to 20' Pest Management

1
Terrestrial ecology

• to 20. Pest Management

2
Whats a pest?

• What characterises a pest?
• How would you define the term pest?

3
Whats a pest?

• an animal that has a detrimental effect on a
  valued resource

4
Whats a valued resource?
5
Whats a valued resource?

• Natural environment / ecosystem / species
• Agricultural / forestry crop
• Something used / needed/ liked / wanted by
  someone

• pest value judgement
• DISAGREEMENT

6
So pests can be

• Introduced / native
• Herbivores / omnivores /carnivores
• In towns / country
• In National Parks / farmland / forestry

detrimental effect on a valued resource
7
and Pests are

• Time specific
• Place specific
• Person specific

8
Pest impact via interactions

• competition
• predation
• herbivory

9
Aim of pest management?

• ? numbers?
• ? detrimental impact?

• Often component of conservation management
• Endangered species
• Communities / ecosystems

10
Manage impact of pests - how?

• List general methods
• Which methods suit which situations?
• Give examples
• Advantages /disadvantages of each?

11
Manage impact of pests - how?

• ? numbers (? population size)
• ? mortality (affect deaths)
• DIRECT shoot, trap, poison
• INDIRECT introduce pathogen e.g. myxoma virus,
  calicivirus - rabbits
• ? fecundity (affect births)
• DIRECT baits with birth control
• INDIRECT introduce self-spreading vector to
  transmit birth control
• ? behaviour

12
Management by numbers (populations)
r rate of increase slope

• Pests
• r high, ve
• or popn. K r 0
• Endangered sp.
• Low population
• r 0 or -ve

13
Pest rates of (populations) increase
Hone L95 p714 Fig 1 A rabbit B red fox C
house mouse

• Pests
• r high, ve
• or popn. K r 0

Hone J. (1999) On rate of increase (r) patterns
of variation in Australian mammals and the
implications for wildlife management. Journal of
Applied Ecology, 36, 709-718.
14
Management by numbers (populations)

• Three problems
• Conservation
• ? abundance
• r gt 0
• Sustained yield
• Maintain abundance
• r 0
• Pest control
• ? abundance
• r lt 0

15
Management by numbers (populations)

• Conservation management of endangered species
• Directional selection against ve rates of
  population increase

Hone J. (1999) On rate of increase (r) patterns
of variation in Australian mammals and the
implications for wildlife management. Journal of
Applied Ecology, 36, 709-718.
16
Management by numbers (populations)

• Sustainable harvesting
• Stabilizing selection against extremes of high
  and low rates of population increase

17
Management by numbers (populations)

• Pest control
• Directional selection to abundance
• Shift rates of increase to lower or -ve levels

18
Management by numbers
Endangered species
Sustained harvest
Pest control
during
after
19
Pest impact management by numbers

• -ve rate of increase ? population
• Methods
• ? mortality (affect deaths)
• ? fecundity (affect births)

20
Aim ? pest impact Method 1 ? pest
numbersProblems ?

• Humaneness?
• Numbers vs. impact?
• Enhanced demographic vigour?
• Non-target species?

21
Humaneness

• Irrespective of status of animal

22
Numbers vs. impact?
23
Numbers vs. impact - example
Tree seedling damage on plantations in Tasmania
Pademelons
BT possums
24
Numbers vs. impact - example
Tree seedling damage on plantations in Tasmania

• 32 E.nitens plantations
• seedlings assessed for damage at 12 months
• vegetation characteristics measured
• index of animal abundance scat counts
• (stepwise) linear regression

25
Numbers vs. impact - example
Tree seedling damage on plantations in Tasmania
26
Numbers vs. impact - example
Tree seedling damage on plantations in Tasmania
y 0.46 2.00x1 1.61x2 0.13x3 r2
0.71 y damage score x1 possum abundance
(scats) partial r2 0.54 x2 grass cover
(transformed) partial r2 0.09 x3
bracken cover (transformed) partial r2 0.09
Bulinski J. McArthur C. (2003) Identifying
factors related to the severity of mammalian
browsing damage in eucalypt plantations. Forest
Ecology and Management, 183, 239-247.
27
Numbers vs. impact - example
Tree seedling damage on plantations in Tasmania
Bracken
Grass
Poss scats
y 0.46 2.00x1 1.61x2 0.13x3 y
damage score x1 possum abundance (scats)
?
Damage
Population size
28
Numbers vs. impact - example
Tree seedling damage on plantations in Tasmania
Bracken
Grass
Poss scats
y 0.46 2.00x1 1.61x2 0.13x3 y
damage score linear pademelon scats not
significant
Damage
Population size
29
Enhanced demographic vigour
30
Enhanced demographic vigour

