Curlew

The curlew is Numenius, a bird with a long downcurved bill (beak). With its beak the bird probes mudflats for food. 
In pre-modern times the world had many more mudflats than it does today. Many have been eliminated by draining so as to give more land for farming. So, in England, the places suitable for the bird were in river estuaries and low-lying land. Originally, southern England had wide areas of mudflats suitable for the bird.
What changed was the draining of the "levels" to make for better farming. In England areas in East Anglia, Kent and Somerset were all drained and made productive farmland. A similar process happened in many countries. The consequence is that the curlews' numbers have dropped and the bird has become rare in places where it was once common.
Broadly speaking, curlews are waders, as are the godwits which look similar but have straight bills.
Most curlews migrate and so one or more species occur at different times of the year in Europe, Ireland, Britain, Iberia, Iceland, Africa, Southeast Asia, Siberia, North America, South America and Australasia. There are nine species of curlew.