Namadgi National Park

Feral Horse Management Plan 2007

Feral Horse Damage

Bimberi Flat 2006 – (top)

Jack’s Flat 2003 – (middle)

Rock Flat 2004 – (Lower)

Table of Contents

Executive Summary 2

1.0 Introduction 3

Figure 1: Key elements of a vertebrate pest management program 4

2.0 Feral horses – the problem 4

2.1 Feral horse biology 4

2.2 Environmental impacts 5

2.3 The history of feral horses in Namadgi National Park (NNP) 6

Figure 2 - Current distribution of feral horses in Namadgi National Park and northern Kosciuszko National Park 8

2.4 Environmental impacts of feral horses in NNP 9

3.0 Setting management priorities for NNP – legislation and policy relating to feral horse control 10

4.0 The 2004 NNP Feral Horse Management Plan 10

4.1 Management options trialled under the 2004 Plan 10

4.2 Management since 2004 - implications for future control options 10

5.0 Objectives for feral horse management in NNP 12

5.1 Management goal 12

5.2 Management objectives 12

6.0 Proposed feral horse management program under the 2007 Plan 13

6.1 Feral horse management options 13

6.2 Trapping and euthanasia 14

6.3 Aerial shooting 14

Table 2: Conditions for aerial shooting of feral horses in NNP 15

8.0 Monitoring and evaluation of the NNP feral horse management program 16

Figure 3 Recovery of Smokers Gap (NNP) following removal of feral horses in 1987 16

9.0 References 17

Appendix: 1 Legislation and policy relevant to feral horse management in NNP 20

Appendix 2: Comparison of the main control options for feral horses in NNP 22

Executive Summary

Namadgi National Park (NNP) forms the northern end of the Australian Alps network of national parks; an area recognised internationally for its unique natural and cultural values. The Cotter River Catchment within NNP provides the main source of potable water for the Canberra region. Protection of water resources in NNP is therefore a primary management concern for the park. The sub-alpine wetlands that filter and regulate stream flows are also important for their biodiversity. The internationally significant Ginini Flats Wetland includes the principal habitat for the endangered Northern Corroboree Frog.

Parks, Conservation and Lands has legislative responsibility to protect the natural, cultural and water quality values within NNP, which includes minimising the negative impact of introduced species, including feral horses. Environmental damage attributed to feral horses includes grazing of sensitive vegetation, trampling of stream banks, trail formation, and erosion. These impacts can lead to the draining of entire bog systems, with loss of habitat for threatened species, and silt deposition downstream.

Feral horses were eradicated from NNP in 1987 and were not sighted again until 2001, when small groups began appearing briefly along the southwestern border with NSW. These horses are part of a much larger population within northern Kosciuszko National Park (KNP). Since 2003 the number of horses within NNP has increased to 15 in 2006 and some horses are remaining over winter, increasing the damage to several grassy flats.

The previous edition of the NNP Feral Horse Management Plan (2004) was a first response to the threat of feral horses re-establishing in NNP. Under that plan, four horses were removed from Rock Flat Wetland. This revised edition of the Plan (2007) has benefited from experience in both the ACT and NSW since 2004, and from review by two independent professionals with expertise in feral horse ecology and animal welfare. The Plan has been adopted following consultation with the relevant ACT advisory committees and will be provided to other local, interested stakeholders.

The Plan has two objectives:

·  Removal of the current feral horses (and therefore their impact) from NNP; and

·  Reduction of the requirement for on-going feral horse control in NNP

It is important to control horse numbers in NNP now, while the population is small, to reduce the risk of further sub-alpine wetlands being impacted, and minimise the number of horses that have to be removed. The second, longer-term objective will be achieved by working cooperatively with NSW National Parks and Wildlife Service to manage the much larger feral horse population in the adjacent area of northern KNP.

The management actions proposed under this Plan adhere to the three essential requirements for pest control techniques – necessity, effectiveness and humaneness. Trapping followed by euthanasia at the trap yard will be the primary method employed, with aerial shooting used as a secondary option if required, and where appropriate. These techniques represent the most humane and effective methods that are suited to the remote terrain and vegetation types in NNP. They accord with the new Model Code of Practice for the Humane Control of Feral Horses and represent current best practice for the animals, the operators, and the environment.

