Bird migration perils cold temperatures on the wintering grounds kills thousands of birds, resulting in 30-90% population declines of migratory birds. For example, between 27000 and 62000 ducks, mostly tufted duck and common pochard, starved to death during a very cold winter in March 1986. The passing of Migratory Bird Treaty (US, 1916) and Migratory Birds Convention Act (Canada, 1917) made it illegal to kill or capture migratory birds. Even though migratory bird acts were passed at the beginning of the 19th century, many countries still have no laws or programs to protect migratory birds. International bird trade is a multibillion-dollar industry and
Baer's pochard found just 131 individuals on Liangzihu Lake, and only another three flocks of ten, eight, and three individuals at other sites. Hunting and wetland destruction are thought to be the causes of the decline; unconfirmed reports from eastern China suggest that as many as 3,000 individuals may be hunted every year. Baer's pochard breeds around lakes with rich aquatic vegetation, nesting in dense grass, flooded tussock meadows, or flooded shrubby meadows. In Liaoning, China, it is normally found in densely vegetated coastal wetlands, or around lakes and ponds surrounded by forest. In winter, it occurs on freshwater lakes and reservoirs.