Captive breeding
It is sometimes employed to help species that are being threatened by the effects of human activities such as climate change, habitat loss, fragmentation, overhunting or fishing, pollution, predation, disease, and parasitism.
[2][3][4] In some cases a captive breeding program can save a species from extinction,[5] but for success, breeders must consider many factors—including genetic, ecological, behavioral, and ethical issues.
These studbooks contain information on birth date, gender, location, and lineage (if known), which helps determine survival and reproduction rates, number of founders of the population, and inbreeding coefficients.
As captive populations are usually small and maintained in artificial environments, genetics factors such as adaptation, inbreeding and loss of diversity can be a major concern.
Selection intensity, initial genetic diversity, and effective population size can impact how much the species adapts to its captive environment.
[16] Modeling works indicate that the duration of the programs (i.e., time from the foundation of the captive population to the last release event) is an important determinant of reintroduction success.
[19] To make these populations the most viable, it is important to monitor and reduce the effects of deleterious allele expression caused by inbreeding depression and to restore genetic diversity.
[20] Closely monitoring the possibility of inbreeding within the captive bred population is also key to the success of reintroduction into the species' native habitat.
It can be difficult to replicate the circumstances surrounding multiple mate systems and allow it to occur naturally in captivity due to limited housing space and lack of information.
Arabian Oryx have now been reintroduced into areas such as Saudi Arabia, Oman, and Israel and they now number 1,100, showing a recovery thanks to captive breeding efforts.
Keeley, Fanson, Masters, and McGreevy (2012) sought to "increase our understanding of the estrous cycle of the devil and elucidate potential causes of failed male-female pairings" by examining temporal patterns of fecal progestogen and corticosterone metabolite concentrations.
They found that the majority of unsuccessful females were captive-born, suggesting that if the species' survival depended solely on captive breeding, the population would probably disappear.
[35] In 2010, the Oregon Zoo found that Columbia Basin pygmy rabbit pairings based on familiarity and preferences resulted in a significant increase in breeding success.
Through captive breeding programs, these factors can be measured in a finite setting and the results can be interpreted and used to aid in ex-situ and in-situ conservation.
A lot of research about elephant reproductive physiology and estrus cycles has been conducted in captivity and a greater understanding of how these factors play into breeding attempts can be established.
Founding populations for captive breeding programs have often had fewer individuals than ideal because of their threatened state, leaving them more susceptible to challenges such as inbreeding depression.
It may be used for many reasons, including to overcome physical breeding difficulties, to allow a male to inseminate a much larger number of females, to control the paternity of offspring, and to avoid injury incurred during natural mating.
Scientist of the Justus-Liebig-University of Giessen, Germany, from the working group of Michael Lierz, developed a novel technique for semen collection and artificial insemination in parrots producing the world's first macaw by assisted reproduction.
[47] Animal species can be preserved in gene banks, which consist of a cryogenic facilities used to store live sperm, eggs, or embryos in ultracold conditions.
[50] The Hungarian government launched a project to preserve the breed, as it possesses valuable traits, such as stamina, calving ease, disease resistance, and easy adaptation to a variety of climates.
[53] In 2001, a cow named Bessie gave birth to a cloned Asian gaur, an endangered species, but the calf died after two days.
Anticipating this possibility, tissue samples from the last bucardo (Pyrenean ibex) were frozen in liquid nitrogen immediately after it died in 2000.
[57] Captive breeding is an important tool used in modern education of conservation issues because it provides a framework for how we care about species and allows institutions to show the beauty that is contained in our natural environment.
These explanations help show a side of the world many people will not engage with because conservation is not something that is inherently known about, it must be shown and taught to others to raise awareness of the issues around the globe.
Bristol Zoo Gardens in the United Kingdom has maintained a species of medicinal leech (Hirudo medicinalis) in their facility to use as an education exhibit.
The display at Bristol Zoo Gardens provides an educational piece and tells the story of a woman who sold leeches to the locals around her for medicinal purposes.
[60] From these actions, those eleven oryx were successfully bred from the brink of extinction, and would go on to be re-released in the deserts of Jordan, Oman, Bahrain, United Arab Emirates and Qatar.
[61] While captive breeding can be an ideal solution for preventing endangered animals from facing serious threats of extinction there are still reasons why these programs can occasionally do more harm than good.
Some detrimental effects include delays in understanding optimal conditions required for reproduction, failure to reach self-sustaining levels or provide sufficient stock for release, loss of genetic diversity due to inbreeding, and poor success in reintroductions despite available captive-bred young.
[63] It has been argued that animals should be released from captivity programs for four main reasons: a lack of sufficient space due to overly successful breeding programs, closure of facilities due to financial reasons, pressure from animal rights advocacy groups, and to aid the conservation of endangered species.
