The Biological Wealth of an Impoverished Country: Birds: Page 2 Endangered Species Handbook

Madagascar and other Islands

The Biological Wealth of an Impoverished Country: Birds: Page 2

Birds native to aquatic habitats have declined even more dramatically than many forest birds. The largest lake on Madagascar, Lake Alaotra in the northeast, was once a paradise of waterbirds, turtles, frogs and other wildlife. Traditionally, portions of the lake were used by the Malagasy for rice cultivation, without serious damage to the environment or resident wildlife. But as their populations and food requirements grew, people began to destroy more and more of the natural marsh and reed beds that lined the lake, and cleared the surrounding forest for firewood and agriculture. This destroyed the lake's water quality. With no trees to hold back the soil and conserve water, this once-beautiful lake became heavily silted by runoff (Durrell 1993). Added to this, non-native tilapia fish were introduced into the lake as a food source for the local people. The fish eat vegetation needed by dragonflies and other fauna that form the basis of the lake's food chain (Preston-Mafham 1991). This ecological collapse has greatly reduced rice production on the lake, although reeds are still being cleared for rice growing, fragmenting wildlife habitat (Garbutt 1999).

The effects on native aquatic birds have been catastrophic. Lake Alaotra is the only known habitat of the endemic Alaotra Grebe (Tachybaptus rufolavatus), which is presumed extinct (BI 2000, Morris and Hawkins 1998). No sightings have been made since 1985, when only two birds were seen. It declined from loss of its habitat, hunting and hybridizing with the Little Grebe (Podiceps ruficollis), a recent arrival from Africa (Morris and Hawkins 1998). Many fruitless searches for the species have been carried out in the lake and surrounding area since then (BI 2000, Morris and Hawkins 1998). This small, black-capped grebe was very sedentary and may have been nearly flightless because of its extremely short wings.

Another waterbird restricted to Lake Alaotra, the Madagascar Pochard (Aythya innotata), is also probably extinct, having been eliminated by the same threats as the Alaotra Grebe (BI 2000). This duck declined steeply from 1930 on, and the last known bird, a male, was captured in August 1991, having been caught in fishing gear. This bird later died, and intensive searches in 1989 and 1990, and again in 1993 and 1994, failed to discover more Madagascar Pochards (BI 2000, Collar et al. 1994). A handsome bird, the pochard was chestnut-colored, with dark gray bill and yellow eyes (see photograph in Morris and Hawkins 1998). A shy species, its breeding and behavior were studied, but apparently nothing was done during its precipitous decline to prevent its extinction. Classified as Critical, hope remains that a few birds exist in wetland habitats around Lake Alaotra (Morris and Hawkins 1998).

The Jersey Wildlife Preservation Trust has begun education campaigns in the vicinity of Lake Alaotra to teach local people about the presence of the highly endangered Alaotra Reed Lemur or Bandru (Hapalemur griseus alaotrensis), a subspecies of the Grey Bamboo Lemur, and the importance of protecting the reed and papyrus beds. This lemur has been classified as Critical by the IUCN. The only lemur to live in an aquatic environment, the Alaotra Reed Lemur is larger than other subspecies of the Grey Gentle Lemur and lives in close, family groups (Garbutt 1999). To move about in the reed beds, they climb up a reed stem until it bends, and then walk along it to reach the next stem; their major food is the endemic papyrus, along with grasses and ferns (Garbutt 1999). Lake Alaotra's reed beds are its sole habitat, and although previously widespread in this and another lake to the north, only two isolated populations of lemurs, one of which numbers fewer than 60 animals and is on the verge of extinction, remain in marsh fragments (Garbutt 1999). This lemur has the most restricted range of any lemur species or subspecies (Garbutt 1999). The film, “Madagascar. A World Apart,” includes a moving segment on these lemurs feeding among the papyrus when a Malagasy canoe enters the marsh and sets a fire, causing the terrified lemurs to flee. (See Video section). Local village leaders have requested that the government set aside a protected zone in the marshes. There is hope that this lake will be brought back as a functioning ecosystem in the future and that a strict sanctuary will be set aside for this endangered lemur and the highly endangered waterbirds.

