White-Winged Tern (Chlidonias Leucopterus)

It has been well written that the identification between Whiskered Terns (Ch. hybridus) and White-Winged Terns (Ch. Leucopterus) during winter/outside its breeding season has been a major headache to the recreational birders / lay people. In fact some articles to some extent has declared that the differences between the two terns species are almost inseparable in the field during winter. Numerous research/articles have thus been written seeking reliable markers/identification patterns/plumages of juvenile, first winter and adult winter birds but the conclusions have always been somewhat inconsistent. For example it was reported that Whiskered Terns have longer bill as compared to White-Winged terns but that was only true for males as females Whiskered Terns were reported to have similar shorter and stockier bill as White Winged Terns. Similarly White-Winged Terns are also reported to retain some black patches/feathers on its body side while molting from breeding to winter plumages. Then the body length of a Whiskered Tern was reportedly to be just about 2cm longer than a White-Winged Tern!

So then how does a lay-person able to differentiate or at least identify them in the field? There are two possible easy identification areas which you could use to identify between Whiskered terns and White-Winged Terns. The two field marks which you can look out for are i) its head patterns and ii) the feather colors near its body areas. The previous post has shown the photos of the Whiskered Terns so this time it will be the White-Winged Tern (Ch. Leucopterus).

In the head pattern of a White-Winged tern, the black patch behind it eyes should be round, the rounder the patch the more conclusive it would be. The black patch would then link to its black crown (with some white flecks in juvenile) forming like a pair of head phones. The second thing is that the body side of a Whiskered Tern has more black smudges than a White-Winged tern. Here are some of the possible photos of White-Winged Terns.

A flock of incoming White-Winged terns.

Here are more recent photos (Feb 2015) below:

Here are some of the photos of terns which i think could also possibly be a White-Winged Tern or is it really? Have a look and you can decide for yourself.

Note: Juvenile Whiskered Terns apparently also "wears" a headphone !

Whatever stuff which have been mentioned here only provided you with some basic pointers as reference. To be thorough there are other jizz which you can compare and observe - for example its wing colors, rump, tail, flight patterns etc. An expert once told me that to learn and obtain a better understanding of the jizz of these terns, one just need to go out to the field and study them thoroughly. 

HAVE FUN !

Whiskered Tern (Chlidonias hybridus)

This is a continuation from my earlier audacious attempt to show the photos of the four most commonly seen terns in Peninsular Malaysia. This time it will be "Whiskered Tern" (C.h hybridus). Said to be one of the largest marsh tern measuring approximately between 25 - 29 cm (10in - 12in). Also known as river terns in some books.

At a certain angle you may think that it could be a common tern. However the bill of a Whiskered Tern was reportedly to be a bit shorter and stubbier. 

It has a black patch and a scally/streaked cap at its hind crown as compared to a common tern. Looks like it also has shorter and broader wings. Its body length also looks a fraction less than a common tern.

The bird above had just undergone molting - probably into its first winter plumage. This is the only tern i think which has black smudges on its body. 

You can see that its tail is rather short and less forked as compared to the Common Terns.

Like all terns it would constantly look down to the waters for food. However it was reported that this tern does not do plunge diving but instead it would prefer to pick its food from the surface of the water.

Now you would know why this tern was also called a river tern. I have observed that there were other terns which would also "scout" for food along the river for example the white-winged and little terns. They however do not travel further up river as the whiskered terns. (more observations are required to confirm this statement).

Occasionally you do find them resting in the sea or on mudflats.

Dive bombing for fish?

You can see the slightly notched tail and a greyish rump.

Here are more recent photos - Feb 2015 below:

Check out its 'balding' head like pattern in the above photos. A common feature of a Whiskered Tern.

IUCN status: "least concern" and its population was reported to be "stable" as of now.

Enjoy Watching Your Terns!