OIA 19-E- 0448/docCM 6029697
1 August 2019
K Lane [FYI request #10673 email]
Dear K Lane
Thank you for your Official Information Act request to the Department of
Conservation, dated 4 July. You requested the following:
Under the Official Information Act 1987 I request the following information
which relates to a recent DOC video which starts off with the words "Overall
native bird numbers have doubled" and goes on to say that in one West
Coast valley birdsong has doubled over the past 20 years" after "two
decades of aerial 1080 and trapping":
1. Which valley is this?
2. Is there a report on this work that is available to the public on
methodology and results?
3. In which years was this valley aerially 1080d?
4. In which years was a trapping program carried out?
Your questions and our responses are listed below.
Doubling native bird numbers in the Landsborough Valley
The valley referred to in the video is the Landsborough in South Westland. The video
and the information you request is publicly available on the Department website:
This webpage includes a link to a scientific report on the methodology for the study:
Quantifying the benefits of long-term integrated pest control for forest bird
populations in a New Zealand temperate rainforest.
Your request is possibly related to misinformation, spread on social media, claiming
inconsistencies in the Department’s evidence for increasing bird numbers.
Conservation House - Whare Kaupapa Atawhai
PO Box 10 420, Wellington 6143
Telephone (04) 471 0726, Fax (04) 381 3057
This misinformation may be based on a 2011 news story, “A bird in the hand”, about
translocation of mohua from the Landsborough to Resolution Island:
This is an informative article, but it was not released by the Department. While the
article referred to trapping, it did not mention the aerial 1080 predator control that
has also been carried out in the valley. This may have led people to claim the article as
evidence that trapping alone is enough to increase bird numbers.
Techniques used in the Landsborough
In fact, three predator control techniques have been used consistently in the
Landsborough area. Introduced mammalian pests have been controlled at the study
site since late 1994 using three techniques:
• trapping aimed at stoats;
• ground control (trapping and poisoning) aimed at brushtail possums;
• aerial (1080) aimed at possums and, from 2009, rats.
Since formal bird counts commenced in 1998, consistent methods of pest control
have been applied in the area. Aerial applications of 1080 baits were undertaken in
July 1998 (7,340 ha), June 2000 (3,750 ha), December 2004 (16,420 ha) October
2009 (12,170 ha), winter 2014 (25,533 ha) and winter 2016 (28,283ha).
For more details about the research protocols for the Landsborough study, see the
article linked on the website, and attached with this response.
We respectfully suggest that in future you check the Department’s website for
publicly available information, before making a request under the Official
Please note that this letter (with your personal details removed) will be published on
the Department’s website.
Director Threats, Biodiversity Group