National recovery plan for the Lord Howe Woodhen (Gallirallus sylvestris)
NSW National Parks and Wildlife Service, 2002
13. Recovery Actions
Protecting existing habitats from developments
Existing habitats occur in two distinct management areas: the Permanent Park Preserve and the settlement area.
The Permanent Park Preserve
The Woodhen habitats within the Permanent Park Preserve (PPP) zone specified in the Regional Environmental Plan are protected from the effects of developments that might occur on the island. However, two indirect impacts may come from if there was an increase in tourism and associated development on Lord Howe Island. Specifically, these would be increased human visitation to key habitat areas, causing increased disturbance and possible interference with the Woodhen's usual behaviour; and the requirement for the installation of additional visitor infrastructure in or near the Woodhen's key habitats. Access to Mt Gower is currently strictly limited to tours with small numbers guided by a local expert.
The installation of new paths, board-walks, lookouts and other visitor infrastructure has the potential to affect the habitat of the Woodhen. Conversely, such infrastructure, appropriately placed, also has the potential to protect areas of significant habitat. In this respect, it is essential that any such developments be appropriately assessed for their impact on the Woodhen and on the habitat factors that sustain it.
Action 1: Continue to implement strict procedures for managing the Permanent Park Preserve (PPP) and for minimising the impacts of infrastructure and tourism in the PPP on the Lord Howe Woodhen. Ensure that a full assessment of proposals is undertaken as required by the EP&A Act.
In the settlement area, Woodhens are found on public land, as well as on perpetual and special leases. In such areas, Woodhen habitat protection derives from the development controls set out in the Lord Howe Island REP and the procedures under the EP&A Act and the TSC Act (see section 9.1).
Action 2: Ensure that the revised REP considers protection of the Woodhen and continue to implement planning controls in the settlement area to ensure protection of habitat for the Lord Howe Woodhen.
Controlling threatening processes
In the settlement area, Woodhens are subject to a range of threats related to human activities.
Predation by domestic Dogs
The Companion Animals Act 1998 applies to Lord Howe Island and the LHIB controls the importation of Dogs to the Island under section 36 of the Lord Howe Island (General) Regulation 1994. Additionally the LHIB has adopted a Dog Control Policy.
This policy outlines the owner's requirements for control of their Dog and identifies areas on the Island designated as Dog exercise (off leash) areas and as Dog prohibited areas. Dogs imported to the Island are required to be de-sexed, only certain breeds are permitted (although some of these are hunting breeds) and Dogs must undergo obedience training.
Action 3: Enforce current Dog controls, and if required review current Dog controls, to ensure protection of the Woodhen.
Feral Pigs and Cats are no longer present on Lord Howe Island. Feral Goats and Ship Rats continue to occur, although the former were subject to a control program in 1999 which reduced the known population to three. Further programs are required to ensure that Goats are eradicated and that domestic Goats are not re-introduced into the wild.
Rats do not appear to be a serious problem for the Woodhen, although they adversely affect the Kentia Palm industry and a control program is currently underway. However there is potential for indirect impacts upon Woodhen the population via rat and mouse control programs. In July 2001 the LHIB commissioned a feasibility study for the eradication of Rats and Mice from the Lord Howe Island group. A risk assessment report is currently being prepared for the proposal. The potential impacts of any eradication actions upon the Woodhen population should form a key component of any assessment of the proposal.
Action 4: Eradicate feral Goats on Lord Howe Island and manage domestic Goats to prevent re-introduction to the wild.
Action 5: Liaise with Rodent Eradication Taskforce regarding potential impacts and mitigation measures relating to Woodhens.
There is some evidence that the introduction of Masked Owls from Tasmania may be contributing significantly to Woodhen mortality. In view of this possibility, the eradication of the owl from the island may reduce the risk to the Woodhen and possibly contribute to an increase in the survival of individuals and, therefore, to an increase in the population size.
An assessment is required to determine if the owl's impact on the Woodhen is significant. Should it be determined that the impact is significant, then knowledge of the population level and ecology of the Masked Owl on the island will be required to develop an effective eradication strategy. The level of impact of owls on Woodhens is likely to increase significantly if the rodent eradication program is approved.
Action 6: Assess the impacts of the introduced Masked Owl on Woodhen population levels and develop appropriate management response.
A number of weeds have the potential to alter the structural, floristic and ecological characteristics of Woodhen habitat in the southern mountains. These weed species are included in the priorities under the Lord Howe Island Noxious Weed Control Procedure (soon to be replaced by the Strategic Plan for weed control) (see Section 10.3).
Action 7: Ensure that implementation of the Lord Howe Island Weed Control Programs protects Woodhen habitat.
Quarantine procedures are in place on Lord Howe Island to prevent the introduction of fowl diseases.
However, procedures for other bird imports are less rigorous (eg. ducks, cage birds). It is appropriate to apply the same level of quarantine control to all imported birds where a risk of disease introduction is identified. This would reduce the risk of a disease affecting the Woodhen population on the island. A number of other quarantine issues affect the island and a quarantine plan is to be prepared by the LHIB.
