Counts of kererū in Kiwi backyards suggest the hefty native pigeon is becoming more abundant. Photo / Mark Mitchell
Counts of kererū in Kiwi backyards suggest the hefty native pigeon is becoming more abundant. Photo / Mark Mitchell
The unmistakable flutter of a low-flying kererū is becoming a more familiar sound in Kiwi backyards, according to new survey data.
The country's longest-running citizen science project – the New Zealand Garden Bird Survey – suggested the hefty pigeon has made a comeback in our suburbs, along with fellow natives fantail/pīwawaka and tūī.
And the survey's organiser thinks the 10-year trend could be down to local predator-trapping projects bearing early fruit.
Since its inception in 2007, nearly 40,000 people across the country have joined the survey to count all the birds they see or hear in their garden in one hour on one day during a nine-day period at the end of June.
The project helped scientists understand the health of garden bird populations - and by association the wider environment – and tracked changes across five and 10-year timeframes.
Data from last year's survey, released this week, showed kererū counts had moderately increased (by 79 per cent) over the past 10 years – and seen rapid boost over the last five years (55 per cent, or 11 per cent annually).
Source / Manaaki Whenua - Landcare Research
Fantail counts also showed a shallow increase over the last 10 years, accelerating to a rapid increase over the last five years (43 per cent, or 8.6 per cent annually).
"After 15 years, the survey results clearly demonstrate that several native bird species, including kererū, tūī and pīwawaka, are increasing in abundance in our gardens," said survey founder Dr Eric Spurr, of Manaaki-Whenua-Landcare Research.
"The survey cannot determine the causes of these increases, but it is tempting to suggest that they reflect the results of ever-increasing community predator control and habitat restoration activities around the country."
Tūī (kōkō) counts still showed a shallow increase over the long-term.
A decline in counts of silvereye/tauhou had also slowed over the decade, and in the last five years had begun to turn around to increases of 1.4 per cent each year.
Meanwhile, numbers of the raucous and aggressive myna had kept stable across the country – but had particularly increased in Wellington – while counts of starling were continuing to fall.
And numbers of song thrush, goldfinch and dunnock were no longer showing national declines over either the short or long term.
As well as scientific data on bird numbers, researchers also collected information about how the public views their role as citizen scientists and the impact of science in their daily lives.
Tūī also appear to be growing more common around New Zealand gardens. Photo / Darren Markin
Environmental social science researcher Dr Gradon Diprose said the responses showed people felt a sense of connectedness both with nature and their communities after completing the survey.
"People report they feel they can contribute without having to join a group," he said.
"People were happy to do the survey, because they could fit it around their other commitments, but still contribute in a meaningful way to a collective environmental effort."
Diprose said 2020's survey had the highest number of participants ever, which was likely influenced by the pandemic response.
