Eudyptula minor
little penguin

Eudyptula minor is found throughout the southern coast of Australia and as far north as the South Solitary Island off the coast of New South Wales. They are also native to the coasts of New Zealand. (Hoskins et al., 2008)

Eudyptula minor has six recognized subspecies. E. m. novaehollandia is geographically located in Australia. The other five subspecies, E. m. iredaei, E. m. variabilis, E. m. albosignata, E. m. minor, E. m. chathamensis, are distributed around the country of New Zealand. (Davis and Renner, 2003)

When on land, Eudyptula minor inhabits coastal habitats with good nesting conditions. Little penguins nest in burrows dug in bare sand or under vegetation. If the ground is too soft to hold a burrow, these penguins also nest in caves and rock crevices. Habitats include rocky coastline, savanna, scrub forest or forests. Little penguins are marine seabirds and spend the majority of their lives swimming underwater. (Ropert-Coudert, Kato, and Chiaradia, 2009)

As the smallest penguin in the world, this flightless bird stands at an average height of 30 cm and has a weight of 1.1 to 1.2 kg. It has a black bill with an average length of 35 mm and eyes ranging from silver to blue, grey, and hazel. Its chin and throat are white along with the underside of its flippers and torso. The top of the head, neck and dorsal side of its flippers and torso are an indigo-blue. The color of the penguin’s feathers can become duller with age, and the color of their undersides can range from white to gray to brown. Sexual dimorphism is not pronounced in this species. Males are larger and have longer and deeper bills than females. Males have an average bill length of 35.7 mm and an average bill depth of 15.4 mm. Females have an average bill length of 34.5 mm and an average depth of 14.1 mm. Flipper length is similar in both genders with an average of 117.5 mm.

Juveniles have a dorsal plumage that is a brighter light blue than the indigo-blue of the adults. The juveniles also have thinner and shorter beaks. (Davis and Renner, 2003; Overeem et al., 2008; Williams, 1995)

Little penguins live an average of 6 years. However a banded little penguin has been recaptured the age of 25 years and 8 months old. Data on the lifespan of the bird in captivity could not be found. ("Little Penguin and Eudyptula minor", 2009; Nisbet and Dann, 2009)

Eudyptula minor has over a dozen different aggressive behavior displays. These displays can ultimately be divided into 4 different categories including stationary warning displays, rapidly advancing towards the intruder, brief physical contact and physical attacks. All four behaviors include a different type of physical display and vocalization.

The stationary warning displays occurs when the threat is 1 to 3 m away from the penguin. The penguin spreads its flippers, holding its body erect and giving the intruder a direct look accompanied by a loud vocalization. When the penguin rapidly advances towards the intruder, it walks quickly or lunges towards the intruder with a bray-like call. Brief physical contact can range from touching bills to slapping the intruder with a flipper. If the penguin is in its burrow, it lunges out to peck the intruder with its bill. If the intruder does not retreat, penguins resort to physical attacks that include biting and beating with flippers. (Williams, 1995)

Little penguins are considered the most nocturnal penguins, but generally spend all day foraging at sea and return to land to roost at dusk. In the breeding season, penguins swim out only an average of 8 to 9 km from shore for about 12 to 18 hours at a time. These short trips are probably because chicks have a limited ability to thermoregulate and need to be fed constantly. During the non-breeding season, penguins can take long distance trips of up to 710 km, but in most cases they continue to stay within 20 km of shore. Little penguins have to use a greater amount of energy to dive into the water than larger penguins, and although they can dive up to 67 m in depth, they mostly remain within 5 m of the surface. When the penguins return to shore from the sea, they parade back to their nests in groups. In good breeding years, these penguins form these groups in a nonrandom fashion, seeking out the same individuals they paraded with in the morning to parade back with at dusk. (Daniel et al., 2007; Williams, 1995)

Home Range

Burrow nests are usually over 2 m apart in little penguin colonies. However, when the penguins nest in caves the nests are often closer than 2 m apart. (Williams, 1995)

Eudyptula minor is a nocturnal species and is highly vocal during the night while roosting. The sound of their calls can range from a low rumble to a trumpet-like noise. Their song can be used for several functions, including attracting mates. Each little penguin has a distinctive individual song that is used by parents and siblings to distinguish one another from strangers. Calls can also be used with an aggressive intent against an intruder around a penguin's nest.

