Garden Bird Survey key research for recording species numbers

Thursday, 28 June 2018

The NZ Garden Bird Survey kicks off on Saturday. Give up an hour of your day to keep track of the birds found in backyards across the country.

Every year for more than a decade, Jan Walker sits in her living room, looks out at the birds in her garden, and counts.

The Christchurch resident is one of thousands who participate in the New Zealand Garden Bird Survey, kicking off on Saturday and running until July 8.

Tui numbers increased nationally by 22 per cent between 2007 and 2017. Greenfinchs took out top spot, increasing nationally by 47 per cent.

'I think it's a very worthwhile thing to do, it's important for people to get interested in the natural life around them,' Walker said.

The survey has been by Landcare Research, a Crown Research Institute, since 2007. For one week a year, they ask Kiwis to take an hour and count birds they see in their backyard and submit their findings.

Sparrows remain one of the most common garden birds in New Zealand. Despite being an introduced species, survey founder Eric Spurr says all birds signal changes in our environment and ecology.

'I've done it every year since [it started]. New Zealand doesn't have any mammals, so the birdlife is important,' Walker said.

On average, 3500 gardens are surveyed every year. The first decade of findings were released last week, collated from more than 31,000 submissions.

A European starling. Details of how to identify different species are available on the Landcare Research website.

From her garden above Halswell Quarry, Walker enjoyed a large variety of both native and introduced species.

'Silvereyes, they are the most common bird in the winter. Otherwise we get great warblers, fantails, blackbirds, thrushes, finches – I haven't had a tui yet,' she said.

New Zealand's native wood pigeon, the Kereru, are one of the larger garden birds to be seen. Kereru numbers have increased nationally 12 per cent since 2007.

In Woolston, Kathryn McNeil said she was building a feeding table in preparation for the survey.

'I'll offer a smorgasbord of treats such as suet pudding, seeds, nuts and different types of fruit – including pineapple, which the silvereyes love,' she said.

The first decade of findings showed greenfinch numbers had increased 47 per cent nationally, tui numbers had increased 22 per cent, but silvereyes, also known as wax-eyes, decreased 43 per cent.

Survey founder and Landcare Research associate Eric Spurr said he thought the silvereye decrease was 'behavioural', rather than their indicative of population.

'They are just not coming into our gardens as much in warmer winters than they do in colder winters, and there is no doubt winters are getting warmer,' Spurr said.

'These birds and the sightings of them, whether native or introduced, signal to use that something is going on. There have been more species that have decreased than increased, so work needs to be done to figure out why these numbers are changing.'

Tui numbers increased a staggering 158 per cent in Canterbury, which Spurr put down to the successful translocation of about 30 tui to Banks Peninsula in 2009.

'I grew up on the Banks Peninsula, and in the 1960s there were heaps of them. We had them taking plums off our tree in Le Bons Bay,' Spurr said. Since the 1980s, tui numbers dropped, he said, and it was positive to see the population bounce back.

Between 2008 and 2016, Walker was the Canterbury representative for the NZ Ornithological Society and organised field trips, surveys and meetings for local bird-lovers. She spent part of her week helping to tag birds in Halswell Quarry to keep track of local populations.

'Birding, that's what we lived for, and still do really,' she said.

Information on how to participate, and bird identification tips, were available on Landcare Research's website.