Reducing the risk of extinction of a globally threatened shorebird: translocations of the shore plover (Thinornis novaeseelandiae), 1990-2012
|Title||Reducing the risk of extinction of a globally threatened shorebird: translocations of the shore plover (Thinornis novaeseelandiae), 1990-2012|
|Publication Type||Journal Article|
|Year of Publication||2013|
|Authors||Dowding, JE, O'Connor, SM|
|Type of Article||Full article|
|Keywords||avian pox, captive-breeding, Chatham Islands, New Zealand, predation, Shore Plover, species recovery, Thinornis novaeseelandiae, threatened species, translocation|
The shore plover (Thinornis novaeseelandiae) is a highly threatened shorebird endemic to New Zealand. It is particularly susceptible to introduced mammalian predators, and has a very small total population and a very limited range. This paper lists the translocations that have formed the core of the shore plover recovery programme over the past 22 years, and summarises the outcomes. In the early 1990s, a captive population was established in mainland New Zealand using birds reared from eggs transferred from the last self-sustaining wild population on the Chatham Islands. Since 1994, captive-bred birds have been released on 5 offshore islands around the New Zealand mainland in attempts to found new populations. There have also been transfers of wild-bred birds from South East I to Mangere I in the Chatham Is. Between 1994 and April 2012, 404 juvenile and 28 adult shore plover have been released at a total of 6 sites. Birds bred at 4 of the 6 sites, and breeding populations established at 3 of them. However, recent mammalian predator incursions at 1 (and probably 2) of those, and habitat limitation at the 3rd, mean that the translocated populations are all currently small (6 pairs or less), and their long-term future is uncertain. Other challenges faced during the programme include avian predation of released birds, high rates of dispersal, and outbreaks of avian pox. In spite of recent setbacks, the risk of extinction for the species has gradually been reduced. Since 1990, a self-sustaining captive population has been set up, the number of breeding pairs has increased, and the number of breeding populations in the wild has risen from 2 to 4 (although 1 is currently facing extirpation). Features of the shore plover programme that have contributed to these outcomes are outlined. Aspects of shore plover ecology revealed by the translocations are noted. While progress has been made, existing populations will need to grow, and further populations will need to be established before the shore plover’s threat ranking improves.