Portland Gannet Colony

The Australasian Gannet is very similar in appearance to the cape gannet, a large seafaring bird that nests in large colonies on coastal islands off Victoria, Tasmania and New Zealand.

The primary breeding colony in Victoria is located at Lawrence rocks just 2 kilometres off the coast at Portland, to the naked eye Lawrence rocks looks to be a large white rock, however take a closer look and you will see that every available space on this massive island is occupied by nesting gannet’s.

Overcrowding on Lawrence rocks led to the establishment of a breeding colony at Point Danger on the mainland in 1996, The only mainland-breeding colony in Australia, like any early settlers in a new land things were not going to be easy. Point Danger had a lot of human traffic being part of a 250-kilometre great southwest walking track and for many years you could walk within feet of the nesting gannets. (No birds fledged that first year)

In 2006 500 birds fledged, 2007 saw a complete failure with not a single bird fledging mainly due to fox predation. The department of sustainability and environment acted swiftly, enclosing the colony within electric vermin proof fences and in the process cutting off access to the site.

Next came a surprise two 5-month-old Italian maremma guard dogs to protect the gannets from exotic predators, after a brief settling in period during which there were some teething problems (The dogs tasted a few gannet eggs and went missing occasionally) things rapidly improved, since December 2007 no Gannets or eggs have been lost to predators.  To my knowledge one of only two cases in the word were dogs are used to protect wildlife.

The male and female are similar in plumage with most of the body being white with dark feathers in the wingtips and inner tail feathers. The head is an orangey yellow colour with a pale blue grey bill. The eye has a striking blue surround. Immature birds are primarily a mottled black/white grey.

The breeding season begins in November/ December with the female producing a single blue/white egg.  The nest is on the ground and built from dirt, Guano and seaweed. Incubation time is around 40+ days, with chicks usually present in the colony shortly after Christmas (No access is allowed to the site until the chicks have hatched), Once hatched both the Male and Female take turns minding the chick whilst the other goes off in search food (Pilchards – a small fish that is abundant in the area). The colony is densely packed, should both parents be away at the same time, their chick is likely to be attacked by other Adult birds and if driven from the nest, the chick will be attacked by one and all until it is driven to the outskirts of the colony, Its survival dependant on locating its parents.

The chick will spend approximately 100 days at the nest before fledging, when they tend to migrate west from where they were born. They reach sexual maturity in 6 or 7 years and return to their birthplace to breed.

A 10-year chick-banding program has provided great insight into the migratory patterns of these birds, with one youngster turning up in Madagascar, 27 days after being banded, a trip of some 7,000 kilometres. Australasian Gannets have also been recorded at each of the three breeding colonies of Cape Gannets in Africa.

The colony continues to grow stronger with more birds nesting and fledging every year, Access to the colony is still restricted by the electric fence and the guard dogs continue to do a fantastic job.