LC
Little Penguin Eudyptula minor



Justification

Justification of Red List Category

The global population size has been quantified and estimated as under 500,000 breeding adults. The population trend is stable overall with localised decreases in population size, usually driven by human disturbance and climatic variability. Increasing ocean temperature and strong winds are linked to negative effects on adult foraging and chick survival. The stable trend should be taken cautiously as 60% of the sites have an “unknown” population trends due to data deficiency. In Australia, there is a decrease in the population size in New South Wales and South Australia while Tasmania is data deficient. Populations are stable in WA and increasing in Victoria. In New Zealand, the situation of the species remains unclear due to inconsistent monitoring efforts over large parts of the country. Little penguins along the South Island’s West Coast, Banks Peninsula seem to be decreasing over the past decades while penguin numbers around Oamaru are stable if not increasing. Although the species has a large estimated extent of occurrence, about 69% of sites have fewer than 100 breeding individuals. For the remaining sites, 28% have between 100 and 5000 individuals and only 3% of sites have a population size above 5,000 individuals. Sites with small populations are more vulnerable with reported local extinctions. Several sites without active conservation measures have experienced a severe decrease in population size, while many former breeding colonies no longer exist. The population range and size do not approach the thresholds for Vulnerable criteria (Extent of Occurrence <20,000 km2 and <10,000 mature individuals with a continuing decline). For these reasons, the species is evaluated as Least Concern.

Population justification

The global population size has been quantified for most sites, with the current population estimate of 469,760 breeding adults. This population size is smaller than the previously estimate, where the total population was only considered as under 1,000,000 individuals, but was based on non-quantified data. With quantified data, there is an increase of 18% in population size when historic and recent data are compared. However, this increase should be interpreted with caution as it is very likely to be related to improved population survey effort rather than an actual increase in population. For sites with current population estimates, 60% of the sites have an “unknown” trend due to data deficiency. Nevertheless, for the sites where data were available, 51% of sites were stable, 29% deteriorating and 20% improving. Fifteen sites are suspected extinct.

Trend justification
The population trend is overall stable, but many populations of little penguins are severely threatened by human disturbance such as introduced predators, domestic dogs, roadkill, coastal development, watercraft injuries, oil spills and gillnet fishing in both Australia and New Zealand (Cannel et al. 2016; Chiaradia 2013, Dann 2013). Sites without active conservation measures have experienced a severe decrease in population size, where many known breeding colonies no longer exist (Dann 1994; Stevenson & Woehler 2007). For sites with current population estimates, 60% of the sites have an “unknown” trend due to data deficiency. Nevertheless, for the sites where data were available, 51% of sites were stable, 29% deteriorating and 20% improving.

Distribution and population

Endemic to Australia and New Zealand. In Australia, the species occurs from Western Australia (Carnac Island, 32.1210° S, 115.6621° E) to New South Wales (Broughton Island 32.61580°S 152.31400°E). The distribution is not continuous, as breeding colonies are absent from some sections of the southern coast of Australia. In New Zealand, Little Penguin occurs from the Chatham Islands (New Zealand) to mainland New Zealand (including Stewart Island), but is absent from Fiordland and South Westland.

Ecology

The little penguin (Eudyptula minor), the smallest of all penguins (~30-40 cm), is endemic to southern Australia and New Zealand, breeding during the austral autumn to summer months. These dark indigo-blue coloured penguins are the only genuinely nocturnal penguin species on land; adults always arrive after dusk and leave before dawn (Klomp & Wooller 1991, Chiaradia et al. 2007, Rodríguez et al. 2016). The global population is estimated as 469,760 individuals. The little penguin population trend is stable overall with localised decrease in some sites. This species is a generalist feeder with significant variability in diet between colonies and even between years at the same colony (Klomp and Wooller 1988, Gales & Pemberton 1990, Cullen et al. 1992, Fraser and Lalas 2004, Chiaradia et al. 2010, Chiaradia et al. 2016). They feed mainly on clupeids such as anchovy Engraulis sp and sardines Sardinops sagax when feeding chicks but they may also feed on krill Nyctiphanes australis and several species of cephalopods at all stages of breeding (Gales & Pemberton 1990, Cullen et al. 1992, Chiaradia et al. 2016) and jellyfish (Cavallo et al. 2018). This variability in the diet is also found in their trophic interactions where penguins can reduce the prey trophic range in response to years of low breeding success (Chiaradia et al. 2010) and segregate foraging areas within the same colony (Sánchez et al. 2018). The species dives to a maximum 72 metres, with a preferred depth zone between 20 to 30 metres (Chiaradia et al. 2007, Ropert-Coudert et al. 2009)

