Magellanic Penguin Spheniscus magellanicus


Justification of Red List category
This species has fluctuated in numbers in different parts of its range. Updated data regarding population trends suggest that the population is overall stable or slowly declining at <10% over three generations. Bycatch from fisheries, particularly during the migration stage, and the potential for further oil development in the region may impact the species, but the extent of these developments and the degree of the potential impacts are currently too uncertain to project population declines in the future with confidence. The species is therefore listed as Least Concern.

Population justification
The world population is estimated at between 1.1 and 1.6 million pairs, which equates to 2.2-3.2 million mature individuals. About 900,000 pairs breed along the Argentinian coast, at least 100,000 pairs breed in the Falkland Islands (Malvinas) and a minimum of 144,000 pairs and a maximum guess of 500,000 pairs breed in Chile (Boersma et al. 2013, 2015).

Trend justification
Population trends vary among colonies and are contrasting among regions. Along the Argentinian coast, trends in the censused colonies are inconsistent. In southern Atlantic Patagonia, at the southern part of the distribution on Bahía Franklin, Staten Island, numbers increased from 500 pairs in 1998 to 1,600 pairs in 2010, reaching 2,300 pairs during the last survey in 2015, while the population on Martillo Island increased by 15% over 20 years (Raya Rey et al. 2014, A. Raya Rey unpubl. data). Numbers from Observatorio Island (around 105,000 pairs) have not been updated since the last survey performed in 1995 (Schiavini et al. 2005). In Santa Cruz Province, Argentina, an overall increase of 12% has been reported for all the 17 colonies in the last 20/25 years (E. Frere unpublished data 2020).

In northern Patagonia (Chubut and Rio Negro provinces, Argentina), which is the stronghold of the known global population, trends are mixed. The largest colonies are declining in the central and southern part of northern Patagonia. For example, Punta Tombo has declined by 40% since 1987 (Rebstock et al. 2016, P. D. Boersma unpublished data) and Isla Leones, Isla Tova and Isla Tovita declines ranged from 50 to 76% (Boersma et al. 2013, 2015, Pozzi et al. 2015, Garcia-Borboroglu et al. 2019). The breeding population has expanded north since the 1960s, with new colonies established and growing rapidly (Schiavini et al. 2005, Boersma et al. 2013, Pozzi et al. 2015). The colony in Estancia San Lorenzo on the Peninsula Valdés increased from a few pairs  in the early 1970s to 200,000 pairs over 45 years and new colonies were established since 2000 north of 43ºS (Schiavini et al. 2005, Pozzi et al. 2015, Garcia-Borboroglu et al. 2019). In this 1,000 km sector of northern Patagonia, the overall trend for 28 colonies, representing 42% of the extant colonies, show a decline of approximately 1%, indicating that in this sector the population is likely stable (Garcia-Borboroglu et al. 2019).

The population trend in Chile is unknown, but colonies in the north of the range and in the Juan Fernández Islands seem to have been abandoned (Boersma et al. 2013, 2015). The large population on Magdalena Island declined by 85.4% over the last 15 years, while the colony in Seno Otway decreased by 89% in the last 11 years (Godoy et al. 2019).

In the Falkland Islands (Malvinas), the historical population estimate was 100,000 pairs at 41 breeding sites (Croxall et al. 1984). Later, Woods and Woods (1997) reported 76,000-142,000 pairs at about 100 breeding sites; however, Croxall et al. (1984) was reported as a minimum, and it is not thought that these changed numbers represent a true increase in the population size. On the other hand, it was also reported that the colonies on the Falkland Islands (Malvinas) have declined by almost 50% since the 1980s, but data are insufficient to substantiate this (R. Woods in litt. 1999, Pütz et al. 2001). Since 1999, burrow occupancy at two sites in the islands fluctuated annually with no clear trend (Stanworth 2015). Data from current annual monitoring of a breeding site since 1999 suggests a fluctuating population (Crofts and Stanworth 2019), with no evidence to suggest long-term declines of the population (A. Stanworth pers. comm.). The global population is overall assessed as stable, with at most a suspected slow decline of <10% over three generations.

Distribution and population

Spheniscus magellanicus breeds on the Atlantic and Pacific coasts of South America, in Argentina (67 sites), Chile (at least 31 known sites, but detailed complete surveys are necessary), and the Falkland Islands (Malvinas, at least 100 sites) (Woods and Woods 1997, Ellis et al. 1998, Boersma et al. 2013, 2015, García-Borboroglu et al. 2019). In the Atlantic, most individuals in the winter migrate north to northern Argentina, Uruguay or southern Brazil, exceptionally to northern Brazil (Stokes et al. 1998, García-Borboroglu et al. 2010, Stokes et al. 2014). Magellanic Penguins in the Pacific Ocean are less migratory, but some travel as much as 1000 km north (Skewgar et al. 2014, Pütz et al. 2016) and are rare non-breeding visitors to Peru (Zavalaga and Paredes 2009). Vagrants have been found as far north as El Salvador (O. Komar in litt. 2007), and south to Avian Island (67°, 46'S) on the Antarctic Peninsula (Barbosa et al. 2007), as well as Australia and New Zealand.


