18-E-0673
15 November 2018
[FYI request #8725 email]
Dear M Hill
Thank you for your Official Information Act request to the Department of
Conservation, dated 20 September 2018. On 9 October 2018 we extended your
request to 15 November 2018 due to the large quantity of information sought. Your
question regarding the tahr cull and our response, is listed below:
‘information on how the estimate of 35000 Tahr on Conservation land is arrived at
including model(s) and method(s) used, criteria/frameworks in data acquisition,
discussions, conclusions, acknowledgments, accuracy and error margins’
In 2014, a report on historic tahr impact monitoring was completed by Landcare
Research. This revealed significant impacts of tahr on tussock and vegetation cover
and concluded that the current tahr monitoring to estimate population numbers was
not meeting the requirement of the 1993 Plan.
To address this, in the 2015/16 summer, DOC began a trial to integrate tahr
abundance and impact monitoring with the national-level monitoring (Tier 1)
undertaken as part of its Biodiversity Monitoring and Reporting System. Additional
measurements targeted at estimating tahr abundance (helicopter aerial counts) were
added to the programme for implementation at 111 sampling locations over a 5-year
period within the tahr management units and exclusion zones.
Analysis of the tahr abundance (helicopter aerial counts) data collected from 2015-
2017 at 38 sites was completed and a population estimate were obtained. The report
detailing the method, analysis, results and confidence intervals is provided below
Item
Document description
Decision
1
Report
Released
Tahr density estimates from aerial surveys (DOC-
in full
3233856).
Available on DOC website:
https://www.doc.govt.nz/globalassets/documents/parks-
and-recreation/hunting/west-coast/tahr-density-
estimates.pdf
I have decided to release the relevant parts of the documents listed above, subject to
information being withheld under one or more of the following sections of the Official
Information Act, as applicable:
• personal contact details of officials, under section 9(2)(a) – to protect the
privacy of natural persons, including deceased people,
• commercially sensitive information, under section 9(2)(b)(ii) – to protect the
commercial position of the person who supplied the information, or who is
the subject of the information,
• advice still under consideration, section 9(2)(f)(iv) – to maintain the current
constitutional conventions protecting the confidentiality of advice tendered by
Ministers and officials,
• advice subject to legal privilege, under section 9(2)(h) - to maintain legal
professional privilege,
In making my decision, I have considered the public interest considerations in
section 9(1) of the Official Information Act.
You are entitled to seek an investigation and review of my decision by writing to an
Ombudsman as provided by section 28(3) of the Official Information Act.
If you wish to discuss this response to your request, please contact Andy Roberts on
phone number 027 280 9186 or by email: [email address]
Yours sincerely
Andy Roberts
Director – Operations, Eastern South Island