Penguins typically lay two eggs per clutch (Stahel et al. 1987), and up to three clutches over a breeding season (Johannesen et al. 2003). The penguins exhibit six main breeding stages: courtship, pre-laying exodus, pre-laying, incubation, guard and post-guard (Chiaradia & Kerry 1999); followed by moulting and inter-breeding stages (Salton et al. 2015). When feeding chicks, some parents make more foraging trips than their mates. This situation represents the norm (72% of cases), rather than the previously expected equal parenting (Saraux et al. 2011). Individuals can also alternate between two consecutive long foraging trips and several shorter ones throughout the chick-rearing period (Saraux et al. 2011). Short trips allow for regular food provisioning of chicks (high feeding frequency and larger meals), whereas longer trips are triggered by a parent’s low body mass and therefore the need to replenish its energy reserves. Little penguins form groups when crossing the beach to nesting sites and individuals seem to choose their travelling partners (Daniel et al. 2007). When foraging,  some individuals can take advantage of human-made features, like ship channels to aid in their foraging (Preston et al. 2008). Breeding age, ranging from 2 to 18+ years, seems to play a crucial role as well, as middle-aged (8-12 years) penguins are better breeders (Nisbet & Dann 2009), employ more effective foraging strategies (Zimmer et al. 2011) and feed in different locations (Pelletier et al. 2014).

Threats

Many populations of little penguins are severely threatened by human disturbance such as introduced predators, domestic dogs, roadkill, coastal development, watercraft injuries, oil spills and gillnet fishing in both Australia and New Zealand (Cannel et al. 2016; Chiaradia 2013, Crawford et al. 2017, Dann 2013). Reduction in prey abundance is another major vulnerability to little penguin populations (Cannel et al. 2016; Chiaradia 2013) as well as natural predators such as fur seals and corvids (Ekanayake at al. 2015a,b). Changes in the abundance of major prey can result in a dramatic change in their diet composition and trophic interactions, resulting in increased mortality and decreased breeding success (Dann et al. 2000; Chiaradia et al. 2010).

A newer and additional challenge for this species is in the fast-changing marine and terrestrial environment, particularly in the rapidly warming sea of south-eastern Australia (Ramirez et al. 2017, Voice et al. 2006; Wu et al. 2012), wherein southwestern Australia the warming sea has been associated with poorer breeding (Cannell et al. 2012). Penguins have also been shown to catch less prey under warmer conditions (Carroll et al. 2016). Oceanographic change may lead to a mismatch between plankton and the small pelagic fish that are also penguin prey (Hinder et al. 2013).

Increasing terrestrial temperatures in the spring and summer months can cause fatal hyperthermia in both chicks and adults (Cannell et al. 2011, Cannell et al. 2012, Cannell et al. 2016). This issue is particularly relevant in those colonies where nesting occurs within the vegetation rather than in burrows as a result of a soft, sandy substrate.

Remarkably, some of these pressures can be locally offset by a wide range of conservation efforts, such as the case of increasing population size at Phillip Island (Sutherland & Dann 2012, 2014), St Kilda (Preston et al. 2010; Preston 2011), Manly (Carlile et al. 2015), Oamaru (Agnew et al. 2016).  Sites without active conservation measures have experienced a severe decrease, where many known breeding colonies no longer exist (Dann 1994; Stevenson & Woehler 2007, Wilson & Mattern 2019). Local extinction of many small colonies continues in Australia and New Zealand.

Conservation actions

Conservation Actions Underway
Little Penguin is fully protected in both Australia and New Zealand. The species is the subject of on-going Australian and New Zealand long term research programs, with research-lead conservation activities in several sites along the distribution. Several volunteer and research groups are actively monitoring and protecting sites in Australia and New Zealand, and there are extensive education programs, including the involvement of local schools and creation of educational resources for all West Coast schools in New Zealand. Various local media outlets report updates on penguin colonies and research, and puppet-shows and door-to-door canvassing is also carried out. The species occurs in many national and state parks, such as Penguin, Breaksea and Cheyne Islands and also in Shoalwater Island Marine Park, for which there is a Marine Park Management Plan. In New South Wales the species has 'Endangered Population Status' placing restrictions on landholder activities and development. An intensive rat baiting program is underway to control rats that have appeared on Penguin Island, and there is a weed eradication program on Breaksea Island for Zantedeschia aethiopica and Cotyledon obiculata. Artificial nestboxes are provided at many sites through the range and can greatly increase breeding success, with ongoing reserach into the optimal design. Successful translocations have taken place at Manly, New South Wales, and Phillip Island, Victoria. Ecotourism ventures are in place at several colonies in Australia and New Zealand.

Conservation Actions Proposed
Continue programs to control invasive fauna and flora species. Increase population survey and monitoring to assess causes of mortality and reduced breeding success in populations throughout the species range. Design and propose MPAs within foraging zone at key sites. Encourage more involvement of community groups and schools on local population awareness and protection. Determine sub-species and/or sub-populations under pressure and with decreasing population that need local protection and tailored conservation status.

Acknowledgements

Text account compilers
Martin, R., Chiaradia, A., Pearmain, L., Wilson, K.-J.

Contributors
Agnew, P., Cannell, B., Carlile, N., Carroll, G., Chiaradia, A., Colombelli-Négrel, D., Dann, P., Grosser, S., Holmberg, R., Houston, D., Mattern, T., O’Neill, L., Ramirez, F., Sutherland, D., Tennyson, A., Waugh, S., Wilson, K.-J. & Woehler, E.


Recommended citation
BirdLife International (2022) Species factsheet: Eudyptula minor. Downloaded from http://www.birdlife.org on 22/05/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 22/05/2022.