State of NZ Garden Birds 2022 | Te Āhua o ngā Manu o te Kāri i Aotearoa
The annual survey, which began 16 years ago, is held every year in the last week of June. Data from the survey helps scientists understand the health of garden bird populations and the wider environment. It does this by showing how bird counts are changing across Aotearoa using two timeframes – over the past 5 years and the past 10 years.
In 2022, thousands of New Zealanders again rugged up warmly and turned out to take part in the survey and count the numbers of birds they saw in gardens, parks and school grounds. Over 5,400 new surveys were added to the analysis to bring us to 44,357 surveys over the past 10 years.
The information gathered in the surveys is put through an analysis using supercomputers that crunch all the data, including taking into account whether birds are fed in each garden, whether the garden is in a rural or urban setting, and how many gardens are in each region of New Zealand.
Our analysis showed positive signals emerging for four native species:
- Fantail (pīwakawaka) counts now show a moderate increase (55%) over 10 years, compared to the shallow increase seen in recent years, and the moderate increase over 5 years continues (26%).
- We continue to see a shallow increase in tūī (kōkō) counts in the long term (30%) and short term (9%). Their regional long-term trends show a rapid increase in Canterbury (266%) and moderate increases in Taranaki (59%) and the West Coast (61%).
- There is still a long-term shallow decline in silvereye (tauhou) counts (12%), but there has been little or no change in their counts over 5 years compared to the short-term moderate increase seen last year.
- Kererū counts show a moderate increase over 10 years (83%), with only a shallow increase over 5 years (10%).
Things are not looking so good for some introduced species. Numbers for both starlings (tāringi) and chaffinch (pahirini) show a decline in populations. For the first time, chaffinch show a moderate decline over the short term (20%), while starlings are continuing their long- and short-term shallow decline.
The trend of little or no change in myna counts nationally continues, except for in Wellington where counts continue to show a rapid increase over both 10- and 5-year periods (193% and 248%, respectively), and now also show a rapid increase in Manawatū-Whanganui (49%), a moderate increase in Gisborne (30%), and a shallow increase in Taranaki (12%) over 5 years.
Manaaki Whenua researcher, Dr Angela Brandt, says the data let us understand how bird populations are changing across New Zealand. "What's exciting about having so many years of surveys now is we can see how trends are changing over time.
“Some species show an uptick - like pīwakawaka, or a lessening decline - like tauhou - compared with earlier reports. Importantly, because the survey is done every year, it gives us an early warning if a species starts to decline."
The NZ Garden Bird Survey founder, Dr Eric Spurr, says he looks forward to the survey every year and is delighted at the increasing number of people who take part.
“The results show the value of long-term citizen science monitoring, and while the survey does not attempt to determine the causes of changes in bird counts, is tempting to think increases in counts of native birds reflect the results of increased predator control and habitat restoration activities around the country.”
Since 2021, we’ve also asked survey participants what more needs to be done to care for birds in Aotearoa New Zealand and this year there was overwhelming response for more to be done to manage weeds and predators. Manaaki Whenua social researcher Dr Gradon Diprose says “Participants suggested a wide range of everyday actions people can take to reduce the impacts of weeds and predators on birds. Not all participants agree on what should be done, but the responses highlight how many New Zealanders care both about birds, and the wider environment”.
This year the survey runs from 24 June – 2 July 2023. There is plenty of bird identification information on the NZ Garden Bird Survey website, so lots of time for everyone to get familiar with the manu that visit our gardens.
A full copy of the State of NZ Garden Birds | Te āhua o ngā manu o te kāri i Aotearoa 2022 can be downloaded from 2022 NZ Garden Bird Survey results.