Overview

Brief Summary

In 2012, Aythya innotata was included among the world's 100 most threatened species in a report by the IUCN Species Survival Commission and the Zoological Society of London.

(Baillie & Butcher 2012; Harvey 2012)

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Distribution

Range Description

This species 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 1950s (Young and Kear 2006, Rene de Roland et al. 2007). 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 Alaotra (S. T. Seing in litt. 2006). 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 minimal (S. T. Seing in litt. 2006). Follow-up surveys in 2006 located c.20 mature individuals with up to nine ducklings observed at the same site (G. Young in litt. 2007). 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. A total of 25 mature individuals were counted in 2008, with six pairs nesting in the 2007/08 season (L.-A. Rene de Roland in litt. 2008). However, no chicks fledged in 2008 or 2009 (P. Cranswick in litt. 2009, H. G. Young in litt. 2012), and only 19 adults were recorded in July 2009 (Jarrett 2010), including six females (Cranswick 2010). In 2011 there was again no successful breeding, and the lake was apparently in poor condition with little available food other than caddis fly larvae (Cranswick 2012), however a total of 29 mature individuals were counted (L.-A. Rene de Roland in litt. 2012).

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Range

Lake Alaotra (Madagascar). On verge of extinction.
  • Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2014. The eBird/Clements checklist of birds of the world: Version 6.9. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/

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Historic Range:
Madagascar

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Ecology

Habitat

Habitat and Ecology

Habitat and Ecology
Behaviour This species is generally sedentary and usually occurs singly, or occasionally in pairs (Langrand 1990). It is not known to flock or to associate with any other species (Kear 2005). Nesting has been observed during the months of July to January (G. Young in litt. 2012). Habitat The species was historically only known from shallow freshwater lakes and marshes that combine open water with nearby areas of dense vegetation (Langrand 1990; Morris and Hawkins 1998; G. Young in litt. 2003). It probably prefers marshy areas and shallow water (G. Young in litt. 2003). However, the site of its rediscovery is a volcanic lake with very little emergent vegetation (G. Young in litt. 2007). 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 rediscovery (G. Young in litt. 2007).The nest is sited amongst lake-edge vegetation (Cyperaceae) and placed 10-20cm above water. The clutch size is 6-10 eggs (L.-A. Réne de Roland and G. Young in litt. 2012). Diet It is believed to feed on benthic invertebrates and aquatic plants and seeds by diving frequently in shallow waters (Langrand 1990).


Systems
  • Freshwater
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Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
CR
Critically Endangered

Red List Criteria
D

Version
3.1

Year Assessed
2013

Assessor/s
BirdLife International

Reviewer/s
Butchart, S.

Contributor/s
Hawkins, F., Rabenandrasana, M., Réné De Roland, L., Seing, S., Watson, R. & Young, G.

Justification
This species was rediscovered in 2006 following the last sighting in 1991. It is currently known from a single location where 29 mature individuals were seen in 2011. While it may also persist at other sites, the population is likely to be tiny and therefore it is classified as Critically Endangered.


History
  • 2012
    Critically Endangered
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Current Listing Status Summary

Status: Endangered
Date Listed: 01/12/1995
Lead Region: Foreign (Region 10) 
Where Listed: Entire


Population detail:

Population location: Entire
Listing status: E

For most current information and documents related to the conservation status and management of Aythya innotata , see its USFWS Species Profile

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In 2012, Aythya innotata was included among the world's 100 most threatened species in a report by the IUCN Species Survival Commission and the Zoological Society of London.

(Baillie & Butcher 2012; Harvey 2012)

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Population

Population
A total of 25 adult birds were counted at the rediscovery site in 2008, with 29 there in 2011 (L.-A. Réne de Roland in litt. 2012). The species may persist elsewhere but the numbers are likely to be tiny, with fewer than 50 individuals and mature individuals.

Population Trend
Stable
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Threats

Major Threats
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 there (L.A. Rene de Roland in litt. 2008), however breeding success has remained low, with no young reared in some years. Young may have trouble finding adequate food and if they do fledge likelihood of dispersing birds surviving away from main site is very low (H. G. Young in litt. 2012). Slash-and-burn agriculture takes place in the catchment around the sole remaining site, and may be causing ash and silt sedimentation which has left the majority of the lake in very poor condition with little suitable food (Cranswick 2012). Previous 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 wetlands (Young and Kear 2006). 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 cultivation (Edhem 1993). Soil erosion from deforested hillsides and more intensive agricultural practices have diminished the water quality of the lake (Pidgeon 1996). Introductions of exotic plants, mammals (Rattus) and fish, especially Tilapia, have depleted essential food supplies and likely increased nest-predation for the species (Pidgeon 1996). The introduction of Tilapia into Alaotra probably had a devastating effect on the pochard and other more widespread waterbirds preferring emergent vegetation (G. Young in litt. 2003). 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 edge (G. Young in litt. 2003). 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 species (Morris and Hawkins 1998).

