Information about reproduction in Merriam's shrews is minimal. In most shrews, mating behaviors are very elementary. A male typically chases a female with his nose close to her posterior. This allows the male to sniff (apparently to determine her reproductive condition) and mount the female when she stops running.
Not much is known about reproduction in Merriam's shrews. It is thought that the breeding season is from mid-March to July, and that females can breed twice in a given year. Gestation for most shrews is 24 to 30 days, with females having between 5 and 7 young per litter. The young are cared for until approximately 25 days, during which time they are completely dependent. Most shrews become sexually mature around 1 year of age. Rarely, some females will mate before five months of age.
Breeding interval: These shrews probably breed twice per year.
Breeding season: It is thought that Merriam's shrews breed from mid March to July.
Range number of offspring: 5 to 7.
Range gestation period: 24 to 30 days.
Range weaning age: 22 to 25 days.
Average time to independence: 25 days.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous
For most shrews, the young are cared for by the mother until they are weened. Care includes provision of food (milk), protection, and grooming. Weening occurs between 22 and 25 days. After the young are weened, they are completely independent. Male parental care has not been reported.
Parental Investment: no parental involvement; altricial ; pre-fertilization (Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female)