In the wintering wildfowl include wigeons, teals, pintails and Bewick's swans. Blue-winged teals and northern shovelers can be seen in spring and summer. It includes the pintails, most teals, and the mallard and its close relatives. Blue-winged geese and Cape teals have been exhibited here as well, though are currently absent. It is one of the "grey teals", a group of related ducks found across Australasia. Upon reaching sexual maturity, ringed teals form strong pair bonds. In teals, the drakes make a call of short bursts of a high pitch whistle. They are known to interbreed with blue-winged teals, which are very close relatives. Most ringed teals average long, with a wingspan. This villu was the home of large flocks of teals (seru) during migratory period. A total of 38 Teals were manufactured. Wang designed a three-month summer class for Microsoft employees who wanted to volunteer with TEALS. The total cost for the endeavor was 200,000 silver teals. Fifteen Model TSC-1A Teals were built by the Thurston Aircraft. This is smaller than the eggs of any of the other "grey teals".