Action 8: Ensure that the quarantine plan being prepared for the island addresses issues of avian disease and the introduction of plants or animals that may impact on the Lord Howe Woodhen.
The Buff-banded Rail and Purple Swamphen have increased in numbers on Lord Howe Island in the last five years (D. Hiscox, LHIB, pers. comm.). It is not known if this represents a significant risk to the Woodhen by increasing competition for food and space. The similar foraging habits of the Blackbird and Song Thrush to those of the Woodhen may also reduce food and space for the Woodhen. Controlling these species, particularly in the settlement area, may result in an increase in Woodhen numbers.
Action 9: Assess the potential impact on the Lord Howe Woodhen of food competition from Buff-banded Rails, Purple Swamphens, Common Blackbirds and Song Thrushes and, if necessary, formulate and implement a control strategy.
A thorough and consistent monitoring program for the Lord Howe Woodhen was undertaken between 1986 and 1998 (Harden 1986, 1987, 1990b, 1998; Harden and Robertshaw 1988, 1989). This monitoring program involved a count and banding in November, and again in March. The most accurate results come from sighting and counting individual banded birds and most (up to more than 90% in some years) of the population of Woodhens on the island to date have been individually colour-banded. This makes repeatable estimates of the total population feasible, providing the most accurate possible assessment of any changes in numbers and distribution on an annual basis.
Notwithstanding the success of the rehabilitation program the Woodhen remains one of the world's rarest birds. An effective monitoring program that measures population change is an essential foundation upon which to base the recovery plan. It is essential to alert managers to increased risks to the Woodhen's survival and to enable the performance of management to be evaluated accurately.
The LHIB currently undertakes the twice-yearly monitoring program. A computer database has been developed by NPWS to manage the data derived from the monitoring program. The LHIB will ultimately be responsible for the management of the database. The LHIB staff will require training and support in the management of the Lord Howe Woodhen database.
Action 10: Continue the Woodhen monitoring program using the methodology developed in 1999. Ensure that LHIB staff are trained and supported in the management of the Lord Howe Woodhen database.
Action 11: The carrying capacity of the Island for Woodhens and the critical number of Woodhens to trigger an on-island captive breeding program will be determined through analysis of habitat availability and monitoring data within six months of approval of the recovery plan.
Establishing the Recovery Team
To date; implementation of management actions for the Lord Howe Woodhen has been undertaken by the LHIB, with input from the NPWS. The establishment of a recovery team would assist the Board in consolidating recovery actions and resources for a number of Lord Howe Island species. A significant role of the recovery team would be the storage, analysis and reporting of the monitoring results to measure the performance of management actions. The recovery team would also co-ordinate the implementation of contingency plans if required.
The team should review the recovery plan every five years.
Action 12: Establish a recovery team under the auspices of the National Parks and Wildlife Service and the LHIB to co-ordinate the implementation and funding of species recovery plans.
Community Cooperation Program
The Lord Howe Woodhen occurs in significant numbers on leasehold land in the settlement area. A number of leaseholders have been feeding Woodhens, which has contributed to the increase in numbers in the area. Many of the Woodhens that now occur in the settlement area are found away from their preferred habitat and on calcareous geology. Their persistence in such apparently unsuitable habitats is in part, due to the food provided by residents.
A risk management framework for the Lord Howe Woodhen was outlined in Section 12.2. A significant plank of this framework was the more intensive management of the Woodhen population in the settlement area. It is proposed to maintain this through the establishment of a community-based program of monitoring, habitat protection and supplementary feeding. The activities proposed for this program are described below.
Community Based Monitoring
Residents who currently take an interest in their local Woodhens are able to report regular sightings and movements of individuals, as well as the outcome of breeding attempts and the results of supplementary feeding. To facilitate continuation of community input to the management of Woodhens, a community information brochure should be prepared. The brochure should describe how the monitoring surveys are undertaken, the colour banding process for identification of individual birds and summarise the findings of the surveys. The brochure should also cover issues of Woodhen management, habitat enhancement and protection and appropriate supplementary feeding strategies.
Action 13: Prepare a community information brochure on Woodhen management.
Habitat Protection and Supplementary Feeding Program
A significant number of Woodhens live in artificial garden habitats in the settlement area, as well as remnant indigenous habitats on leases. The planning provisions covering leases provide significant mechanisms for protecting Woodhen habitat. However, the positive involvement of the island's leaseholders in habitat protection is the most effective way of assuring the future of such habitat in the settlement area. This component of the community co-operation program is designed to facilitate this involvement.
The successful ingredients of such a program would include but not be limited to:
- a positive relationship between leaseholders with habitat on their leases and the LHIB and Recovery Team;
- willingness of the leaseholder to protect and manage Woodhen habitat on their lease; and
- provision of information on how to protect, manage and/or enhance habitat for the Woodhen.
The leaseholder needs a personal contact, most appropriately in the LHIB, with whom to discuss and develop individual approaches, and from whom to seek information.
In addition, such a program could be pro-active in identifying leaseholders whose leases support areas of potential habitat in which Woodhens may survive, given additional protection and/or supplementary feeding.
