test 5, exotics, invasive species

extinction vs area size

the number of species is affected by: distance from mainland size of the island

exotics

those organisms that have been introduced into places they have no previously occupied introduced: -intentionally -by accident

risks of introducing exotics

three groups affected: intro species native species humans

impact of invasive species

-50000 foreign species in us and number is increasing -20-30 of these species are pests and cause environmental problems -ability to out-compete native species (42% of T&E species are at risk -may alter or destroy ecosystems and wildlife habitat -27% of species in GSMNP are exotic -spotted knapweed can reduce forage 80-90% on elk winter range -threat of hybridization w native species -invasive species are spreading at a rate of 1.73 mil acres of wildlife habitat/year -note: introduced species (wheat, rice, cattle, chickens) provide 98% of us food system at a value of 800 billion/year

invasive plants come in many different sizes and forms: -trees and shrubs -grasses and forbs -ferns

-and can affect almost any type of habitat -forests and meadows -wetlands and lakes -streams and pastures -agricultural fields -roadsides and rights of way

exotic is introduced into a vacant niche

-exotic is usually successful spread is rapid population densities increase rapidly and become very dense competition is minimal

3. prohibited actions

-include possession, importation, and taking -taking is defined as harass, harm, pursue, hunt, shoot, collect -harass and harm have been denied as broadly as possible to include significant habitat modification (this does apply to private land) -taking has been further interpreted to include declines in population trends that suggest long-term injury to the population (as least for federal agencies since federal agencies have the added responsibility of stewardship) -the listed species was increasing but not as fast as predicted, therefore the federal agency was in jeopardy of a taking - the federal agency failed to correct natural habitat changed or modification, and therefore was in jeopardy of a taking -the usfws recognizes that it is very difficult to win a case against a non-government land owner unless there is a warm body. therefore, most landowners specifically addressed in legislation, or for lack of action -however, a third party can sue the usfws for not taking action and the land owner can wind up in court that way. industry land, being large and visible targets, get more third party actions than individual private owners.

seeds arrive on site by

-nearby infestations spreading (animals, wind, water) -contaminated material (feed, crop seeds) -equipment being used on the land (tractors, combines, ATVs, trucks, boats)

site characteristics determine which species become invasive on a particular area

-soil type, light and water availability -disturbance history and climate

three main ways humans have cause extinctions

-uncontrolled exploitation by expanding human populations ecosystem alterations multiple factors

B the native species where introduction is taking place

1 can be low if the native population is one at extremes of its species distribution, population may be lost but is doing well in other parts of its distribution 2 can be very high if the impacted population represents a significatn portion of the species, such as an endangered species w limited range

reasons for failure

1 failure to evaluate biology and ecology of species and act accordingly 2 failure to release sufficient numbers in good health 3 failure to condition hand reared animals to the wild before releases: or recondition wild caught animals 4. failure to intensively manage and monitor released populations (may take 25 years to determine success or failure)

case for exotics

1 fill vacant niches 2 bolster habitats that have native populations that are not adequately abundant (mottled ducks in the southeast us) replace native species that cannot adapt to mans perturbations of the environment (pheasants do better than prairie chickens in agricultural fields) commercial enterprises (game ranching, aquaculture) to control pests (grass carp, talapia)

problems with reintro of native species

1 pen reared wild turkeys introduced into wild always failed. only wild birds of the correct subspecies were successful 2elk in kentucky-growing heards in areas experiencing rapid human population growth have created a rapidly rising number of nuisance calls and conflicts draining monies from wildlife management budgets

C humans

1. ethical traditional- loss of ecosystem/wildlife integrity 2. public health- potential zoonotic diseases 3. economic: -loss of public funds diverted from other programs for native species and used for introductions and combating problems w introductions - increased costs of goods and services due to industries costs for combating problems w exotics -direct loss of livestock and crops and damage to equipment homes etc

A. the introduced species- relatively small risk because

1. the only portion of populaiton taking risks is the population being introduced. the rest of the population is usually far removed from site 2 this population represents small portion of the entire species which is usually a successful species 3 if entire stocked population is lost, the impact on species usually is minimal

extinction due to mans impact

1. uncontrolled exploitation -subsistence hunting -market hunting types of markets (furs, pelts, hides, pets, items for religious or cultural traditions, collections) -market hunting most wildlife trade moves from impoverished countries to more industrialized countries impacts: probably twice as severe as market indicates because- 30/50 of hides and pets are lost before reaching the market. concetrated on rare species. juveniles are preferred and adults are often discarded.

