In the western parts of its range, the ruddy shelduck is threatened by habitat loss and hunting and is thought to be in decline (7). Across the Mediterranean region as a whole, approximately 50 percent of wetlands have already been lost (8) due to water extraction for irrigation, drainage, salt extraction and urban development (5) (6) (7), and wetland loss has accelerated over the past two decades in many areas. In Morocco, the ruddy shelduck’s habitat is threatened by an increasing human population and by development, and most Moroccan wetlands are unprotected (8). The ruddy shelduck’s habitat is further threatened by sand mining and pollution in Bulgaria (7), and by agricultural encroachment and tourist developments in China (9).
The ruddy shelduck is hunted in much of south-eastern Europe and south Asia, but is relatively well protected from hunting in many Buddhist countries by its status as a ‘sacred’ bird (7). Consequently, numbers of ruddy shelducks in central and eastern Asia are thought to be stable or even increasing (6) (7). The ruddy shelduck is, however, susceptible to avian influenza and could become threatened by future outbreaks of this deadly disease (7).
In contrast to its eastern European status, the ruddy shelduck is increasing in western Europe, but is considered an invasive species there. Many captive populations have escaped and established in the wild and are threatening native species due to the ruddy shelduck’s aggressive nature towards other waterfowl. The ruddy shelduck is also able to interbreed with other shelduck species, resulting in the pollution of both species’ gene pools. Consequently, the ruddy shelduck is subject to eradication measures in western Europe (4) (7).