Backyard beats | What are our birds telling us ?
Birds act as 'backyard barometers' - telling us about the health of the environment we live in.
Birds are signalling significant changes in our environment over the last 10 and 5 years, according to the State of NZ Garden Birds 2018 | Te Āhua o ngā Manu o te Kāri i Aotearoa 2018 report just released by Manaaki Whenua – Landcare Research. Using cutting-edge techniques, researchers have distilled a large information base – bird counts gathered by New Zealanders from over 34,000 garden surveys since 2008 – into simple but powerful metrics.
Positive signals are emerging for four native species:
- A moderate increase in kererū counts (56%) over 10 years, accelerating to a rapid increase in the last five years – a pattern that is visible across all regions.
- The long-term trend for a shallow increase in tūī (kōkō) counts (27% over 10 years) continues, with the rate of increase also accelerating nationally for this species in the last five years.
- An emerging trend for a shallow increase in fantail (pīwaiwaka) counts (15% over 10 years), with the rate of increase also accelerating in Canterbury, Otago and Southland in the short term.
- The moderate decline in silvereye (tauhou) counts (28% over the last 10 years) is still apparent, but this rate of decline has slowed nationally (to 2%) in the last five years.
For introduced species, which also act environmental indicators, the key signals are:
- Consistent with last year’s observations, shallow or moderate declines in counts (14-32% over 10 years) were detected for dunnock, song thrush, goldfinch and starling.
- Although myna counts show little or no change in the long term, an early warning has been raised with a shallow increase in their counts nationally. Of particular concern are the moderate increases observed in Bay of Plenty (71% and 29% over 10- and 5-year periods respectively).
