Lecture 7a: Returning Animals to the Wild (Theory) Flashcards
Methods of maintaining threatened speacies
- removing other stressors
- in-situ management
- assisted migration
- species rescue
Goal of establishing new populations
establish self-sustaining populations
Translocation
movement of living organisms from one area with free release in another area (IUCN definition)
Three types of translocation
Introduction - releasing animals into habitat they have never occurred naturally (purposefully or accidently)
Reintroduction - releasing animals into an area where they have declined or disappeared
Reinforcement - restocking of a population by adding individuals to it from elsewhere
Reintroductions can involve..
- translocations of non-captive individuals (ex. Moving Canada geese from one population to another)
- release of captive born individuals
- release of wild-born but captive raised animals or plants (ex. head starting - take it out of a wild during young and keep until over the age where mortality occurs in the wild)
Why translocate organisms?
- establish new populations or enhance existing populations to improve species’ chances of survival
- restore a damaged ecosystem
- remove stressors
- establish a species for specific purposes
- protect animal/people from each other (polar bear jail - prevent them from coming into town)
Rehabilitation
process by which naive animals are trained to live in their natural habitat (which needs to take place BEFORE they can be released into wild)
Can a captive-reared population be reintroduced?
- does the captive population contain rare species who can be used to restock small populations/reintroduce species to area where extirpated?
- large enough to act as self-sustaining populations?
- adequate supply of individuals (need to release many individuals over months)
Establishing new plant populations
Germinate seeds and grow plants in greenhouse, then translocate them once past seedling stage
> this increases chance of success, but new populations can still fail
Three factors to increase success for establishing new plant species
- use multiple sites for translocation
- maximize the number of transplants (don’t just release a few)
- reintroduce species over several successive years at the same site (can’t just put them in all out at once)
How do zoos/botanical gardens contribute to reintroductions
- organisms from captive breeding programs
- people for overseas project administration
- funds
- specialized technical expertise
- zoos could focus on small species that are easier to maintain in large numbers (eg. retiles and amphibians)
- Millennium Seed Bank Project aims to conserve plants in seedbanks
Successful Translocations (theoretical considerations)
- strategic approach
- ecological setting for release
- genetics of populations
Strategic Approach
- you have to have a plan and your plan has to be strategic
- types of releases: hard and soft
- soft is ideal for success because they get to acclimate to the area. For hard, they all disperse and they never see each other again.
Ecological Setting for Release
- where are you going to release them
- determine reasons for species decline
- assess population’s life history in a natural setting
- assess habitat before any reintroductions can occur:
>ecological factors that influence age-specific birth and death rates
>smaller animals that are specialists/have complex life cycles are harder to successfully translocate
>may no longer have wild populations to study (have to make inferences from close relatives)
Life history traits
- reproductive strategies of organisms (how many / when to produce)
- timing of life cycle events
