VU
Macaroni Penguin Eudyptes chrysolophus



Justification

Justification of Red List Category
This species qualifies as Vulnerable because the global population appears to have declined rapidly over the last three generations (37 years). The primary drivers of declines are uncertain but could include climatic variation, at-sea overwinter foraging and competition for food from Antarctic fur seals.

Population justification
The global population is estimated at 6.3 million breeding pairs in at least 258 colonies at c.55 breeding sites (Crossin et al. 2013), with key populations on Isles Crozet (2,200,000 pairs, including 1 million on Ilots des Pingouins), Kerguelen (1.8 million pairs), Heard Island (1 million pairs), South Georgia (1 million pairs) and Marion Island (290,000 pairs).

Trend justification
The current global population estimate of 6.3 million breeding pairs (Crossin et al. 2013) represents a 47% reduction over three generations (37 years) on the previous estimate of 9 million pairs (Woehler 1993, Ellis et al. 1998). At South Georgia, c.5 million pairs were estimated in the 1980s, falling to c.2.7 million pairs in the mid 1990s and to <1 million pairs in 2002 (Trathan et al. 1998, 2012; Crossin et al. 2013). Volcanic activity eliminated a colony of c.1 million pairs on McDonald Island, though satellite images show unidentified penguins that may be recolonising Macaronis (Crossin et al. 2013); photographic images from tourist vessels suggest that the penguins are indeed Macaroni Penguins (E.J. Woehler in litt. 2019). Surveys on Heard Island (c.1 million pairs) suggest a decrease owing to losses in some smaller colonies. The population at Marion has decreased by over 30% from 434,000 pairs in 1994-1995 to 290,000 pairs in 2008-2009 (Crawford et al. 2009), and 267,000 pairs in 2012-2013 (Dyer and Crawford 2015). Recent trends at Crozet are unknown, as there has been no assessment since Jouventin (1988). At Kerguelen populations increased by c.1.06% per annum between 1962 and 2014, and have been stable since (CNRS-CEBC unpublished data). Populations in South America may be stable but data are few (Oehler et al. 2008). A rapid ongoing decline is estimated overall.

Distribution and population

Eudyptes chrysolophus breeds in at least 258 colonies at c. 55 breeding sites (Crossin et al. 2013), including southern Chile, the Falkland Islands (Malvinas), South Georgia (Georgia del Sur) and the South Sandwich Islands (Islas Sandwich del Sur), the South Orkney and South Shetland Islands, Bouvet Island (to Norway), Prince Edward and Marion Islands (South Africa), Crozet Islands, Kerguelen Islands (French Southern Territories), Heard and McDonald Islands (to Australia) and very locally on the Antarctic Peninsula.

Important populations exist at Isles Crozet (2.2 million pairs, including 1 million on Iles des Pingouins), Kerguelen (1.8 million pairs), Heard Island (1 million pairs), South Georgia (1 million pairs) and Marion Island (290,000 pairs). The population in the Patagonian Shelf region is estimated at 25,000 breeding pairs (Oehler et al. 2008, Kirkwood et al. 2007, Crossin et al. 2013). The Falkland Islands (Malvinas) population is estimated at no more than 1000 individuals (Stanworth Pers. Comm.). The rest of the population is contained in Chile in at least 12 known colonies. Diego Ramirez is the largest colony with 15,600 pairs (Kirkwood et al. 2007).

Winter PTT tracking from Marion Island shows some association with mesoscale eddies and sub-mesoscale filaments (Whitehead et al. 2016). Geolocation tracking from Kerguelen during winter revealed that individuals showed strong inter-annual fidelity to their wintering sites. They spent most of their time in a narrow latitudinal band (47°-49° S) within the central Indian Ocean (70°-110° E), corresponding oceanographically to the Polar Frontal Zone (Bost et al. 2009, Thiebot et al. 2011). In contrast, individuals from South Georgia spend most of their time widely distributed across the Scotia Sea during winter (Ratcliffe et al. 2015).

