Justification of Red List Category
This species is classified as Endangered because its population is estimated to have declined very rapidly over the last three generations, and it is almost certainly still declining. Furthermore, it has a very small breeding range, which may now be restricted to just two locations.
Population trends indicate a severe decline between the mid-1970s and mid-1990s (Davis 2013). On the Bounty Islands, estimated numbers of erect-crested penguins were 115,000 pairs (Robertson and van Tets 1982) in 1978, declining to 28,000 pairs by 1997 (Taylor 2000), with 26,000 breeding pairs recorded in 2011 (Miskelly 2013). On the Antipodes Islands, an estimated 115,000 breeding pairs were recorded in 1978 (Taylor 2000), which have declined to 52,000 pairs by 1995, and to 34,226 pairs by 2011 (Hiscock and Chilvers 2014). Overall it appears that the population decline apparent until the 1990s has since slowed somewhat, which corresponds to the population of the sympatric breeding Rockhopper penguins (Morrison et al. 2015). Based on 2011 estimates of breeding pairs and assuming that only 80% of the mature individuals engage in breeding each year, there are c.150,000 mature individuals.
The Bounty Islands population declined 76% during 1978-1998, but census methods were variable. The Antipodes population declined by c.50% during 1978-1995, and there have been further decreases since (G. A. Taylor in litt. 1999, Taylor 2000, D. Houston in litt. 2008). Based on this information, a very rapid decline is estimated to have occurred over the last three generations. However, recent surveys indicate that the rate of decline may be slower than this (J. Hiscock in litt. 2012).
Eudyptes sclateri breeds on the Antipodes and Bounty Islands (20 km2 and 1 km2 respectively), New Zealand. The most recent population survey conducted in 2011 found 34,226 nests on the Antipodes (Hisock and Chilvers 2014); on the Bounty Islands there were an estimated 26.000 nests in the same year (Miskelly 2013). In the mid-20th century breeding erect-crested penguins were observed on the New Zealand mainland, although these were individual pairs that were not part of a larger population (Richdale 1950). Outside the breeding period, erect-crested penguins have been reported on other sub-Antarctic islands, such as Campbell Island (Miskelly et al. 2015) and the Snares Islands (Morrison and Sagar 2014), and it is a frequent visitor to the New Zealand mainland and the Chatham Islands (Miskelly 2013). Outside the New Zealand territory, erect-crested penguins have been observed along the southern coasts of Australia, and the Kerguelen and the Falkland Islands (Miskelly 2013).
With a severe lack of data on the species it is difficult to assess what causes population declines in erect-crested penguins (Davis 2013). The absence of introduced terrestrial predators disrupting penguin populations on the mainland point towards sea-based issues, which most likely consist of changes in marine productivity due to ocean warming and, potentially, fisheries interactions (Trathan et al. 2015).
The reason for the large population declines is thought to be associated with marine factors affecting survivorship (Ellis et al. 1998, Taylor 2000). There are no mammalian predators on the Bounty or Antipodes Islands, except for mice on the main Antipodes Island.
Conservation Actions Underway
Both islands are Nature Reserves and part of a World Heritage Site designated in 1998. Opportunistic monitoring of population size takes place.
Conservation Actions Proposed
Survey a sample of Antipodes Island colonies every five years, and re-photograph photo-points from the 1978 and 1995 expeditions. Survey Proclamation Island (Bounty Islands) every five years (Hiscock and Chilvers 2014). Compare aerial and ground surveys of the Bounty Islands to ascertain the viability of using the former method for monitoring colonies (Taylor 2000). Conduct detailed studies to determine foraging ranges, commercial fisheries interactions, and oceanographic or climatic changes (Davis 2013).
60 cm. Medium-sized, yellow-crested, black-and-white penguin. Bluish-black to jet black upperparts. White underparts. Broad, bright yellow eyebrow-stripe extends over eye to form short, erect crest. Similar spp. Differs from all other crested penguin species in having an erect crest.
Text account compilers
Benstead, P., Calvert, R., Ellenberg, U., Mahood, S., Mattern, T., McClellan, R., Moreno, R., Seddon, P., Taylor, J., Webster, T., van Heezik, Y.
Webster, T., Taylor, G.A., Booth, A., Amey, J., Ellenberg, U., Houston, D., van Heezik, Y., Hiscock, J.
BirdLife International (2017) Species factsheet: Eudyptes sclateri. Downloaded from http://www.birdlife.org on 19/10/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/10/2017.