Tambo Bluff Estate - Pest Control...

RTD4402A Define the Pest Problem in a Local Area Kate Gordon‐Addison 26 August 2010

Tambo Bluff Estate ‐ Pest Control Strategy

Introduction

This paper will discuss the various pest problems that exist on the Tambo Bluff Estate. The most intrusive pest is the rabbit but other pests include foxes, weeds and one of the world’s most enduring and widespread pests; man – a pest that will be acknowledged at this point but not discussed further. The Tambo Bluff has seen a variety of uses by man in recent history, from fishing and shelter for indigenous Australians, to cattle and sheep farming and currently a housing estate. The estate still retains some remnant vegetation and small pockets of uncleared land, providing the potential for a future where a housing estate could also be home to native birds and animals. The current development plans of local council (supported by some residents) are a limiting factor to creating a location that supports this potential future and current plans do not fully embrace the opportunity to create an environment for native flora and fauna. However, the main barrier to realising this potential is the presence of rabbits on the estate and this problem will be the main focus of this paper.

The Tambo Bluff Estate

Location

The Tambo Buff Estate is approximately 1.3km² (130ha) and is located by Lake King of the Gippsland Lakes; 31km south east of Bairnsdale and 23km west of Lakes Entrance (refer Appendix 1). It is primarily a housing estate with privately owned properties ranging in size from 800m² to 4,000m². The East Gippsland Shire Council owns some of the land, but their intention for future use of the land is unclear. The satellite photo (Appendix 4) shows that housing is sparse and much of the estate is open land with some vegetation. There are two lagoons (Bluff and Dolphin) within the estate and the west and south water boundaries are designated as park land and cannot be used for residential purposes.

On the west and south, the Tambo Bluff Estate is boarded by Lake King. To the north is agricultural land and to the east is the Kings Cove Golf Club and the Kings Cove Estate (refer Appendix 2). Most of the surrounding land is open with sparse vegetation and only small pockets of natural bush.

History

The Tambo Bluff was cleared for cattle farming in the mid 1800s and only a few remnant trees were left untouched and remain today. The Tambo Bluff proved unsuitable for cattle farming and sheep farming took over around 1920. Aerial photos taken in later years of the 1940s, show the area was almost totally devoid of understory with only the same remnant trees that remain today.

Historians of rabbits in Australia (Stodart & Parer, 1988) (Coman, 1999) (Williams, Parer, Coman, Burley, & Braysher, 1995) (Olsen, 1998), et al, agree that rabbits were fully established in the East Gippsland region by 1890. With the land already cleared, native ground dwelling animals would have, in all likelihood, already fled the Tambo Bluff by this time to seek shelter and food in a more densely vegetated home. Thus rabbits would have found a readymade home at the Tambo Bluff; an environment devoid of competition for food, with few predators and room to establish thriving colonies.

The Tambo Bluff Landcare Coastcare Group has conducted several revegetation projects over the last 20 years, specifically within the gullies and along the cliff edges. It is not known if there have been any previous attempts to reduce rabbit population, but there is no current program or initiatives in progress to cull rabbit numbers or maintain a low population.


Fauna

Some of the native fauna making the Tambo Bluff their home today includes: Echidnas, Sugar Gliders, Swamp Wallabies, Eastern and Crimson Rosellas, Swift Parrots, Magpies, Kookaburras, Rainbow Lorikeets, Common Bronzewings, Wattlebirds, Whipbirds, Sea Eagles, Whistling Kites, ducks and other water birds, frogs, and probably other reptiles, animals and birds that can’t be seen easily or observed by evidence such as scats. There is evidence – scats and burrows – of wombats living on the estate, but they generally remain true to their reclusive personalities and remain out of sight from human residents. Visitors to the estate include the Australian White Ibis, Yellow‐tailed Black Cockatoos, Galahs and many other birds.

