Galea musteloides
Common Yellow-Toothed Cavy
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
www.asher.de/Galea_ musteloides.jpg
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 (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 08-08-05.