Rare Shore Birds Vanish After Relocation to New Area

The 30 rare shore plovers or tuturautu relocated to Mana Island off the coast of Porirua New Zealand vanished, leaving ornithologists baffled and concerned.

These shore plovers are considered critically threatened in New Zealand, with only about 250 left. The majority of the population is in the Chatham Islands. 

The shore plovers were relocated to Mana Island since February as part of the effort to establish a new colony. She said that three of those 30 had been recaptured. The whereabouts of the other birds are still unknown. It is not clear why the birds left, MacKenzie said although she could think of various reasons like being lost to predation or a single bird decided to return to the mainland, and the others followed. Avian predators may also have threatened them, or it could be due to random behavior, Mackenzie surmised.

This is not the first time that shore plovers were relocated to the island. In 2007, the department also did a relocation, but the shover birds were decimated by the rats on the island.  

This time, measures to keep the rats from the plovers were done. As Nick Fisentzidis, the Mana Island Ranger, said in February, "We are very aware of the devastation caused by a single rat to Mana in 2011. We've put a lot of effort into keeping Mana predator-free since then." 

Dave Houston, the Shore plover recovery group leader, said that it is challenging to move the birds to the new island. It requires "fixing" them in their new homes by holding them in an aviary for a week or so to try to help them adjust to the new environment, but it does not always work.

He cited that there are instances that the birds would disappear entirely and get eaten by predators, or the birds might also fly away, but in some cases, they would also return to their island home.

The birds were seen in various places like Miramar Peninsula, near Foxton Beach, Tihati Bay Pāuatahanui Inlet, but frequent sightings were reported in Plimmerton. None of the released birds stayed on the island, Houston noted.

A woman reported having spotted three plovers near the fire station. She reckons that it looks like the plovers have now settled on the beach, but shared her concerns that the beach may not be a safe place for the rare birds as Norwegian Rats and cats are a threat.

The expert staff from the department would try to recapture the birds in Plimmerton with special equipment as the department will consider putting radio transmitters on the birds. 

Once a common sight along the coastlines of New Zealand, the tūturuatu /shore plover population had declined dramatically since the 1880s. The loss was attributed to introduced predators such as rats and cats as the rare birds are prone to predation.

But translocation of plovers has a silver lining. The shore plover population in Waikawa, Portland Island are steadily increasing, the Department of Conservation reported. 

The birds, which were introduced in 1999, had 37 pairs in 2012. However, rats decimated the population, with only four pairs surviving. 

Rigorous predation control was done after, and the population of the shore plovers increased dramatically since.