Aythya innotata

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

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Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	AVES	Anseriformes	Anatidae

Scientific Name:

Aythya innotata

Species Authority:

(Salvadori, 1894)

Common Name/s:

English	–	Madagascar Pochard
French	–	Fuligule De Madagascar

Assessment Information [top]

Red List Category & Criteria:

Critically Endangered D ver 3.1

Year Assessed:

2009

Assessor/s

BirdLife International

Evaluator/s:

Bird, J., Butchart, S., Symes, A.(BirdLife International)

Justification:
This species was rediscovered in 2006 following the last sighting in 1991. It is currently known from a single location where 25 mature individuals were seen in 2008. While it may also persist at other sites, the population is likely to be tiny and therefore it is classified as Critically Endangered.

History:

2008	–	Critically Endangered
2007	–	Critically Endangered
2006	–	Critically Endangered
2004	–	Critically Endangered
2000	–	Critically Endangered
1994	–	Critically Endangered
1988	–	Threatened

Geographic Range [top]

Range Description:	Aythya innotata is endemic to Madagascar (although sub-fossil remains of an Aythya duck on Reunion are attributed to A. innotata), where it was found historically in the Lake Alaotra basin in the northern central plateau. It was considered relatively common at Lake Alaotra in the 1930s, but declined dramatically through the 1940s and 1950s⁹. Until the 1990s, the last certain record was at Lake Alaotra in 1960, with one unconfirmed sighting near Antananarivo in 1970 and several other possible records. Then a single male was captured alive in August 1991. Intensive searches (including major publicity campaigns) at Alaotra during 1989-1990 and 1993-1994 failed to discover more birds. However, in 2006 the species was rediscovered when nine adults and four juveniles were observed at a volcanic lake situated 330 km north of the last known site, Lake Alaotra⁶. Reports from local people that the lake was not suitable for rice cultivation round the edge, it contained no fish and that the water was cold suggest that the species may have persisted at this new location because human disturbance has been minimal⁶. Follow-up surveys in 2006 located c.20 mature individuals with up to nine ducklings observed at the same site⁸. Five birds were seen at a second lake c.3-4 km from the site but these may be part of the 20 individuals counted previously. 25 mature individuals were counted in 2008, with six pairs nesting in the 2007/08 season¹³.
Countries:	Possibly extinct: Madagascar
Range Map:	(click map to view full version)

Population [top]

Population:	25 adult birds were counted at the rediscovery site in 2008 - the species may persist elsewhere but numbers are likely to be tiny (Réné De Roland 2008).
Population Trend:	Unknown

Habitat and Ecology [top]

Habitat and Ecology:	Behaviour This species is sedentary and usually occurs singly, or occasionally in pairs². It is not known to flock or to associate with any other species¹². Nesting has been observed during the months of October to January⁵. Habitat The species was historically only known from shallow freshwater lakes and marshes that combine open water with nearby areas of dense vegetation^2,3,5. It probably prefers marshy areas and shallow water⁵. However, the site of its rediscovery is a volcanic lake with very little emergent vegetation⁸. What vegetation does grow at the lake edge may provide suitable nesting habitat. The requirement for shallow water may prevent it from using other volcanic lakes similar to the site of its rediscovery⁸. Diet It is believed to feed on benthic invertebrates and aquatic plants and seeds by diving frequently in shallow waters². The nest is unknown¹², but is presumably sited amongst lake-edge vegetation. Its clutch-size is 6-8 eggs⁵.
Systems:	Freshwater

Habitat and Ecology:

Behaviour This species is sedentary and usually occurs singly, or occasionally in pairs². It is not known to flock or to associate with any other species¹². Nesting has been observed during the months of October to January⁵. Habitat The species was historically only known from shallow freshwater lakes and marshes that combine open water with nearby areas of dense vegetation^2,3,5. It probably prefers marshy areas and shallow water⁵. However, the site of its rediscovery is a volcanic lake with very little emergent vegetation⁸. What vegetation does grow at the lake edge may provide suitable nesting habitat. The requirement for shallow water may prevent it from using other volcanic lakes similar to the site of its rediscovery⁸. Diet It is believed to feed on benthic invertebrates and aquatic plants and seeds by diving frequently in shallow waters². The nest is unknown¹², but is presumably sited amongst lake-edge vegetation. Its clutch-size is 6-8 eggs⁵.