Magellanic Penguins forage only in the oceans and breed on land in a variety of island and mainland coastal habitats (Stokes and Boersma 1991, 1998, Garcia-Borboroglu et al. 2002, Rebstock et al. 2016). They use intertidal and beach habitats to avoid excessive heat at colonies (Pozzi et al. 2013). At sea, they typically remain over the continental shelf in Argentina (Stokes et al. 1998, Boersma et al. 2002, Wilson et al. 2005, Boersma and Rebstock 2009, Raya Rey et al. 2010, Yorio et al. 2010, Raya Rey et al. 2012, Sala et al. 2012, Gómez-Laich et al. 2015, Rosciano et al. 2016), but may forage in deep waters off the (very narrow) shelf in Chile (Raya Rey et al. 2013, Pütz et al. 2016) and in the Falkland Islands (Malvinas) (Pütz et al. 2002). Individuals may also forage on the continental slope; males tend to be more offshore-foragers compared to females. They dive up to almost 100 m, but more often to a few dozen metres (Walker and Boersma 2003, Raya Rey et al. 2012, Sala et al. 2014, Gómez-Laich et al. 2015, Rosciano et al. 2016). They may be seen foraging in shallow water close to the shore, but more often forage out of sight of land. Penguins tracked by satellite, GPS and geolocation tags during incubation typically foraged more than 100 km, and sometimes as much as 600 km from various colonies in Argentina (Wilson et al. 2005, Boersma and Rebstock 2009, Boersma et al. 2009, 2013, 2015). Even when provisioning chicks, adults forage hundreds of kilometers from the colony (Boersma and Rebstock 2009, Boersma et al. 2009), although at many colonies they travel up to a few dozen km (Raya Rey et al. 2010, Yorio et al. 2010, Sala et al. 2012, Gómez-Laich et al. 2015, Rosciano et al. 2016). Breeding habitats include scrublands and grasslands in Argentina, tussock grass in the Falkland Islands (Malvinas) and temperate forests in Chile.


The primary current threats are oil pollution, fisheries interactions, and climate change. In the 1980s and early 1990s, oil pollution was estimated to kill more than 20,000 adults and 22,000 juveniles every year on the Argentinian coast (Gandini et al. 1994, Garcia-Borboroglu et al. 2006, Boersma 2008), which is also the wintering ground for the population from the Falkland Islands (Malvinas) (Pütz et al. 2000). This threat is now much reduced at least in Chubut Province, which now experiences mortality of less than 100 individuals every year (Boersma 2008, P. D. Boersma and E. Frere pers. comm. 2016). Chronic oil pollution and mortality still occurs off Brazil, Uruguay, northern Argentina and Chile (Garcia-Borboroglu et al. 2006, 2008, Matus and Blank 2008). Future petroleum extraction is under consideration offshore of the Falkland Islands (Malvinas), Patagonia and Uruguay, which would likely increase mortality. Southern colonies are subject to disproportionately high mercury levels for their trophic level (Brasso et al. 2015). Birds from the northern colony in Punta Tombo colony have been found to have much lower mercury levels (Frias et al. 2012). Detrimental effects were not evident in that study, but mercury exposure could be a long-term or synergetic threat.

This species interacts with fisheries along the coast of South America, through bycatch mortality from gillnets, trawls and purse-seines (Gandini et al. 1999, Tamini et al. 2002, González-Zevallos and Yorio 2006, Schlatter et al. 2009, Yorio et al. 2010, Cardoso et al. 2011, González-Zevallos et al. 2011, Marinao and Yorio 2011, Seco Pon et al. 2013, Marinao et al. 2014, Suazo et al. 2014, Trathan et al. 2014, Boersma et al. 2015, Suazo et al. 2016, L. Tamini pers. comm. 2016, Crawford et al. 2017, Marques et al. 2018, Paz et al. 2018, Fogliarini et al. 2019, Ropert-Coudert et al. 2019) and potential reduction of prey resources (Gandini et al. 1999, Boersma et al. 2015). Population trends in response to these threats have not been quantified. Fisheries may also reduce prey for penguins; the hake fishery in Argentina for example collapsed due to overfishing during the 1990s (Alemany et al. 2013). A potential expansion of the Argentinian anchovy fishery might impact breeding penguins (Skewgar et al. 2007). Fisheries in northern Argentine Patagonia may be having an additional effect, as bycatch includes anchovy and juvenile hake, which are an important part of the species's diet (Frere et al. 1996, Gandini et al. 1999, Scolaro et al. 1999, Wilson et al. 2005, Yorio et al. 2017). Further, fisheries for anchovy and sprat, both considered “underexploited” stocks, may be developed in Argentina and Brazil (Sanchez et al. 1995, Skewgar et al. 2007, Carvalho and Castello 2013).

