(kim) 24. Flashcards
What is a pest?
Cause of quantifiable economic/conservational damage (alien or native)
Give an example of a native animal in the uk that cause economic damage and explain how it causes damage economically?
Native stoats kill alien birds
- Alien birds originally imported to the UK for hunting/shooting
- Gamebird shooting is a big business in the UK and basicly the people who have an industry are killing the stoats as they are damaging the gamebird industry and losing them money
Give an example of damage caused to native eco systems..
Alien invasive stoats in NZ killing native bird fauna
What is a conflicting value in NZ?
Deer
- Alien species in NZ
- Regarded as a pest to DOC
- Prized to trophy hunters (like gamebird industry in UK)
First thing you have to do before you do any type of pest control:
- Know exactly what is causing the problem (stoat or possum etc)
- Follow this action with a reversible experiment
Give an example of a reversible experiment in the UK.
Funded by Birdgame Organisation
1. Assertain what is causing decline in partridge population
2. Chose two areas 1km apart and counted partridges
- (Large circles = family groups / Squares = pairs with no chicks)*
- (triangle = individual males)*
3. In ‘right’ area predator control and ‘left’ area no control
4. Did two operations every year for three years
5. Results show more partridges in areas where there are fewer predators
THIS IS NOT PROOF OF CAUSATION, IN ORDER TO PIN DOWN CAUSE, YOU MUST REVERSE EXPERIMENT AND DO PREDATOR CONTROL IN THE OTHER AREA AND LEAVE THE ORIGINALLY PROTECTED AREA UNPROTECTED
6. Reverse experiment results as expected, and area under new predator control allowed partridge population to increase with a decline in the population in the other area.
5 steps of strategy 1
‘Effective single action’
- Prevent new introductions (biosecurity, boarder control)
- Habitat manipulation (remove grass to remove rabbits etc)
- Fencing (Maungatautari Restoration Project - effective but expensive)
- Eradication (Best if you can achieve it, must be able to preven reinvasion. Easy to do on offshore islands but very hard on mainland and close to short islands)
- Biological control (Using disease to attack population - usually doesnt work)
What is strategy 2 & 3?
‘Sustained control & Do nothing’
Sustained control
-Sustained control by DoC, or sustained harvest by recreational hunters or commercial exploitation
Do nothing
No management solution exists
-effective control techniques not available or to expensive
If you Conditions for achieving eradication 1
(single effective action)
- ABSOLUTELTY EVERYTHING MUST BE AT RISK
(MUST BE ABLE TO REACH EVERYWHERE etc Aerial drop in hard to access areas)
- Must be able to get the last few otherwise eradication is impossible
Conditions for achieving eradication 2
(single effective action)
No recolonisation
What is the problem with stoats and close to shore islands?
Stoats are excellent swimmers
(can swim 2km comfortably)
(kapiti island and Rangitoto island)
conditions for achieving eradication 3
Effort must not slacken as returns diminish
(last few are most expensive, most vital, so funding must be gaurenteed to the end)
(control funds often switched to other targets too soon)
(So do native predators hunting native prey, which is why natural eradications rare - can’t waste energy seeking out low population of food source so they switch to more available foods)
Success in eradication
- Coypu: Large South American rodent introduced to UK for fur farming
- Escaped and established huge population centered on norfolk broads
- Tried to eradicate
What were advantages?
- Confined to small area relatively
- Very succeptible to cold winters
- Encouraged trappers to kill them and monitored programme very well
- Trappers not encouraged to put themselves out of work
(promised 3 years salary if they eradicated coyupu - excellent insentive)
Failure in eradication
American mink in the UK
- Imported for fur farming
- Escaped damaging native vole populations
(much loved native british mammal - ratty wind in the willows)
-National eradication campaign abandoned 1970
Consequences
Distribution of water vole decreased as mink spread through river thames catchment
Failure: Myxomatosis
-Classic animal example
- Very high mortality rates common at first, potential to wipe out population
- Killed 99% of population (never 100%)
- Huge selective advantage of relative immunity
- Survivors had immunity and next generation of rabbits were immune to disease.
What were the unintended consequence?
-Massive population crash of UK stoats in 1950’s
Why didn’t Myxomatosis work in NZ?
*Vectors
-Spread by blood sucking insects
(European rabbits lost their specific flea on route to AUS/NZ)
-Mosquitos spread it in Aus, not enough in NZ
What happened next?
RHD (Rabbit haemorrhagic disease)
1978 - RHD introduced and population drops
1984 - Population plateaus
1996 - pest control on cats to help sea birds
(As a result of cat pest control rabbits began to recover)
2006 - More intensive trapping campaign and more intensive khaleesi virus
2011 - Massive population plummet as a result of RHD, baiting, hunting and rabbit dogs.
2012 - R.I.P (Rabbit in peace)
