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Reintroductions & Translocations Continue to be an important tool in wildlife management
Reintroductions & Translocations
Continue to be an important tool in wildlife management
Wildlife Reintroductions• Does habitat
remain?– How much?– Connected?– Management?– Competition /
Predation / Diseases
Wildlife Reintroductions
• Viable Population?– PVA
• VORTEX• RAMAS
Wildlife Reintroductions
• Viable Population?– PVA
• VORTEX• RAMAS• Incorporate GIS
Wildlife Reintroductions• Genetic
Considerations – Why should you care?– Genetic swamping?
Genetic Considerations: Genetic Considerations: Why Should You Care?Why Should You Care?
• Genetic variation is the underlying basis for adaptation to future environmental change
• Loss of genetic variation is often a direct consequence of species reintroduction
• Understanding how genetic loss occurs can help to prevent management actions that decrease the genetic diversity of reintroduced wildlife species
Wildlife Reintroductions• Genetic
Considerations– Inbreeding– Did we release
highly related individuals?
Wildlife Reintroductions• Genetic
Considerations– Founder Effect
Founder EffectFounder Effect
• The reduction in overall genetic diversity experienced as a consequence of population establishment from a limited sample of individuals– Most reintroductions and natural
colonization events exhibit Founder Effects– The magnitude of the effect depends upon
the number of animals translocated or colonizing an area
Wildlife Reintroductions• Genetic
Considerations– Genetic Bottleneck
BottleneckBottleneck
• An event in which a population drops significantly in size and then recovers
• Events such as habitat loss, over harvest, or reintroduction can create bottlenecks and the magnitude of the effect on genetic diversity depends upon:
– Number of individuals at lowest point– Length of time population remains depressed
Genetic DriftGenetic Drift
• Random fluctuations in gene frequencies due to temporal variance in survival and reproduction– Small populations drift more rapidly than large
ones– Higher reproductive and survival rates can
slow the rate of genetic drift– Genetic drift can result in loss of genetic
diversity as well as increases in the frequency of rare alleles
InbreedingInbreeding
• Mating of closely related individuals• Anytime genes that are alike by descent (i.e.,
from a shared ancestor) come together within individuals– Enhanced by slow population growth rates– Affected by mating system– Influenced by the relatedness of the initial
population founders (e.g. reintroductions)
Hypothetical Source Population
Different Colors Represent Copies of Different Genes
Loss of Alleles Due to
Original Sampling
Event
Trap and Transplant
• Small Samples From Source
• Incomplete Sampling of Genes
• Sampling of Related Groups
Reintroduced Population
Loss of Alleles Due to Post-Release
Stochastic Processes
Founder Effects
• Differential Survival of Founders
• Differential Survival of Offspring
• Differential Reproductive Contributions
Genetic DriftInbreeding
Loss of Alleles Due to Stochastic And
Deterministic Processes
Over Generations
• Inefficient Transfer of Genes
• Unequal Reproductive Contributions
• Differential Survival
• Mating of Closely Related Individuals10
10 Generation Bottleneck
Genetic DriftInbreedingLoss of Allelic
Diversity Apparent
20 Generation Bottleneck
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Genetic DriftInbreeding
Loss of Allelic Diversity Dramatic
Common Allele Predominant
30 Generation Bottleneck
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Loss of Allelic Diversity Dramatic
Rare Allele Predominant
Wildlife Reintroductions• Genetic
Considerations– Marten
reintroductions
