Improving Fox Management Strategies in 2009. 7. 17.¢  The European red fox was introduced...

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Transcript of Improving Fox Management Strategies in 2009. 7. 17.¢  The European red fox was introduced...

  • D E P A R T M E N T O F A G R I C U L T U R E , F I S H E R I E S A N D F O R E S T R Y

    Improving Fox Management Strategies in Australia Glen Saunders and Lynette McLeod

  • The European red fox was introduced into Australia in the 1870s for recreational hunting. Their subsequent spread was rapid and

    they are now responsible for environmental and agricultural impacts valued at over $200 million per annum.

    Despite greater public awareness about feral cats, foxes are considered

    to be Australia’s greatest predation threat to the survival of native fauna –

    particularly relevant given their recent introduction to Tasmania.

    Foxes are also widely regarded as a major threat to lamb production,

    although it is important to recognise that many factors involved in

    poor lambing percentages are inconspicuous, whereas damage

    inflicted by predators is usually highly visible.

    There have been surprisingly few scientifically-rigorous studies to confirm

    or refute many of the perceived impacts of foxes on agriculture and the

    environment. The need for further impact and cost–benefit studies is a

    common theme in this review.

    Over the past decade there has been a dramatic increase in the use of

    1080 fox baits, and whilst the continuing trend toward coordinated regional

    fox baiting should be encouraged, it is also important to

    ensure that such baiting is conducted effectively, particularly

    considering that recent surveys suggest that fox impacts

    may be increasing in many areas.

    This report provides a comprehensive review of fox management

    strategies along with impacts and monitoring techniques. This

    includes a critical appraisal of past research studies and ongoing fox

    management programmes. A key finding is that problems with the

    experimental design and analysis of research and management has

    sometimes hindered progress in defining fox impacts and determining the

    best approach to reducing these impacts.

    This report offers a set of key recommendations for consideration

    by research agencies, land managers and policy-makers to

    improve and harmonise approaches to measuring and

    managing fox impacts.

  • 1080 poison baiting 76.7%

    Fox drives 0.4%

    Guard animals 3.6%

    Den fumigation 2.2%

    Exclusion fencing 1.4%

    Trapping 2.3%

    Ground shooting 13%

    Other 0.4%

  • Foxoff® baits 48%

    Heart 0.68%

    Tongue 2.42% Kidney 0.03%

    Liver 5.67%

    Unspecified red meat 14.03%

    Lamb 0.62% Horse 1.01% Beef 0.19%

    Sausage 0.32%

    Chicken heads 16.65%

    Chicken wingettes 9.74%

  • Baiting Strategy

    < 7 days

    > 7 days

    Cost-effectiveness

    Cost-effectiveness

    Min cost per lethal bait presented

    Min cost per bait consumed

    Min cost per bait consumed

    Min cost of bait procurement

    Min cost of bait distribution

    Min number of baits required

    Min number of procurements

    Min replacement

    Min persistence

    Min caching

    Min uptake

    Min cost per bait presented

    Min total cost per bait consumed

    Min total cost per bait consumed

    Min total cost

    Min total cost

    Min persistence

    Min caching

    Min uptake

    Longevity

    NONE

    7-14 days

    > 14 days

    DOC/WINGETTE

    DOC/WINGETTE

    DOC/WINGETTE

    DOC/WINGETTE

    DOC/WINGETTE

    DOC/WINGETTE

    DOC/WINGETTE

    DOC/WINGETTE

    DOC/WINGETTE

    DOC/WINGETTE

    DOC/WINGETTE

    FOXOFF

    FOXOFF

    FOXOFF

    FOXOFF

    FOXOFF

    FOXOFF

    FOXOFF

    FOXOFF

    FOXOFF

    Non-target safety

    Non-target safety

    Handling

    No replacement

    Replacement

  • 0

    0.1

    0.2

    0.3

    0.4

    0.5

    0.6

    0.7

    0.8

    0.9

    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

    R el

    at ive

    P ay

    of f

  • 0

    1

    2

    3

    4

    5

    6

    J F M A M J J A S O N D J F M A M

    April only

    July only

    Nov only

    No Control

    J J A S O N D J F M A M J J A S O N D

    Month

    D en

    si ty

    ( fo

    xe s/

    km 2 )

    0

    1

    2

    3

    4

    5

    6

    J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D

    Month

    D en

    si ty

    ( fo

    xe s/

    km 2 )

    April only

    July only

    April and July

    No Control

  • J F M A M J J A S O N D

    Peak fox energy gain

    Birth of fox cubs

    Pre vixen pregnancy

    Lowest fox pop. numbers

    Juvenile fox dispersal

    Lambing period SpringAutumn

  • 0

    100

    200

    300

    400

    500

    600

    19 79

    /8 0

    19 81

    /8 2

    19 83

    /8 4

    19 85

    /8 6

    19 87

    /8 8

    19 89

    /9 0

    19 91

    /9 2

    19 93

    /9 4

    19 95

    /9 6

    19 97

    /9 8

    19 99

    /0 0

    20 01

    /0 2

    20 03

    /0 4

    N um

    be r (

    x1 00

    0)

  • Mound of soil

    fc d

    e

    b

    a

    Ground level

  • 0

    500

    1000

    1500

    2000

    2500

    3000

    3500

    4000

    4500

    5000

    1980 82 84 86 88 90 92 94 96 98 2000 02

    10 80

    (g )

  • O N

    p

    p O N O N

    i

    i i p

    O N

    ˆ ˆ

    i N p

    O i

    F̂ i

    A

    A

    FO D iii

    ˆ ˆ

    D i

  • f x

    f = 1–e x

    x

  • F

    F = S / KD

    S K

    D

    F

    S L

    L D

    N P

    F = ________ SLt

    Ln DNP

  • n 1

    n 2

    m 2

    2

    21ˆ m

    nn N

    Oi

  • N 1 = (I

    1 C)/(I

    2 – I

    1 ) and,

    N 2 = (I

    2 C)/(I

    2 – I

    1 )

    I 1

    I 2

    C

  • Pest Abundance

    D am

    ag e

    (i)

    (ii)

    (iii)