Like the ebb and flow of the tides, the coming and going of the seasons, birds are in constant movement.
We know of the great migrations and the migration routes which criss-cross the world but even birds which appear at first glance sedentary and resident in a specific area are often moving from one location to another. The latest news from the bird world in Tasmania is that coots are on the march.
A reader wrote late last year to say he had noticed coots – members of the rail and moorhen family – turning up in wet places he had never seen them before and I remembered visiting a spot on the Browns River in Kingston at the urging of another reader several years ago to confirm the first sighting of coots there.
At that time I was just about to depart on holiday to Britain and, after watching coots in London’s Crystal Palace Park, I returned home in the spring of 2011 to find that coots had arrived at my local birdwatching spot, the Waterworks Reserve, south of city.
Over the last four years coots have also bred there for the first time, rearing fluffy black chicks which, like the young of lapwings and native-hens, have to avoid the predations of brown goshawks.
A call to Eric Woehler, the president of BirdLife Tasmania, confirms that coot numbers are indeed on the increase. When he checked the group’s extensive records – some of which go back 50 years – he found that these waterbirds had steadily increased in number in recent years.
The reason for the coot “explosion”, as some describe it, isn’t yet fully understood. Numbers of some species of duck have also increased in recent years but this is largely put down to drought on the mainland and wildfowl crossing Bass Strait in search of lakes and rivers with water actually in them, although drought has afflicted Tasmania this summer.
It is more likely that small numbers of coots have simply found their way into waters they have not inhabited before and have found conditions there to their liking. This can happen sometimes, without explanation.
Coots may be members of the rail family but they behave more like ducks than their other kin, which includes Tasmania’s endemic native-hen. The coots, which carry a jet-black plumage, a white face disc and red eye, are more likely to be seen in open water, where they dive to feed on aquatic vegetation on the river or lake floor.
Two other members of the family found in Tasmania include the dusky moorhen and the purple swamphen, the latter a striking and colourful bird which gives a clue to the great diversity in size and colour of this extensive family. The family also includes the tiny crakes which hide in reedbeds.
The coot, somewhat comical in appearance on land where it always appears to waddle on long legs in a seemingly uncomfortable manner, might not be spectacular but it is a welcome addition to the wildlife of urban parks and reserves where it is increasingly turning up.