1.0 Introduction

Namadgi National Park (NNP) occupies the southern and western portions of the Australian Capital Territory (ACT) at the northern end of the Australian Alps network of national parks; an area recognised internationally for its unique natural and cultural values. The area of NNP is 106,095 hectares; approximately 45% of the area of the ACT. The park includes the headwaters of the Cotter River, which provides the main source of water for the 350,000 people of Canberra and Queanbeyan. A feature of the Cotter Catchment is the large number of sub-alpine wetlands. They are important for their biodiversity and because they store water and release it steadily through all months of the year. All of these wetlands are regionally important and eleven are listed as wetlands of national significance. The Ginini Flats Wetland within the Cotter Catchment is of international significance; listed under the Ramsar Convention, an international treaty developed to ensure conservation and wise use of wetlands.

Parks, Conservation and Lands has legislative responsibility to protect the natural, cultural and water quality values within NNP; which includes minimising the negative impact of introduced species, including horses. A population of feral horses was present from the early years of the ACT and grew to 200 in the early 1960’s. This horse population is said to have been almost eliminated by a large snow event in 1964. The remaining horses (33) were eradicated in 1987. Since 2001, small groups of feral horses have been recorded in the southwestern area of the park. The location of these horses suggests they are associated with the much larger horse population within northern Kosciuszko National Park (KNP).

The first edition of the Namadgi National Park Feral Horse Management Plan (ACT Government 2004a) was prepared in response to concerns over the potential for re-establishment of feral horse populations within NNP. Under that plan a number of feral horse management techniques were trialled and four horses were removed from Rock Flat Wetland. This revised edition of the Plan (2007) has benefited from experience in both the ACT and NSW since the 2004 Plan was written.

The 2007 Plan has been developed using the strategic framework for vertebrate pest management programs outlined in the ACT Vertebrate Pest Management Strategy (ACT Government 2002). This structured approach is summarised in Figure 1.

Figure 1: Key elements of a vertebrate pest management program

Define the problem

Determine management priorities

Decide feasibility

Determine objectives

Develop the program

Implement the program

Monitor and evaluate

Accordingly the Plan includes:

·  A summary of feral horse biology, their environmental impacts, and the history, current impacts and potential future problems associated with feral horses in NNP.

·  A summary of the legislation and policy relating to the setting of management priorities, including feral horse management, in NNP.

·  A report on the outcome of feral horse management options trialled under the 2004 NNP Feral Horse Management Plan, and their feasibility as future control methods.

·  The objectives for feral horse management in NNP.

·  The feral horse management program proposed under this (2007) Plan.

·  Monitoring and evaluation of the NNP feral horse management program.

2.0 Feral horses – the problem

2.1 Feral horse biology

Information provided in this section has been summarised mainly from Dobbie et al. (1993) – readers should refer to this reference for more detail and for the original sources.

Horses have adapted to many Australian environments and inhabit a wide range of ecosystems including semi arid rangelands and sub-alpine mountains. Most of the estimated 400,000 feral horses in Australia are found in the Northern Territory, Queensland and parts of Western Australia and South Australia. The majority of the feral horses in New South Wales and Victoria occur in the sub-alpine national parks.


Feral horses form small breeding groups, known as harems, and all male associations known as bachelor groups. Harem groups, comprising a dominant stallion and three or more mares and their offspring, occupy a territory within a small geographic area, provided that food and water are available. In contrast, bachelor groups are more mobile as they move in search of new territories. Studies from central Australia suggest that harem groups have a strong affinity for their home range, resisting attempts to move them on by mustering.

The peak breeding season for horses is spring and summer. Mares reach puberty between 12 and 24 months of age and although capable of foaling every year, generally raise one foal every two years. Feral horse populations can increase by 20% per year when resources are not limiting.

2.2 Environmental impacts

Numerous studies have shown that herbivores alter vegetation by feeding and trampling. In areas where feral horses are present at high densities, most managers accept from observational evidence that environmental impacts can be significant. However, these impacts are difficult to quantify because of the influence of co-existing factors including season, weather conditions, the effects of other herbivores, and recreational impacts. As with other herbivores, resident feral horses have the potential to disperse weed seeds in their dung (Taylor 1995), although introduction of weed seed is more likely via birds, recreational horse riders and people (on foot and in vehicles).