• Caughley Sinclair p292 Table 17.1

Caughley G. Sinclair A. R. E. (1994) Wildlife
Ecology and Management, 1st edn. Blackwell
Science, Cambridge, Massachusetts.
31
Enhanced demographic vigour

• ? proportion of breeding females
• ? mortality of young (? survival)
• Younger age to maturity

32
Non-target species

• Affect pest - affect others?
• Direct indirect interactions

pest
33
Non-target species - example
Prey switching by wedge-tailed eagles as rabbit
numbers ?

• Mutawintji National Park
• 120km NE of Broken Hill, NSW
• Destructive sampling of nests (not recommended)
• Assess eagle diets
• before (1995)
• during (1996)
• after (1997) RCD rabbit calicivirus disease
• RCD rabbit abundance ? 44 78

Sharp A., Gibson L., Norton M., Ryan B., Marks A.
Semeraro L. (2002) The breeding-season diet of
wedge-tailed eagles (Aquila audax) in western New
South Wales and the influence of Rabbit
Calicivirus Disease. Wildlife Research, 29,
175-184.
34
Non-target species - example
Prey switching by wedge-tailed eagles as rabbit
numbers ?
eagle
reptiles
rabbit
others
35
Non-target species - example
Prey switching by wedge-tailed eagles as rabbit
numbers ?

• 2071 prey items identified

Sharp A., Gibson L., Norton M., Ryan B., Marks A.
Semeraro L. (2002) The breeding-season diet of
wedge-tailed eagles (Aquila audax) in western New
South Wales and the influence of Rabbit
Calicivirus Disease. Wildlife Research, 29,
175-184.
36
Non-target species - example
Prey switching by wedge-tailed eagles as rabbit
numbers ?

• Dietary items (as of total)

Sharp A., Gibson L., Norton M., Ryan B., Marks A.
Semeraro L. (2002) The breeding-season diet of
wedge-tailed eagles (Aquila audax) in western New
South Wales and the influence of Rabbit
Calicivirus Disease. Wildlife Research, 29,
175-184.
37
Non-target species - example
Prey switching by wedge-tailed eagles as rabbit
numbers ?

• Evidence consistent with prey switching
• Impact of rabbit control on non-targets
• Enough alternative prey to sustain eagles?
• Effect of change in diet on native prey?
• Need to monitor populations

Sharp A., Gibson L., Norton M., Ryan B., Marks A.
Semeraro L. (2002) The breeding-season diet of
wedge-tailed eagles (Aquila audax) in western New
South Wales and the influence of Rabbit
Calicivirus Disease. Wildlife Research, 29,
175-184.
38
Aim ? impact Method 1 ? numbersProblems ?

• Humaneness?
• Numbers vs. impact?
• Enhanced demographic vigour?
• Non-target species?

Ecology
39
Aim ? impact Method 1 ? numbersProblems ?

• Can you kill enough animals?

• Sustained yield
• Maintain abundance
• r 0
• Pest control
• ? abundance
• r lt 0

40
Can you kill enough animals?
Goats in Egmont National Park can they be
eradicated?
Forsyth D. M., Hone J., Parkes J. P., Reid G. H.
Stronge D. (2003) Feral goat control in Egmont
National Park, New Zealand, and the implications
for eradication. Wildlife Research, 30, 437-450.
41
Can you kill enough animals?
Goats in Egmont National Park can they be
eradicated?

• 1910 Goats 1st report in ENP
• 1920 large goat herds
• 1925 Ranger appointed to control goats
• 1925 1940 control intermittent
• 1950 bounty introduced
• 1961 1987 NZFS hunters to control goats
• 1987 present DOC hunters to control goats

Forsyth D. M., Hone J., Parkes J. P., Reid G. H.
Stronge D. (2003) Feral goat control in Egmont
National Park, New Zealand, and the implications
for eradication. Wildlife Research, 30, 437-450.
42
Can you kill enough animals?
Goats in Egmont National Park can they be
eradicated?

