Wetlands and Pateke on Okiwi Station
Practical steps make signifcant impact on teal habitat
by Joanna Sim
 

Great Barrier is a stronghold for pateke but they struggle over the typically very dry summer months to find food (especially juveniles) as all the previously soggy pasture dries up and wetlands become overgrown with weed species. We do still graze some “wetlands” periodically over summer specifically for pateke (these are generally heavily modified seeps that have been grazed for decades and if are not grazed, quickly become rank with thick swards mercer or kikuyu grass). But apart from grazing I have been looking at other alternatives over the past year. This has involved spraying some wetlands & digging out small ponds, building bunds & damming up a few drains. Spraying sounds terrible but these wetlands were so overgrown (with mercer grass & Lotus major) that they were taking over the wetlands & making it practically impenetrable for foraging teal to access. Its still early days but so far the results look promising with water pooling on the surface of these areas.

“Airport Pond’ wetland is now riddled with teal foot prints and probing bill marks. There are juvenile teal living on the edges of it and teal have been seen feeding there at night (as well as eels, pukeko & stilts).

One trial bund has been built and seems to have worked so far. This involved damming up & building a bund across one branch of a drain that was trickling slowly downstream into a road ditch. The aim here is to hold some water back that will encourage damp pasture around the edges and retain shallow water over summer. Monitoring is and will be done at night to check whether teal are using these areas. So far, over two nights (only a couple of hours) I have caught/ seen 10 teal associated with this area. One teal seems to be residing there in the day as well.

Damming up other small drains & culverts has also been carried out with instant gratification! I am also going to trial hoses off the water troughs to keep shallow ponding areas wet in paddocks. Some areas we literally want flooded pasture but in others I am hoping to restore wetlands to their former glory. I have been planting some wetlands with help from the local school and other area staff, and plan a big planting of wetlands and their margins, next autumn.

Three more roosting rafts have been built & have been launched onto ponds. The first raft built in 2007 has proved to be hit and currently has over 20 teal on it. Hopefully the new rafts will prove to be as popular as pateke start flocking at their favourite sites.

Jo Sim is Ranger in charge of monitoring and conserving teal on Great Barrier Island.


'Airport Pond' overgrown with mercer grass. December 2008

'Airport Pond' October 2009

Roosting pateke on their
mussel buoy raft.

Looking upstream at the old drain before any work was done.

Looking upstream 3 weeks
 after bund built.