Cages put a stop to shocking statistics of Kaikōura's banded dots survival

Monday, 19 February 2018

In an otherwise disastrous breeding season Kaikōura banded dotterel researcher Ailsa Howard found using cages to protect birds from predators increased the chances of chicks surviving to fledgling stage.

A system using cages to protect breeding birds from predators has been a saviour for a researcher's banded dotterel project.

Caged birds in the wild may seen unusual however, the technology may help save some nesting birds from extinction.

Kaikōura researcher and advocate for native eco-systems Ailsa Howard started observing the 'nationally vulnerable' banded dotterels in South Bay five years ago, and has been collecting breeding data for three years.

Howard said Kaikōura is the stronghold for the species because of it's rich nutritious marine area.

* Did you know the banded dotterel is as vulnerable as the great spotted kiwi?

* The tiny dotterel's terrible year**

It's been a disastrous breeding year for the tiny birds, however it shouldn't have been this way.

The earthquake that struck the district in 2016 lifted land around South Bay by one metre.

'This year was good because there was a significant increase in the amount of habitat for breeding, and new reefs in South Bay provided an abundant food supply for dotterels,' said Howard.

Despite that by late October none of the chicks had survived the first round of nests, even though there were birds everywhere.

Howard started using cameras and traps to see what was happening, before they thought about using cages.

The technology had been used elsewhere in the world to protect ground nesting species and she'd used cages before, but to alert people to a nest, more than a protecting the birds from predators.

'The camera was interesting,' said Howard.

'We started to see what type of predators were there and observe what they did, how prevalent and smart they were, and that weren't just dealing with wild cats, but people's pet moggies, and dogs and hedgehogs.

'There was evidence of cats taking chicks, but other evidence suggest dogs also take chicks, and disturb birds if they are unleashed or the owner is inattentative so adult birds became too frightened to sit on their nests at dark.'

'It was a total breakthrough,' said Howard.

'The dotterels loved their cages because they felt secure in them and they would come back to hatch their third egg.

'Previously they would often just hatch two of their three eggs and do a runner, but with the cages the birds would return and hatch the third eggs so immediately we had more dotterels on the beach.'

'Without the cages it would've been shocking and no eggs would've hatched or birds fledged.

The nests that were caged had at least one fledgling and out of 33 nests 11 fledglings were known to have survived the nest.

Howard said the results didn't show how successful the cages had been because it was the end of the season, however next season they will continue to use the cages, and trap hedgehogs and cats because when the birds leave the next the nest they are even more vulnerable unable to fly until they are at least five weeks old.

Howard wants the beaches around Kaikōura to be labelled as 'wildlife beaches'.

'People need to start doing something differently,' she said.

'We have a way to go with understanding and recognising the value of eco-syems. and learning to live in a natural ecosystems.

'Many of these species can't cope with the changes humans make and peg out and disappear.'