And now there are four....

It's been over a week since I last checked on the nesting pair of semipalmated plovers.  To my delight there are now four eggs in the nest.  According to The Birder's Handbook the incubation period is between 23-25 days.

I spent a few minutes observing and photographing the nest as both parents took turns at incubating their clutch.  Every so often they would switch while one flew to the marsh in search of food. 

I've also included an image of the plover ruffling its feathers as it was about to preen itself.