extinction due to mans impact

2. ecosystem alteration changes in a species complex A. introduction of exotics competition and predation diseases and parasites hybridization B. reintroduction of populations where they had been previously extirpated (loss of genetic integrity, white tailed deer, largemouth bass) C. removal of keystone species (top predators on islands in south america alligators, beaver) Habitat alteration-most important dramatic losses (urban expansion, agriculture, forest management, dam and reservoir construction, draining wetlands, visible pollution) Insidious losses (inconspicuous or cover) invisible forms of pollution highway construction small scale drainage projects climate change conversions of forest systems to monocultures

extinction due to mans impact

3. multiple factors- a combination of natural and man-made factors may lead to extinction -extreme specialization make species more venerable to mans affects snail kite passenger pigeon american buffalo

extinction due to mans impact

75% of extinctions were dues to mans impact rates of extinction may be as high as 40-100 species per day of all species that have lived and died on the earth, 90% have gone extinct and most of these since mans arrival

natural phenomena

A. impact of other species -the length of the association influences the stability of the association -normal processes of competition and predation -hybridization

natural phenomena

B. natural environmental or habitat changes -gradual changes -abrupt or cataclysmic changes -species specialization

4. enforcement

a. authorizes civil penalties in original act for: -knowingly violating the act- max of 25000 per citaation -unknowingly violating the act- max of 500 per citation b. authorizes criminal penalties in original act for knowingly violating the act- max of 50000 per cite c. these maximums were increased by 250% in 1988 d. authorizes the department of justice or any citizen to bring action in federal county for an injunction to stop any jeopardy or taking e. also authorizes "incidental takings" as part of the consultation process

2. required federal conduct

a. federal agencies must conserve listed species generally b. and must ensure that their activities are not likely to: -jeopardize the continued existence of the species or -adversely affect critical habitat c. federal agencies also must consult w USFWS to assess whether or not the proposed action will comply with the ESA. 1) if the usfws rules that the proposed action will cause a negative impact on the endangered species, they issue a jeopardy opinion, and the plan must be modified 2) the affected agency can petition the interior for a exemption 3) the issue is resolved by a panel of experts or review board that reports to the endangered species committee (God Squad) which then makes the decision whether or not to make an exemption. cabinet level committee 4)GS grants exemption if they agree that -no acceptable alternatives to the proposed action that jeopardize the endangered species -benefits of the action outweigh the benefits of alternatives -action is in the public interest does not violate international treaty -action is of regional or national significance - reasonable mitigation is established

1. required initial process and actions of the USFWS

a. the listing process can be initiated by any individual, agency, or group by submitting a petition to the secretary of the interior, or the USFWS can initiate the process themselves b. the USFWS must follow a set procedure to determine if the species warrants listing c. this decision must be base solely on available biological evidence d. requests for delisting are handled the same way. e. criteria used to make this determination 1) habitat destruction-either current or threatened loss 2) over exploitation 3) disease or predation 4) inadequate regulations for protection 5) other natural or manmade factors f. secretary of interior does have emergency powers to delcare a species endangered g. the usfws is also to designate "critical habitat" 1)to be done at the time of listing, but usually takes much longer 2) this is where the economic impact enters the picture, economics can be considered when defining critical habitat h. the USFWS must adopt a recovery plan for the species- which often takes years to develop the research and write the plan.

