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Madagascar Grebe Tachybaptus pelzelnii

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, and the rate of decline is likely to accelerate in the next 16 years (three generations). It has been suggested that the population size is now very small, and should this suspicion be confirmed the species may warrant uplisting in the future.

Taxonomic source(s)
Dowsett, R. J.; Forbes-Watson, A. D. 1993. Checklist of birds of the Afrotropical and Malagasy regions. Tauraco Press, Li
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

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.

Distribution and population
Tachybaptus pelzelnii is still widespread and reasonably common in western and central Madagascar, with pairs or individuals on many small lakes. Surveys in the late 1990s recorded the species at 25 Important Bird Areas distributed throughout Madagascar (ZICOMA 1999), but it is suspected to be undergoing rapid declines. 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 1999 (ZICOMA 1999), but 100-200 survive in the forested lakes of the northwest plateau where Aythya innotata survives (H. G. Young in litt. 2012). The current total population may number as few as 1,500-2,500 individuals (M. Rabenandrasana in litt. 2007), although clarification is required. 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 (H.G. Young in litt. 2007; M. Rabenandrasana in litt. 2007; O. Langrand in litt. 2007).

Population justification
The population estimate of at least 5,000 individuals, roughly equivalent to 3,300 mature individuals, is based on recent records and results of surveys since Collar and Stuart (1985). Although it has been suggested that the population is now lower than this (M. Rabenandrasana in litt. 2007), further surveys are required to confirm this suspicion.

Trend justification
The species is suspected to be in decline owing to habitat loss, introduced species and bycatch. This decline is expected to accelerate over the next 16 years (three generations) as wetlands are increasingly targeted for cultivation and the species becomes more restricted to small wetlands that are unused by humans (O. Langrand in litt. 2007; M. Rabenandrasana in litt. 2007; H.G. Young in litt. 2007).

Ecology
Behaviour This species is sedentary but will disperse in search of suitable habitat (del Hoyo et al. 1992). Breeding has been observed during the months of August to March (Langrand 1995). Breeding pairs are territorial but sometimes nest close to one another, and groups of 150 individuals have been recorded (del Hoyo et al. 1992; Fjeldså 2004). Habitat It was thought to prefer shallow, freshwater lakes and pools, with a dense covering of lily-pads Nymphaea (Langrand 1995; del Hoyo et al. 1992; Fjeldså 2004), but has also been found in several much deeper lakes (H. G. Young in litt. 2012). It occasionally occurs in brackish waters and slow-flowing rivers (Langrand 1995; del Hoyo et al. 1992; Fjeldså 2004). It appears to be capable of breeding in the above-mentioned habitats, including small temporary lakes (ZICOMA 1999), where a suitable covering of vegetation exists. Diet It probably feeds mainly on insects, but is also known to take small fish and crustaceans (Langrand 1995; Fjeldså 2004). Breeding site The nest is a floating structure of aquatic plants, anchored to offshore vegetation, particularly waterliles (Fjeldså 2004). Clutch-size is 3-4 (Fjeldså 2004).

Threats
The most serious threat in the west is from reduction of habitat, especially conversion for rice cultivation and cash crops, as well as the introduction of exotic fish and intensification of fishery practices (H.G. Young in litt. 2007; O. Langrand in litt. 2007). Elsewhere, e.g. at Lake Alaotra, predation of adults by carnivorous snakehead fish Channa spp. (H. G. Young in litt. 2007) 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. ruficollis (Langrand 1995). Hybridisation with T. ruficollis has been suggested as a serious threat (Langrand 1995), but there is no supporting evidence (ZICOMA 1999), and it should be noted that all grebe species in Madagascar are extremely threatened by fishing activities and widespread habitat conversion (H. G. Young in litt. 2007). 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. (O. Langrand in litt. 2007). The species is apparently considered a delicacy (H. G. Young in litt. 2012) and may therefore be subject to an unknown level of hunting pressure.

Conservation Actions 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 indicators (Langrand and Goodman 1995). The Malagasy government has recently ratified the Ramsar Convention, and this may herald improved conservation measures for wetlands.Conservation Actions Proposed
Initiate a monitoring programme (O'Donnell and Fjeldså 1997; ZICOMA 1999). Conduct studies to evaluate the causes of its decline, especially in relation to changes in wetlands caused by exotic plants and animals ZICOMA 1999). Evaluate the possibility of hybridisation (ZICOMA 1999). 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, N. J.; Stuart, S. N. 1985. Threatened birds of Africa and related islands: the ICBP/IUCN Red Data Book. International Council for Bird Preservation, and International Union for Conservation of Nature and Natural Resources, Cambridge, U.K.

del Hoyo, J.; Elliot, A.; Sargatal, J. 1992. Handbook of the Birds of the World, vol. 1: Ostrich to Ducks. Lynx Edicions, Barcelona, Spain.

Fjeldså, J. 2004. The grebes. Oxford University Press, Oxford, U.K.

Langrand, O. 1995. Recensement des oiseaux d'eau à Madagascar et observation de la Sarcelle de Bernier Anas bernieri. Madagascar Region Newsletter 5: 13-14.

Langrand, O.; Goodman, S. M. 1995. Monitoring Madagascar's ecosystems: a look at the past, present, and future of its wetlands. In: Herman, T.B.; Bondrup-Nielsen, S.; Willison, J.H.M.; Munro, N.W.P. (ed.), Ecosystem monitoring and protected areas, pp. 204-214. Science and Management of Protected Areas Association, Wolfville, Canada.

O'Donnel, C.; Fjeldså, J. 1997. Grebes: status survey and conservation action plan. IUCN/SSC Grebe Specialist Group, Cambridge, U.K.

ZICOMA. 1999. Zones d'Importance pour la Conservation des Oiseaux a Madagascar.

Text account compilers
Calvert, R., Ekstrom, J., Evans, S., Shutes, S., Starkey, M., Symes, A., Taylor, P.

Contributors
Hawkins, F., Langrand, O., Rabenandrasana, M., Young, G.

IUCN Red List evaluators
Butchart, S., Taylor, J.

Recommended citation
BirdLife International (2014) Species factsheet: Tachybaptus pelzelnii. Downloaded from http://www.birdlife.org on 16/04/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/04/2014.

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.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

ARKive species - Madagascar grebe (Tachybaptus pelzelnii)

Key facts
Current IUCN Red List category Vulnerable
Family Podicipedidae (Grebes)
Species name author (Hartlaub, 1861)
Population size 3300 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 593,000 km2
Country endemic? Yes
Links to further information
- Additional Information on this species