BIOC63Fall2013 Lecture 22.docx

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Biological Sciences
Karen Williams

BIOC63Fall2013 Lecture 22: Ex situ conservation II Criticism for captive breeding  7 main reasons why captive breeding should be done as a last resort only  Focus on few, charismatic species o o Only 10% of species are mammals but conservation is skewed favouring them even though there are more threatened non-mammals o close to 90% of threatened species are non mammals  but most species in breeding programs are mammals o So species we are conserving is a small portion of the species that are actually threatened o Of the mammals, skew towards the big megafauna for conservation o o all the groups on x axis are mammas  numbers are skewed towards large mammals in captive breeding programs  Cost vs effectiveness o Large mammals breed at slower rates o o Mammals have larger size but smallest reproductive outputs o More expensive to handle 1 o o Ex situ much more expensive than in situ conservation o So slow to ‘get’ animals and to be able to put them out in the wild o The breeding of the large animals (bottom left) is also greater than non-mammals o Population growth rate in situ vs. ex situ o o X – axis is all large mammals o For panthers, rhinocerus and gorillas, reproduce faster in in situ than ex situ o o It is a lot more expensive to keep breeding going ex situ than in the natural habitat o It woul dbe more efficient and cheaper to just put money into restoring natural habitat for these species  Erosion of genetic diversity o Small populations (i.e. captive populations)  increased genetic driftdecrease in genetic variation = therefore loss of (rare) alleles  inbreeding and inbreeding depression  inbreeding coefficient increases  mean litter size decreases o i.e.  Red Wolf in US  inbreeding depression through biparental inbreeding  close cousin mating 2   inbreeding coefficient goes up as effective population size (first grapgh) of red wolf goes down    as offspring are more and more related to eahc other, recesssive alleles are more inherited, and so therefore there is decrease in litter size (more die)  = inbreeding depression o inbreeding compromises the fitness of captive animals o o ungulates = deer, horses, zebras, rhinos  Transmission of disease in captivity and into wild o Zoos have dense living quarters  Increased chance of disease transmission within zoo (within species and between species) and between zoo and the wild animals after reintroduction o Example: Whooping crane is succseptible to equine encephalitits  between species disease o Deterimental fitness effects in both species  Change of behaviour (domestication) o Food handling 3 o o Captive animals are not taught the skills to access their naturlal food  don’t have the survival skills for wild o animal interactions: o o animals are more submissive, and less aggressive than in the wild  Probably due to higher density o Butterfly splitfin (fish) example (EW) o o non-natural artificial selection  fish are less aggressive in the wild probably because there is lower density  Ex situ animals in zoos; the living dead? o Habitat loss is the main threat to animals  especially primates o There is small chances for successful relocations o Captive primates and many carnivores = living daed o o Primates  100% of primates in captive breeding programs have become endangered because of habittat loss o The ones that are not in programs, 70% are endangered because of habitat loss 4 o Carnivores only 65% of the ones in programs are endangered because of habitat loss and almost 80% of those that are not in programs o Ungulates = deer and stuff  Gives false sense that battle against extinction is being won o Number of extinctions over time is increasing o A little wrong because a hundred years ago the measurememnts would not have been as accurate as right now o Ex Situ Plant Conservation  Botanical gardens (living collections) o Outdoors or indoors o Beause of space restrictions = low number of individuals per species, but grea
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