Justification of Red List Category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The King Penguin has two subspecies; A. patagonicus patagonicus and A. patagonicus halli. It breeds on various sub-Antarctic islands, with the latter found at the Kerguelen Islands and Crozet Island (French Southern Territories), Prince Edward Islands (South Africa), Heard Island and McDonald Islands, and Macquarie Island (Australia); the former breeds at South Georgia (Georgias del Sur) with small colonies also present on the Falkland Islands (Islas Malvinas) that are still increasing (del Hoyo et al. 1992) and in southern Chile (Kusch and Marín 2012). Occasionally one or two pairs also appear to attempt breeding at the South Sandwich Islands (Convey et al. 1999).
The population has begun to stabilize over the past decade, and the global population is estimated at 1.6 million annual breeding pairs (range 1,584,320–1,728,320) (Bost et al. 2013). Important populations occur at South Georgia c. 450,000, Falkland Is. c. 1,000, Prince Edward Is. 2,000, Marion Is. 65,000, Crozet Is. 611,700–735,700, Kerguelen Is. 342,000, Heard Is. 80,000, and Macquarie Is. 150,000–170,000.
At Marion Island, numbers of King Penguins breeding in summer (December–January) between 2008/09 and 2011/12 averaged 69,405 ± 3,417 pairs (Dyer and Crawford 2015). At Prince Edward Island, it was estimated that there were 2,228 ± 117 pairs in the 2008/09 summer (Crawford et al. 2009). Therefore, it is thought that about 69 000 pairs of King Penguins breed annually at the Prince Edward Islands. However, since ca. 20% of King Penguins at Marion Island do not breed in each season (van Heezik et al. 1994), the overall population is of the order of 90,000 pairs (Dyer and Crawford 2015). Counts of King Penguin chicks at Marion Island surviving to the end of winter (September or October) were made in a consistent manner over 21 years between 1987 and 2011. They averaged 51,900 ± 21,715 and there was no significant trend over time (Crawford et al. 2009).
This species has a prolonged breeding season (14-15 months) with an asynchronous laying period. Hence, it spends much of its time near breeding areas. The King Penguin does not build a nest but incubates its egg on the feet. It is highly territorial. The prey comprises mainly myctophid fish but ice fish and cephalopods are also taken. It captures prey by means of pursuit-diving mostly during the day, and forages at depths of 160-200 m. It arrives at colonies to breed between September and November, forming colonies on flattish beaches free of ice. The annual moult takes place from October until January. The main marine predators of both adults and young are killer whales (Orcinus orca) and leopard seals (Hydrurga leptonyx). Antarctic fur seals (Arctocephalus gazella) occasionally prey on this species as well. In the colonies, giant petrels (Macronectes spp.) prey on chicks, and skuas (Stercoraria spp.) and lesser sheathbills (Chionis minor) take eggs and sometimes small chicks (Bost et al. 2013).
A recent modelling exercise showed that sea surface temperatures constitute an important driver of the foraging distribution of this species. The results of this study imply that the projected southwards shift of the Antarctic Polar Front (APF) could have negative consequences for King Penguins as, for at least at some colonies in the Southern Indian Ocean, they would have to travel significantly farther to reach their preferred cold water foraging grounds (Péron et al. 2012). IPCC climate models suggest that the APF could shift southward 25-40 km per decade, with the northern colonies likely to be more affected than southern ones. The severity of the threat posed by climate change is still unclear, as it may be responsible for recent observed increases, but equally may drive rapid declines over relatively short periods (Péron et al. 2012, Trucchi et al. 2014, Cristofari et al. 2018).
Furthermore, the depth of the mixed layer may deepen as the Southern Ocean warms and positive Southern Annual Mode (SAM) anomalies occur more frequently. Although there is still uncertainty about how the mixed layer may respond to alterations in the atmosphere, changes in SAM could alter the exchange of heat and carbon between ocean and atmosphere (Sallée et al. 2010). This in turn has the potential to drive the main prey of King Penguins to greater depths forcing the penguins to dive deeper (Péron et al. 2012). Additionally, insufficient food may decrease survival of adults (Olsson and van der Jeugd 2002); and an unknown disease killed 250–300 King Penguins at Marion Island in late October 1992 (Cooper et al. 2009).
Disturbance from helicopter flights may cause some breeding failure or lead pairs to relocate to alternative breeding sites (Cooper et al. 1994), and a large scale mortality event associated with aerial logistical operations occurred at Macquarie Island in 1990 (Rounsevell and Bins 1991). Other human impacts could potentially include disturbance from tourists, scientists, construction of new science facilities and fisheries, particularly fisheries for myctophid fish if they develop (e.g. Moore et al. 1998). Oil spills may also be important at local scales.
Invasive species may have low-level impacts on King Penguins in parts of the range. Feral cats Felis catus may depredate chicks (reduced reproductive success), but has no impact on adult mortality (Bost et al. 2014). However, cats are present only at a minority of sites, and no population declines have been associated with cat predation. The Argentine Gray Fox (Chilla) Lycalopex griseus, is native to much of the southern extreme of south America, but was introduced to Tierra del Fuego island in 1951 in an attempt to control rabbits (Jaksic and Yáñez 1983). Foxes are now causing some chick mortality at newly formed (and increasing) King Penguin colonies (Godoy & Borboroglu unpubl. data). As yet, no assessment has been made of the impact of fox predation, but given that these colonies are increasing and there is no reported adult mortality, it is unlikely to be significant. Rabbits Oryctolagus cuniculus are present at a few sites with potential to impact a small percentage of the global population. Rabbits have now been eradicated from Macquarie (Parks and Wildlife Service 2014) and the previous notable impact from herbivory, erosion and landslides on the island (Rounsevell & Binns 1991), is highly unlikely to recur. No population declines have been attributed to the impact of rabbits.
Conservation Actions Underway
The species is the subject of on-going international research but there are currently no special conservation activities. Human visitation to King penguin colonies is increasing and has the potential to increase disturbance, introduction of non-native species and transmission of disease. Although many operators have good biosecurity procedures in place, there is always a residual risk.
Conservation Actions Proposed
Conduct regular surveys to monitor population trends. Continue to improve on existing modelling work to better predict future population changes. Determine the use of marine habitats throughout the annual cycle for breeders and non-breeders. Model foraging habitat to determine the variables that govern distribution. Model foraging responses in years with varying sea surface temperatures. Examine the taxonomic status through population genetics.
Management plans must include good biosecurity procedures (e.g. Commonwealth of Australia 2014) and preferably also strategies to deal with disease outbreaks and stipulate actions to prevent further spread (Cooper et al. 2009, Waller and Underhill 2007).
Text account compilers
Calvert, R., Moreno, R., Butchart, S., Trathan, P., Ekstrom, J., Wienecke, B., Martin, R., Pearmain, L.
Crawford, R.J.M., Borboroglu, G., Ballard, G., Woehler, E., DuBois, L., Trathan, P., Makhado, A., Schneider, T., Pütz, K., Wienecke, B., Schmidt, A., Simeone, A.
BirdLife International (2019) Species factsheet: Aptenodytes patagonicus. Downloaded from http://www.birdlife.org on 26/05/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 26/05/2019.