Climate change has been reported to have an impact, as precipitation has increased over the last 30 years and young chicks that get wet often die from hypothermia (Boersma and Rebstock 2014). Precipitation causes nest burrows to collapse (Boersma 2009, Boersma and Rebstock 2014). Climate models show precipitation will increase over much of the species’s range, lowering reproductive output of many colonies (Boersma and Rebstock 2014). Decreasing breeding synchrony interacted with climate change to increase the part of the season when chicks are vulnerable to wetting (Boersma and Rebstock 2014). High temperatures in the breeding colonies can kill adults and chicks (Boersma and Rebstock 2014, P. D. Boersma unpublished data). Changing patterns of precipitation and atmospheric and oceanic circulation are likely to affect winter conditions in the Atlantic, indirectly affecting breeding, as the extent of the Rio de la Plata plume affects females' colony arrival timing and body condition (Rebstock and Boersma 2018). Indirect effects of climate change through changes in prey populations or availability are completely unknown.

In some areas of Chile, eggs and adults are collected for human consumption and adults are taken for bait (Boersma et al. 2013, Suazo et al. 2013, Trathan et al. 2014, Boersma et al. 2015). Egg-collection occurred also in the Falklands Islands (Malvinas). The introduction of feral dogs and other invasive species in the breeding colonies have resulted in local extirpations (Suazo et al. 2013), but population level declines have not been quantified. Tourism may disturb individuals at breeding colonies when not well managed (Boersma 2008). Long-term physiological effects of visits by tourists are not understood (Walker et al. 2005, 2006). Many of the threats may result in low impacts on the population, but there are many threats that probably have additive effects.

Conservation actions

Conservation Actions Underway
Many non-governmental organizations, academic institutions and individuals work on the conservation of Magellanic Penguins, and data from many studies have advanced conservation. Tanker lanes were moved 40 kilometers farther offshore along the coast of Chubut in 1997. This added to improvements at port loading facilities, which greatly reduced the number of oiled penguins in that area (Boersma 2008). The Management Plan for Punta Tombo is in place, but has not yet been effectively implemented by Chubut Province authorities. The Argentine government has created new marine protected parks along the coast, which include some penguin breeding areas and fragments of foraging areas (Patagonia Austral, Isla Pinguino, Makenke and Monte Leon). Specifically, a new UNESCO Biosphere Reserve will help give protection to 20 colonies (Garcia-Borboroglu et al. 2015). A new Marine Protected Area (MPA) for the large colony has been designated in Argentina (Boersma et al. 2015, Garcia-Borboroglu et al. 2015). Unfortunately, many of the parks lack effective planning and/or implementation. As MPAs are in general ineffective for the protection of highly mobile species such as penguins (Boersma and Parrish 1999), protection of penguin populations requires new conservation tools (Boersma et al. 2002, 2007, Garcia-Borboroglu et al. 2008, Yorio 2009, Stokes et al. 2014, Boersma et al. 2015). The Rio Negro Province has elaborated a Management Plan for the northernmost colony along the Atlantic coast. CADIC-CONICET is working together with the Tierra del Fuego government on the Management Plan for the Staten Island reserve and the intention is to include marine protected regions based on the tracking studies (Rosciano et al. 2016).

Conservation Actions Proposed
Conduct population censuses, determine the ratios of juveniles to adults and the adult sex ratio in Argentina, Chile and the Falkland Islands (Malvinas). Monitor effects of fisheries in breeding and wintering areas. Reduce bycatch and oiling incidents. Place or improve design of Marine Protected Areas or marine zoning in wintering and breeding areas. Implement complementary conservation and management tools to marine protected areas. Eradicate introduced predators from islands with colonies. Reduce impact of tourism and recreation at breeding colonies, for example by controlling unrestricted visits and defining appropriate visiting hours. Prepare contingency plans for emerging diseases or fires.


Text account compilers
Martin, R., Everest, J., Garcia Borboroglu , P., Hermes, C., Boersma, P.

Calvert, R., Clay, R.P., Frere, E., Godoy, C., Harris, S., Komar, O., Lascelles, B., Moreno, R., Nisbet, I., Pearmain, L., Pozzi, L., Raya Rey, A., Rebstock, G., Ruoppolo, V., Sharpe, C.J., Simeone, A., Stanworth, A., Tamini, L., Taylor, J., Woods, R.W. & Yorio, P.M.

Recommended citation
BirdLife International (2023) Species factsheet: Spheniscus magellanicus. Downloaded from on 04/12/2023.
Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from on 04/12/2023.