methods of conserving biodiversity: breeding and release programmes Flashcards
what is ex-situ conservation
conservation of species away from where they usually live
what are the issues with keeping species in captivity
1) habitat size- some species require large habitats so cant be kept in captivity ie whales
2) food requirements- some species need food that isn’t easily provided such as insectivores bats
3) species interrelationships- some species have complicated relationships such as symbiotic root fungi so all species need to be in captivity
4) cost- keeping animals in a zoo is expensive and there is not enough money available to keep all endangered species in captivity
what factors inhibit the success of captive breeding programmes
1) conditions for breeding
2) population interactions
3) breeding habitat
4) gene pool size
how do conditions for breeding limit captive breeding success
many species require precise timing- such as day length, light levels, temperature and amount of food available, in order to increase breeding and survival.
- if these are not provided they will not breed
how do population interactions limit breeding success
- in the wild breeding pairs may isolate themselves from the group whilst non-breeding pairs live elsewhere
- in captivity the mixing of breeding and nonbreeding individuals may cause conflict and reduce survival of offspring such as eggs and chicks
how does the breeding habitat reduce breeding success
some species only breed with suitable habitats such as having suitable sites for courtship displays or areas for hunting, for example flamingos only breed in large groups.
how does gene pool size limit breeding success
- small gene pool in captivity increases risk of inbreeding
- cause harmful recessive genes to be expressed causing undesirable characteristics
- increase risk of diseases and mutations
- increased chance of smaller range of tolerance for changes in abiotic factors
what are the methods of increasing breeding success
1) cryopreservation
2) artificial insemination
3) embryo transfer
4) microprogation
5) cloning
outline cryopreservation
the storage of eggs and semen and embryos by freezing for future breeding programmes. They can be transported long distances more easily than moving the entire animal
they can be used even when donor species has died
outline AI
the collection of sperm from a male and its insertion into a female to produce offspring
- semen can be stored for many years
- animals don’t have to live in the same zoo
- mating can be dangerous
- potential partners may not accept each other
outline embryo transfer
- female of the species is treated with hormones so she ovulates and releases large amounts of eggs
- the eggs are fertilised with the sperm of the male
- each embryo is implanted into a female of a similar species
- this allows many offspring and avoids gestation periods limiting numbers
outline micropropagation
a form of tissue culture where many clusters of cells are produced from a single plant
- each cell cluster can be used for an individual plant
- this way many plants can be produced from a single parent= genetically identical
outline cloning
- transferring the nucleus of a stemcell of endangered species into an empty egg cell
- a division of cells is stimulated by electric shock
- the egg is implanted into the surrogate mother
- eventually a genetically identical off spring is produced
what are they key features of a successful release programme
- large enough habitat
- reliable food supply
- low predation risk
- suitable breeding sites
- support of local human population
what is the difference between hard and soft release programmes
hard- involves the release of species with no post release support
soft- involves post release support such as gradual release into larger areas and provision of food as they learn to survive themselves
