Captive breeding programs
Advertisement
This presentation is the property of its rightful owner.
1 / 20

Captive breeding programs PowerPoint PPT Presentation

Captive breeding programs. (Conservation vs. preservation revisited….). Purposes of captive breeding programs:. protection of threatened species ( captive maintenance) habitat is completely lost threats to extinction cannot be overcome duration of captivity has irrevocably altered species.

Download Presentation

Captive breeding programs

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Captive breeding programs

Captive breeding programs

(Conservation vs. preservation revisited….)


Purposes of captive breeding programs

Purposes of captive breeding programs:

  • protection of threatened species (captive maintenance)

    • habitat is completely lost

    • threats to extinction cannot be overcome

    • duration of captivity has irrevocably altered species


Purposes of captive breeding programs1

Purposes of captive breeding programs:

  • conservation of threatened species

    • objective to restore wild populations (no wild individuals

      left)

    • objective to supplement wild populations that have

      declined or are threatened


Captive propagation

maintain in permanent captivity

re-establish wild population

supplement wild population

minor major

consequences of genetic mismanagement


Stages in a captive breeding program

Stages in a captive breeding program

  • decline of wild population, genetic consequences

  • choice of founder population

  • growing captive population

  • maintaining captive population

  • reintroducing individuals

  • managing reintroduced population


Issues for captive propagation

Issues for captive propagation

  • source of founder population(s)

  • space requirements in captivity/space availability in zoos

  • courtship/mating behaviors

  • intrinsic rate of increase

  • isolation of sub-populations

  • availability of wild populations as sources of new variation


Rules for captive propagation

Rules for captive propagation

Founding the population - minimize genetic and phenotypic change

  • collect random sample of founders

  • collect data on locality, habitat of origin

  • collect genetic data from founders


Rules for captive propagation1

Rules for captive propagation

Maintenance of the population

  • maximize N and Ne (maximize sex ratio)

  • maximize generation time (minimize generations in captivity)

  • maintain equal family sizes

Lion: average family size 1.65

variance in family size 32.7

reduces effective popn. size to 8%


Rules for captive propagation2

Rules for captive propagation

Maintenance of the population

golden lion tamarin - founder population 242 individuals

48 contributed to subsequent gene pool

most of offspring (2/3) from single pair


Rules for captive propagation3

Rules for captive propagation

  • minimize loss of genetic variation

    • maximize N and Ne (maximize sex ratio)

    • maximize generation time

    • maintain equal family sizes

  • minimize behavioral changes

    • minimize duration of captivity

  • minimize inbreeding

    • conduct pedigree analysis/management

    • outcross population with new individuals


Rules for captive propagation4

Rules for captive propagation

  • manage demographics

    • determine reasonable carrying capacity (note effect on other taxa)

    • achieve carrying capacity rapidly

    • stabilize population at carrying capacity

      • maintain representation of age classes

      • what to do with excess animals?


Rules for captive propagation5

Rules for captive propagation

Species Survival Plans (SSPs) for zoo species

goal: preserve genetic variation – 90% of H over 100 years

  • list each individual in a studbook – sex, sire and dam, likely alternatives if uncertain parentage

  • acquire data: age-specific fecundity, mortality, lifetime reproductive success, inbreeding

  • equalize reproductive contributions of each individual

  • pair individuals of lowest mean kinship

  • work with other zoos to share genetic material

    Limits to zoo taxa….


Rules for captive propagation6

Rules for captive propagation

Use “50/500 rule”

  • 50 parents for single generation

  • Ne of 500 for long-term maintenance

    Conduct periodic ‘genetic checking’

  • compare present population variability with that of founder/wild population(s)


  • Problems with captive propagation

    Problems with captive propagation

    Deliberate (artificial) selection

    • for increased productivity – fecundity, growth, or both

    • for ‘better’ type or traits (color, size)

    • for tractability (handling, breeding season)

      • problems with linkage of undesirable traits


    Problems with captive propagation1

    Problems with captive propagation

    Deliberate (artificial) selection

    • to remove genetic diseases

      Chondrodystrophy in California condor:

      - lethal recessive trait – hatchlings die

      - gene could be removed in one generation by removing 77 of 146 condors

      - careful breeding program was implemented instead


    Problems with captive propagation2

    Problems with captive propagation

    Accidental selection

    • for increased productivity – fecundity, growth, or both

    • domestication – select for fitness under captive conditions

      • tends to homogenize differences among sub-populations


    Problems with captive propagation3

    Problems with captive propagation

    Absence of selection


    General post release problems

    General post-release problems

    • lower fitness in wild

      • domestication – genetic and/or behavioral

      • loss of variation

    • increased fitness in wild

      • loss of wild populations through competition for mates, habitat – captive-bred may be healthier

      • different development stages


    General post release problems1

    General post-release problems

    • lower fitness in wild

    • increased fitness in wild

    • Lake trout (Foster 1984)

      • rapid early growth in hatchery

      • young age at sexual maturity

      • premature reproductive senescence


    General post release problems2

    General post-release problems

    • captive individuals may hybridize with wild indivs.

      • pollution of wild genome

      • loss of variation if lowered variance in captive stock


  • Login