The State of NZ Garden Birds

June 24, 2019

The latest garden bird counts show three of our native species are thriving, while another’s decline is slowing.

The State of New Zealand Garden Birds 2018, released today by Manaaki Whenua – Landcare Research, shows positive changes in counts for four of the country’s native bird species.

The report is based on more than 34,600 garden bird survey counts gathered nationwide by volunteers in their backyards since 2008. Participation hit an all-time high last year, with 4,376 surveys completed.

The report shows that over the past five years there has been a rapid increase in kererū (New Zealand pigeon) numbers and a moderate increase in tūī (Kōkō).

Manaaki Whenua research associate Dr Eric Spurr, who initiated this nationwide citizen science project in 2007, says the results show increases in fantail (pīwaiwaka), tūī (kōkō) and kererū (New Zealand pigeon) counts in the last 10 years, with the rate of change accelerating in the past five years for the latter two species.

Kererū counts have risen rapidly since 2013, with an increase of more than 80% noted in Canterbury and Marlborough and more than 70% in Waikato and Hawke’s Bay. The numbers of tūī seen by survey participants have increased 245% in Canterbury and 73% in Marlborough over the same period.

Dr Spurr says that while the survey isn’t designed to determine why these changes have occurred, it is likely to be down to recent predator control and restoration planting.

‘Predator control is increasingly being undertaken by councils and local community groups, partly in response to the Government’s Predator Free 2050 initiative,’ Dr Spurr says. ‘Reducing predator numbers enables birds to breed more successfully and potentially increase in number.’

Conversely, numbers of silvereye (also known as waxeye or tauhou) noted by survey participants have reduced by 28%. ‘The decline in silvereyes may be a reflection of climate change – in warmer winters fewer silvereyes come into gardens, presumably because more remain in surrounding farmlands and forests,’ says Dr Spurr.

Despite the decline, this is good news for silvereye counts as the decline appears to be slowing.

Dr Spurr says that while the effects of climate change on birds are difficult to predict, our native birds have already adapted to a highly variable climate.

‘At this stage we simply do not know what changes in climate – such as warmer temperatures, changing patterns of rainfall, and more extreme weather events – will mean for birds.’

The 2018 report also revealed key trends for introduced species that act as environmental indicators. The report also signals a warning for myna, with a small increase in their counts nationally. Consistent with last year’s observations, shallow to moderate declines (14–32% over 10 years) were detected for dunnock, song thrush, goldfinch and starling.

Dr Spurr says ‘these results are important because birds act as backyard barometers - telling us about the health of the environment we live in.’

‘The survey would not have been possible without volunteers,’ he says. ‘We are grateful to the many thousands of people, citizen scientists, who have spent an hour each year counting birds in their gardens since the survey began 12 years ago.’

The 2019 New Zealand Garden Birds Survey takes place from June 29 through until July 7. The more people that take part the clearer the picture we will be able to build about the state of our environment.

It’s easy to take part and survey your garden, local park or school. For more information visit

https://www.landcareresearch.co.nz/science/plants-animals-fungi/animals/birds/garden-bird-surveys

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