BirdLife International factsheet for Fiordland Penguin, developed in collaboration with the IUCN SSC Penguin Specialist Group
The Fiordland Penguin breeds only in New Zealand, nesting along the coastline in temperate rainforests and coastal caves (BirdLife International, 2020). The global population size has recently been estimated to be 12,500 – 50,000 mature individuals (Mattern & Wilson, 2019). Fiordland Penguin is at varying degrees of risk from a variety of threats, including disease, fisheries by-catch, and nest predation from both native endemics and introduced mustelids (Otley et al., 2018).
Previously, Fiordland Penguin has been considered Vulnerable under Criteria A2bce+3bce+4bce; C2a(i). However, new information regarding population size and rates of decline may mean that the current Red List category is no longer tenable. We have therefore fully reviewed this species here against all Red List Criteria.
Criterion A: IUCN guidelines stipulate that rates of decline should be measured over the longer of ten years or three generations (IUCN Standards and Petitions Committee, 2019). The generation length of Fiordland Penguin has recently been recalculated as 11.6 years (Bird et al. 2020)*. Therefore, trends must be considered over 34.8 years.
Assessing the species-wide population trend for Fiordland Penguin is difficult. Reports from some colonies suggest declines, while others suggest the population may be increasing. Historically, a decline of 33% was reported on Open Bay island between 1988 and 1995 (St Clair, 1998), but it has been argued that this decline may have resulted from the species’s susceptibility to human disturbance through research activities in this period (Mattern & Wilson, 2019). It is also only representative of only one portion of the species’ range.
More recently, Otley et al. (2018) suggested an annual rate of decline of 1.2-2.6% for the whole population, which when extrapolated over three generations equates to a rate of decline of 34-60%. However, this study was based on nest-chick data, and due to the cryptic breeding behaviour of Fiordland Penguin, this traditional method of surveying populations is not thought to yield reliable data for this species (Mattern & Wilson, 2019). Additionally, these rates of decline contrast with more comprehensive surveys and anecdotal evidence from other regions, which suggest the population may be increasing (Mattern & Wilson, 2019). Although larger population sizes have now been recorded, there is a lack of historical evidence to put these into perspective, so deriving a trend is difficult, especially given the species’s cryptic behaviour (Mattern & Wilson, 2019). In the absence of more data, and taking a precautionary approach, the Fiordland Penguin is suspected to be experiencing an ongoing decline, placed in the 20-29% range. This does not meet the threshold for Vulnerable (≥30% decline over three generations), but Fiordland Penguin may be considered Near Threatened under Criterion A2bce+3bce+4bce.
Criterion B: The Extent of Occurrence (EOO) of Fiordland Penguin is calculated to be 81,800 km². This is too large to trigger the threatened threshold (EOO <20,000 km²). This species may therefore be considered Least Concern under Criterion B.
Criterion C: The new estimated population size for this species is 12,500 – 50,000 mature individuals. This does not meet the threshold to be classified as Vulnerable (<10,000 mature individuals). Additionally, the continued decline is only suspected, and for classification under C, it needs to be observed, estimated, projected or inferred. The number of subpopulations has previously been considered to be 12 (BirdLife International, 2020). Genetic diversity assessments may prove otherwise, but in the absence of this, and assuming there are 12 subpopulations of equal size, and that the total population size is closer to 12,500, this still produces subpopulations containing >1,000 mature individuals. In reality, some subpopulations are likely to be much larger, and if the population size is at the higher end of the estimate, larger still. The vast majority of this large range estimate also falls above the value suggested by IUCN as appropriate to invoke Near Threatened if other conditions are met (c. 15,000 mature individuals; IUCN Standards and Petitions Committee, 2019). Overall, therefore, the species does not meet sufficient conditions to list as threatened or Near Threatened, and as such Fiordland Penguin may be considered Least Concern under Criterion C.
Criterion D: The estimated population size is far too high to trigger the threatened threshold (<1,000 mature individuals). Fiordland Penguin may therefore be considered Least Concern under Criterion D.
Criterion E: To the best of our knowledge, no quantitative analysis has been carried out on this species. We therefore cannot assess Fiordland Penguin against Criterion E.
We therefore suggest that Fiordland Penguin be listed as Near Threatened, approaching classification as threatened under criterion A2bce+3bce+4bce. We welcome any comments on the proposed listing.
Please note that this topic is not designed to be a general discussion about the ecology of the species, rather a discussion of the species’ Red List status. Therefore, please make sure your comments are relevant to the species’ Red List status and the information requested. By submitting a comment, you confirm that you agree to the Comment Policy.
* Bird generation lengths are estimated using the methodology of Bird et al. (2020), as applied to parameter values updated for use in each IUCN Red List for birds reassessment cycle. Values used for the current assessment are available on request. We encourage people to contact us with additional or improved values for the following parameters; adult survival (true survival accounting for dispersal derived from an apparently stable population); mean age at first breeding; and maximum longevity (i.e. the biological maximum, hence values from captive individuals are acceptable).
An information booklet on the Red List Categories and Criteria can be downloaded here and the Red List Criteria Summary Sheet can be downloaded here. Detailed guidance on IUCN Red List terms and definitions and the application of the Red List Categories and Criteria can be downloaded here.
Bird, J.P., Martin, R., Akçakaya, H.R., Gilroy, J., Burfield, I.J., Garnett, S., Symes, A., Taylor, J., Şekercioğlu, Ç.H. and Butchart, S.H.M. (2020), Generation lengths of the world’s birds and their implications for extinction risk. Conservation Biology. Accepted Author Manuscript. doi:10.1111/cobi.13486
BirdLife International (2020) Species factsheet: Eudyptes pachyrhynchus. Downloaded from http://www.birdlife.org on 25/05/2020.
IUCN Standards and Petitions Committee. 2019. Guidelines for using the IUCN Red List Categories and Criteria. Version 14. http://www.iucnredlist.org/documents/RedListGuidelines.pdf
Mattern, T., Wilson, K.-J. 2019. Fiordland penguin/tawaki, Eudyptes pachyrhynchus. State of Penguins, New Zealand Penguin Initiative & Birds NZ. Dunedin & Wellington, NZ. DOI: 10.36617/SoP.tawaki.2019-04
Otley, H., Edmonds, H., Hiscock, J., Newton, G., Tansell, J., van Klink, P., Wilson, R., Westbrooke, I. (2018) Assessing the population trend and threats to New Zealand’s Fiordland crested penguin using counting and demographic modelling approaches. New Zealand Journal of Ecology 42: DOI: 10.20417/nzjecol.42.15
St. Clair, CC. (1998) Eudyptes pachyrhynchus. in Report from a workshop held 8-9 September 1996, Cape Town, South Africa (eds. Ellis, S., Croxall, J. P. & Cooper, J.) 69–72 (IUCN/SSC Conservation Breeding Specialist Group).