Restoring the Balance

Transcription

1 Restoring the Balance - managing wildlife in modified ecosystems Wild about Welfare RSPCA seminar 22 March 2016

2 Managing parks and reserves

3 Parks and reserves Parks Victoria manages 2988 parks across 4.1 million hectares (18% of Victoria) 139 areas managed under the National Parks Act covering 3.45 million hectares (84% of total area) Of the 1405 native species of fauna that have been recorded in Victoria, 1,102 (78%) are recorded in Victoria s parks network Of the 306 listed rare and threatened fauna species that have been recorded in Victoria, 277 (91%) are recorded in Victoria's parks network Of the 1857 listed rare and threatened flora species recorded in Victoria, 646 (90%) are recorded in Victoria s parks network

4 Conservation planning Structured process for planning using international standard: identifying the key ecological assets in a landscape determining their current and desired condition assessing threats developing and prioritising actions to address the threats. Monitoring and evaluation are incorporated to enable effectiveness of management actions to be measured and to adapt management based on learnings.

5 Managing threats Effort is directed to minimise threatening processes that are having the greatest impact on the most significant conservation values These threats include: weeds (competition, displacement) pest animals (predation, competition, overgrazing/browsing) non-compliance from illegal activities inappropriate fire frequency and intensity inappropriate watering regimes visitor impacts over-grazing or browsing from overabundant native fauna

6 Native animals Overabundance problems Populations may increase until there are insufficient food resources Leads to mortality from starvation, often associated with extremes of climate (winter cold or summer vegetation die-off ) disease spread through congregation and faecal matter Degradation of habitats through: overgrazing/browsing, trampling competition or displacement, Impacts on agricultural or cultural assets, or human health and safety

7 Overabundant native animals - causes Native wildlife populations become overabundant due to environmental factors legacy of previous land uses (eg vegetation clearance) fragmentation of habitat (may limit ranging behaviour) increased food and water availability (eg from agricultural improvements) absence of natural regulation of populations by predators (human, dingo) Compounding factors park ecosystems are in long term recovery from previous land uses climate change is increasing the impact of other threats

8 Parks Victoria intervenes only when wildlife populations are: suffering as a result of confinement or habitat loss threatening the survival of rare or threatened species or communities; a major contributor to serious environmental damage or long-term degradation of habitat; a major factor preventing habitat recovery impacting on agricultural values, and support is required for the management of wildlife populations occurring across land tenure

9 Interventions Management options include: deterrents exclusion translocation fertility control lethal control Options are assessed according to effects on: welfare of treated animals welfare of untreated animals habitat degradation other significant flora or fauna values human health feasibility

10 Interventions Intervention undertaken using standards: formal code of practice (ie for humane shooting of kangaroos) methods developed during research trials methods developed with guidance from welfare and species experts for performance Species subject to management include: koala macropods birds (galah, miner) long spined sea urchin

11 Planning and implementation Problem identification Monitoring, evaluation and review Technical assessment (survey) of population size & habitat impacts Implementation (to specified standards) Stakeholder engagement Assessment of management alternatives Oversight of, and advice on assessments by Kangaroo Technical Advisory Committee Submission of plan to DELWP

12 Overabundant native species across parks network

13 Case Study Mount Eccles koalas Annual program for the in-situ contraception of koalas: To improve ecosystem health of the 6000 hectares of Coastal Manna Gum Woodland in the Mount Eccles National Park To maintain a sustainable and healthy koala population Project history: Commenced 1998 (following crashes at Framlingham Forest, Snake Island and Westernport) Population surveys and tree condition assessment Commenced large scale translocation program (with surgical sterilisation) to sites assessed as suitable habitat Advice on management and monitoring design from koala experts (Koala Technical Advisory Committee) Program overseen by vets

14 Mount Eccles koalas - outcomes Monitoring showed unacceptable rates of mortality for surgically sterilised and translocated animals, and that health and survival outcomes were dependent on habitat quality Translocation program was ceased Contraceptive implant program developed and trialled Since 2004, 4613 female koalas have been implanted Captured koalas health assessed by vets Monitor any injuries sustained as part of capture and data used to help train staff and respond appropriately to koala behaviour Tree condition stabilised: tree mortality and canopy decline stabilised Population stabilised, but have not reached density targets, that would ensure sustainable and ongoing koala health. Program reviewed annually by expert committee

15 Koala population trend

16 Tree health 2014 assessment shows Manna Gum condition continues to be generally poor. 30% of trees assessed (n.959) were dead or dying. Defoliation levels of greater than 50% occurred in 62% of trees assessed. Despite this, overall tree condition has improved since the 2012 study. Mean foliage cover has increased from 20.4% in 2012 to 23.6% in 2014 canopy area has increased from 25.9 m² to 47.9 m² leaf area / ha has increased from 1,079 to 1,979 m²/ha

17 Case Study Mallee parks Western Grey and Red Kangaroo population management: To improve ecosystem health of the 170,000 hectares of threatened and grazing sensitive communities (semi-arid woodland and floodplain vegetation communities) To maintain healthy and ecologically sustainable kangaroo population levels that are not subject to boom-bust cycles (kangaroo management is a component of a total grazing management plan, also dealing with rabbits and goats) Project history: History of boom-bust kangaroo population cycles monitored since the 1970 s. Impacts of high kangaroo population densities occur even when rabbits densities are held low Target population density set to allow sufficient grassy biomass to persist, and so that tree seedlings are not browsed

18 Western grey kangaroo population density Wyperfeld NP Density Estime (kangaroos/km²) Kangaroo management commences 10 5 Central Wyperfeld Pine Plains

19 Mallee parks - outcomes Ground shooting assessed to be only feasible and humane method Commenced 1990 in Hattah-Kulkyne, 1998 in Wyperfeld, and 2001 in Murray-Sunset Employ shooters that are tested to comply with accuracy standards PV authorised officers accompany shooters and control shooting Protocols to minimise the risk of orphaning joeys Data collected on accuracy, age class and sex Program reviewed annually by expert committee Open houses held with public to discuss restoration goals and actions Results Surface erosion has been stabilised, cover of perennial grasses has improved and there are some signs of natural recovery are now being seen in the recruitment of the key woody species

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23 Conclusion In some ecosystems, subject to a number of stresses that cannot be directly addressed, the direct and ongoing management of wildlife populations is unavoidable In these situations management involves difficult trade-offs between the different values we are entrusted to protect We engage with experts to help make decisions about what to do, and how best to do it We collect data that will help us evaluate our approach and are willing to improve our methods based on evidence

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