The impacts of feral horses on vegetation are being monitored as part of a trial of feral horse management techniques in the alpine areas of Kosciuszko National Park (NSW NPWS 2003). As selective grazers that spend between 51 and 75% of their time feeding, feral horses undoubtedly have the potential to alter the species composition of the grassy areas on which they feed. Feral horses have been linked to compromise of rare plant habitat and landscape nature conservation values in New Zealand (Rogers 1991).

Studies of grazing and trampling by feral horses in the Australian Alps (Dyring 1990,1993) have shown the main impacts of feral horses include:

·  Track formation - feral horses travel in defined routes causing tracks to form. Soil beneath these tracks becomes compacted and drier than the surrounding soil, has fewer native plants, more weeds and higher rates of soil loss. Vegetation is also killed in areas where horses roll, creating bare ground that becomes subject to erosion and invasion by exotic plants.

·  Stream bank erosion - high rates of bank disturbance have been noted where horses access streams for drinking or at crossing points. The damage includes bank slumping and loss of riparian vegetation.

·  Damage to wetlands and bogs - grazing and trampling in wetlands and bogs can result in a decrease in Sphagnum and sedges. This vegetation loss combined with tracking leads to lateral erosion, stream incision and ultimately to the draining of the entire bog, with attendant silt deposition downstream.

Feral horses have also been shown to impact the native fauna of countries into which they have been introduced including the survival of grass nesting birds (Zalba and Cozzani 2004), reptiles, and small mammals (Beever and Brussard 2004).

Research is required to quantify the relationship between feral horse density and degree of environmental impact (Dawson et al. 2006). If feral horses can be successfully removed from NNP the park could provide ‘horse free’ sites for comparative studies in the Australian Alps (Dawson, pers. comm.).

2.3 The history of feral horses in Namadgi National Park (NNP)

Feral horses probably established in the area now encompassed by NNP from animals escaping from Brindabella Station, Yaouk, Tidbinbilly property (Moore 1999) and from the Cotter Hut area in the mid 1800’s. By the 1860’s feral horses were already considered a nuisance and to be competing with cattle, and were caught for sale or shot, with the hides and hair sold when possible (Higgins 1993).

Organised ‘brumby running’ (the chasing and capturing of wild horses) was undertaken at least as early as the 1920’s, and remained popular in the area up until the early 1960’s (Higgins 1993). Almost all of the early brumby running undertaken in the Brindabella area was co-ordinated by the first Cotter Catchment ranger, Jack Maxwell. Over 200 feral horses were reported to have been sighted near Snowy Flats and Mt Ginini in 1929. Other populations were present at Smokers, Kangaroo and Creamy Flats. The historic distribution of feral horses within NNP is illustrated by the location of horse trapping yards (Higgins 1993) (Figure 2).

The local population of approximately 200 feral horses is said to have been almost eliminated by a large snow event in 1964 (Walter 2002) and the remaining horses (33) were eradicated by aerial and ground shooting in 1987 in accordance with the Namadgi National Park Management Plan (Department of Territories, ACT Parks & Conservation Service 1986). While best culling practice was observed, the action attracted considerable media attention and community concern.

Namadgi National Park remained free of feral horses until 2001-02 when there was a trickle of reports from bushwalkers of horses and horse sign at Murrays Gap and Leura Gap on the ACT border. The first sightings by management staff of feral horses within NNP since 1987 occurred in June 2003. A harem group of seven animals were observed in an area known as Jack’s Flat on the park boundary to the south of Mount Murray (see Figure 2). These horses had disappeared from NNP in July 2003, being observed just over the border in Kosciuszko National Park (KNP) in September. In December 2003 the same horses plus three foals were sighted again at Jack’s Flat by which time their presence had caused some damage to the Flat (see photograph on the cover of this Plan). Trap yards were erected at Jack’s Flat in March 2004 but the horses had apparently returned to KNP due to the prevailing dry conditions. Horses returned to the Mt Murray area in October 2005 and 13 horses (including two foals) were observed at Jack’s Flat in March 2006. Eleven horses were sighted at the Flat in June 2006 suggesting that the mild winter conditions permitted the group to over-winter in NNP. The movement of this group of horses to and from Jack’s Flat accords with Dyring’s (1990) observation that feral horses are highly mobile, using movement corridors between suitable grazing sites in montane areas.