Thursday, July 4, 2013

Field identification of the three male Blue Flycatchers of Tawau Hills Park

The male of Bornean Blue Flycatcher Cyornis superbus, Mangrove Blue Flycatcher Cyornis rufigastra and Large-billed Blue Flycatcher Cyornis caerulatus are little blue flycatchers with blue upperparts and varying rufous orange underparts found along the trails of Tawau Hills Park. They are similar looking birds of about same size, which are confusing at first glance, but with more careful observations, they can be separated with ease.

The female of all three are distinct and unmistakable, if a pair is seen together, their ID should be readily confirmed.

The males, on the other hand, are a different story, they look puzzling at first but there are subtle features to tell them apart as described below.

Bornean Blue Flycatcher

The identification features of male Bornean Blue Flycatcher are lack of dark chin and a bright shiny turquoise blue down its mantle and back as indicated in the above image.

This species is endemic to Borneo.

Mangrove Blue Flycatcher

Though Tawau Hills Park is considered quite inland, and is lack of any mangrove trees, Mangrove Blue Flycatchers do occur here, see my earlier post here.

You can see that Mangrove Blue does have dark chin, contrary to the plate in Susan Myers, however, its mantle and back lacks the bright and shiny turquoise blue of the Bornean Blue. Its upperparts are also more uniformly colored.

Large-billed Blue Flycatcher

This image is courtesy of Kong Ket Leong

Large-billed Blue Flycatcher, on the other hand has relatively more saturated and extensive rufous orange underparts,  the legs look paler on birds that I have photographed.

It has more extensive dark chin than Mangrove Blue. Its back is dull blue in contrast to the darker mantle, whereas Mangrove Blue has the back uniformly colored with the mantle.

Large-billed Blue Flycatcher is only found on Borneo and Sumatra.

In Summary, the key to separate them is as follows:

1. If no dark chin = Bornean Blue Flycatcher.

2. If has dark chin

                    2A, back and mantle uniformly colored = Mangrove Blue Flycatcher.

                    2B, mantle dark and back dull blue = Large-billed Blue Flycatcher.

It is not that hard, is it?

Happy birding.

Photodocument of the wild birds of Borneo.

Standard References for my blog.