Pygoscelis adeliae


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Pygoscelis adeliae
Species Authority: (Hombron & Jacquinot, 1841)
Common Name(s):
English Adelie Penguin

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Ainley, D., Kooyman, G. & Woehler, E.
Facilitator/Compiler(s): Butchart, S., Calvert, R., Ekstrom, J., Taylor, J.
This species has been uplisted to Near Threatened because it is expected to undergo a moderately rapid population decline over the next three generations owing to the effects of projected climate change. It should be noted, however, that there are considerable uncertainties over future climatic changes and how they will impact the species.

Geographic Range [top]

Range Description: Pygoscelis adeliae is found along the entire Antarctic coast and some of its nearby islands. Individuals are dispersive, moving towards areas of persistent sea ice to moult after breeding (Ainley et al. 2010). Numbers are increasing in the Ross Sea region and decreasing in the Peninsula region, with the net global population increasing overall (Ainley et al. 2010). However, analyses based on the modelling of climate effects suggest that the population could start to decline in a few decades (Ainley et al. 2010, D. Ainley in litt. 2012). Although these declines may only start after a warming of 2°C above pre-industrial levels is reached, and overall trends will potentially be positive before this point (D. Ainley in litt. 2012), BirdLife International has precautionarily projected a population decline approaching 30% over the next three generations, factoring in the potential for negative impacts to take place within this timescale, as well as substantial uncertainties over climate predictions and the adaptability of the species. 

Antarctica; South Georgia and the South Sandwich Islands
Argentina; Australia; Falkland Islands (Malvinas); French Southern Territories; Heard Island and McDonald Islands; New Zealand
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The total number of breeding pairs is estimated at c.2.37 million (range 1.83-2.88 million), based on survey data collated and published by Woehler (1993) and Woehler and Croxall (1997), equating to at least 4.74 million mature individuals.
Population Trend: Increasing

Habitat and Ecology [top]

Habitat and Ecology: This species nests on ice-free rocky coasts, often in extensive open areas to accommodate typically large colonies which may be far from the open sea. Females lay two eggs, which are incubated by both sexes in alternating stints. It mainly feeds on krill, with smaller quantities of fish, amphipods and cephalopods. It captures such prey by pursuit diving, usually less than 20 m down (del Hoyo et al. 1992).

Systems: Terrestrial; Marine

Threats [top]

Major Threat(s): It is thought to be threatened by the effects of projected climate change, primarily through future decreases in sea ice concentration, as affected by wind speed and persistence, as well as associated changes in other climatic variables such as precipitation (Ainley et al. 2010). Reduced suitability of nesting habitat could result from an increase in the incidence of severe snowfall. In addition, annual migration and winter survival may be negatively affected by decreases in sea ice coverage at northern latitudes where the species requires a few hours of daylight in each 24-hour period (Ainley et al. 2010, Ballard et al. 2010). The location of research stations near colonies has led to reductions in suitable ground for breeding, excessive visits to colonies and disturbance caused by aircraft movements (del Hoyo et al. 1992), although the impact of disturbance in relation to environmental conditions appears to vary with location (Bricher et al. 2008). Oil-pollution and fishing (for krill and finfish) also pose threats (D. Ainley in litt. 2012).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
This is the most studied penguin species (del Hoyo et al. 1992), and is the subject of on-going research. Some colonies are located within protected areas. Human disturbance is strictly regulated.

Conservation Actions Proposed
Carry out surveys to obtain an improved and more up-to-date population estimate. Continue to monitor population trends. Continue to closely monitor trends in the extent and persistence of sea ice, and associated climatic variables. Carry out further research into the species's ecology to improve understanding of how environmental changes and human activities, such as fishing, will affect the population. Improve predictions of future environmental changes and how these will impact the species's population, and conduct research into the potential effects of fish and krill extraction (D. Ainley in litt. 2012). Continue international work to tackle the drivers of projected climate change.

Citation: BirdLife International 2012. Pygoscelis adeliae. The IUCN Red List of Threatened Species. Version 2015.2. <>. Downloaded on 29 August 2015.
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