The impact of conservation translocations on vector-borne parasites : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Ecology at Massey University, Palmerston North, New Zealand
Wildlife conservation in New Zealand relies on translocations of endangered species
to safe sites. While knowledge of the biology and behaviour of translocated hosts
has steadily increased, the role of parasites in wildlife translocations has been
largely overlooked. Parasites can affect their host’s survivorship during
translocations by causing disease. However, failure to translocate or reintroduce a
host specific parasite with its endangered host can contribute to the extinction of the
parasite with unforeseen consequences for the future of the host or even the whole
ecosystem. The main aims of this study were to establish baseline data on the
impact of North Island saddleback translocations on their avian malaria (Plasmodium
spp.) parasites as well as gaining further insight into potential vectors in New
Zealand. The study was also intended to contribute to the development of
recommendations for future parasite screening programmes for native passerine
translocations. Saddlebacks and Plasmodium were chosen because of the detailed
saddleback translocation history and its known relationship with the parasite.
As a result of this study, several Plasmodium lineages previously unrecorded in
saddlebacks and New Zealand were identified, for example, the native Kokako01
and one lineage closest related to two lineages from the Americas. Nonetheless, the
most frequent lineages found were the cosmopolitan P. elongatum GRW6 and
LINN1, and P. vaughani SYAT05, common in birds introduced to New Zealand. This
finding suggests that endemic parasites may have already become rare or extinct. In
addition, Plasmodium DNA was detected in both native and introduced mosquitoes
that may act as vectors. A qPCR assay was developed that was found to be a cost
effective and rapid screening tool for the detection of Plasmodium in native birds
suffering from acute infection, presenting with clinical symptoms, and in birds that
were found dead. .
I conclude that future translocations should consider the movement of endemic
parasites with their hosts. How this should happen is open for future studies.
However, I urge managers to start considering this issue now as New Zealand has
already recorded the extinction of one endemic parasite and many more may have
already been lost without knowledge.