Junín grebe (Podiceps taczanowskii)

Description

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Junín grebe fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Junín grebe description

The small, declining population of flightless Junin grebes is found only in one lake in the Andes, and therefore faces an extremely high risk of extinction. Like all other grebes, it is a specialized waterbird that is virtually unable to move on land, but is an excellent swimmer and diver. Its soft, dense plumage is dark grey on the top of the head, contrasting with a large black area on the nape. The lower part of the face, chin, neck and underparts are white. The silvery drab-grey feathers on the sides of the head are slightly elongated, a feature which juveniles and non-breeding adults lack ^{(2) (3)}. Its slim, long neck and small head are perfectly streamlined for diving when searching for food, and its lobed, flexible toes, are used to propel and steer them underwater, making grebes extremely agile swimmers ⁽⁴⁾. The slender bill is mostly grey ⁽⁵⁾, the feet are pale yellowish, and it has bright red eyes ⁽³⁾. Melodic whistles, such as doo’ith, wit, or a long phooee-th, are heard when this bird is trying to attract a mate ⁽³⁾.

Size

Length: 33 – 38 cm ⁽²⁾

Junín grebe biology

The Junin grebe’s impressive diving ability allows the bird to feed on a diet primarily of small fish, but it also eats invertebrate nymphs and adults from the lake’s surface ⁽²⁾. They also consume feathers which form a ball in the centre of the stomach and a plug in the pyloric region. The main function of this may be to rid the grebe of gastric parasites when the ball is regurgitated ⁽³⁾. Often they can be seen feeding in groups; several birds will swim along in a line and dive down simultaneously ⁽²⁾. The Junin grebe lays eggs in December and January, during the rainy season ⁽²⁾. They nest amongst the reed beds in colonies of up to 20. The usual clutch size is two eggs, and it is likely that only one clutch is laid per year. In years when there are very low water levels, no young are raised at all. It is presumed that this is a long-lived species, and its very low reproductive rate probably evolved in a stable and predictable environment ⁽²⁾. Once the eggs hatch, the new family of grebes leave the reed beds and head out to open water, with the fledglings carried on the back of the male parent whilst the female dives for their food ⁽⁶⁾.

The Junin grebe performs an array of sequences during courtship. This includes ‘head-shaking’, when two grebes facing breast to breast turn their head rapidly from side to side in synchronous jerks; and ‘penguin-dance’, when the grebes carry out ‘head-shaking’ whilst paddling vigorously, and extending their bodies and neck vertically out of the water ⁽³⁾.

Junín grebe range

Endemic to Lake Junin in central Peru ⁽²⁾.

Junín grebe habitat

Lake Junin, situated at an elevation of 4,080 m, covers an area of approximately 140 km² and reaches a depth of 10 m, although most parts are less than 5 m. The lake is bordered by extensive reed marshes. The grebe shows a preference for open water and generally stays far from the shore, except for in the breeding season when it can be found in bays and channels nearer the edge of the lake, and enters the reed marshes for nesting and roosting ⁽²⁾.

Junín grebe status

Classified as Critically Endangered (CR) on the IUCN Red List 2006 ⁽¹⁾.

Junín grebe threats

Being restricted to only one lake makes the Junin grebe extremely vulnerable to any changes in the lake. Changes to Lake Junin have resulted in the decline of the grebe from over 1,000 in 1961, to probably around 200 individuals in 2007 ^{(5) (7)}. In addition to this general decline, population numbers also fluctuate according to the water level of the lake ⁽⁷⁾. The Upamayo Dam, as part of a hydro-electric plant, regulates the water level of Lake Junin, creating fluctuations in the water level that can cause nearly half the lake’s surface to dry up, including important nesting and foraging areas for the grebes ^{(3) (6) (8)}. As no young are raised when water levels are very low, this regulation has a significant negative impact on the Junin grebe. However, the greatest threat it faces, and what will ultimately lead to its extinction if not halted, is pollution of the lake from mining waste. Waste waters from surrounding mines in the area enter the lake, causing water pollution and an accumulation of iron oxides in the lake sediments. The sedimentation of iron oxides causes large parts of the lake bottom to become lifeless, and therefore much of the offshore area is no longer adequate feeding habitat ^{(3) (9)}.

Junín grebe conservation

Lake Junin was designated a National Reserve in 1974, which has limited hunting and fishing in the lake, but has had no affect on the primary threats of mining and dam-building activities ⁽⁵⁾. In 1999 Lake Junin was declared to be in a state of emergency, resulting in the formation of a committee which implemented an environmental management plan ⁽⁸⁾. This involves further protection of the lake, restrictions on the extraction of water and provisions for its cleaning ⁽⁵⁾. However, much work is still required to prevent further pollution of the lake and restore the habitat. Continuing pollution will inevitably lead to the extinction of the Junin grebe, unless a “reserve” population is established in another location. Translocation of the Junin grebe to a lake north of Lake Junin was attempted, but unfortunately the use of gill-nets to fish trout in this lake made it unsuitable ⁽⁷⁾. In 1997 the IUCN Grebe Specialist Group created a Global Conservation Strategy to ensure the successful recovery of grebe populations and the management of wetlands ⁽⁹⁾. Particular conservation actions recommended for this species include carrying out studies of other lakes to identify suitable locations for further translocation attempts, as well as taking steps to prevent pollutants from entering Lake Junin and to de-toxify lake sediments ⁽⁹⁾.

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more

For further information on the status and conservation of grebes see Grebes Status Survey and Conservation Action Plan, IUCN:
http://data.iucn.org/dbtw-wpd/edocs/1997-058.pdf

For more information on this and other bird species please see:

• BirdLife International:
  http://www.birdlife.org

Authentication

Authenticated (19/06/07) by Professor Jon Fjeldså, Zoological Museum, University of Copenhagen.  
http://zoologi.snm.ku.dk/english/staff/

Glossary

Endemic

A species or taxonomic group that is only found in one particular country or geographic area.

Invertebrate

Animals with no backbone.

Nymphs

Stage in an animal’s lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.

Pyloric region

The region of the stomach that connects to the first part of the small intestine.

Translocation

The movement of a species, by people, from one area to another.

References

1. IUCN Red List (January, 2007)
   http://www.iucnredlist.org
2. del Hoyo, J., Elliott, A. and Sargatal, J. (1992) Handbook of the Birds of the World. Vol. 1: Ostrich to Ducks. Lynx Edicions, Barcelona.
3. Fjeldså, J. (2004) The Grebes: Podicipedidae. Oxford University Press, Oxford.
4. Burnie, D. (2001) Animal. Dorling Kindersley, London.
5. Birdlife International (May, 2007)
   http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=3644&m=0
6. Konter, A. (2001) Grebes of our World. Lynx Edicions, Barcelona.
7. Fjeldså, J. (2007) Pers. comm.
8. ParksWatch (May, 2007)
   http://www.parkswatch.org/parkprofile.php?l=eng&country=per&park=jnar&page=inf
9. O’Donnel, C. and Fjeldså, J. (1997) Grebes – Status Survey and Conservation Action Plan. IUCN, Gland, Switzerland and Cambridge, UK.