Q. These animals could not breed together on their own?

Different varieties of a species will be able to breed together if given the opportunity.

Inbreeding - In a small population, related individuals are more likely to breed together.

One is to breed together different parental lines that differ for the trait of interest.

All of these types were bred together to create the modern Boulonnais horse.

A biological species is a group of individuals which can breed together (panmixia).

A sexual population is a set of organisms in which any pair of members can breed together.

The Cannibals also tend to stay in groups with other mutants and breed together to form families.

When the long-legged birds are bred together, they never produce offspring with short legs.

Nests are often solitary, although a few pairs may breed relatively close together at good locations.