Galea musteloides leucoblephara (Burmeister, 1861)

Taxonomic Classification

The common yellow-toothed cavy (Galea musteloides) is a rodent species in the family Caviidae, closely related to the domesticated guinea pig.

Distribution

This species is found in Argentina, Bolivia, Chile, and Peru, with a full range extending from southern Peru to central Argentina, and occurs at elevations from 20 to 5000 m above sea level.

Karyotype and Dental Trait

Its karyotype has 2n = 68 and FN = 136, and it has yellow teeth.

Genus Distribution Status

It is the most common and most widely distributed member of the genus Galea.

Recognized Subspecies

A recent study has recognized five subspecies of G. musteloides: boliviensis, demissa, leucoblephara, littoralis, and musteloides.

Subspecies Distinguishing Features

These subspecies are distinguished based on pelage coloration, skull size and shape, auditory bullae size, and tooth shape.

Proposed Taxonomic Revision

Growing evidence suggests that the lowland form previously classified as G. musteloides leucoblephara is actually an independent species, which should be called G. leucoblephara.

General Ecological Traits

The common yellow-toothed cavy is a diurnal, group-living herbivore about the size of a squirrel that occupies open habitats.

Habitat Preference

It is mostly found in moist areas such as stream edges and croplands.

Neonatal Weight

At birth, female common yellow-toothed cavies average 37.6 g, while males average 36.4 g.

Reproductive Maturity Age

G. musteloides first reproduces at one to three months of age, with a minimum reproductive age of twenty-eight days.

Reproductive Life History Parameters

Gestation lasts fifty-three days, lactation lasts three weeks, and average litter size is 2.7.

Interspecific Association in Peru

In Peru, Galea musteloides sometimes associates with tuco-tucos of the genus Ctenomys, using tuco-tuco burrows and responding to tuco-tuco alarm calls, according to Sanborn and Pearson.

Captive Social Hierarchy

In captive groups, G. musteloides develops separate hierarchical social orders for males and females.

Captive Mating Patterns

Alpha males regularly guard receptive females, but this guarding has little effect: usually other males also mate with the same female, and more than 80% of litters have multiple sires.

Captive Female Mating Behavior

In captivity, females are clearly promiscuous and always mate with multiple males in their group.

Wild Social Structure Uncertainty

In the wild, G. musteloides is clearly territorial, but it remains unclear whether a similar hierarchical social structure exists in wild populations, or if wild individuals live solitarily.

Male Aggression Patterns

Aggression between adult males occurs regularly.

Male Parental and Offspring Behavior

Adult male G. musteloides never participate in parental care, and are aggressive toward subadult males even when the subadults are their own very young offspring.

Male-Female Aggression

Males are not aggressive toward females.

Allonursing Behavior

Adult females lactate and nurse the offspring of other females during the offspring’s first week of life.

Offspring Nursing Patterns

Nearly all offspring receive some milk from females other than their own mother, though a female prioritizes care for her own offspring and continues caring for them longer than one week.

Genus Mating System Diversity

Closely related Galea species have a range of mating systems from monogamy to promiscuity, making this genus suitable for comparative studies of mating systems.

Comparative Mating System Trends

Two general trends have been identified from these studies: first, testis size relative to body size is larger in promiscuous species; and second, higher social tolerance in captive groups is associated with greater promiscuity and higher testosterone levels in males.

Behavioral Correlates

Testosterone levels and aggression levels in males are not correlated, and females avoid males with higher than average aggression.