Little Pied Cormorant drying its wings at Coombs Pond. Its yellow stubby bill is distinctive. Photo: Ian Fraser.
There are not many water bodies in Australia, including Canberra, where you can visit and not see a cormorant or several.
There are five species in Australia (four of which are found in Canberra), found right around the coast and out to sea, as well as inland in rivers, lakes, swamps, farm dams and urban ponds.
The smallest, the Little Pied Cormorant, is less than 60 cm long and weighs less than 1 kg while the largest, the Great Cormorant, can be 1 m long and weigh 3.5 kg.
They hunt fish underwater, but depending on their size they also take yabbies, shrimps, insect larvae, worms, tadpoles, frogs and even small snakes and turtles.
Cormorants hunt by actively chasing prey underwater; consider for a moment the difficulties of trying to catch a fish with your mouth!
They have several adaptations which help them in this skill and fortunately they spend a lot of time just standing still on branches or banks with their wings out, which enables us to have a good look at them.
Firstly, the wing-drying is itself a strong clue. Ducks also live in water of course, but we never see them drip-drying. This is because they don’t get wet – no, really! If you can get close to a duck in the water you can see the water drops rolling off the feathers, which are heavily oiled and so waterproofed.
But ducks spend most of their time on the surface, not beneath it. Cormorants spend the most important time of their lives under the water, but oils are lighter than water so a bird with oily feathers has to work a lot harder to stay submerged.
In this situation it would actually be disadvantageous to have waterproof feathers and being waterlogged helps a cormorant to stay down.
However, this means that they must also spend a lot of time hanging their wings out to dry, but since fish is high energy food and cormorants can get their daily energy requirements fairly easily, this isn’t a problem.
Another difference between cormorants and ducks is in their feet. Ducks and some other waterbirds such as gulls have membranes between their three front toes to make a swimming “flipper”.
Pied Cormorant at Jervis Bay. Unlike the more locally common Little Pied Cormorant, it has a long bone-coloured bill and black “trousers”. Photo: Ian Fraser.
However, cormorants (and some other groups such as darters, pelicans and gannets) have taken this a step further. A cormorant’s fourth toe has moved from the back to the front and the webbing has extended to this one too, so that they have even more efficient swimming feet.
Like many other swimming birds, a cormorant’s feet are way back on the body, operating a bit like a propellor at the very end of a boat. However, this also means that they are awkward on land, and are really quite rubbishy at walking. Nature is full of trade-offs.
Birds long ago dispensed with heavy teeth and associated muscles to assist with flying by shedding weight. But smooth bills aren’t much good for catching and holding fish, which are notoriously slippery, so cormorants have a sharp hook at the bill tip to assist in this.
Cormorants (some 40 species of them) are found throughout the world. In Europe the Romans named the same species as our Great Cormorant corvus marinus, the “sea crow”, which in time was anglicised as cormorant. Most cormorants (and all Australian species) are either black or black-and-white.
Little Black Cormorant drying wings by Lake Burley Griffin. It has a dark bill and no yellow on the face. Photo: Ian Fraser.
Locally the Great is the most common cormorant, along with the Little Pied.
Both are found from the coast to the far inland, depending on the rains. Little Pied Cormorants can be found on any small farm dam in the country.
Little Black Cormorants are also regularly seen here, they are glossier black than the dusty-black Great Cormorant.
Unlike the Great Cormorant, Little Blacks also have dark bills and bright blue eyes and no yellow on the face. The Pied Cormorant is of course larger than the Little Pied, with a slim pale bill, unlike the Little Pied’s stubby bright yellow one. It is uncommon in the ACT, though some tend to hang around the Kingston waterfront.
All nest in colonies, including some along the Molonglo above Lake Burley Griffin. They often fish in flocks and Little Black Cormorants in particular often combine with pelicans to take the fish that the pelicans miss.
Next time you take a walk around any of the Canberra lakes, keep your eyes open for cormorants, either on the water or perched with their wings out to dry. I’d be surprised if you don’t see some.
