Podiceps gallardoi

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

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Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	AVES	Podicipediformes	Podicipedidae

Scientific Name:

Podiceps gallardoi

Species Authority:

Rumboll, 1974

Common Name/s:

English

–

Hooded Grebe

Assessment Information [top]

Red List Category & Criteria:

Endangered A2bce+3bce+4bce ver 3.1

Year Assessed:

2009

Assessor/s

BirdLife International

Evaluator/s:

Bird, J., Butchart, S.(BirdLife International)

Justification:
This species has a very small and very rapidly declining population within a moderately small range. It is likely that birds may move between breeding sites on an annual basis but recent absences from former breeding sites are now thought to represent genuine declines. Therefore, the species has been uplisted to Endangered, and further survey work is required to determine population trends.

History:

2008	–	Near Threatened
2007	–	Near Threatened
2006	–	Near Threatened
2004	–	Near Threatened
2000	–	Lower Risk/near threatened
1994	–	Lower Risk/near threatened
1988	–	Threatened

Geographic Range [top]

Range Description:	Podiceps gallardoi breeds on a few basaltic lakes in the interior of Santa Cruz, extreme south-west Argentina, and casually near Torres del Paine, in Magallanes, south Chile⁵; the only known wintering grounds are the río Coyle and río Gallegos estuaries on the Atlantic coast of Santa Cruz^2,8. The total population was estimated at 3,000-5,000 individuals in 1997 with half of these on Meseta de Strobel⁵. Counts on the wintering grounds suggested a decline of 40% over a seven year period⁷, and surveys conducted in December 2006 and January 2009 that revisited key known breeding sites surveyed in 1987 (Lagunas del Sello, del Isolte and Tolderia Grande) and 1998 (Encadenadas) also found sharp declines; numbers fell from 452 to 51 at Laguna del Sello, from 700 to 0 at Laguna del Islote, from 90 to 0 at Tolderia Grande⁹ and from 198 to 0 at Lagunas Encadenadas¹⁰. While there is speculation that numbers fluctuate dramatically at breeding sites from year to year driven by movements rather than actual population fluctuations³, overall declines detected on the wintering and breeding grounds appear to be real and rapid. Examination of photographs from the 1980s suggests that P. gallardoi was formerly the commonest waterbird on its core breeding grounds, the Buenos Aires, Strobel and San Martin plateaus; the 2009 surveys visited two of these areas and recorded the declines above as well as noting that a number of former breeding sites were completely dry. The global population is now suspected to number well below 2,500 mature individuals.
Countries:	Native: Argentina; Chile
Range Map:	(click map to view full version)

Population [top]

Population:	O'Donnell and Fjeldsa (1997) estimated the population as 3,000-5,000 individuals. Following recent and rapid declines the population is now assumed to be well below this figure but owing to difficulties in surveying its remote breeding grounds a precise estimate is unavailable.
Population Trend:	Decreasing

Habitat and Ecology [top]

Habitat and Ecology:	During the breeding season, it inhabits basaltic lakes in the arid Patagonian steppes at elevations of 500-1,200 m⁴; saline and bitter-salt lakes are used by non-breeding flocks and at least some birds wintering on the Argentine coast². Aquatic vegetation (mainly Myriophyllum elatinoides) on its breeding lakes is essential material for its floating nest and as habitat for several aquatic invertebrates that form its basic diet⁴. During the first week after hatching, chicks are fed with aquatic beetles (Limnaea spp.)⁴. It breeds in colonies of up to 130 pairs from October-March⁴, but has an exceedingly low reproductive rate with an average of 0.2 young reared per adult per year⁵. However, while potential resources for breeding are apparently limited, the resources for adult survival appear to be plentiful and under natural circumstances adult mortality may be extremely low⁵. It occasionally establishes colonies in areas marginal to its main range⁵.
Systems:	Freshwater

Habitat and Ecology:

During the breeding season, it inhabits basaltic lakes in the arid Patagonian steppes at elevations of 500-1,200 m⁴; saline and bitter-salt lakes are used by non-breeding flocks and at least some birds wintering on the Argentine coast². Aquatic vegetation (mainly Myriophyllum elatinoides) on its breeding lakes is essential material for its floating nest and as habitat for several aquatic invertebrates that form its basic diet⁴. During the first week after hatching, chicks are fed with aquatic beetles (Limnaea spp.)⁴. It breeds in colonies of up to 130 pairs from October-March⁴, but has an exceedingly low reproductive rate with an average of 0.2 young reared per adult per year⁵. However, while potential resources for breeding are apparently limited, the resources for adult survival appear to be plentiful and under natural circumstances adult mortality may be extremely low⁵. It occasionally establishes colonies in areas marginal to its main range⁵.