Flora

There are three DSE recognised EVCs on the estate: Plains Grassy Forest, Shrubby Damp Forest and Deep Freshwater Marsh. Dominant tree species in the gullies include: Black Wattle (Acacia mearnsii), Black She‐oak (Allocasuarina littoralis), Blue Box (Eucalyptus bauerana), Southern Mahogany (Eucalyptus botryoides) and Forest Red Gum (Eucalyptus tereticornis). Along the bluff itself and foreshore tree species include: Coast Banksia (Banksia integriflora) and Sweet Pittosporum (Pittosporum undulatum). Understory species across the estate include: Prickly Currant‐bush (Coprosma quadrifida), Prickly Tea‐tree (Leptospermum continentale), Hop Goodenia (Goodenia ovata) and Hazel Pomaderris (Pomaderris aspera).

Pests Present on the Estate

Fauna Pests

Rabbits are the most obvious and prevalent fauna pest on the estate. Residents have reported the occasional sighting of a fox and as they are known to rely on rabbits as a food source, it is likely that foxes have found a living on the estate. However, the fox’s innate shyness and masterful ability to remain unobserved means it is virtually impossible to determine fox numbers solely by observation. Other pest animals of East Gippsland, such as Sambar and Hog Deer, wild dogs and feral cats show no signs of being present on the estate.

Juvenile and adult rabbits are easy to spot throughout the estate. At any time of the day they can be seen feeding and quickly hopping off to safety when any perceived threat approaches. There are rabbit droppings covering every part of the estate and fresh droppings can be found daily. There is also extensive evidence of rabbit scratchings both recent and old.

Flora Pests

Non indigenous / non native weeds present on the estate include:

Bridal Creeper (Asparagus asparagoides) (Muyt, 2001)

Agapanthus (possibly Agapanthus praecox)

Blackberry (Rubus fruticosus) (Muyt, 2001)

Kikuyu (Pennisetum clandestinum) (Muyt, 2001)

The Agapanthus and Blackberry has been subject to spraying and weeding by the Tambo Bluff Landcare Coastcare Group and other residents and is generally showing signs of being under control. Bridal Creeper can be found forming dense, smothering curtains in many areas of the Tambo Bluff and is especially vigorous during winter. With the advent of warmer weather, the rust fungus (Puccinia myrsiphylli) (CSIRO, 2009) seems effective in retarding the growth of individual plants and containing the spread of new plants.

RTD4402A DKate Gordon

There is no

Damage

The damaperiod) anJonathan S

Economic

As the esresponsiblthe rabbit conduct recost of reabove‐req

Environme

Somewhatsigns of phFigures 3 &over‐graziAny assessof a variet

Once cattlwould havdwelling mand their animals. Afoxes ‐ not

The physicThe estateunfair to presponsibi

Figures 3 & 4

Define the Pest n‐Addison

o evidence o

e to the Es

age rabbits hnd in consulSmith, Biolog

Damage

state does nle for any prpopulation evegetation eplanting is uirement nu

ental Damag

t surprisinglyhysical dama& 4). Howevng and this sment of damy of non indi

le grazing, ave naturally smammals to innate abilityAny native at an ideal situ

cal damage be has sufferpoint the finility lies for t

4 – two sites on t

Problem in a Lo

of native or in

state

have done ttation with gist and resid

not generaterivate econoon the estatplanting, plarequired du

umber of new

ge

y, 100+ yearage from waver, it is likelwould have mage to the igenous gras

nd later shestarted to remove back iy to dominaanimal returuation for th

being done ted long‐termger of blamhe introduct

he estate where

ocal Area

ndigenous pl

to the estatethe Tambo dent of the e

e income frmic costs orte. When thant loss due ue to the nw plants to c

rs of rabbit iarrens and tly that the nallowed intestate mustsses and the

eep grazing, eappear and nto the areate an area wrning to the he successful

oday is a conm from a lace squarely ation of this p

rabbits have clea

lants becom

e was assesBluff Landc

estate for ov

rom farmingr damage. Hhe Tambo Bluto rabbits m

need to provcover project

nfestation othere are onative grasseroduced grat include theeffective thi

were no lonthis may haa. However,would have estate woul repopulatio

ntinuation ock of diversat the rabbitpest.

ared the vegetati

ing a weed s

sed by ongocare Coastcaer 30 years.

g, it could bHowever theuff Landcaremust be takevide plants ted losses.

