Action: Use artificial insemination in captive breeding
- A review of artificial insemination argued that it could be a useful tool to conservationists, but that there were challenges to its use. Deep and repeated inseminations increased fertility.
- Two trials from the USA found that artificial insemination of raptors achieved approximately 50% fertility or 0%.
- A review of a houbara bustard Chlamydotis undulata macqueenii captive breeding programme in Saudi Arabia found that artificial insemination increased fertility, whilst another review found that the highest fertility levels were achieved with inseminations of at least 10 million spermatozoa every 4–5 days.
Artificial insemination involves artificially introducing sperm into a female’s reproductive tract to fertilise her eggs. It may have advantages over natural insemination through mating if, for example, captive birds will not form pair bonds, or if males in some pairs are infertile. The ability to transport frozen sperm between geographically isolated populations can also substantially increase the genetic diversity of species. However, the methods used may be very species-specific and research may be needed before it can be adopted for any one species.
Supporting evidence from individual studies
A replicated ex situ study in the USA in 1973-5 (Boyd et al. 1977) found that five prairie falcons Falco mexicanus that were artificially inseminated laid a total of 37 eggs (although none in 1973), of which 19 were fertile and 15 hatched. Twelve chicks eventually fledged. Sperm was taken from a single male and either used immediately or refrigerated and used within ten hours.
A small study in a breeding centre in Maryland, USA, in 1980 (Wiemeyer 1981) found that an artificially inseminated, wild-bred, female bald eagle Haliaeetus leucocephalus laid two eggs, but both were infertile. The sperm was taken from one wild-bred male and one captive-bred male and mixed and the female was inseminated within an hour. The authors suggested that repeated inseminations would have been preferable, but that the disturbance caused by capturing and inseminating the female risked disturbing other breeding birds nearby. This study is also discussed in ‘Use captive breeding to increase or maintain populations’, ‘Release captive-bred individuals’ and ‘Foster birds with wild conspecifics’.
A review of a houbara bustard Chlamydotis undulata macqueenii captive breeding programme in Saudi Arabia (Seddon et al. 1995) found that artificial insemination increased fertility rates from 50% to 85% between 1989 and 1993. At least 440 chicks were hatched during the study period. This study is also discussed in ‘Use captive breeding to increase or maintain populations’, Artificially incubate and hand-rear birds in captivity’ and ‘Release captive-bred individuals’.
Another review (Jaime et al. 1996) of the same houbara bustard Chlamydotis undulata macqueenii programme as Seddon et al. 1995 found that artificial insemination achieved the highest rates of fertility with inseminations of more than 10 million spermatozoa every 4-5 days. This study is also discussed in ‘Use captive breeding to increase or maintain populations’, ‘Release captive-bred individuals’, ‘Use holding pens at site of release’, ‘Release birds in ‘coveys’ and ‘Use holding pens at site of release and clip birds’ wings’.
A review in 2009 (Blanco et al. 2009) of the challenges of artificial insemination argued that it has the potential to be an important component of bird conservation and population restoration. Extracting good quality sperm is a major barrier, with the ‘abdominal massage technique’ being the most practical and widely applicable method (although it is prone to urine contamination). Trained birds are more likely to accept insemination. The authors found that fertility is up to 400% higher when sperm are deposited into the vagina compared to the cloaca. However, this constraint can be overcome by boosting sperm volume and insemination frequency (2-3 times/week), which has resulted in 80% fertility in crane species using cloacal insemination. Multiple, deep inseminations improves fertility and can help to overcome poor semen quality. Even when eggs are mostly fertile, artificial insemination can increase fertility by an additional 5-10%.
- Boyd L.L., Boyd N.S. & Dobler F.C. (1977) Reproduction of prairie falcons by artificial insemination. The Journal of Wildlife Management, 41, 266-271
- Wiemeyer S.N. (1981) Captive propagation of bald eagles at Patuxent Wildlife Research Center and introductions into the wild. Raptor Research, 15, 68-82
- Seddon P.J., Saint Jalme M., van Heezik Y., Paillat P., Gaucher P. & Combreau O. (1995) Restoration of houbara bustard populations in Saudi Arabia: developments and future directions. Oryx, 29, 136-142
- Jaime M.S., Combreau O., Seddon P.J., Paillat P. & van Heezik Y. (1996) Restoration of Chlamydotis undulata macqueenii (Houbara Bustard) Populations in Saudi Arabia: A Progress Report. Restoration Ecology, 4, 81-87
- Blanco J.M., Wildt D.E., Holfe U., Voelker W. & Donoghue A.M. (2009) Implementing artificial insemination as an effective tool for ex situ conservation of endangered avian species. Theriogenology, 71, 200-213