Hawaiian duck's population is affected by habitat loss, modifications to wetland habitats for flood control, non-native invasive plants, diseases, environmental contaminants, hunting and predation. The primary avian diseases of concern in Hawai’i are avian malaria and avian pox, which have devastated forest birds and greatly limited their distributions (Reed, et al. 2012). Predation threats to the koloa maoli include feral cats, rats, and small Asian mongooses, which eat the eggs and young. Other ways that the Hawaiian ducks are being threatened is through the predation of dogs, introduced fish, and also other birds that are being introduced into their habitat. The previous hunting of water birds in these area from 1800s to the 1900s also played a major role in the decline of this species. Urban development along with loss of their natural habitat due to the use of the land for local agriculture plays a major role to the indefinite decline of this now endangered species (U.S. Fish and Wildlife Service 2005). Amongst the threat of urban development certain problems arise such as human disturbance, whether it be recreation or through tourism. Through their constant migration from their ever-degrading habitat, another obstacle arises, that which is drought. In the late 1800s, the mallard, also known as Anas platyrhynchos, were flown in to stock up the ponds of Hawaii for ornamental purposes, but soon enough they were massively imported throughout the 1950s and the 1960s (U.S. Fish and Wildlife Service 2005). Interbreeding with feral mallards is the result, as the hybrids seem to be less well adapted to the local ecosystem. This interbreeding is rather common due to the high numbers of feral mallards. Several attempted reintroductions have already failed due to the hybrid ducks produced in captivity faring badly in the wild (Rhymer & Simberloff 1996). The "conversion of flooded taro fields to dry sugar-cane acreage" destroys parts of this species' habitat.[3] Conservation actions Throughout the cold winters a wild refuge is a very important factor for this species. The Hanalei National Wildlife Refuge makes this all possible for the Anas wyvilliana to procreate when their habitat is not suitable for their survival (Todd 1996). The species was then for the first time introduced into O’ahu where only a scarce amount of almost 326 captive birds of the species were released into the wilderness between the years of 1958 and 1982. Later on in 1989 only twelve of these