• Model population change based on
• Assume logistic growth
• Maximum rate of increase of goats (rm) 0.468
• Carrying capacity K 10000
• Current population size 1047

Forsyth D. M., Hone J., Parkes J. P., Reid G. H.
Stronge D. (2003) Feral goat control in Egmont
National Park, New Zealand, and the implications
for eradication. Wildlife Research, 30, 437-450.
43
Can you kill enough animals?
Goats in Egmont National Park can they be
eradicated?
Forsyth D. M., Hone J., Parkes J. P., Reid G. H.
Stronge D. (2003) Feral goat control in Egmont
National Park, New Zealand, and the implications
for eradication. Wildlife Research, 30, 437-450.
44
Can you kill enough animals?

• killed must be high enough to ? population
• Eradication
• High effort ()
• often not feasible

45
Manage impact of pests - how?

• ? numbers (? population size)
• ? mortality (affect deaths)
• DIRECT shoot, trap, poison
• INDIRECT introduce pathogen e.g. myxoma virus,
  calicivirus - rabbits

• Humaneness?
• Numbers vs. impact?
• Enhanced demographic vigour?
• Non-target species?
• Can you kill enough?

46
Manage impact of pests - how?

• ? numbers (? population size)
• ? mortality (affect deaths)
• ? fecundity (affect births)
• Especially for vertebrate pests
• DIRECT baits with birth control
• INDIRECT introduce self-spreading vector to
  transmit birth control

Barlow N. D. (2000) The ecological challenge of
immunocontraception editor's introduction.
Journal of Applied Ecology, 37, 897-902.
47
Pest management by fertility control

• Fertility control
• any technique that ? production of young
• Methods
• temporary or permanent sterilisation
• E.g. immunocontraceptionallergic to
  reproducing
• Steps in R D
• Develop something which inhibits reproduction
• Does it ? population size?
• Does this ? impact of pests?

48
Pest management by fertility control

• Risks e.g. SARS
• Bird virus
• Bird ? human
• Human ? very sick/die
• Recently
• 1st case human-human transfer

• Advantages
• More humane?
• More sustained effect?
• Disadvantages
• Could it ever work?
• Risks?

49
Step 1 immunocontraception
50
Step 1 immunocontraception
Lloyd M. L., Shellam G. R., Papadimitriou J. M.
Lawson M. A. (2003) Immunocontraception is
induced in BALB/c mice inoculated with murine
cytomegalovirus expressing mouse zona pellucida
3. Biology of Reproduction, 68, 2024-2032.
51
Step 1 immunocontraception

• Trials
• Short term
• 10 females innoculated (virus or placebo)
• 1 male mouse until females pregnant
• Long term
• Groups of females (virus or placebo)
• 1 male per group females long-term

Lloyd M. L., Shellam G. R., Papadimitriou J. M.
Lawson M. A. (2003) Immunocontraception is
induced in BALB/c mice inoculated with murine
cytomegalovirus expressing mouse zona pellucida
3. Biology of Reproduction, 68, 2024-2032.
52
Step 1 immunocontraception

• Short term trial results

• Lloyd et al 2003 SC31
• Table 4 short term male intro - effects
• Fig 5A long term male pesence effects on
  births

Lloyd M. L., Shellam G. R., Papadimitriou J. M.
Lawson M. A. (2003) Immunocontraception is
induced in BALB/c mice inoculated with murine
cytomegalovirus expressing mouse zona pellucida
3. Biology of Reproduction, 68, 2024-2032.
53
Step 1 immunocontraception

• Long term trial results

Lloyd M. L., Shellam G. R., Papadimitriou J. M.
Lawson M. A. (2003) Immunocontraception is
induced in BALB/c mice inoculated with murine
cytomegalovirus expressing mouse zona pellucida
3. Biology of Reproduction, 68, 2024-2032.
54
Pest management by fertility control
?

• Steps in R D
• Develop something which inhibits reproduction
• Does it ? population size?
• Does this ? impact of pests?

55
Step 2 does sterilisation ? population size?

• Sterilisation of females may change?

