The Return of Long-billed Curlews and Rhyncokinesis

Each day for the past several weeks while on our way out to the island either Mia or I will say to the other “I wonder if we’ll see or hear the curlews this morning”.  For both of us the return of the curlews is a sure sign that true spring has finally arrived.  And each morning we’ve been disappointed.

Until yesterday!  We first heard them while waiting for some magpies to return to their nest and then looked up and saw several flying toward us.

 

1/2500, f/6.3, ISO 500, 500 f/4

This bird is one of them – a truly unremarkable photograph except for its significance to us.  It’s almost like this bird (and its companion) were flying over us to personally announce their return to us.  The curlews are back – finally!

 

 

 1/1600, f/7.1, ISO 500, 500 f/4, 1.4 tc

 It wasn’t long before we were able to find several curlews foraging on the ground and they even let us  get close.  This one is busy preening in the morning sun.

 

 

 1/1600, f/7.1, ISO 500, 500 f/4, 1.4 tc

Rhyncokinesis (rhynco – upper beak or bill, kinesis – movement or motion) is the ability of some birds to bend or flex their upper bill.  Only cranes, shorebirds, swifts and hummingbirds are known to be capable of doing so.  The bill is made of a protein called keratin (like hair or fingernails) and it’s quite a remarkable feat to be able to control its shape to some degree.  Notice in the photo above that the shapes of the upper and lower bills normally conform perfectly to each other, though the upper is noticeably longer than the lower.

 

 1/1600, f/7.1, ISO 500, 500 f/4, 1.4 tc

But in this shot (the very next frame after the previous photo) the upper bill has been “bent” into a much straighter shape and no longer conforms to the curve of the lower bill.  This only lasted for an instant and in the next shot in the burst the shape had returned to “normal”.   The upper bill can also be flexed in the opposite direction, making its shape more curved than normal which means the two bills would touch only in front and back, leaving a gap in the middle.  The advantage of rhyncokinesis is obvious for shorebirds who use their bills for probing for food in mud, dirt and sand but the adaptive advantage for birds who don’t probe for food is not fully understood.

I love catching this kind of “stuff” in my photographs.  There’s always an interesting surprise or two to be found “out there” if you take lots of shots and are observant enough before you hit the delete key.

Ron