2-3 months.  Males mark females with secretions from their chin glands during the courtship process (Redford and Eisenberg 1992).  During breeding, it is not unusual for both males and females to exhibit aggressive behavior towards conspecifics.  As a result of their promiscuity, multiple paternities are common (83%) (Hohoff et. al. 2002), yet males offer very little parental care (Lacher Jr. 1999, Sachser et. al. 1999).  Relative testis mass in males is one of the highest ever recorded in terrestrial mammals (Schwarz-Weig and Sachser 1996, Sachser et. al. 1999, Cooper et. al. 2000, Hohoff et. al. 2003).    In captivity, the gestation period for Galea is 53 days and lactation lasts ~3 weeks (Redford and Eisenberg 1992, Noris 2002).  Künkle and Hoeck (1995) have observed captive female Galea engaging in communal suckling.  Nursing females were tolerant of suckling by unfamiliar pups younger then 8 days, but became aggressive towards unfamiliar pups that were older then 8 days (Künkle and Hoeck 1989). 

Ecology and Behavior:

Galea is diurnal, being most active at dawn and dusk.  Its diet consists mostly of herbs and grasses (Lacher Jr. 1999).    Galea communities are a social hierarchy, with dominant males achieving a higher number of breeding opportunities.  Sympatric interactions have been observed on numerous occasions between Galea and Microcavia australis.  The two species have been documented sharing runways, feeding together, and even grooming each other (Rood 1970, Redford and Eisenberg 1992).

Remarks:

Due to its abundance, G. musteloides is both eaten, and kept as pets wherever it is found (Neris 2002).

Literature Cited:

Cooper, T. G., S. Weydert, C. Yeung, C. Künzl and N. Sachser.  2000.  Maturation of epididymal spermatozoa in the non-domesticated guinea pigs Cavia aperea and Galea musteloides.  Journal of andrology 21:154-163.

Hohoff, C., K. Franzen and N. Sachser.  2003.  Female choice in a promiscuous wild guinea pig, the yellow-toothed cavy (Galea musteloides).  Behavioral ecology and sociobiology 53:341-349.

Künkele, J. and H. N. Hoeck.  1995.  Communal suckling in the cavy Galea musteloides.  Behavioral ecology and sociobiology 37:385-391.

           and           .  1989.  Age-dependent discrimination of unfamiliar pups in Galea musteloides (Mammalia, Caviidae).  Ethology 83:316-319

Lacher Jr., T. E.  Encyclopedia of mammals.  Edited by D. Macdonald.  1992.  Andromeda Oxford Limited 690-692.

Neris, N., F. Colmán, E. Ovelar, N. Sukigara and N. Ishii.  Kato’s data book on larger mammals of Paraguay – Distribution, population trends, and utilization.  2002.  Secretaria del Ambiente, Asunción, Paraguay.

Redford, K. H., and J. F. Eisenberg.  Mammals of the neotropics.  Volume 2.  1992.  The University of Chicago Press 340-341.

Rood, J. P.  1970.  Ecology and social behavior of the desert cavy (Microcavia australis).  American midland naturalist 83:415-454.

          .  1972.  Ecological and behavioural comparisons of three genera of Argentine cavies.  Animal behaviour monographs 5:1-83.

Sachser, N., E. Schwarz-weig, A. Keil and J.T. Epper.  1999.  Behavioral strategies, testis size, and reproductive success in two caviomorph rodents with different mating systems.  Behaviour 136, 1203-1217.

          .  1998.  Of domestic and wild guinea pigs: studies in sociophysiology, domestication, and social evolution.  Naturwissenschaften 85:307-317.

Schwarz-Weig, E. and N. Sachser.  1996.  Social behaviour, mating system and testes size in cuis (Galea musteloides). Z Säugestierkd 61:25-38.

Walker, E. P.  1975.  Mammals of the world.  Johns Hopkins Baltimore MD USA. Pgs1018.

Reference written by Chris Yarbrough, Biology 378 (Mammalogy), University of Wisconsin – Stevens Point.  Edited by Chris Yahnke.  Page last updated August 8, 2005.