• Dominance
• Territoriality
• Proportion of breeding females

56
Step 2 does sterilisation ? population size?

• Example 1
• dominance relationship within group hasNO EFFECT
  on a females probability of breeding

Caughley G., Pech R. Grice D. (1992) Effect of
fertility control on a population's productivity.
Wildlife Research, 19, 623-627.
57
Step 2 does sterilisation ? population size?

• Example 2
• dominance relationship within group is linear
• only top dominant breeds
• sterilisation removes female from dominance
  hierarchy

Caughley G., Pech R. Grice D. (1992) Effect of
fertility control on a population's productivity.
Wildlife Research, 19, 623-627.
58
Step 2 does sterilisation ? population size?

• Example 3
• 1 female dominant (all others equally
  subordinate)
• only top dominant breeds
• sterilisation removes dominant female, all
  others free to breed

Caughley G., Pech R. Grice D. (1992) Effect of
fertility control on a population's productivity.
Wildlife Research, 19, 623-627.
59
Step 2 does sterilisation ? population size?

• Example 1
• dominance relationship within group hasNO EFFECT
  on a females probability of breeding

• Example 2
• dominance relationship within group is linear
• only top dominant breeds
• sterilisation removes female from dominance
  hierarchy

• Example 3
• 1 female dominant (all others equally
  subordinate)
• only top dominant breeds
• sterilisation removes dominant female, all
  others free to breed

60
Step 2 does sterilisation ? population size?

• Example 1
• dominance relationship within group hasNO EFFECT
  on a females probability of breeding

Caughley G., Pech R. Grice D. (1992) Effect of
fertility control on a population's productivity.
Wildlife Research, 19, 623-627.
61
Step 2 does sterilisation ? population size?
Example 1

• Result
• ? females sterilised
• ? number of offspring

Caughley G., Pech R. Grice D. (1992) Effect of
fertility control on a population's productivity.
Wildlife Research, 19, 623-627.
62
Step 2 does sterilisation ? population size?
If N 1 If N 5 Where N number of females in
a group

• Example 2
• dominance relationship within group is linear
• only top dominant breeds
• sterilisation removes female from dominance
  hierarchy

• Example 3
• 1 female dominant (all others equally
  subordinate)
• only top dominant breeds
• sterilisation removes dominant female, all
  others free to breed

63
Step 2 does sterilisation ? population size?

• Example 2
• dominance relationship within group is linear
• only top dominant breeds
• sterilisation removes female from dominance
  hierarchy

Caughley G., Pech R. Grice D. (1992) Effect of
fertility control on a population's productivity.
Wildlife Research, 19, 623-627.
64
Step 2 does sterilisation ? population size?
Example 2

• Result
• ? females per group
• ? must be sterilised
• to get same mean number of litters per group

Caughley G., Pech R. Grice D. (1992) Effect of
fertility control on a population's productivity.
Wildlife Research, 19, 623-627.
65
Step 2 does sterilisation ? population size?

• Example 3
• 1 female dominant (all others equally
  subordinate)
• only top dominant breeds
• sterilisation removes dominant female, all
  others free to breed

Caughley G., Pech R. Grice D. (1992) Effect of
fertility control on a population's productivity.
Wildlife Research, 19, 623-627.
66
Step 2 does sterilisation ? population size?
Example 3

• Result
• sterilising may lead to ? number of litters per
  group
• opposite of desired effect

Caughley G., Pech R. Grice D. (1992) Effect of
fertility control on a population's productivity.
Wildlife Research, 19, 623-627.
67
Pest management by fertility control
?

• Steps in R D
• Develop something which inhibits reproduction
• Does it ? population size?
• Does this ? impact of pests?

Not always
68
Manage impact of pests - how?

• ? numbers (? population size)
• ? mortality (affect deaths)
• ? fecundity (affect births)
• Fencing - exclusion

69
Manage impact of pests - how?

• ? numbers (? population size)
• ? mortality (affect deaths)
• ? fecundity (affect births)
• Fencing (exclusion)
• ? behaviour

70
Changing pest behaviour

• ? numbers (? population size)
• ? behaviour
• How?
• Suitable for which pest problems?
• Give examples

71
Repellents to deter pests
Example 1 Big Game Repellent, apple twigs,
deer browsing

• How concentrated?

Andelt W. F., Burnham K. P. Baker D. L. (1994)
Effectiveness of capsaicin and bitrex repellents
for deterring browsing by captive mule deer.
Journal of Wildlife Management, 58, 330-334.
72
Repellents to deter pests
Example 1 Big Game Repellent, apple twigs,
deer browsing

• How effective over time?