on the Tambly a few plas once foundass species, se eliminationis change has

nger in operaave been a sm the overbeaprevented thld have alsoon of native g

f the same dity in groun; although it

on and exposed t

species on th

oing observare Group an

be argued tre are publicCoastcare Gn into accouwith tree g

o Bluff has oces of rabbid on the estasuch as Kiku of native grs had on bio

ation, some mall inducemaring compehe natural reo faced the tground dwel

damage doned dwelling mt should nev

the sides of the g

26

he estate.

ation (over nd the grou

that the rabc costs assocGroup and Gunt. An increguards and

only left a feit induced eate have sufyu, to gain arasses and indiversity in t

understory ment for natetitiveness ofeintroductiothreat of prlling animals

e over past 1mammals anver be forgot

gully to erosion.

August 2010

a 6 month p’s leader,

bbit is not ciated with reen Corps ease in the include an

ew obvious rosion (see ffered from a foothold. ntroduction the area.

vegetation tive ground f the rabbit n of native redation by .

100+ years. nd it is not tten where

RTD4402A DKate Gordon

Figure 1 – Tminutes and displayed thewere obliging

Future Dam

Looking foestate; a fonce livedstatus on biodiversit

Damage b

The rabbitTambo BluCove and north and

Rabbit B

Habitat Us

The Europwith areas1995); maBluff provthere are mbracken theasily acceEagles livinthe immed

Breeding C

The rabbituntil the ftake full adof giving bcombined days, it is n

Define the Pest n‐Addison

This patch of br7 rabbits were

e shy and wary nag to pause long en

mage

orward, it cauture whered on the Tamthe estate, ty.

eyond the Ta

t problem in uff estate. Metung to north east is

Biology

se & Behavio

pean wild ras of vegetatioaking the Tamides excellenmany warrenhat grow freessible placeng / huntingdiacy of cove

Cycle

t’s breeding food source dvantage of birth and thwith a femnot surprisin

Problem in a Lo

racken was obse counted in thaatures of their spnough to be phot

n be argued e a residentiambo Bluff. Wthe Tambo

ambo Bluff E

the region iRabbits and the east, ans similarly af

our

bbit (Oryctoon cover andmbo Bluff annt conditionsns on the esteely throughes to hide (sg, on the ester available t

cycle in Ausmatures anthe season;e stimulatioale’s capacitng that the ra

ocal Area

erved for at leaat time. All rabecies ‐ none of thtographed.

that there ial estate couWhile the raBluff will ne

Estate

s widespreatheir impac

nd further effected.

lagus cunicud an intermen ideal homs for buildingtate. There hout the estsee Figure 1ate, but theto them; cove

stralia starts d dries out. autumn is tn of matingty to reprodabbit is fame

Figretand

st 5bbitshem

s also damauld also be hbbit, and itsever realise

d and affectct are easily east through

ulus) residenediate rainfae of choice.g warrens this also vast atate, giving t). There ar rabbits haver that is im

when feedi Spring pro

the slowest bg prompts ovduce at 6 weed for its pro

ure 2 ‐ As a rabbreat to safety und Prickly Currant‐

ge being donome to the ss silent partna potential

ts propertiesspotted on Nungurner

nt in Australall (Williams, The elevathat rabbits namount of cothe rabbits e Whistling ve a distinct penetrable t

ng pastures vides optimbreeding timvulation to oeeks of age lific fecundit

it, why hop to yoder the protectio‐bush?

ne is to one same varietyner the fox, future of ec

and commuthe borderito Nyerimil

ia favour anParer, Comated, deep saneed to survover in the san added adKites and atadvantage oo birds of pr

green up afal breeding

me. Females occur ten hoand a gestaty.

26

our burrow whenon of a dense tan

potential fuy of native anretain their cological ha

unities surroing propertilang. Farml

n open grassan, Burley, &andy soil of tvive and reprsaltbush and dvantage oft least one over these prey (see Figu

fter rain andconditions acan mate wours later. ation period

August 2010

you can easilygle of saltbush

ture of the nimals that “overlord” rmony and

ounding the es in Kings and to the

land home & Braysher, the Tambo roduce and patches of f quick and pair of Sea redators in re 2).

d continues and rabbits within hours This ability of only 30


Exploitation of Rabbit Weaknesses

The rabbit’s dependency on warrens and other cover is probably their greatest weakness; providing the best opportunity to break down the rabbit’s defences and reduce their population. By removing this one vertex of the survival triangle (food, shelter, water) it is possible to almost eliminate an entire rabbit population.

