Oystercatchers in buttercups and bill-tip clines
![Oystercatcher - The Hall of Einar - photograph (c) David Bailey (not the)](https://www.thehallofeinar.com/wp-content/uploads/2022/07/Oystercatcher-The-Hall-of-Einar-12-725x483.jpg)
Eurasian Oystercatchers are loud in volume and loud in plumage. There are no words for skulking, camouflage or whisper in the Oystercatcher’s vocabulary. They have a completely different method of maintaining themselves and prospering from the Eurasian Curlew with which they are sharing this buttercup field.
![Oystercatcher - The Hall of Einar - photograph (c) David Bailey (not the)](https://www.thehallofeinar.com/wp-content/uploads/2022/07/Oystercatcher-The-Hall-of-Einar-9-725x483.jpg)
Oystercatchers are widespread birds. They occur in Western Europe as well as China and Korea. Across that huge distance they show an interesting feature; there’s a subtle change in their bill from west to east (or east to west depending upon your origin). Some Oystercatchers have broad-tipped bills and use them to prise open molluscs or hammer through the shell. while some have pointed-bills and dig up worms. Individual birds specialise in one technique or the other and they learn the feeding method from their parents.
![Oystercatcher - The Hall of Einar - photograph (c) David Bailey (not the)](https://www.thehallofeinar.com/wp-content/uploads/2022/07/Oystercatcher-The-Hall-of-Einar-2-725x483.jpg)
There’s a change in the bill and in the feeding method across the Oystercatcher’s population. This kind of a geographical gradient of features is called a cline. It’s a bill cline.
![Oystercatcher - The Hall of Einar - photograph (c) David Bailey (not the)](https://www.thehallofeinar.com/wp-content/uploads/2022/07/Oystercatcher-The-Hall-of-Einar-4-725x484.jpg)
If only it would stop shouting at me I would be able to think how cool that is.