Recent phylogenetic analyses have shown that the species shows little genetic divergence from Royal Penguin populations (Frugone et al. 2018, 2019), suggesting that a reappraisal of the taxonomic status is needed.

Ecology

Macaroni penguins nest on level to steep ground, often walking hundreds of metres across steep scree slopes to nest-sites. Whatever the locality, the breeding cycle is characterized by a high level of synchrony with a laying period protracted over a period of less than 2 weeks. Breeding areas usually have little or no vegetation due to erosion by birds.

Macaroni penguins are pelagic foragers, searching for prey at moderate depths, usually less than 50 m.  They feed mainly on small krill (Marchant and Higgins 1990, Deagle et al. 2008); at South Georgia they feed extensively on Antarctic krill (Euphausia superba), while at Crozet and Kerguelen they have a more diverse diet, feeding on small euphausiids, amphipods (Themisto gaudichaudii) and small amounts of myctophid fish. Their diets show a shift after incubation, with an increase in fish (myctophid). During their winter dispersal, they rely mostly on crustaceans (Bost et al. 2009).

Macaroni penguins show extensive changes in their foraging range throughout their breeding cycle. For example, incubating birds from Crozet target the distant, turbulent waters of the sub-Antarctic Front (Bon et al. 2015) while South Georgia, Kerguelen and Prince Edward Islands birds target the waters of the Polar Front (Barlow and Croxall 2000, Bon et al. 2015, Whitehead et al. 2016). Brooding birds forage closer to their colonies over the shelf and the shelf break, increasing their range during crèche (Trathan et al. 2006, Barlow and Croxall 2002, Crossin et al. 2015, Bon et al. 2015, Whitehead et al. 2016).

Patterns of movement are well known for adults during breeding  (e.g. Trathan et al. 2006, Barlow and Croxall 2002, Crossin et al. 2015, Bon et al. 2015), but information for the non-breeding period (e.g. Bost et al. 2009; Thiebot et al. 2011 Ratcliffe et al. 2015) is less well known for several populations, and poorly known for juveniles.

At-sea habitats overlap with those of recovering populations of marine mammals; as such, recovering populations of Antarctic fur seals (Arctocephalus gazella) have been identified at South Georgia as potential resource competitors and a plausible cause of Macaroni Penguin population decrease (Barlow et al. 2002, Trathan et al. 2012). At some locations fur seals are penguin predators, as they have been identified catching and preying on Macaroni Penguins. 



Threats

Climate change is an important potential candidate for explaining recent declines. Large-scale environmental changes, particularly those related to sea temperatures could be contributing to habitat loss, indirect ecosystem effects, direct species mortality and reduced reproductive success, but the nature and level of impacts remain unclear as there may be divergent responses in different populations; climate was found to be have potentially positive effects in the short to medium term for the population studied at Bird Island, South Georgia, whereas changes to predation dynamics appear to be an important factor driving declines (Horswill et al. 2014, 2016).

Historical and continuing prey competition with fur seals Arctocephalus spp. at South Georgia is considered to have substantially contributed to declines noted over the past several decades, with the fur seal population increasing from an estimated 30,000 to c. 3 million in the past few decades (Barlow et al. 2002, Trathan et al. 2012). Recovery of fur seals at the Prince Edward Islands could increase competition for prey as well as causing increased predation pressure on penguins (Dyer and Crawford 2015). Increasing seal populations could also block access to breeding sites thereby inhibiting colony growth, as demonstrated on Bouvet Island (Isaksen et al. 1997). In the South Georgia population, predation appears to be of secondary concern with relatively few fur seals predating penguins and local penguin declines starting well in advance of increases in seal predation (J. Croxall in litt. 2017). Giant Petrels Macronectes spp. contribute to predation pressures on immature penguins, targeting them in the vulnerable fledgling phase (Horswill et al. 2014, 2016).