Little penguins perform unique courtship displays. Males take a particular stance, with heads facing up and wings back, while braying to females. If the female accepts, she will join the male in a courtship "dance" where they march in circles together and make braying calls.

Like all birds, little penguins perceive their environments through visual, auditory, tactile and chemical stimuli. ("Little Penguin and Eudyptula minor", 2009; Jouventin and Aubin, 2000; Miyazaki and Waas, 2002; Nakagawa, Waas, and Miyazaki, 2001)

Eudyptula minor is mainly piscivorous and employs a pursuit-diving technique to catch prey in shallow depths. The majority of its diet is composed of Clupeiformes fish, such as anchovies and sardines. The variety of fish consumed depends on the locality of the penguin. This species also preys on small squid, octopi and crustaceans. It has been observed that in recent years the number of prey available is decreasing. This results in longer foraging trips for the penguin, greater energy expenditures, and can ultimately decrease population sizes. (Hoskins et al., 2008; Overeem et al., 2008; Williams, 1995)

Key predators of little penguins are introduced species. These include dogs, weasels, rats, foxes and cats. Pacific gulls and King's skinks are natural predators that eat the eggs and young of little penguins. In an effort to decrease predation, little penguins move in groups to and from the ocean. This anti-predator technique occurs a few hours before dawn and a few hours after dusk when it is dark. As penguins are less mobile on land, making mass land movements under the cover of darkness is likely another method used to avoid predation. Despite these techniques, adult little penguins often fall prey to sharks, seals, and orca whales. (Daniel et al., 2007; Overeem et al., 2008; Williams, 1995)

Eudyptula minor plays multiple roles in its ecosystem as a predator and a host to parasites. It preys on small fish, squids, octopi, or occasionally crustaceans and likely impacts these populations. Little penguin eggs and chicks are food sources to local populations of dogs, rats, cats, and other introduced predators. Adult little penguins fall prey to sharks, seals, and orca whales and are a valuable food source to these predators. (Hoskins et al., 2008; Williams, 1995)

In recent years, a new species of feather mite, Ingrassia eudyptula, has been discovered which is believed to parasitize Eudyptula minor. These mites eat preening oil on the feathers of the penguin. (Mironov and Proctor, 2008)

There are no known effects of little penguins on humans.

The penguin parade of the Eudyptula minor is a popular tourist attraction. It has been recorded that 500,000 tourists annually come to watch the colony of penguins parade to and from the water at Phillip Island. ("Little Penguin and Eudyptula minor", 2009; Overeem et al., 2008)

This specific species is also of great interest to scientists because of their small sizes and the increased amounts of energy needed to survive, especially in cold temperatures. This subject is important in the study of thermoregulation in endotherms, and the penguin's physical characteristics allow scientists to use this penguin in comparisons with other endotherms. (Fallow et al., 2009; Thomas and Fordyce, 2007)

Currently Eudyptula minor is not considered to be threatened by extinction. It is believed that the global population of these birds averages around 1,000,000 individuals. Their population is declining, however, due to introduced predators, decreasing populations of prey and oil spills. The intensity of industrial fisheries results in low prey densities for penguins and other piscivores. Factors such as human settlement, coastal erosion, and pollution have also affected the breeding habitats of these birds. (Davis and Renner, 2003; Overeem et al., 2008)

The subspecies E. m. albosignata is now considered endangered. It is only found on the Banks Peninsula on South Island, New Zealand. (Davis and Renner, 2003)