The Wiskered Tern (Chlidonias hybridus),
aka Marsh Tern, is found in Africa, Europe, Asia and Australia. There are three
sub species hybridus (Eurasia), delandi (Africa) and javanicus (Australia).
Adult Whiskered Tern in breeding plumage - note full black cap, red bill and legs and the dark grey under parts. |
Adult bird - Whiskered Terns have a slight V in tail only visible when the tail is closed. |
The Whiskered Tern is widespread across
Australia during the non breeding season and a rare vagrant to Tasmania. It
breeds erratically according to seasonal conditions, but generally from
September to December, in southeastern Australia.
The Whiskered Tern frequents inland waters.
It is not a marine species, however it can sometimes be found in estuaries and
wetlands near the coast, such as the Gippsland Lakes, particularly the adjacent
wetlands. A gregarious species, these terns feed, roost, travel and nest together,
mostly in small flocks, however occasionally large flocks containing a thousand
or more birds are encountered. They are certainly a nomadic species however
some are thought to be migratory moving from the Top End to Indonesia and Asia
and back again.
In East Gippsland, we see small parties of
Whiskered Terns over our wetlands from time to time. This year we are seeing
more flocks than normal and larger flocks. Conditions in East Gippsland are
generally good this spring with plenty of water in our wetlands. Inland
Australia is drying out following a run of wet years when many water birds took
advantage of the favourable conditions to breed up. So perhaps it is not
surprising that we are now seeing larger than normal numbers of Whiskered Terns
in suitable near coastal habitats as many species head for the coast when
inland Australia dries out.
I discovered a larger than normal flock of
Whiskered Terns on Wednesday the 6th of November near Hollands
Landing, a very small fishing hamlet on McLennans Straits at the western end of
Lake Victoria. Returning from a Gippsland Lakes Important Bird Area (GLIBA)
survey in the Sale area I decided to detour in to Hollands Landing to check out
the birds there – it is a good location for water and shore birds, including
migratory wader species.
From Bengworden Road, a back road between
Sale and Bairnsdale, driving along Hollands Landing Road I came across a large
number of white birds flying low over the flat sheep and cattle paddocks. It soon became obvious they were Whiskered
Terns, well over a 1,000 birds, and they were coursing low over the paddocks.
From time to time birds would dive into the long grass. They were clearly
feeding. For me this was odd as I had always seen them feeding over water in
the past. Like all terns their diet consists mainly of small fish taken by
diving into water. Checking some field guides and other reference books later I
found that feeding over dry land was not mentioned so I assume this behavior is
at least a little unusual.
The bird in the lower foreground has just caught an insect on the ground - see next shot. |
Note the small food item in this bird's bill. |
In this shot a bird's wings are just visible above the top of the long grass. |
It was a marvelous spectacle to stand by the
side of the road and watch such a large number of birds in action. In every
direction I looked I could see terns over the adjacent paddocks. As they
coursed around and back and forth over the paddocks, they alternated between
dispersal to chase food and aggregating into strung out flocks. They seemed to
randomly follow a leader for a short while and then the flocks would break up
again and birds would spread out over a paddock and look for insects in the
head down position typical of all terns.
As I watched them and took the opportunity
to take some photos now and again as random chance brought some of them close
enough for photos, the landowner, out checking his stock on a motor bike, came
over for a chat. He was interested to know what species of bird they were, as
he had not seen them before. He said they had turned up two days earlier (the 4th).
The birds were still feeding over the same
paddocks 14 days latter on the 18th of November when a group from Birdlife
East Gippsland visited Hollands Landing as a regular Monday outing and to
conduct three GLIBA surveys there. The farmer mentioned above has had a
valuable service performed by these birds as a thousand birds or more must have
converted a lot of pasture eating insects into fertiliser over the 14 days.
Many of the birds were in breeding plumage
with black caps, red bills and feet and dark grey under parts. When in non-breeding
condition the under parts are white, the forehead white and the bill and feet
are blackish.
I wonder if these birds have recently bred
or are going to breed? Perhaps the latter as there did not look to be any
juvenile birds in the flock – it is not that easy to pick as adult birds in
non-breeding plumage look similar to juveniles?
An adult in non-breeding plumage. |
How wonderful to see such a large flock. They are "regulars" at Werribee at this time of the year and great to watch as they catch items over and in the ponds.
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