Systems:

Freshwater

Threats [top]

Major Threat(s):	Declines have been attributed to the widespread loss of habitat through siltation and conversion to agriculture throughout the central plateau and, from the 1950s, introduction of exotic fish species to Alaotra and other wetlands¹¹. Lake Alaotra, one of very few unconverted central plateau wetlands, is under considerable and increasing pressure: the area is one of Madagascar's major rice producers, with 250 km² of the 350 km² surrounding the lake converted to rice cultivation¹. Soil erosion from deforested hillsides and more intensive agricultural practices have diminished the water quality of the lake⁴. Introductions of exotic plants, mammals (Rattus) and fish, especially Tilapia, have depleted essential food supplies and likely increased nest-predation for the species⁴. The introduction of Tilapia into Alaotra probably had a devastating affect on the pochard and other more widespread waterbirds preferring emergent vegetation⁵. Some of these species apparently died out at Alaotra but have repopulated from other parts of their ranges as water-lilies and other emergent vegetation have made a comeback along the marsh's southern edge⁵. Hunting and trapping of adults for food, and death through entanglement in monofilament gill-nets, are thought to have contributed to the decline of this species³. The introduction of carnivorous fish has further threatened waterbirds in Madagascar's wetlands as young of many species are vulnerable to predation. It is, however, likely that the pochard became extinct at Alaotra before predatory fish (Micropterus followed by Ophiocephalus) became a significant threat here. There do not appear to be any immediate threats to the species at the site of its rediscovery, but given that it has a tiny known population, it faces significant risk from stochastic events and genetic factors, particularly inbreeding depression. Since permanent guards have been positioned at the rediscovery site the population appears to have increased, suggesting that hunting may have been a threat there¹³.

Major Threat(s):

Declines have been attributed to the widespread loss of habitat through siltation and conversion to agriculture throughout the central plateau and, from the 1950s, introduction of exotic fish species to Alaotra and other wetlands¹¹. Lake Alaotra, one of very few unconverted central plateau wetlands, is under considerable and increasing pressure: the area is one of Madagascar's major rice producers, with 250 km² of the 350 km² surrounding the lake converted to rice cultivation¹. Soil erosion from deforested hillsides and more intensive agricultural practices have diminished the water quality of the lake⁴. Introductions of exotic plants, mammals (Rattus) and fish, especially Tilapia, have depleted essential food supplies and likely increased nest-predation for the species⁴. The introduction of Tilapia into Alaotra probably had a devastating affect on the pochard and other more widespread waterbirds preferring emergent vegetation⁵. Some of these species apparently died out at Alaotra but have repopulated from other parts of their ranges as water-lilies and other emergent vegetation have made a comeback along the marsh's southern edge⁵. Hunting and trapping of adults for food, and death through entanglement in monofilament gill-nets, are thought to have contributed to the decline of this species³. The introduction of carnivorous fish has further threatened waterbirds in Madagascar's wetlands as young of many species are vulnerable to predation. It is, however, likely that the pochard became extinct at Alaotra before predatory fish (Micropterus followed by Ophiocephalus) became a significant threat here. There do not appear to be any immediate threats to the species at the site of its rediscovery, but given that it has a tiny known population, it faces significant risk from stochastic events and genetic factors, particularly inbreeding depression. Since permanent guards have been positioned at the rediscovery site the population appears to have increased, suggesting that hunting may have been a threat there¹³.

Conservation Actions [top]

Conservation Actions:	Conservation actions underway: Efforts are underway to conserve the last vestiges of suitable habitat at Lake Alaotra³. The Malagasy government has ratified the Ramsar Convention, and Lake Alaotra became a Ramsar Site in 2003. Searches for the species continue, as do education and awareness programmes on the benefits of maintaining natural wetlands. However, implementation of any conservation policy for the area will be very difficult owing to Alaotra's huge economic importance for agriculture and fisheries⁴. The Peregrine Fund and Durrell Wildlife Conservation Trust are conducting further surveys at the site of rediscovery, which is currently permanently guarded, and are now seeking the support of locals to gain formal protection for the area^7,13,14. Conservation actions proposed: Continue searches for extant populations, with a particular focus around former high-plateau wetlands⁹. Protect areas of least-modified wetland at Lake Alaotra. Continue community surveys and wetland awareness programmes. Conduct further surveys to determine the existing population size.

Conservation Actions:

Conservation actions underway:

Efforts are underway to conserve the last vestiges of suitable habitat at Lake Alaotra³. The Malagasy government has ratified the Ramsar Convention, and Lake Alaotra became a Ramsar Site in 2003. Searches for the species continue, as do education and awareness programmes on the benefits of maintaining natural wetlands. However, implementation of any conservation policy for the area will be very difficult owing to Alaotra's huge economic importance for agriculture and fisheries⁴. The Peregrine Fund and Durrell Wildlife Conservation Trust are conducting further surveys at the site of rediscovery, which is currently permanently guarded, and are now seeking the support of locals to gain formal protection for the area^7,13,14.

Conservation actions proposed:

Continue searches for extant populations, with a particular focus around former high-plateau wetlands⁹. Protect areas of least-modified wetland at Lake Alaotra. Continue community surveys and wetland awareness programmes. Conduct further surveys to determine the existing population size.

Citation:	BirdLife International 2009. Aythya innotata. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2009.2. <www.iucnredlist.org>. Downloaded on 09 February 2010.
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