Justification This species qualifies as Vulnerable because it has a small population which is suspected to be in decline. It has been eliminated from some sites by a combination of predation by introduced fish and entanglement in monofilament gill-nets, and is suffering habitat loss to rice cultivation. Its decline is likely to accelerate in the next ten years.

Family/Sub-family Podicipedidae

Species name author (Hartlaub, 1861)

Taxonomic source(s) Dowsett and Forbes-Watson (1993), Sibley and Monroe (1990, 1993)

Identification 25 cm. Small grebe with distinctive facial pattern. In breeding plumage, blackish cap and line down neck, reddish rear ear-coverts and sides of neck, pale grey cheeks, throat and foreneck, and narrow whitish line under eye between cap and ear-coverts. Reddish eye, black bill with slight whitish tip. Pale brown underparts, dark brown-grey back. Similar spp. From other grebes by greyish cheeks and front of neck, lack of gape-wattles, and white line between cap and ear-coverts. Also, from Alaotra Grebe T. rufolavatus by red eye. Hints Often on small lakes and forested wetlands, where it is easily missed, but also on larger water bodies, including rivers, where it may be found among fringing vegetation.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

5,000

decreasing

593,000 km²

Yes

Range & population Tachybaptus pelzelnii is still widespread and reasonably common in western and central Madagascar, with pairs or individuals on many small lakes. Recent surveys recorded the species at 25 Important Bird Areas distributed throughout Madagascar⁴. On Lake Alaotra the number of Tachybaptus (including a small proportion of T. rufolavatus) declined from several hundred in 1985 to 10-20 in 1993, to none in 1999⁴. The current total population may number as few as 1,500-2,500 individuals⁶. The present decline in the population is expected to accelerate over the next 10 years as increasing wetland conversion and overfishing continues to restrict the species to small lakes that are inaccessible and unsuitable for human use^5,6,7.

Important Bird Areas Click here to view map showing IBAs where species is recorded and triggers any of the IBA criteria.

Ecology: Behaviour This species is sedentary but will disperse in search of suitable habitat⁸. Breeding has been observed during the months of August to March¹. Breeding pairs are territorial⁹ but sometimes nest close to one another, and groups of 150 individuals have been recorded^8,9. Habitat It prefers shallow, freshwater lakes and pools, with a dense covering of lily-pads Nymphaea^1,8,9. It occasionally occurs in brackish waters and slow-flowing rivers^1,8,9. Breeding It appears to be capable of breeding in the above-mentioned habitats, including small temporary lakes⁴, where a suitable covering of vegetation exists. Diet It probably feeds mainly on insects⁹, but is also known to take small fish and crustaceans^1,9. Breeding site The nest is a floating structure of aquatic plants, anchored to offshore vegetation, particularly waterliles⁹. Clutch-size is 3-4⁹.

Threats The most serious threat, in the west, is from reduction of habitat, especially for rice cultivation and cash crops, as well as the introduction of exotic fish and intensification of fishery practices^5,7. Elsewhere, e.g. at Lake Alaotra, predation of adults by carnivorous snakehead fish Channa spp.⁵ and death through entanglement in monofilament gill-nets are probably significant threats. The introduction of exotic, herbivorous fish (Tilapia melanopleura and T. zillii) has considerably limited the development of aquatic vegetation and favoured the Little Grebe T. ruficollis¹. Hybridisation with T. ruficollis has been suggested as a serious threat¹, but there is no supporting evidence⁴, and it should be noted that all grebe species in Madagascar are extremely threatened by fishing activities and widespread habitat conversion⁵. In addition, the use of pesticides and fertilisers in agriculture is increasing and freshwater ecosystems in Madagascar are severely degraded by the proliferation of exotic aquatic plants such as Eichhornia and Salvinia spp.⁷.

Conservation measures underway It is recorded from six protected areas, but numbers within them are small. To assess and prioritise wetlands for protection, a monitoring procedure has been proposed using birds, particularly T. pelzelnii, as indicators². The Malagasy government has recently ratified the Ramsar Convention, and this may herald improved conservation measures for wetlands.

Conservation measures proposed Initiate a monitoring programme^3,4. Conduct studies to evaluate the causes of its decline, especially in relation to changes in wetlands caused by exotic plants and animals⁴. Evaluate the possibility of hybridisation⁴. Increase the number of occupied sites that have protected status. Work with fishermen to develop bycatch reduction measures. Employ measures to control exotic aquatic plants (such has Eichhornia and Salvinia spp.). Target awareness campaigns at farmers in an effort to reduce the use of pesticides and fertilisers. If necessary, control populations of exotic fish species.

References Collar and Stuart (1985). 1. Langrand (1995). 2. Langrand and Goodman (1995). 3. O'Donnel and Fjeldså (1997). 4. ZICOMA (1999). 5. H.G. Young in litt. (2007). 6. M. Rabenandrasana in litt. (2007). 7. O. Langrand in litt. (2007). 8. del Hoyo et al. (1992).9. Fjeldså (2004)

Text account compilers Jonathan Ekstrom (BirdLife International), Mike Evans (BirdLife International), Sue Shutes (BirdLife International), Malcolm Starkey (BirdLife International), Joe Taylor (BirdLife International)

Contributors Frank Hawkins (Conservation International), Olivier Langrand (Conservation International), Marc Rabenandrasana (Asity: Ligue Malagache pour la Protec. des Oiseaux), Glyn Young (Durrell Wildlife Conservation Trust)

IUCN Red List evaluators Stuart Butchart (BirdLife International), Joe Taylor (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Tachybaptus pelzelnii. Downloaded from http://www.birdlife.org on 10/2/2010

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

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