Zoos and aquariums around the world manage genetically the populations of animals from thousands of different species that they hold in their collections. “Genetic management” means that the pairings and reproductions between males and females of each institution is carefully planned, controlled and registered. Offspring(s) from these pairings are registered in the so-called studbook, a record system where details about parentage (i.e. who’s the sire and the dam), date of birth and possible medical issues from the new individual are stored in specific softwares (e.g. Sparks). This information about parentage and date of birth makes it possible for zoos to hold a pedigree from most of the species they keep, i.e. a document with the ancestry of the individuals in a populations, and where the relationships of the individuals can be established. But of course, a pedigree relies on the fact that each individual can be recognized, this means, that we can easily distinguished giraffe “number 8” from giraffe “number 9”. With these pedigrees zoo experts in genetic management can calculate the best matches between couples to maximize genetic diversity of the population. Avoiding matings of individuals that are related makes the population genetically healthier in the short and long term. Hence, having a good and complete pedigree is essential for the conservation of a population.
However, what happens with those species in which individuals that do not present clear external differences among them? Think, for instance, about species of amphibians, reptiles or fishes. Would you be able to (correctly!) identify who’s who if these individuals were together? Try distinguishing which is the female and the male individuals in this image. Isn’t that easy, right? If we add on top that many of these species usually live in groups and are kept like that in zoos’ enclosures, then the difficulty in recognizing each individual with a high degree of certainty increases. Trying to record pedigree information for this type of species is therefore a real challenge. And without pedigree, genetic management might be complicated. One can argue that molecular techniques to recognize individuals can be a solution. Yet this solution is not affordable for many zoo institutions and the techniques are not as developed as for other economically important species/breeds, e.g. farm species (cattle, sheep, pigs, chicken).
I think that we are coming into a new era of conservation, what I like to call “Conservation 2.0”. Not just because of the technology and scientific improvements, that yes, it has made such a big impact in moving conservation science forward -we are now able to look at the whole DNA sequence from individuals at a decreasing cost, and use these genomic information to answer evolution and molecular ecology and biology questions that we could not solve before. But also because there is an on-going shift for the subject species to conserve. Society is no longer just interested in conserving cute, big mammals such as elephants, rhinos and giant pandas. There is also a raising concern about other type of species that are in the same endangered status which maybe are not as cute. This means that amphibians, reptiles and fishes can also have a chance in being conserved! In this context, zoos are devoting lots of effort in conservation programs for many species of amphibians, reptiles and fishes. And this also means that having a way to make it possible to record pedigrees for these species that live in groups and are hard to distinguish among individuals will greatly contribute to make conservation programs of these species a reality.
In collaboration with the European Association of Zoos and Aquariums (EAZA), the Chicago Zoological Society and the Audubon Nature Institute, I collaborated on the extension of pedigree methods to estimate genetic diversity and other genetic measures for group-living species. This method has been implemented in the software PMx, which is a computer program used by zoos and aquariums to manage genetically and demographically their collections. I developed a computer software that allows to record pedigree data of group-living species and import it in PMx. More information about the project and the software can be found in the manuscript we published in Ecology and Evolution:
Jiménez-Mena, B., Schad, K., Hanna, N. & Lacy, R. C. (2016) Pedigree analysis for the genetic management of group-living species. Ecology and Evolution, 6: 3067–3078. doi:10.1002/ece3.1831 (pdf here),
as well as in the official website from PMx and the group-management project (by Bob Lacy, here). The pedigree datasheet and the software have been made freely available and can be downloaded from the official GitHub site.
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