The relative flat open spaces and sandy soil of the Tambo Bluff would be easily ripped. The slopes of the gullies may be gentle enough to prevent the use of tractors and ripping equipment, but professional advice should be sought.

Legislative Requirements

“Mr Connor prophesied in the Victorian Parliament in 1869 that ‘the rabbit nuisance in this colony promised to be as great as that of the locusts in the land of Egypt’ and unsuccessfully moved to introduce control measure into the Local Government Bill.” (Stodart & Parer, 1988, p. 7). Although profound, Mr Connor’s foresight and warnings went unheeded and it wasn’t until 1875 that South Australia introduced the first Rabbit Destruction Act in Australia. In 1886 The Observer described government policies for controlling rabbits as effective as “trying to stop the tide with a pitchfork”. (Williams, Parer, Coman, Burley, & Braysher, 1995).

The current “pitchfork” approach in Victoria is covered by the Catchment and Land Protection Act (1994) (Victorian Government, 2009) and places the responsibility on landholders to take “sufficient action to destroy and suppress all vermin and to keep land clear and free of vermin.” (Williams, Parer, Coman, Burley, & Braysher, 1995).

Legislation covering the methods to control pest animals include Commonwealth Agricultural and Veterinary Chemicals Act (1988), Victorian Agricultural and Veterinary Chemical (Control of Use) Act (1992), Health Act (1958), Drugs, Poisons and Controlled Substance Act (1981) and the Occupational Health and Safety Act (1985). (Mitchell, 2006).

Objectives

The initial objective for the Tambo Bluff Estate is to reduce rabbit numbers to 0.5 rabbits per km² within 3 years. This objective supports the goal to create an environment where the existing native birds and animals thrive and face minimal competition from dominant pest species

Long term objectives, to be achieved over a 20+ year period, include the eradication of non indigenous predators (foxes), the sustained population control of non indigenous competitor species (rabbits), continued revegetation of gullies, lagoons, riparian zones and open public lands, and the reintroduction of appropriate native animals to the estate.

To achieve these objectives necessary activities include:

Minimise the rabbit population

Eradicate foxes

Provide the vegetation required to support the native birds and animals

Develop and maintain an ongoing strategy for maintenance and future development

Endorsement from current and future residents of the estate

Cohesive approach by residents of the Tambo Bluff estate, properties and communities surrounding the estate, local council and government bodies, such as CMA, DSE, Landcare etc


Management Options

Three options for the management of the rabbit population follows; a forth option – “do nothing” – has not be considered. Option 3 is the recommended approach.

Option 1 ‐ Eradication of rabbits from the estate

This option would require the extermination of all rabbits currently living on the estate and the creation of barriers to permanently prevent new populations of rabbits from moving in. A large scale approach; this option would require active participation by the communities and properties bordering the estate and would encompass many different property owners and interest groups. Although eradication of rabbits is an ideal outcome, this option is prohibitive due to the huge costs involved in the initial eradication and the ongoing cost and effort required to thwart repopulation.

Option 2 – One‐off Control of the current rabbit population

One‐off control might include a reduction of the rabbit population by poisoning and this may be an effective way to reduce the population of rabbits on the estate in the short term. However, the rabbit’s propensity to reproduce at alarming, yet highly effective, rates means any one‐off population cull would not provide any relief from the negative effects of the rabbit for long enough to allow for revegetation to be fully established and support the return of native animals. The costs of this option would show no return on investment, rendering this option futile.

Option 3 – Sustained control of the rabbit population

This option is an enduring program requiring the implementation and ongoing management of several activities, both short term and long term, including: a detailed site assessment of the estate, an initial and potent reduction the rabbit population and ongoing actions to keep the rabbit population at low numbers and discourage new rabbit populations from migrating on to the estate. This option requires a combination of approaches to ensure an overall and lasting reduction in the rabbit population.

