MARGARET
STANSFIELD
A COMMON waterbird on King Island is the Purple Swamphen, which also inhabits outlying islands including Lord Howe and Norfolk Islands.
Our friends in New Zealand call it the Pukeko, but the classification is the same, belonging to the rail family along with crakes and coots.
They were mentioned by McGarvie and Green as plentiful in 1971 in the north of the island, though interestingly, they were not listed by the Victorian Field Naturalists expedition led by Archibald Campbell in 1887.
The Purple Swamphen is a large water hen with a distinctive heavy red bill and forehead shield. They have red eyes and a deep blue head and breast with black upperparts and wings.
In bright sunlight, the plumage shines with an intense blue sheen. Legs and feet are deep orange and as it walks it flicks its tail revealing its white coverts. Both male and female are similar in appearance and their voice is often a loud, harsh screeching which increases as the call progresses, often at night.
On King Island, the predominant habitat is wet areas where there is plenty of vegetation such as paperbark ti-tree, rushes, around farm dams, fresh, brackish and saline creek lines and swampy areas. Roost sites are often in vegetation over water. They frequent road verges near drains where the grass is lush and where they can quickly hide in the undergrowth if threatened. Today, vegetation clearing is the greatest threat to these birds, especially when swampy land is over-drained.
Nests are often in the tops of rushes where the birds trample them to just above water level. A secure platform is made with slender and finer rushes to provide safety for the eggs and chicks. The female usually lays five eggs between July and January and sometimes rears two broods. Living in family groups, responsibilities like feeding the chicks and chasing any predators away is a combined task. When disturbed these birds run or fly with their legs and large toes trailing, though they can also swim.
The Purple Swamphen is an omnivore which means eating a wide variety of aquatic vegetation, plants, seeds, insects and small animals including frogs. I have also observed them taking eggs and other young birds such as ducklings.
When the Agricultural Bank of Tasmania commenced full-scale land clearing after World War 2 for the Pegarah Estate Soldier Settlement Scheme, many unforeseen problems emerged as new pasture was sown.
One was the presence of a host of insects that ate the pastures. To eradicate them, the landowners were encouraged by the Agricultural Bank to broadcast Lindane with their fertiliser to eradicate the insects.
Lindane is an organochlorine used as an agricultural insecticide.
The unwanted side effect was that it killed many birds who survived their habitat destruction, but then lost the food resources they depended on.
Birds mostly affected were the small bush birds and birds who mainly forage on insects and feed among leaf litter along drains and creeks.
The Purple Swamphen was among these victims. Fortunately, with many creeks and dams being fenced off, it has given these birds the opportunity to survive, and you will see them in many parts of the island.
As for my previous endings let me reiterate ‘This is a warning of the consequences of indiscriminate land clearing’.