Ryan Stewart, of Gore, asks :-
I photographed these ducks, which are smaller than mallards but have a larger beak and are shy. What are they and what is known about them.
Mary Thompson, a zoologist from the Otago Branch, Ornithological Society of New Zealand, responded.
Not every duck you see is a Mallard even though there are several million in New Zealand! Mallards were introduced from Europe and North America in the 1900s and have adapted extremely well our conditions. There are also seven native ducks on our mainland, but these are far less abundant. You have actually spotted two of them and both are about half the size of a Mallard.
The New Zealand Shoveler (on left) is one of our most colourful ducks. Males loose their bright colours when they moult in summer. Shovelers have a distinctive bill, with a flattened, shovel-shaped tip, from which they derive their name. The inner edge of the bill has tiny, fine comb-like lamellae that interlock to provide an efficient sieve. Shovelers use their specialised bill to sieve out their food of small aquatic plants and invertebrates from water. There are about 200,000 Shovelers in a patchy distribution as they prefer fertile large shallow lakes and swamps.
The Grey Teal (on right) is one of our smallest ducks. They are found in coastal lakes, lagoons and estuaries, but are not all that common as there are only about 50,000 of them. Grey Teal feed by dabbling in shallow water or soft mud.
Other native ducks you are likely to see are pairs of Paradise Shelduck near farm ponds and Scaup (Black Teal), a diving duck, in deep freshwater or hydro lakes.
All these ducks are secretive when breeding, but in autumn and winter, they form large flocks on lakes and estuaries. Most survive for 2 to 3 years, but can live as long as 20 years.
Next time you spot some ducks, don’t just assume they are all Mallards; take a careful look. Use a bird identification book to help you decide what they are.