18.3.4—Assisted reproduction in endangered mammals

Endangered mammals may have small, isolated populations, inbreeding and too few suitable reproductive mates. Assisted reproduction can move gametes or embryos between animals and give reproduction more controlled support.

1. Obtain eggs and sperm from suitable individuals while protecting the reproductive female; the source animals retain the species’ genetic identity.
2. In IVF, extract eggs, keep them briefly in culture, mix them with semen outside the body, and allow zygotes to develop into embryos.
3. Transfer an embryo to the mother or a suitable surrogate; embryo transfer can reduce pregnancy risk for a vulnerable female.
4. In surrogacy, a female carries an embryo to full term after her uterus has been prepared; artificial insemination or IVF can be used to create the embryo.
5. Offspring may be managed in captivity and, if the habitat and population conditions are suitable, used in a later reintroduction programme.

IVF confirms fertilisation outside the body. Embryo transfer moves an embryo after fertilisation, and surrogacy focuses on the female that carries it; a surrogate may be the same or a closely related species when compatibility permits.

Assisted reproduction can increase reproductive opportunities, but it does not by itself restore habitat, remove inbreeding risk or guarantee adaptation after release. Cost, welfare, genetic diversity, suitable habitat and reintroduction success remain constraints. General conservation settings, invasive-species control and IUCN/CITES roles are separate cards.