Brown Teal Habitat
As already discussed, the main source of food for Brown Teal appears to be invertebrates.
Invertebrate could cover:
(a) All aquatic insects – water boatmen, bugs, back swimmers, etc
(b) Insects that spend their larval stages in water – stoneflies, mosquitoes, black flies, gnats, midges, caddis flies, mayflies, alderflies, dragonflies, damsel flies and lacewings
(c) Insects which spend no time in water, but use wetlands extensively – moths, bees, wasps, beetles, ants and butterflies
(d) Crustaceans – fairy shrimps, clam shrimps, water fleas, seed shrimps and Cyclops
The other critical part of the Brown Teal food chain appears to be seed-bearing plants and wetland vegetation.
Historically the seed-bearing plants would have included seeds from most of New Zealand’s native trees – kahikatea, tawa, titoki, etc., and the suitable wetland plants – raupo, rushes, sedges and grasses of all types, ferns, flowering plants and flaxes of all types.
Today, there are still a number of wetlands which have an immediate association with the majority of these plants. Many are protected by a QEII National Trust Open Space Covenant, or other covenant; many are not shot and with extensive predator control could fulfil all other requirements.
Whilst water quality is nowhere near as important as invertebrates and other food sources, water quality should be checked and regularly monitored to ensure that there are no forms of pollution entering the wetland
Grazing of Agricultural Livestock
A strict management regime must exist where farm livestock are grazing close to Brown Teal release sites.
To protect vegetation from the negative influences of livestock the Brown Teal release site must be fenced, but at the same time teal must have easy access to the surrounding farmland so that they can graze in the paddocks and dissect the cow dung, as they do on Great Barrier Island.