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Management

Conservation Actions

Conservation Actions
Conservation Actions Underway
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 (R. Watson in litt. 2006; L.A. Rene de Roland in litt. 2008; Watson 2007; Cranswick 2010). Furthermore, together with the Wildfowl and Wetlands Trust and the government of Madagascar, and with support from with Mitsubishi Corporation Fund for Europe and Africa, a conservation breeding facility has been built, and a Malagasy warden was to be appointed to help protect the breeding site (Anon 2009). A small number of eggs were opportunistically taken from the wild in 2009, leading to hatching of the first captively-reared individuals (Jarrett 2010), with three clutches successfully hatched by the end of the year, producing 20 young (Cranswick 2010). The long-term aims of such efforts are to secure of the existing population and to establish another viable population in the wild (Cranswick 2010). Work is ongoing through WWT, the Peregrine Fund and two PhD students to identify potential areas for the release of captive-bred birds, which will probably necessitate some habitat restoration (Cranswick 2010, 2012). Efforts are underway to conserve the last vestiges of suitable habitat at Lake Alaotra (Morris and Hawkins 1998). 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 fisheries (Pidgeon 1996).

Conservation Actions Proposed
Continue searches for extant populations, with a particular focus around former high-plateau wetlands (Rene de Roland et al. 2007). 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. Continue work to establish a captive-breeding programme. Carry out inventory of wetlands near remaining population to identify sites for release of captive-bred birds and assess the need for habitat restoration (Cranswick 2010).

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Wikipedia

Madagascan pochard

The Madagascan pochard or Madagascar pochard (Aythya innotata; Malagasy: Fotsy maso, Onjo[2]) is an extremely rare diving duck of the genus Aythya. Thought to be extinct in the late 1990s, specimens of the species were rediscovered at Lake Matsaborimena in Madagascar in 2006. As of March 2013, the population is around 80 individuals.[3]

Threats and decline[edit]

The Madagascan pochard in the Catalogue of the Birds in the British Museum. Volume 27, 1895.

Based on the accounts written by Webb and Delacour's in the 1920s and 1930s it seemed that the bird was still relatively common at Lake Alaotra. The duck probably started to decline dramatically sometime in the late 1940s or early 1950s. The cause of decline was the introduction of numerous fish species in the lake that killed most of the pochard chicks and damaged nesting sites. Adult birds are also likely to have become victims of introduced fishes. Rice cultivation, cattle grazing on the shores, burning of shore vegetation, introduced mammals (rats), gill-net fishing and hunting are all factors that led to the duck's disappearance from the lake.[4] The last record of multiple birds at Lake Alaotra is from 9 June 1960 when a small flock of about 20 birds was spotted on the lake. Despite the rarity of the species in 1960, a male was shot, and the specimen is now held by the Zoological Museum Amsterdam. There is a very dubious report of a sighting made outside Antananarivo in 1970.[4]

Searches and rediscovery[edit]

Prior to a rediscovery in 2006, the last confirmed sighting of the species was at Lake Alaotra on the Central Plateau of Madagascar in 1991. The single male then encountered was captured and kept in the Antananarivo Botanical Gardens until its death one year later. Intensive searches and publicity campaigns in 1989-1990, 1993-1994 and 2000-2001 failed to produce any more records of this bird.

However, a flock of nine adults and four recently hatched ducklings were discovered at Lake Matsaborimena, in a remote area of northern Madagascar, in November 2006.[5][6] The species was placed in the new "Possibly Extinct" category in the 2006 IUCN Red List; following the rediscovery, its old status of Critically Endangered was restored in the 2007 issue.[4][7] As of 2008, only 25 adult birds had been counted in the wild.[8]

In 2009, a rescue plan involving the Durrell Wildlife Conservation Trust and the Wildfowl and Wetlands Trust removed a batch of ready-to-hatch eggs from a lake-side nest and incubated them in a lab that was set up in a tent by the side of the lake. After hatching, the day-old chicks were taken to a holding facility in a local hotel.[8] Reared in captivity, they hatched eighteen ducklings in April 2012 at the captive breeding centre in Antsohihy, bringing the total population to 60.[6][9][10] In April 2013, the population reached 80.[3]

References[edit]

  1. ^ BirdLife International (2008). Aythya innotata. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 14 December 2009.
  2. ^ Avibase
  3. ^ a b "Critically Endangered Madagascar pochard population has quadrupled". Wildlife Extra. March 2013. 
  4. ^ a b c BirdLife International (2007b): Madagascar Pochard - BirdLife Species Factsheet. Retrieved 26 August 2007.
  5. ^ "Diving duck resurfaces". Birdlife. 20 November 2006. 
  6. ^ a b "Rare Madagascar duck successfully bred by Durrell". BBC News. 6 April 2012. 
  7. ^ BirdLife International (2007a): [ 2006-2007 Red List status changes ]. Retrieved 26 August 2007.
  8. ^ a b Gill, Victoria (6 November 2009). "Quest to save world's rarest duck". BBC News. Retrieved 18 October 2014. 
  9. ^ Moore, Andy (6 April 2012). "World's rarest ducklings hatch in Madagascar". BBC News. Retrieved 18 October 2014. 
  10. ^ Gill, Victoria (6 April 2012). "World's rarest ducklings Madagascan pochards hatch". BBC News. Retrieved 18 October 2014. 
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