Justification of Red List Category
This species qualifies as Vulnerable because it has a small population which is estimated to be undergoing rapid reduction, based on trend data from a few sites due to a variety of threats, especially introduced predators.
The population has been estimated at c.5,500-7,000 mature individuals (Mattern 2013, Long 2014). Due to the cryptic breeding habit and resulting difficulty of surveying the species, this number is likely to be an underestimate (Mattern 2013). Therefore, the population size is placed here in the range 2,500-9,999.
Introduced predators, human disturbance and accidental deaths caused by fisheries are all contributing to an on-going decline in this species's population. Recently, at some sites numbers appear to have declined, while slightly increasing numbers have been reported from others making it difficult to identify clear species-wide population trends (Mattern 2013). At Open Bay Island, there was a decline of 33% between 1988 and 1995 (Ellis et al. 1998), and at Dusky Sound there were anecdotal reports of thousands of birds in 1900, but only a few hundred remained in the 1990s (Russ et al. 1992). The use of unstandardised methods and the fact that results are hard to interpret, means further research is urgently needed, but declines are suspected to have been rapid, and are placed here in the range 30-49% over three generations (c. 29 years).
Eudyptes pachyrhynchus nests on Stewart Island and several of its offshore islands, Solander Island and on the west to south-west coast of the South Island, New Zealand. Non-breeding dispersal patterns at sea are largely unknown.
This species breeds in loose colonies along stretches of coastline in habitats ranging from mature temperate rainforest and dense scrub, to coastal caves and rocky shorelines. Penguins arrive at their breeding sites from mid-June onwards, with most nests established by mid-July. Two eggs are laid, which are incubated by both parents and hatch after 33 days (Warham 1974). Chicks fledge around mid- to late November. A diet study on the West Coast found that penguins brought predominantly squid (85%) ashore, followed by krill (13%) and fish (2%) (van Heezik 1989). Penguins from Codfish Island, took primarily fish (85%) and squid (15%) (van Heezik 1990). While breeding the penguins show site-dependent differences in foraging ranges, with birds from the Jackson Head, West Coast foraging within 20-100 km radii from their breeding colonies, while penguins breeding in Milford Sound remained within the fiord most of the time (foraging radius <10 km) (Mattern and Ellenberg 2016).
Introduced terrestrial predators are an eminent threat. Stoats Mustela erminea are considered the most significant predator of the species at present (Ellenberg 2013, Wilson and Long 2017), with three trapped in 2016 following observations of stoats predating chicks at Jackson's Bay colony (Mattern and Ellenberg 2016). In this and the preceding year productivity at this site was very low, but improved in 2017 (Mattern and Ellenberg 2016). Dogs also represent a potentially significant predator, particularly when moulting adults are confined ashore for 20-30 days, during which time a single dog would have the potential to wipe out a whole colony (DOC 2012). Feral cats Felis catus, rats Rattus spp., Weka Gallirallus australis (Marchant and Higgins 1990, Mattern 2013) and Common Brushtail Possum Trichosurus vulpecula are also potential predators, but none appear to be having anything more than negligible impacts on Fiordland Penguin populations (Mattern and Ellenberg 2016).
Resource competition with squid fisheries (Ellis et al. 1998) and bycatch are both threats imposed by local fisheries. In 2011 annual bycatch mortality was estimated to be between 38-176 birds (Ellenberg 2013) with set nets of particular concern close to shore or within the fiords themselves (e.g. Milford Sound). Birds are occasionally disturbed by humans at nest-sites (Ellenberg et al. 2015), with human disturbance in the more accessible colonies in South Westland anecdotally attributed as causing nest failures and a decline in population (Wilson and Long 2017; DOC 2012). Small numbers are killed on roads (DOC 2012). The pathogen Leucocytozoon tawaki has been identified from the species, but infections are of low prevalence and there appear to be no ill-effects reported (Jones and Shellam 1999). Pollution could become a major threat if proposed deep-sea oil exploration off the West Coast proceeds (Mattern 2013), and oil spills represent an ongoing, chronic threat with potential for a dramatic incident, but likely to be limited to a portion of the breeding range. El Niño events were found to have a detrimental effect on the breeding success of Fiordland penguins from the West Coast, although penguins breeding in Fiordland seem to be less affected by the climate phenomenon (Mattern and Ellenberg 2016).
Conservation Actions Underway
The NZ Department of Conservation (DOC) has established a Fiordland penguin Recovery Strategy 2012-17 plan that includes continued population monitoring at representative sites, implementation of island biosecurity measures, and the investigation of effects of predator control (DOC 2012). Several major research projects have been established since 2014. Between 2014 and 2019, the marine ecology (foraging ranges, diving behaviour, diet composition) of breeding Fiordland penguins is being studied across their entire breeding range; the project will also investigate the pre-moult dispersal of adult penguins (Mattern and Ellenberg 2016). The species’ winter migration will be investigated between 2016 and 2021 (S. Waugh, pers. comm.). A video monitoring study examines the impact of introduced terrestrial predators on breeding Fiordland penguins (Wilson & Long 2015). The Department of Conservation continues its monitoring program at various monitoring sites throughout the species breeding range (Ellenberg et al. 2015).
Conservation Actions Proposed
Expand the use of standardized census methods (Ellenberg et al. 2015) and survey areas of coastline not surveyed in the 1990s (Ellis et al. 1998). Predator eradication/control – particularly mustelids – is necessary to prevent reproductive failure and mortality (Mattern 2013). Establish guidelines to control visitor access to colonies. Obtain legal protection for accessible colony sites (Taylor 2000).
60 cm. Medium-sized, yellow-crested, black-and-white penguin. Dark, bluish-grey upperparts. Darker head. Broad yellow eyebrow-stripe that drops down neck. Most have 3-6 whitish stripes on cheeks. Similar spp. Only crested penguin with white stripes. Snares Island Penguin E. robustus has pink skin at base of bill. Erect-crested Penguin E. sclateri has erect crest. Rockhopper penguins E. chrysocome and E. moseleyi have crests that begins with a thin eyebrow-stripe.
Text account compilers
Pearmain, L., Martin, R., Mattern, T., Benstead, P., McClellan, R., Moreno, R., Mahood, S., Seddon, P., Allinson, T, Taylor, J.
van Heezik, Y., Otley, H., Wilson, K., Seddon, P., Garcia Borboroglu , P., Long, R., Taylor, G.A., Mattern, T., Webster, T., Ellenberg, U.
BirdLife International (2020) Species factsheet: Eudyptes pachyrhynchus. Downloaded from http://www.birdlife.org on 04/07/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 04/07/2020.