Flashcards in exam III-supplement 13 Deck (5)
what is a reintroduction program?
involves releasing captive-bred or wild-collected individuals into an ecologically suitable site within their historical range where species no longer occur.
Main purpose – create new population in its original environment and help restore a damaged ecosystem; wolves at Yellowstone, do research to understand what forces will have upon existing populations
– do we have to know reintroducing wolves will affect beavers?
Probably not – native species that hasn’t been around in 65 years but shouldn’t affect it too greatly.
Reasonable to do within guided instances (depth of investigation wouldn’t be as great as an introduction program) all wolves extinct, bring Indian dholes over and put in Yellowstone (wild canid), this would be a bad example and not good practice. (rabbit vs elephant at Wesleyan)
what is a reinforcement program?
restocking/augmenting individuals into an existing population to increase its size and gene pool.
Main purpose – increase small population sizes to prevent against local extinction; soft releases, reinforcements to population via small releases; facilitate reintroduction, increase genetic diversity.
Zoo with captive breeding keep detailed genealogies - why? Mate with genetic variance – prevent inbreeding.
Logic could apply to facilitating long distance populations of same species (put different individuals into different populations).
Why not let nature take its course? We are already super involved with buildings, roads, people between species and habitats.
what is an introduction program?
moving captive-bred or wild-collected plants or animals to areas suitable for the species outside their historical range. Main purpose – environment inside known range has deteriorated where species can no longer thrive there, or factor causing original decline is still present. (generally frowned upon); last ditch effort to save species or environment; similar species went extinct – introduce similar species to have same impact. Coyotes became larger and started running in larger packs, not just relatives (65 lbs vs 35 lbs) latitudinal effects (species get larger, limbs get smaller) but difference between NE and Wyoming not that great. More food available if wolves weren’t present. Shift in phenotype of coyotes backwards now. Dhole would compete more directly with coyotes than wolves. Dholes might get larger or vice versa, unknown factors are a problem.
Introduction program example
wolves were believed to pose a threat to herds of elk and other game animals, 1995 and 1996 elements of 5 wolf packs were transplanted, wolves are helping to reshape the ecological structure of the park through trophic interactions – elk numbers are declining and congregating in larger numbers for herd protection, availability of carrion from wolf kills provides food for scavengers, some tree species are already recovering from increased grazing pressure from too many elk. 1987 proposed wolf be reintroduced, people were concerned they were going to kill elk… duh. Said wolves and bears would attack children as they got off the bus, government attempt to take over lands, wolves would reduce number of elk in Yellowstone and elsewhere so they couldn’t be hunted anymore, no one would be able to do anything else than visit (no logging, mining etc) fearful outcries. Defenders of wildlife said they would reimburse for damages due to wolves, and they do. Quieted most folks down except anti-federal government shit.