Systems:

Freshwater

Threats [top]

Major Threat(s):	The two principal threats to the species appear to be climate change and the introduction of salmon and trout to private lakes on the Strobel plateau⁶. Recently the introduction of trout has been correlated with a decline in breeding numbers at certain lakes^7,10. Surveys in 2006 found a number of lakes completely dry and that water levels at known breeding sites were 2-3 m lower than in previous years¹⁰. Anecdotal reports indicated reduced winter snowfall without a corresponding increase in precipitation at other times¹⁰. Excessive grazing by sheep (which causes erosion at lakeshores and limits the growth of emergent vegetation), predation by Kelp Gulls Larus dominicanus at some lakes, an inhospitable breeding climate and low breeding potential have been cited as threats^1,5, but the species's life history strategy is apparently well adapted to these conditions³. The population may be limited by the carrying capacity of rather few lakes with good nest vegetation⁵. Volcanic eruptions in the breeding area may have a negative short-term effect because of heavy ash fall, but a long-term positive effect on the productivity of the wetlands⁵. There is oil exploitation on the potential migration route to the Atlantic⁶.

Major Threat(s):

The two principal threats to the species appear to be climate change and the introduction of salmon and trout to private lakes on the Strobel plateau⁶. Recently the introduction of trout has been correlated with a decline in breeding numbers at certain lakes^7,10. Surveys in 2006 found a number of lakes completely dry and that water levels at known breeding sites were 2-3 m lower than in previous years¹⁰. Anecdotal reports indicated reduced winter snowfall without a corresponding increase in precipitation at other times¹⁰. Excessive grazing by sheep (which causes erosion at lakeshores and limits the growth of emergent vegetation), predation by Kelp Gulls Larus dominicanus at some lakes, an inhospitable breeding climate and low breeding potential have been cited as threats^1,5, but the species's life history strategy is apparently well adapted to these conditions³. The population may be limited by the carrying capacity of rather few lakes with good nest vegetation⁵. Volcanic eruptions in the breeding area may have a negative short-term effect because of heavy ash fall, but a long-term positive effect on the productivity of the wetlands⁵. There is oil exploitation on the potential migration route to the Atlantic⁶.

Conservation Actions [top]

Conservation Actions:	Conservation actions underway: The site where the species was discovered in 1974, Laguna Los Escarchados, was declared a reserve in 1979 but is now known to hold only a marginal population⁵, and six individuals were recorded within Perito Moreno National Park, Argentina in 1992. Its key breeding lakes in the core of its range lack any kind of legal protection, but the population stronghold on Meseta de Strobel is afforded some protection from its remoteness and inaccessibility¹. Conservation actions proposed: Continue monitoring at key sites at intervals of a few years⁵. Survey upland and coastal sites to identify wintering and staging sites⁵. Write and implement a species recovery plan. Work with landowners to raise awareness of the impacts on Hooded Grebes of introducing salmonids to lakes, and identify lakes where salmonids could be introduced without negatively impacting Hooded Grebes. Study the species's ecology to understand population movements. Identify breeding sites. Gather empirical data on population size and trends. Clarify the threats to the species and the reasons behind recent declines.

Conservation Actions:

Conservation actions underway:

The site where the species was discovered in 1974, Laguna Los Escarchados, was declared a reserve in 1979 but is now known to hold only a marginal population⁵, and six individuals were recorded within Perito Moreno National Park, Argentina in 1992. Its key breeding lakes in the core of its range lack any kind of legal protection, but the population stronghold on Meseta de Strobel is afforded some protection from its remoteness and inaccessibility¹.

Conservation actions proposed:

Continue monitoring at key sites at intervals of a few years⁵. Survey upland and coastal sites to identify wintering and staging sites⁵. Write and implement a species recovery plan. Work with landowners to raise awareness of the impacts on Hooded Grebes of introducing salmonids to lakes, and identify lakes where salmonids could be introduced without negatively impacting Hooded Grebes. Study the species's ecology to understand population movements. Identify breeding sites. Gather empirical data on population size and trends. Clarify the threats to the species and the reasons behind recent declines.

Citation:	BirdLife International 2009. Podiceps gallardoi. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2009.2. <www.iucnredlist.org>. Downloaded on 09 February 2010.
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