Latest rook target identified in Te Puia
Efforts to eradicate rooks from Tairawhiti are progressing with a nest of birds in Te Puia the latest target.
Rooks, also referred to as crows, are a declared pest bird in New Zealand; a native bird of Europe and Britain introduced into New Zealand by early settlers from around 1862 to 1874 and now established in many parts of New Zealand.
Due to the destruction of pasture and crops by large established groups of rooks, control of these pest birds is considered a priority by pest control authorities.
Present control of rooks is initiated through their inclusion in the Regional Pest Management Plan (RPMP) having an Eradication status in regions where they are present. Gisborne District Council undertakes control of rooks in the Gisborne region through implementation of the RPMP 2017–2027 and Operational Plan 2018/19.
In a report to GDC, the council's biosecurity team leader Phillip Karaitiana revealed details of the latest efforts to eradicate the birds from the region.
“Monitoring and active control of rooks in our district has been an annual undertaking since the 1970s and continues to the present as a pest listed in the Regional Pest Management Policy (RPMP) for the Gisborne region.
“Bird numbers reported over past years have fluctuated from 80 rooks controlled at Tolaga Bay in 1972 to 35 near Tiniroto in 2009 and up to 5 to 6 birds in recent years.
“Control pressure by the HBRC to eradicate rooks from Wairoa southward in recent years has contributed to surviving rooks spreading into our district, usually in low numbers.
“Gisborne District Council has combined resources in past years with the HBRC to control rooks at newly established rookeries along our southern boundary. Approximately seven combined aerial nest baiting programmes using a helicopter have been undertaken at Tiniroto, Hangaroa and Waerenga-o-Kuri.
“These targeted sites held populations of between 15 and 35 rooks. Kill rate achieved was about 95 percent. Follow-up controlled shooting was successfully carried out during early mornings to destroy any surviving rooks.
“Because rooks feed communally, they will return each day to selected feed areas until food sources are exhausted. Their overall effect on crops can be catastrophic and pasture damage quite significant.”
The report also noted a small group of 4 to 5 birds had been roosting in a large macrocarpa tree on a property north of Te Puia Springs.
“Council officers have been aware of these birds for the past two years and have monitored them at appropriate times in preparation for implementing control work.”
Planned culling in September/October 2018 was not carried out due to a delay with staff deployment and restricted firearms use.
Monitoring of the site resumed in August, 2019 through to September 2019.
“Controlled shooting was undertaken at day-break over two mornings in late October and early November. Two rooks were shot and three others became wary of our activity and have not returned.
“Prior to controlled shooting taking place, activity around localised stockyards and vehicle movements had made these birds wary and that, no doubt, affected the end result.
“Council officers will continue to keep an eye on this rook location as the birds will most likely return during August – September 2020.”
Follow-up monitoring of the site at East Cape near Te Araroa in August 2019, was found to be clear and residents had not seen any rooks since a lone rook was shot in November 2018 by a GDC officer.