Auckland Zoo helping world's rarest duck
5 August 2004
Auckland Zoo helping world's rarest duck
Auckland Zoo is to provide vital veterinary skills and financial support for the translocation of what is believed to be the world’s rarest duck, from Codfish Island and some captive breeding centres, back to its sub-antarctic Campbell Island home south of Bluff.
Like the kiwi, the Campbell Island teal (of which there are less than 100) is endemic to New Zealand, flightless, mainly nocturnal, and has been a victim of predators.
Auckland Zoo's Wildlife Health & Research Centre (WHRC) vet Dr Richard Jakob-Hoff says now predators have been successfully eradicated from Campbell Island, "disease remains the most significant potential threat to the re-establishment of teal onto the island.
"At Auckland Zoo we have gained a lot of experience in disease screening of native species, including Campbell Island teal. I am thrilled to be asked to work alongside the Department of Conservation (DOC) to help ensure the success of this re-introduction. For DOC, the release will be the culmination of over 20 years work, and we really want to support them in any way we can" says Dr Jakob-Hoff.
Through its Conservation Fund, Auckland Zoo has just donated $5,000 towards the collection of health data from resident Campbell Island birds prior to the planned September 2005 release.
Dr Jakob-Hoff has been invited to be a member of the DOC release team. He will examine other wildlife the released ducks will encounter on the island to assess the disease risks they may face after release.
Some preliminary screening has already been done by Dr Jakob-Hoff. In March 2003, the zoo's WHRC was commissioned to conduct the first pre-translocation health screen of the teal on Codfish Island. Twelve birds were captured and given comprehensive health examinations including the collection of diagnostic samples to screen for 12 diseases considered of greatest significance to these birds.
"It's this information that has provided the basis on which to establish the most appropriate pre-translocation quarantine and disease screening for these ducks prior to transfer to Campbell Island," says Dr Jakob-Hoff.
"We also intended to collect baseline data from waterfowl and penguins on Campbell Island to enable us to assess the risk of exposing the translocated teal to diseases to which they may not have been exposed. But for logistical and funding reasons this hasn't yet taken place.”
However, Auckland Zoo’s recent contribution of $5,000 will now enable the screening of 40 rockhopper penguins (a number that will ensure a statistically meaningful result).
"Ideally we would also like to health screen 40 mallards but this will cost another $10,000. We are looking for other donors interested in supporting this exciting programme," says Dr Jakob-Hoff.
The isolation of the sub-antarctic islands makes the Campbell Island teal particularly vulnerable to the introduction of disease to which the local fauna have no immunity.
"Currently in New Zealand there is little or no documented information about the diseases carried by the majority of native species, which is why this health screening is so vital. Assessing what diseases are already there will be important in deciding what measures, if any, are needed to protect the birds from illness," says Dr Jakob-Hoff.
As best practice, DOC has recently established a standard operating procedure aimed at taking all necessary steps to minimise disease risks when translocating threatened wildlife.
Up to 50 birds to be translocated will be sourced from Codfish Island and a number of captive holding sites, and will be fully health screened prior to departure. Once on the islands the birds will be maintained in holding pens for two weeks prior to release.
"This time will provide the window of opportunity to collect the baseline health data on mallard ducks and rockhopper penguins prior to the teals' release," says Dr Jakob-Hoff.
Auckland Zoo's Conservation Fund, established in 2000 to support native and exotic in-situ projects, is also an active supporter and contributor to the Ark in the Park restoration project in the Waitakeres. The zoo is actively involved in a wide range of native species breeding programmes, and is soon to receive its first BNZ Kiwi Recovery Operation Nest Egg project eggs for the 2004 season. To date the zoo has reared and released 110 kiwi for this project.
At one time thought to be extinct, the Campbell Island teal was re-discovered in 1975 on Dent Island, a tiny islet off the main 11,000ha Campbell Island.
1984: DOC began the capture of small number of teals to establish a captive-breeding colony at the National Wildlife Centre Mt Bruce. After 10 years of trialing different management techniques the birds finally bred in 1994.
1999 - 2000: A total of 24 captive-bred birds were released onto rodent free Codfish Island, and these have subsequently established and bred well.
DOC carried out a rat eradication programme on Campbell Island in 2001. It has now officially been declared rat free.
Campbell Island teal: Flightless, nocturnal, and remarkable in surviving in such an inhospitable environment (Campbell Island is surrounded by 200m high cliffs, is battered by wind and rain 325 days per year, and records an average temperature of 6 degrees!). These birds have distinctively long claws and short, stiff tail feathers, which enable them to climb up steep cliffs and crawl through dense vegetation. While they swim, and will feed amongst kelp on the sea, they do spend a lot of their time on land.