Okere Falls Store Conservation Project
Dabchick count on Lake Rotoiti

New Zealand Dabchick (Poliocephalus rufopectus), or Weweia, is a protected endemic New Zealand grebe that is probably extinct in the South Island, and now confined to the central North Island – living right at our door step!

The total population is estimated at 1200 – 1500 birds of which about one third live on Rotorua lakes. Dabchicks are listed as endangered (defined as having a 20% chance of extinction in 20 years).

Our project is to:

• Carry out monthly counts of dabchicks between Otaramarae and Okere Falls.

• Map these sightings.

• Correlate our data with other dabchick counting projects in the Rotorua area.

• Highlight any population reduction/changes to Wildlands (www.wildlands.co.nz) and Department of Conservation (www.doc.govt.nz) so urgent action can be taken.

Method:
Dabchicks are counted by travelling 30 – 100m from the shore by canoe or small boat. Conditions need to be calm with clear visibility (no rain).
Dabchicks, while easily distinguished from other water birds, are not very easy to count accurately because they move rapidly away from approaching boats and will dive below the water surface when alarmed.
We learned to look well ahead to catch views of the dab chicks swimming or diving towards the shore.

Currently there is no other safe way to capture and tag dabchicks as an alternative way to monitor population fluctuations.

Our first count was at the end of May 2011. Dab chicks will not start breeding again till the spring. Our first counts are therefore adult dabchicks. When we come to our counts in spring and summer we will start recording juveniles.

At the moment, five-yearly counts have been completed over the last 15 years by OSNZ (Ornithological Society of NZ), DOC (Department of Conservation) and the Eastern Region Fish and Game Council. It is recommended that these counts continue.

Our single most important objective of our counts is to monitor the number of dabchicks in our immediate area, especially given that the reason for dabchicks' disappearance from the South Island remains unknown.

While the dabchick population is currently stable in our area, a serious threat could arise inside the five year time span because of many recent changes in the Lake Rotoiti environment (the wall and ensuing increased water levels, algae blooms, increased lake usage, possible changes in weather patterns).
We believe a regular count on a more frequent time scale could help detect threats to the population early and prevent the risk of extinction of this species.

Picture (below): Dabchick count by Okere Falls Store staff 10.9.2011

Picture (below): Dabchick count by Okere Falls Store staff 19.7.2011

Picture (below): Dabchick count by Okere Falls Store staff and Willie Shaw (Wildlands) 29.5.2011

Acknowledgements

Thanks to Willie Shaw from Wildlands for his time and being an amazing source of information on just about everything on (and sometimes off) the lake between Otaramarae and Okere Falls!