Supplementary feeding by local residents of wild Lord Howe Woodhens has contributed significantly to the rehabilitation of the species. The settlement is likely to be supporting artificially high populations levels through community based supplementary feeding. Caution will be required in interpreting a population decline following any cessation of food provision. Such a decline may meet the criteria for implementing the on-island captive breeding; however, in fact, the wild population may be stable and at carrying capacity.
A survey of the community based supplementary feeding program for Woodhens in the settlement area should be undertaken to establish how many people are feeding Woodhens, how frequently, and what quantities and types of food are being provided. Guidelines should be prepared for the community on the most appropriate feed types for the Woodhen. Any formal supplementary feeding program should be managed by the LHIB and have an annual budgetary allocation.
Action 14: Formulate and implement guidelines for the protection, management and enhancement of Woodhen habitat on leasehold land. Undertake a study to determine the most appropriate supplementary food types and assess the effectiveness of a community based supplementary feeding program for Woodhen on leasehold land.
Establishing a Captive Population
The Woodhen occurs only on Lord Howe Island. Such a small distribution, combined with low numbers, makes it vulnerable to catastrophic extinction. The precise mechanism of catastrophic extinction is difficult to anticipate. Catastrophic extinction could occur due to:
- extended drought;
- introduction of an avian disease;
- introduction of an exotic predator;
- introduction of a particularly invasive weed;
- reduced reproductive ability relating to low genetic diversity of population.
As insurance against these or other eventualities, a captive colony outside Lord Howe Island, for example on mainland Australia, is required.
The Woodhen is listed as a category one species by the Australian Species Management Program (C. Hibbard, Taronga Park Zoo, pers. comm.). This means that participating zoos around Australia and New Zealand have identified it as a priority for captive management. Zoos that participate in the Australian Species Management Program manage captive populations of endangered indigenous fauna. The Australian Regional Association of Zoological Parks and Aquaria (ARAZPA) Taxon Advisory Group Convenor - Australian Non-passerines has provided the following recommended approach for establishing a captive population as insurance against catastrophe (Hibbard pers comm, August 2001).
This includes actions such as:
- Appoint a regional captive management coordinator within the Australian Regional Association of Zoological Parks and Aquaria (ARAZPA) to coordinate the captive management of the species.
- Develop a draft Husbandry Manual for the species based on review of all available literature on natural history of the species, previous management and husbandry of the species in captivity and related material for other Gallirallus if further information is required.
- Develop a Population Management Plan that outlines the steps needed to meet the objectives of the captive management program.
- Establish a complex of approximately 12 purpose built aviaries at a major zoological institution on the Australian mainland. This would act as the primary breeding institution for the establishment phase of the program.
- Establish a protocol for the recruitment of suitable founders from Lord Howe Island and their establishment in the captive facility. It is proposed that eight to ten birds form the initial base for the establishment of the captive population.
- Following the initial establishment of the mainland Australian population, specimens would be provided to other statutory zoos within Australia for expansion of the captive population. This would be undertaken under advice from the Species Coordinator and in consultation with the Recovery Team.
- Additional specimens may need to be recruited from Lord Howe Island in order to maintain the genetic integrity of the captive population. It is estimated that this would only require a few individuals every five or so years.
- Once fully established the captive population would remain highly managed to ensure its genetic and demographic health, however, the specimens would need to be integrated into the general collection facilities as it would be financially not realistic to hold the birds in dedicated off-exhibit facilities on an indefinite basis.
- At no stage would the birds be considered for trade, sale or export. All major decisions involving the birds would coordinated through the Recovery Team. The birds would remain the property of the Government, not the zoological park at which they may be residing.
- Initial establishment costs will be high as the project has limited capacity to be phased in over time. As the program expands to include secondary institutions it would be expected that they use existing facilities to house the birds, otherwise the overall cost would become prohibitive.
Cost estimates are:
|Development of Husbandry Protocols and Population Management Plan||$5000|
|Establishment of purpose built facilities at primary institution
(12 aviaries @ $6000ea)
|Recruitment of founder specimens from LH Island
(transport, quarantine etc)
|Staffing costs for dedicated staff member to implement program
(half staff member for two years)
Some expenses relating to the establishment of this project may be supported by the institution initiating this project, however a funding source for a significant proportion of the funds will need to be secured.
Individuals from this population should only be re-introduced to Lord Howe Island in the event of extinction in the wild, as the risk of introducing disease is too high.
Action 15: Establish and manage captive populations of the Lord Howe Woodhen in appropriate off-island institutions, consistent with the protocols of the Australian Species Management Program.
The risk management framework described in Section 12.2 identified on-island captive breeding as a contingency in the event that the wild Woodhen population fell substantially. Before such an eventuality, it would be necessary to have already identified and costed options for the establishment and staffing of a facility. This facility may be required if the rodent eradication program proceeds. To this end, the recovery team should ensure that, early in the implementation of the current plan, these options have been identified.
Action 16: Develop a plan within eighteen months for establishing and resourcing an on-island captive breeding facility, for implementation in the event of a substantial reduction in Woodhen numbers below a population size which will be identified as part of Action 11 or if the rodent eradication program is approved.