New birds in Sabangau: Suspicions and confirmations

Since Sabangau's birder-in-chief Marc Dragiewicz arrived around a week ago we have been out in the field nearly every day, eagerly trying to identify some new bird species that have recently been heard or seen in the area.

One particularly pleasing new identification is the violet cuckoo (Chysococcyx xanthorhynchus). In August I started noticing a repeated high-pitched whistle from above the canopy, and having consulted books and recordings, started to suspect it was a flight call of the violet cuckoo, a species that had only been seen once before by Marc D about five years ago. I was not content with this diagnosis without having seen the bird clearly, but two months later Marc at last found an adult male feeding in a mixed flock. With its iridescent violet sheen over the head, breast and wings, its zebra-striped belly, a deep orange bill and a red eye-ring, there was no mistaking this stunning bird, which treated us to clear views for a good five minutes. Two days later we saw two males from the weather tower, flying from treetop to treetop, doing both the flight call that I had been hearing previously and a beautiful trilled song.

Unfortunately not all species are so easily confirmed on sight. A few days ago I saw three frogmouths (a group of elusive, nocturnal, well-camouflaged birds from the family Podargidae) on a transect survey along the edge of the forest. I had a good view of a pair in some asam asam shrubs, and later managed to get to within a couple of metres of a rufous-coloured individual to produce a sketch on the back of my data sheet.. For all three birds I suspected Blyth's frogmouth (Batrachostomus affinis), a species not yet confirmed in Sabangau, but frogmouths are notoriously difficult to identify on sight alone due to their wide variation in colouring and feather patterns. However, Marc and I have been investigating a loud, descending series of whistles (possible frogmouth calls) that we have been hearing shortly after 4am every morning, and we are hopeful that a local expert will be able to identify them.

Other birds that have not yet graced me with quite a good enough view/song to identify with confidence include:

• Plain sunbird (Anthreptes simplex) - have previously been seen by a canal on the adjacent Megarice site. We have seen drab-coloured birds in Sabangau, but as yet have been unable to see the male’s iridescent forehead patch.
• Brown-backed needletail (Hirundapus giganticus) - a bird resembling this huge swift shot past us in the tower on Thursday evening. Clearer view with diagnostic features in mind needed next time!
• Snipe (Gallinago sp.) - a single bird recently flew over me while surveying in the deforested sedge area. The likely candidates are pintail snipe (Gallinago stenura) and Swinhoe's snipe (Gallinago megala), however these are among the world's hardest species to separate in the field so, whether or not I see it again, I may be forced to leave this wintering wader at genus level.
• Sooty-capped babbler (Malacopteron affine) - has been seen in a neighbouring forest and had one unconfirmed record in Sabangau. As with the plain sunbird, a clear view of the cap is needed, in this case to separate it from the closely related rufous-crowned babbler (Malacopteron magnum) and scaly-crowned babbler (Malacopteron cinereum).

Thankfully not all new species to Sabangau involve so much effort to confirm, as Marc and I were happy to discover when a juvenile tiger shrike (Lanius tigrinus) turned up in a tree above the camp kitchen just as we returned from a survey. This migrant may be hanging around for the whole of the northern winter as we saw it again in the same place several days later. I just wish all birding were so convenient!

Sampai jumpa,

Nick Boyd