Common Greenshank and Marsh Sandpiper
Sometimes you will find that some birds might resemble another bird species based on its photo images. One of those bird species which may caught you off guard if not for closer observation is the similarity between Common Greenshank (Tringa nebularia) and Marsh Sandpiper (Tringa stagnatilis). How close are their similarities? - have a look at the photo below:
For an expert who is familiar with the differences between the two bird species, he/she could have easily identify the Marsh Sandpiper and the Common Greenshank from the above photo. According to Dave Bakewell, "Marsh Sandpiper is rarely mistaken for a Common Greenshank. It is usually the other way around when a Common Greenshank contrives to make itself look thinner and more elegant than usual"
I was lucky recently to be able to watch the two bird species close to each other on the mudflats. For a start i will first show you the photos of some Common Greenshank.
A trio of Common Greenshank
which was later joined by a Little Egret
Now here are some photos of the Marsh Sandpiper.
A Marsh Sandpiper strolling beside a Common Greenshank
From the first photo of the Marsh Sandpiper above, you could clearly see that its size is smaller than a Common Greenshank. You could have also noticed that its bill is thinner than a Common Greenshank. If you are in the mudflats quite often you will also noticed that the Marsh Sandpiper's movement is quicker than a Common Greenshank. In addition i have also observed that when they (the Marsh Sandpipers) are wading for food in the mudflats they tend to move their bill from side to side.
So as you can see, photography can play the role of both educating as well as confusing people but like most experts would advise you, the best way to observe/study the birds is to look at them in the field or rather in the mudflats in this case.