Justification of Red List Category
This species qualifies as Critically Endangered as it is endemic to one Andean lake where it has undergone significant population declines, such that an extremely small number of adults remain. Although numbers are known to fluctuate considerably, most probably as a result of extractive pressure combined with relatively unstable climatic conditions linked to ENSO events, with numbers lowest during dry years, recent surveys suggest a continuing rapid population decline.
Different surveying methods and identification challenges have made population estimates difficult. However, three surveys in 2001, 2002 and 2007 indicate a population of between 217 and 304 individuals, hence the population is best placed in the band 50-249 mature individuals.
Standardised surveying methods reveal a decline from 304 individuals in 2001 to 217 individuals in 2007 (ECOAN 2009), hence the population decline is estimated to be c. 50-79% over the past 21 years (three generations).
Podiceps taczanowskii is a flightless waterbird confined to Lake Junín in the highlands of Junín, west-central Peru. It was extremely abundant in 1938, and the population was probably well over 1,000 birds in 1961. In the early and mid-1980s there were c. 250 birds, but only 100 were counted in 1992, falling to around 50 in 1993 (Valqui 1994). New extrapolations in early 1995, using a different methodology, estimated 205 individuals (O'Donnell and Fjeldså 1997). The 1995-1996 and 1996-1997 breeding seasons were unsuccessful, but two broods apparently fledged in 1997-1998 (T. Valqui in litt. 1999). In August 1998, over 250 Podiceps sp. were found in 4 km2 of the lake (suggesting a total of 350-400 birds) and all those identified (over 20) were P. taczanowskii (T. Valqui in litt. 1999). Counts in 2001, 2002 and 2007 using standardised survey methods estimated the population at 304, 249 and 217 individuals respectively (ECOAN 2009). The population now appears to be restricted to the south of the lake, though individuals are still seen attempting to colonise the north and north-west (ECOAN 2009).
Lake Junín is fairly shallow and bordered by extensive reed marshes at 4,080 m. The grebe forages in open water, near the shore in the (wet) breeding season (November-March), and in the centre of the lake in the dry austral winter. It feeds mainly on small Orestias fish (which become scarce when the reedbeds dry out [O'Donnell and Fjeldså 1997]), and invertebrate larvae and adults. Nests are built in flooded reedbeds; clutch size is two eggs (O'Donnell and Fjeldså 1997). It is probably long-lived, and invests little in recruitment per season (O'Donnell and Fjeldså 1997).
Declines followed a deterioration in water quality owing to mining activities, and extreme water-level fluctuations (Valqui 1994). Water-level regulation for a hydroelectric plant supplying nearby mines causes nesting and foraging areas to dry out, and breeding to fail. Mining activities also pollute the lake, with the north-western part rendered lifeless by iron-oxide sedimentation (O'Donnell and Fjeldså 1997, ECOAN 2009). Dead grebes, possibly killed by pollution, were reportedly found in 2008 (Hirschfeld 2008), and this is presumably the most significant threat to the species. Relatively unstable climatic conditions, linked to El Niño Southern Oscillation events, may have contributed to large population fluctuations, with a recovery in years with high water levels (e.g. 1997-1998) (T. Valqui in litt. 1999), and previous poor breeding successes. Although the population has shown major fluctuations, its ability to recover were it to experience a series of poor years is in doubt. Many individuals died during extreme cold conditions in 1982; similar conditions in June 2007 gave cause for concern (G. Engblom in litt. 2007), but the impacts are, as yet, unknown.
Conservation Actions Underway
Lake Junín has been declared a national reserve. Hunting and fishing are regulated but little has been done to interfere with the management of the water level, which is controlled by mining companies (O'Donnell and Fjeldså 1997). An attempt was made to translocate grebes to a lake north of Junín; capture and transfer were feasible, but the chosen lake (and others) was unsuitable because gill-nets are used to fish rainbow trout (O'Donnell and Fjeldså 1997). In 2002, the Peruvian government passed an emergency law to protect the lake which makes provisions for its cleaning and places greater restrictions on the extraction of water (Valqui 1994), but this has so far proved ineffective (BirdLife International 2009). Asociación Ecosistemas Andinos (ECOAN) is working in the area to educate local communities about the lake's two endemic birds. A programme involving education, workshops, press releases and a photo exhibit is underway with the aim of drawing attention to the problems facing Lake Junín (B. Hennessey in litt. 2008). In 2009 the species was adopted as a symbol of wetland conservation in the high Andes by groups including BirdLife International, American Bird Conservancy, ECOAN and INRENA, who have called for an independent environmental audit and continuous environmental monitoring of the lake (BirdLife International 2009).
Conservation Actions Proposed
Monitor the population and reproductive success biannually (O'Donnell and Fjeldså 1997, T. Valqui in litt. 1999, Anon. 2007). Research the species's requirements throughout its life-cycle (O'Donnell and Fjeldså 1997). Prepare and implement a species recovery plan (O'Donnell and Fjeldså 1997) and involve local people in a participatory species action plan as well as environmental education and awareness-raising campaigns (Anon. 2007). Reduce pollution (and continue monitoring water quality [Anon. 2007]) and regulate water-levels for the benefit of local people and wildlife (O'Donnell and Fjeldså 1997) with the agreement and participation of the local mining company (Anon. 2007). Assess the feasibility of a sustainable habitat management programme (O'Donnell and Fjeldså 1997). Identify a lake for potential translocation of individuals (O'Donnell and Fjeldså 1997) and consider establishing a captive-breeding population. Develop ecotourism in the area including building a lookout platform for the lake to aid population monitoring (Hirschfeld 2008).
35 cm. Slim, long-necked grebe with pointed-head appearance. Grey frontal area and auricular. Blackish hind crown, continuing down upperside of neck. Completely dark upperparts. White throat to crissum, mottled dusky on sides of breast and belly. Slender, mostly grey bill. Red iris and buffy tarsus. Immature is greyer on flanks. Similar spp. Race juninensis of Silvery Grebe P. occipitalis is smaller, shorter necked, and has shorter, mostly blackish bill. Voice Melodic whistles dooi'th and wit reported.
Text account compilers
Benstead, P., Bird, J., Calvert, R., Clay, R., Pilgrim, J., Sharpe, C J, Symes, A. & Ashpole, J
Engblom, G., Fjeldså, J., Hennessey, A., Valqui, T. & Angulo Pratolongo, F.
BirdLife International (2019) Species factsheet: Podiceps taczanowskii. Downloaded from http://www.birdlife.org on 18/11/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 18/11/2019.