Option 3 ‐ Recommendations & Actions

Short Term

1. Agreed strategy by Tambo Bluff residents and neighbouring property owners, local council and other stakeholders for the allocation of financial, human and equipment resources.

2. Conduct an extensive rabbit count to determine rabbit numbers per square kilometre. This may involve vehicle spotlight transect counts, walk transect counts, counts of rabbits near warrens and/or counts and mapping of warrens

3. Conduct a flora and fauna survey to ascertain precise data on all plants and animals living on the estate and any other current issues or potential problems not discovered to date.

4. The initial approach to cull the rabbit population involves using a trail of poison‐free carrots and/or oats leading to bait refuge with poisoned carrots and oats. As a residential zone with domestic pets, using baits must be conducted in the most risk‐free manner possible to avoid poisoning non‐target species (Mitchell, 2006). This would also provide protection against poisoning of native animals.

5. One month after the initial control method, another rabbit count should be conducted to assess the effectiveness of the poisoning and to determine if further action, i.e. step 6, is required.

6. If required, the second/follow‐up approach to rabbit population reduction includes: fumigating burrows, ripping warrens and removing ground cover (this should be assessed for any adverse impact on native animals). Williams, Parer, Coman, Burley, & Braysher, 1995 believe “treating rabbit populations when density is low greatly improves effectiveness, economy and


humaneness of control”. Given this, fumigation and ripping could be done in late autumn, at this time the soil would be relatively dry, making ripping easy, and it would coincide with the low point of the breeding season.

7. One month on, repeat rabbit count. 8. Review and evaluate short term activities and proposed long term activities.

Long Term

1. Commitment to agreed strategy by Tambo Bluff residents and neighbouring property owners, local council and other stakeholders for the allocation of financial, human and equipment resources.

2. Implement ongoing monitoring strategy – refer following section 3. If required , repeat fumigating of burrows 4. If required , repeated ripping of warrens 5. Commence eradication of the foxes. The Southern Ark Project could be contacted for advice and

possible involvement. 6. Fencing of sensitive areas may be appropriate as there are limited numbers of native ground

dwelling animals that would be negatively impacted. However, such fencing would require constant monitoring to ensure the well‐being of existing native animals. The costs associated with such monitoring may result in fencing being ultimately prohibitive, but the option still merits consideration.

7. Annual review of actions and monitoring strategy – any new developments in biological control may be included in ongoing management.

Monitoring & Evaluation

Ongoing monitoring and evaluation are vital steps in this program and allow for the program to be assessed for effectiveness and, if required, remodelled. Monitoring should continue for long enough to allow native vegetation to regenerate and native animals to become established in the area.

Annual monitoring activities should include:

Rabbit population counts – is further poisoning, ripping etc required?

Native flora and fauna surveys – is vegetation flourishing?

Ongoing evaluation of the program’s objectives and all activities is vital to ensure the long term success of the program. Evaluation allows for changes to be made to the program based on the effectiveness of current activities and the inclusion of new control techniques as they evolve.

Conclusion

The argument for reducing and controlling populations of rabbits, and other pest animals, is well understood hardly requires repeating or reinforcing here. The Tambo Bluff, with its natural borders of water, is ideally located and represents an excellent opportunity to commence pest animal control in the wider region. Fanning out from the south‐west corner of the bluff, pest animal control could push north and east with the knowledge that populations will not be replaced by new animals arriving from the west and the south.

Ongoing engagement and participation of all stakeholders will be a major challenge in a program of this size, but a challenge that is worth meeting head on, if a coordinated and consistent approach results in benefits to the biodiversity of the region.

The Tambo Bluff estate and community could become a leading example of successful pest animal control resulting in a haven for native birds and animals, all in the surrounds of a residential estate.


References

Coman, B. (1999). Tooth & Nail: The Story of the Rabbit in Australia. Melbourne: The Text Publishing Company.