Andelt W. F., Burnham K. P. Baker D. L. (1994)
Effectiveness of capsaicin and bitrex repellents
for deterring browsing by captive mule deer.
Journal of Wildlife Management, 58, 330-334.
73
Repellents to deter pests
Example 2 WR-1, eucalypt seedlings,
pademelon browsing
(but new growth eaten)
Witt A. Effects of repellents on seedling growth
and herbivory. B.Sc. (Hons.) Thesis, University
of Tasmania, Hobart.
74
Diversionary food to ? impact of pests
Example 3 Sunflower seeds, lodgepole pine trees,
red squirrel

• 3 paired sites
• 2 treatments
• Expt. control
• Diversionary sunflower seeds
• Damage to pine trees?

Sullivan T. P. Klenner W. (1993) Influence of
diversionary food on red squirrel populations and
damage to crop trees in young lodgepole pine
forest. Ecological Applications, 3, 708-718.
75
Diversionary food to ? impact of pests
Sullivan T. P. Klenner W. (1993) Influence of
diversionary food on red squirrel populations and
damage to crop trees in young lodgepole pine
forest. Ecological Applications, 3, 708-718.
76
Manage impact of pests

• ? numbers
• ? mortality (affect deaths)
• ? fecundity (affect births)
• Fencing (exclusion)
• ? behaviour
• Repellents
• Diversions

77
Main points

• Aim ? impact of pest
• Methods
• ? population or
• change behaviour
• Can ? population by
• ? Mortality
• ? Fecundity
• MUST consider
• Humaneness
• Effectiveness
• Numbers vs. impact
• Enhanced demographic vigour
• Can you kill enough?
• Non-targets

78
References

• Andelt W. F., Burnham K. P. Baker D. L. (1994)
  Effectiveness of capsaicin and bitrex repellents
  for deterring browsing by captive mule deer.
  Journal of Wildlife Management, 58, 330-334.
• Barlow N. D. (2000) The ecological challenge of
  immunocontraception editor's introduction.
  Journal of Applied Ecology, 37, 897-902.
• Caughley G., Pech R. Grice D. (1992) Effect of
  fertility control on a population's productivity.
  Wildlife Research, 19, 623-627.
• Caughley G. Sinclair A. R. E. (1994) Wildlife
  Ecology and Management, 1st edn. Blackwell
  Science, Cambridge, Massachusetts.
• Forsyth D. M., Hone J., Parkes J. P., Reid G. H.
  Stronge D. (2003) Feral goat control in Egmont
  National Park, New Zealand, and the implications
  for eradication. Wildlife Research, 30, 437-450.
• Hone J. (2004) Yield, compensation and fertility
  control a model for vertebrate pests. Wildlife
  Research, 31, 357-368.

79
References

• Hone J. (1999) On rate of increase (r) patterns
  of variation in Australian mammals and the
  implications for wildlife management. Journal of
  Applied Ecology, 36, 709-718.
• Lloyd M. L., Shellam G. R., Papadimitriou J. M.
  Lawson M. A. (2003) Immunocontraception is
  induced in BALB/c mice inoculated with murine
  cytomegalovirus expressing mouse zona pellucida
  3. Biology of Reproduction, 68, 2024-2032.
• Saunders G., McIlroy J., Berghout M., Kay B.,
  Gifford E., Perry R. van de Ven R. (2002) The
  effects of induced sterility on the territorial
  behaviour and survival of foxes. Journal of
  Applied Ecology, 39, 56-66.
• Sharp A., Gibson L., Norton M., Ryan B., Marks A.
  Semeraro L. (2002) The breeding-season diet of
  wedge-tailed eagles (Aquila audax) in western New
  South Wales and the influence of Rabbit
  Calicivirus Disease. Wildlife Research, 29,
  175-184.
• Sullivan T. P. Klenner W. (1993) Influence of
  diversionary food on red squirrel populations and
  damage to crop trees in young lodgepole pine
  forest. Ecological Applications, 3, 708-718.
• Witt A. Effects of repellents on seedling growth
  and herbivory. B.Sc. (Hons.) Thesis, University
  of Tasmania, Hobart.