Commercial fisheries could represent a potential threat through incidental capture and resource competition. Long-line fisheries at winter feeding grounds have inflicted limited bycatch mortality on Macaroni Penguins (Dyer and Crawford 2015) and harvesting of Antarctic krill could reduce food availability if management does not adequately take into account the dietary needs of the species. Invasive mammals including cats, mice and rabbits are present on a number of sub-Antarctic islands but their current impact on the species is thought to be negligible (Crossin et al. 2013). Breeding colonies on Marion Island have previously shown declines following outbreaks of avian cholera and other unknown diseases (Cooper et al. 2009). Human impacts potentially also include disturbance from tourists, scientists, construction of new science facilities and fisheries. Oil spills may also be important at local scales. Protection of habitat on land and at sea remains important, with the designation of appropriate protection for transit, foraging and rafting areas at sea.

Conservation actions

Conservation Actions Underway

Long-term monitoring programmes are in place at several breeding colonies (Ellis et al. 1998). Most breeding islands are protected as reserves of various kinds and Heard and McDonald Islands are a World Heritage Site. Eradication of rats and mice at South Georgia are complete, and after more than three years there has been no sign of rodent activity. However, it is unknown as to whether rats or mice depredated penguin chicks at South Georgia. Fisheries for Antarctic krill are managed at South Georgia in such a way as to reduce resource competition with land-based predators that target the same resource (Trathan et al. 2014); during the summer krill fisheries are prohibited from all waters surrounding South Georgia and the South Sandwich Islands, and during the winter they must stay at least 30 km and 50 km from the coast, respectively.


Conservation Actions Proposed

Survey or resurvey all main breeding populations at major breeding sites, and research its distribution outside the breeding season. Conduct research into demography with robust estimates of survival of different sex and age classes. Undertake research into reproductive performance and foraging ecology. Maintain monitoring programmes at selected sites. Assess: i) the status and trends of populations breeding at colonies in the Indian Ocean, especially at Crozet and Kerguelen Islands, ii) the impacts of the recovery of previously depleted populations of marine mammals that compete for the same prey with Macaroni Penguins iii) the implications of fisheries that compete for the same prey with macaroni penguins iv) the implications of environmental change v) further document the decrease in population at South Georgia and v) whether historical genetic bottlenecks occurred. Also monitor threats such as the ingestion of and entanglement in marine debris, including the frequency of marine oiling. Ensure monitoring and mitigation of possible conflicts with fisheries. Investigate any potential impacts of disturbance associated with tourism. Continue eradication of introduced species (e.g. potential for eradication of invasive mice at Marion) as well as investigate the impacts of disease outbreaks. Best practice guidelines for reducing risk of disease outbreaks at islands are being developed by the Agreement on the Conservation of Albatrosses and Petrels. Once available, these guidelines should be implemented. Develop studies of the potential impacts of climate change.

Identification

71 cm. Large, yellow-crested, black-and-white penguin. Black upperparts. White underparts. Dark grey to black head and cheeks. Long yellow, orange and black plumes project from forehead patch back along crown and droop behind eye. Similar spp. E. chrysolophus and Royal Penguin E. schlegeli are the only crested penguins with crests that meet on the forehead. E. schlegeli has pure white to pale grey cheeks, but light-faced E. chrysolophus are also reported at some sites (although it is not known whether these are local mutations or hybrids).

Acknowledgements

Text account compilers
Symes, A., Martin, R., Taylor, J., Trathan, P. N., Moreno, R., McClellan, R., Pearmain, L.

Contributors
Ballard, G., Barbraud, C., Bost, C., Crawford, R.J.M., Crossin, G.T., Croxall, J., DuBois, L., García Borboroglu, P., Makhado, A., Micol, T., Nisbet, I., Ratcliffe, N., Schmidt, A., Schneider, T., Trathan, P. N., Weimerskirsch, H. & Woehler, E.


Recommended citation
BirdLife International (2021) Species factsheet: Eudyptes chrysolophus. Downloaded from http://www.birdlife.org on 07/03/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 07/03/2021.