The Diving Duck Conservation Program
The Diving Duck (Aythya nyroca), sometimes called the Fudge Duck or Ferruginous Duck is a dark, chestnut-colored duck with the males having a distinctive pale iris (hence it is also often called the common white-eye). They eat mainly aquatic plants, but also some molluscs, insects and small fish, collected or caught by diving or dabbling and are capable of diving down to depths of 10 meters. Their natural habitat is well-vegetated wetlands where theynest in low platformsof reeds and other vegetationplaced on the ground in thick shoreline vegetation. Their breeding range extends from southern and eastern Europe to southern and western Asia and they are chiefly migratory. These are gregarious birds, forming large flocks in winter, often mixed with other ducks, such as Tufted Ducks and Pochards.
Diving ducks are threatened by the degradation and destruction of well-vegetated shallow pools and other wetland habitatsas a result of excessive drainage; reed cutting and burning; covering of water reservoirs; extensively managed fishponds; and the introduction of non-native species. Hunting is a serious threat and disturbance by fishing boats and anglers alongside fringe vegetation can cause nest abandonment and disruption of the breeding cycle. Other lower-level threats include fires; drowning in fishing nets; and hybridization with native species.
The species has declined markedly in Europe where there have been declines of more than 20% in eight European countries. Small numbers occur in various Middle Eastern countries. The species is listed as Near Threatened on IUCN Red List. Although it is already fully protected in 15 European countries and protected from hunting in 6 more, it has received little international conservation action, although a number of national initiatives have been developed recently, notably habitat management in Bulgaria and re-introduction schemes in Italy.
These ducks have all but disappeared from Israeli wildlife as nesters because of the loss of wetlands habitats. In 2010, the Jerusalem Zoo in Israel began a breeding program with a core group of four captive-born individuals. This group has continued to produce eggs every year. Over the last two years, a pilot reintroduction program was conducted by releasing 9 individuals into the Zoo’s central lake – an open area where the birds are not prevented from flying away. However, all 9 individuals chose to remain in the lake and did not venture further afield (probably because of the readily available food source). This past June, 21 eggs hatched (inexplicably, all males!). The chicks were allowed to mature until mid-October when they were identified and banded in preparation for release into the wild. Most birds are banded on the leg using a numbered or colored band to enable conservationists to watch from a distance and readily identify the bird. This does not work with aquatic birds, however, because their legs are hidden in the water most of the time so a special technique developed in Portugal is used to band their bills. They are individually sized to the birds’ bills and threaded through their nostrils with a fine nylon thread. The nylon does not bother the bird and does not interfere with breathing, eating or breeding. The bands are easily read from a distance. Because diving ducks are more sensitive than most ducks and prone to sudden stress-induced heart attacks, a special protocol was developed at the Jerusalem Zoo to fit the bands as quickly as possible with minimal stress to the birds. A few days later the ducks were taken to the north of Israel where 15 males and 2 females were released into the Hula Valley Nature Reserve in conjunction with the Israel Nature and National Parks Protection Authority (INNPPA).
This is only the beginning of what is hoped will be a long term breeding and reintroduction program. Coupled with raising public awareness of wetlands habitat preservation, we hope to see a population recovery in Israel.