intentionally

as keepsakes to enhance native flora and fauna

problems

asain eels -aquarium pet set free in the wild competes w reduced populations of american eels disrupts predator-prey relationships of native species can burrow in mud and stay out of water for 7 months, resistant to pesticides, no known predators (except alligators) and can breathe air

exotics introduced onto islands

can cause the heaviest damage or loss of native species native species are often easily out competed and easy prey ex: hawaii-old world rats introduced frmo ships have eliminated 60% of native land birds and all but one of its native mammals. mongoose introduced to control rats further reduced native species. native species also suffered from habitat loss due to intro of goats

by accident

carried in or on food, plants or cargo brought from foreign countries (zebra mussels, old world rats, fire ants) as a result of engineering projects that link two previously isolated ecosystems (sea lampreys)

problems

european boar and feral hogs -released by hunt club in smoky mountains destroys delicate climax plant communities, outcompetes native species for food, spreads swine brucellosis (zoonotic) and pseudorabies crop damage

exotics introduced onto islands

ex: brown tree snakes introduced in guam from cargo ships eliminated 9 species of birds and 5 species of lizards aggressive and mildly venomous commonly invade human dwellings

long list not to stock exotics

exotics may not stay where its put recreational quality may be reduced for the public that wishes to only go where native exist an evolutionary natural legacy will be lost, do people have the right to change the legacies for future gens?

problems

fallow deer pet, game species, food number one carrier of deer tuberculosis can outcompete native white-tailed deer

long list of reasons not to stock exotics

few successes species may be pest or failure impossible to do prestocking research on either area suitability or pest hazards the ecological community may be disrupted, and it may not be restored by simply removing the problem animals foreign diseases and parasites of wildlife can be transmitted and become epidemic

the release of wildlife into territory foreign to it involves not a calculated risk, but a risk too great to calculate

from the alien animals by george laycock

problems

house sparrow brought from england as pet displacement of native species crop damage

exotic is introduced into an occupied niche

introduced exotic will fail native species will be replaced both will adapt hybridization will occur which can cause loss of the integrity of the species and/or change in protective coloration, breeding habits, etc

fragmentation of habitats

isolation habitat size

management options:

many are so common that eradication is impossible -manage at low levels by incorporating invasive control as part of management activites -be watchful and take action as soon as you spot an invasive species -firebreaks, food plots, roadsides, cut-over areas (disturbances) -inspect and clean equipment to remove any seeds or plant material before using it on your land

extinction vs area size

most affected: those that require large homeranges top level carnivores large bodied species territorial species those at precariously low densities

top ten invasive species in the southeast

multiflora rose kudzu autumn olive exotic lespedezas (sericea, bicolor) japanese climbing fern cogongrass privet japanese honeysuckle tallow tree (popcorn tree) nepalese browntop (jaspanese stiltgrass)

factors that threaten a species or cause extinction

natural phenomena mans impact multiple factors

because invasive species are in a new environment, and are free from the natural predators, parasites, and competitors of their native habitats, their populations can explode

results- -these can out compete and replace native species -lead to reductions in wildlife food and habitat -also disrupt land use and management -potential to alter vital ecosystem functions such as water flow, nutrient cycling or soil decomposition

successes

ring necked pheasant- most successful example game animal introduction in us brown trout from europe rainbow trout from western states stocked into eastern rivers and lakes

a note on controversial species

some invasive species are planted and/or managed as wildlife food and cover but can exhibit invasive characteristics and spread aggressively if not properly contained -privet -japanese honeysuckle -bi-color lespedeza -autumn olive -saw-tooth oaks

extinction is a natural process and is part of evolution

species lost through natural extinction are usually replaced by new species. that is, rates of new species evolution have kept up with or exceeded rates of extinction

invasive species

species that is not native to a specific location (an introduced species) and that has a tendency to spread to a degree believed to cause damage to the environment, human economy or human health

problems due to intro of exotics

starlings -introduced by poet in ny -loss of grain and crop damage, spread diseases, aviation hazard, pre-empted many cavity nesting sites of bluebirds

long list of reasons not to stock exotics

stocking efforts tend to detract from native species management importations are an admission of defeat in managing native populations to meet existing needs stocking exotics is usually a response to few people with loud demand, and rarely representative of the will of most people the total selection, transportation, quarantine, and supervision costs are very great. costs are usually relayed to the public

Endangered species

the endangered species act has four principle elements, that each describe a set of actions or regulations that must be folowed

gauses rule of competitive exclusion

two species cannot coexist permanently in the same niche

problems due to intro of exotic

water hyacinth introduced by an individual who thought it would add beauty to the backwaters of florida rapid growth, blocks waterways, limits boat traffic, recreation, crowds out native species, reduces bio diversity, decaying plants reduces oxygen levels and increases eutrophication to extreme levels for many fish populations