Talpa occidentalis Cabrera, 1907

Sexual Size Dimorphism

Adult males of Talpa occidentalis are slightly larger than adult females, with average weights of 65 grams (2.3 oz) and 53.5 grams (1.89 oz) respectively.

Species Distribution

This species occurs in Spain and Portugal, primarily in the northwestern region of these countries.

Typical Habitats

It is most commonly found in meadows, cropland, pastures, and woodlands, and can live in any temperate area that has deep, moist soil that is not too rocky, sandy, or otherwise unsuitable for digging.

Diet and Habitat Correlation

It feeds primarily on earthworms, and its habitats tend to be areas with high earthworm populations.

Soil Moisture Preference

It prefers wetter areas, as long as the soil is not too damp to allow digging.

This preference includes both naturally wet soils and artificially irrigated croplands and pastures.

Agricultural Habitat Suitability

The species is common in areas managed with traditional agricultural practices.

Breeding Period

Its breeding period runs from September to May, and pregnancy can occur between October and April.

Gestation Duration

Gestation lasts approximately 28 days.

Juvenile Development

Young are weaned by May, after around 30 days of nursing.

Male Sexual Maturity

Males reach sexual maturity at approximately one year old.

Female Reproductive Trait

Like other species in the genus Talpa, females are hermaphroditic and have ovotestis.

Gonadal Tissue Seasonal Change

The prominence of testicular tissue relative to ovarian tissue decreases during the breeding season.

XX Chromosome Males

Some phenotypically male individuals of this species have been found with XX chromosomes.

These XX individuals are externally similar to XY males, but have much smaller testicles.

XX Male Infertility

Internally, the testicles of these XX males have a different structure than those of XY males, and these affected males are infertile.

Sex Reversal Significance

The authors of a 1988 paper considered this the first recorded case of "sex reversal" in mammals found outside of captivity.