CSIRO. (2009, September 30). Bridal Creeper Rust Fungus. Retrieved October 17, 2009, from CSIRO: http://www.csiro.au/resources/Bridal‐Creeper‐Rust‐Fungus.html

Department of Primary Industries (1). (2008, October 26). Rabbit: monitoring rabbit populations. Retrieved September 26, 2009, from Department of Primary Industries: http://www.dpi.vic.gov.au/dpi/nreninf.nsf/childdocs/‐89E7A8DAFEA417624A2568B30004C26A‐3DB1800178777EB4CA256BC700811D61‐C5FB00DC3F8D200C4A256DEA00274BC2‐CC061288BE861FF6CA256BCF000AD595?open

Department of Primary Industries (2). (2008, October 26). Rabbits and Their Impact. Retrieved September 26, 2009, from Department of Primary Industries: http://www.dpi.vic.gov.au/dpi/nreninf.nsf/childdocs/‐89E7A8DAFEA417624A2568B30004C26A‐3DB1800178777EB4CA256BC700811D61‐C5FB00DC3F8D200C4A256DEA00274BC2‐11EFFB79F53338B3CA256BCF000AD589?open

Department of Primary Industries (3). (2007, December). Rabbits: Using Integrated Rabbit. Retrieved September 26, 2009, from Department of Primary Industries: http://www.dpi.vic.gov.au/dpi/nreninf.nsf/v/37B0A155D51887A4CA25740F007C4965/$file/Rabbits_Using_Integrated_Rabbit_Control.pdf

Department of Primary Industries (4). (2008, October 26). Rabbit control in wildlife habitat. Retrieved September 26, 2009, from Department of Primary Industries: http://www.dpi.vic.gov.au/dpi/nreninf.nsf/childdocs/‐9599F8E44B161F63CA256BC800079622‐ADE2FBD0C557DFF5CA256BC8000909B9‐0BBDC63C90B4E1EE4A256DEA00293306‐CCC7198B069481E0CA256BCF00088828?open

Mitchell, P. (2006). Notes for Pest Animal Management. East Gippsland Institute of TAFE.

Muyt, A. (2001). Bush Invaders of Sout‐East Australia. Meredith: RG & FJ Richardson.

Olsen, P. (1998). Australia's Pest Animals: New Solutions to Old Problems. East Roseville: Kangaroo Press Pty Ltd.

Stodart, E., & Parer, I. (1988). Colonisation of Australia by the Rabbit. Canberra: Bureau of Resource Sciences / CSIRO Division of Wildlife and Ecology, Australian Government Publishing Service.

Victorian Government. (2009, July 1). Catchment and Land Protection Act 1994. Retrieved November 2, 2009, from Victorian Law Toady: http://www.legislation.vic.gov.au/Domino/Web_Notes/LDMS/PubLawToday.nsf/a12f6f60fbd56800ca256de500201e54/57CBD8A2FDC227CCCA257353000483ED/$FILE/94‐52a041.pdf

Williams, K., Parer, I., Coman, B., Burley, J., & Braysher, M. (1995). Managing Vertebrate Pests: Rabbits. Canberra: Bureau of Resource Sciences / CSIRO Division of Wildlife and Ecology, Australian Government Publishing Service.


Acknowledgments

I would like to thank Jonathan Smith for sharing his understanding of the history (biological and human) of the Tambo Bluff and his professional knowledge and opinions on the current status of area.

I am also grateful for the time, observations and information provided by other members of the Tambo Bluff Landcare Coastcare Group.

RTD4Kate G

App

402A Define the PestGordon‐Addison

pendix 1 – Reg

t Problem in a Local A

gional Map

Area 26 August 2010

RTD4Kate G

App


pendix 2 – Tam


mbo Bluff Esta

Area

ate – Roads

26 August

2010

RTD4Kate G

App


pendix 3 – Tam


mbo Bluff Esta

Area

ate – Contourr Lines (10m)

and 2005 EVCCs

26 August 2010

RTD4Kate G

App


pendix 4 – Tam


mbo Bluff Esta

Area

ate Satellite PPhoto

26 August 2010

Tambo Bluff Estate - Pest Control...

Documents

Transcript of Tambo Bluff Estate - Pest Control...