Penguin Centre | Breeding Program | Little Penguins pdf

Scientific Name: Eudyptula minor
Accepted Common Name: Little Penguin
Other Common Names: Blue Penguin, Fairy Penguin, Little Blue Penguin (NZ)
Granite Island Population: Approximately 700 individuals

Distribution:
Found only in Australia and New Zealand. The breeding range extends from Fremantle in Western Australia, right across the Southern Coastline of the continent including Tasmania, and up the New South Wales coastline, nearly as far as Sydney.

Habitat:
Favour rocky shorelines, which provide suitable breeding sites, Mainly inhabit scattered offshore islands, like Granite Island, where they are generally free from disturbance.

Burrrow Distribution on Granite Island:
The less developed southern side of the Island accommodates the majority of the Islands penguins, however a number of active burrows exist on the northern side. Figure 1 shows the distribution of burrows on the Island, as at 1991 | TOP

Description:
Little penguins are the only penguin species known to breed in Australia. They stand approximately 35cm and weigh about 1.2kg. When compared to their Antarctic cousins, (the Emperor Penguin), who stands approximately 110cm and can weigh over 30kg, it is easy to understand why Little Penguins are the worlds’ smallest penguin species.

Daily Activity:
Due to their lack of movement on land during the day the penguins are often mistakenly thought to be nocturnal. However they actually leave Granite Island before dawn to begin their days fishing, and return to the Island after dusk, to rest. Apart from during the breeding and moulting seasons and the occasional “rest day”, this daily pattern continues year round.

Diet and Feeding:
Major food items are small schooling fish (76%), squid (24%), and occasionally krill (small shrimps, 1%). The penguin feeds only in surface waters as they are not deep divers, The tip of the beak is hooked and edges very sharp to firmly grasp the prey. The tongue and roof of the mouth are covered with stiff backward-pointing spines which help the penguin swallow its’ prey | TOP

Adults:
Adult penguins have about 10,000 steel blue downy feather, This is about three to four times the feather density of flighted birds, which is necessary to provide insulation from the cool waters, It is often difficult to tell male and female penguins apart, however generally males beaks are longer and heavier than females.

Juveniles:
Hatchlings are first covered in black down, however, at 8-14 days of age this is replaced by chocolate brown down, The brown down is moulted and replaced with adult feathers at 29-56 days. Following this the penguin is independent from its’ parents, and will leave the colony and may not return fro 12 months or more.

Breeding Cycle:
Burrow construction usually begins in April/May and again in August/September, and is undertaken by the males who seek to impress the females with their burrows. The female chooses the burrow she likes best, and that male will mate with her for the year. Breeding success is largely determined by food availability | TOP

Eggs:
A clutch of two eggs is laid in winter or spring, two or three days apart, Incubation time is 36 days with male and female penguins taking shifts to incubate the eggs. Hatching success is approximately 60%, however in a good season three clutches of eggs may be laid.

Moulting:
All adults moult at the end of the breeding season (Mid-late summer). Over a period of about two or three weeks, all the feathers are shed and replaced with new ones. During moult penguins are particularly vulnerable, as they are unable to leave their burrows because their feathers are not yet waterproofed. The penguins loose about 50% of their body weight during this time. It should be noted that this high risk penguin season coincides with the summer holidays, when large numbers of tourists visit the Island.

Territories:
During breeding season, males defend a small space around their burrow, and will fight off intruders by locking beaks and hitting each other with their flippers | TOP

Sight and Hearing:
Penguins have excellent vision both in and out of the water, day and night. They depend on their vision to locate prey. A ‘third eye-lid’ protects the eyes underwater, and on land is used as a ‘windscreen wiper’ to clear sand from the eyes. Penguin hearing is also very good, but is better in the water, due waters physical properties.

Voice and Sound:
Penguin calls are complex and serve many purposes such as attracting mates, aggression, pair communication, danger and location. Often the Granite Island penguin calls can be heard from halfway across the causeway.

Sleep:
Penguins only sleep for four minutes at a time, either standing up or lying down | TOP

Diving:
A penguin dive lasts for approximately 24 seconds, and reaches depths of 5-20 metres. The maximum dive depth is approximately 60 metres. Penguins literally fly underwater, using the same motion as a conventional flight bird.

Preditation:
Natural predators of penguins include sea eagles, fur seals, goannas and snakes. Introduced predators such as dogs, foxes and cats can significantly reduce numbers. Preditation by rats, cats, foxes and dogs, as well as disturbance by humans, are the major threats to the Granite Island penguin colony. When you consider that nearby West Island, (which is about one third of the size of Granite Island), accommodates approximately 2000 Little Penguins, it becomes questionable whether the available habitat on Granite Island is becoming unfavourable to the penguins, due to the pressures of preditation by feral animals and disturbance by humans | TOP