While sizeable areas of forest have been protected, few aquatic environments on Madagascar have been preserved, and native waterbird species are declining precipitously. The Madagascar Little Grebe (Tachybaptus pelzelnii) was once common and widespread in many parts of the island; with the pollution and destruction of marshes throughout the island for rice farms, this bird has declined greatly. The introduced tilapia was threatening this species by consuming its food supply. This grebe also hybridizes with the introduced Little Grebe (Collar et al. 1994). The Little Grebe, an African species which has colonized the island, prefers the habitat created by the tilapia, and is now abundant (Langrand 1990). The Madagascar Little Grebe has also drowned in fish nets, and has lost the vegetation it needed for nesting (BI 2000). It is expected to follow the Alaotra Grebe and Madagascar Pochard into extinction.

Another endemic waterbird, the Sakalava Rail (Amaurornis olivieri), native to western wetlands, is also extinct or nearly so. A small, sooty-black bird with yellow beak and pinkish-red legs and feet, it was native to streams and marshes in the western parts of the island. For more than 30 years, this species was not seen at all. In 1995, one was glimpsed at Lake Bemamba, and another in 1999 at the same lake (BI 2000). This species is classified as Critical (BI 2000), and Lake Bemamba and other lakes and wetlands on the west coast may be given protection by the Malagasy government, which has ratified the Ramsar Convention on wetlands preservation (BI 2000).

As a result of extensive habitat destruction and hunting, the Madagascar or Bernier's Teal (Anas bernieri) has likewise declined to endangered status in the few sites from which it is known on the west coast. Once widespread on the island, it is now restricted to a few marshes and shallow lakes. Small populations remain on Bemamba Lake and a few other sites (Morris and Hawkins 1998), and a flock of 67 was seen in another area (BI 2000). In 1970, 60 of these birds were seen on a lake, and as soon as this became known, European sportsmen went to the lake and killed more than 25 percent of the population (Curry-Lindahl 1972). In the 1970s, Bernier's Teal inhabited Lake Masama, but heavy hunting by both Europeans and natives with dogs has nearly eliminated them (Todd 1979). In 1993, four birds were captured for captive breeding (Collar et al. 1994). The Jersey Wildlife Preservation Trust is working to preserve this beleaguered species and the marshes of the west. The Madagascar Teal has been seen in three protected areas, and a conservation program at one lake has been initiated (BI 2000).

The critically endangered Madagascar Fish Eagle (Haliaeetus vociferoides) numbers about 250 pairs in the 600-kilometer stretch of western coastline to which it has become confined (BI 2000). This large eagle resembles the African Fish Eagle, from which it probably evolved, but instead of a snowy white head and upper body, it is streaked with brown and has shaggy, buff crown feathers. About 35 inches long, with a 6.5-foot-wingspan, it is by far the largest bird on Madagascar. Persecuted by local people, these eagles have been shot and their nests destroyed. On one occasion in the 1990s, ornithologists saw some immigrants cut the tree where an active nest of a Madagascar Fish Eagle was located, and proceed to kill and eat the chicks! The only remaining habitat for this species is the western coast, where mangrove swamps are rapidly being destroyed (Langrand 1990, Preston-Mafham 1991). The Peregrine Fund is sponsoring research on this species, and 10 nests have been located in an area on the west coast in the Three Lakes Complex (BI 2000). The Fund has removed and raised chicks that would have been killed by siblings and released them to augment the population. The fish it feeds on are being depleted, however, by a gill-net fishery that has recently been established. A new Malagasy law allows local communities to control their own resources, and the people in this region are being encouraged to formalize conservation regulations prohibiting gill netting and tree cutting.