Download Ch. 14: Zoos and Gardens

Ch. 14: Zoos and
Gardens
Ex Situ Conservation
• Ex situ: outside of a species’ habitat
• Historically, zoos and gardens were an entertaining diversion
for the wealthy
• Now goals include
• educating general public
• gaining support for biodiversity conservation
• scientific research
The ark metaphor
• 24 species of plant and 36 species of
animal exist only in captivity
• Captive populations may be an
insurance program in case of
extinction in the wild
• Some species went extinct in captivity
• and others may never be kept in
captivity
Studbooks and Pedigrees
• Avoid artificial selection ~ don’t want to domesticate them, want
to release them into the wild
• or keep two breeding stocks, one for reintroduction, one for captivity
• Want to avoid inbreeding, but record keeping when siblings are in
different institutions is complicated.
• use studbooks and pedigrees, usually one per species
• Logistics of maintaining genetic diversity
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shipping breeders from one zoo to another
transferring embryos
using domestics as surrogates
calculating mean kinship ~ identify individuals who are more
different
Storing Biodiversity
• Some life-history stages are easier to keep ex situ than others
• Microbes ~ freeze-dry samples
• easier to store than culture
• don’t have to worry about evolutionary changes in culture
• Animals ~ cryopreservation of semen and embryos
• common for domesticated species, beginning for wild ones
• Plants ~ many seeds easily maintain viability
• but viability decreases over time, so occasionally grow-out seeds to
get new ones.
• otherwise, retain pollen, plantlets, tissue samples
• common for domestics, but wild species representation increasing
• Genetic Material ~ tissue for DNA extraction, DNA
Conservation of Domestics
• Few species dominate our diet, but several different varieties
• plants may be called cultivars
• animals usually called breeds
• Ideally crops are high yield, don’t require pesticides,
herbicides, too much water, fertilizer or anything else
• landraces: local varieties that do well in local conditions
• but often not high yield
• International repositories for different plant varieties
• Maintenance of local breeds becoming a hobby of ranchers
• but wild ancestors of domestic animals generally overlooked as
source of diversity
Ex Situ – In Situ Interface
• Zoos and gardens are not a replacement for natural
ecosystems
• Reintroductions are often unsuccessful
• to date, no self-sustaining populations
• Not all captive animals were born in captivity
• remove individuals for use in zoos and gardens
• remove individuals because low chance of survival in wild
• what about when this means removing breeding individuals from
a threatened, but breeding population?
• Shift from exhibiting the most species to exhibiting species
who can best benefit from captive breeding programs
• but resources often directed toward most popular exhibits
Ex Situ Conservation is
Controversial
• Just let species go extinct with dignity?
• Easier to augment with captive breeding than mitigate threat?
• Spending time and money on husbandry and captivity rather
than on the ground conservation and management?
• But still does good things
• Increasingly involved in advocating for conservation and funneling
money to in situ conservation
• If in situ conservation is successful, zoos and gardens stop being a
Noah’s arc and focus on education and outreach
But it has supporters
• Increasingly involved in advocating for conservation and
funneling money to in situ conservation