April 2024

Back in France now to work on our conservation project there. We were delighted to see thousands of Eurasian cranes (Grus grus) flying over our place on migration mainly from Iberia and North Africa. Cranes fly in V-shaped formation in groups of up to c. 500 birds, making memorable and fluty croaking calls, often heard before the birds come into sight. When setting off, cranes will often find thermals, rising currents of warm air on which they spiral to an altitude of up to ten thousand metres, before flying north to their breeding grounds. Cranes are closely related to coots (Fulica atra) and moorhens (Gallinula chloropus), both common British breeding birds. When you hear these birds call it is understandable that all 3 species are related with similar complex vocal apparatus. However, their external body forms are of course quite different. All three are wetland birds in the taxonomic order of Gruiformes (crane-like birds). The French word for crane is grue, also true for mechanical cranes.

Cranes breed across Northern Eurasia, with small numbers in Norfolk and Somerset. Their main breeding range includes Scandinavia, Siberia, Mongolia and Northern China. Cranes spend winter in the sub-tropics of NW and NE Africa, parts of Iberia, Northern India and SE Asia. The experience of thousands of cranes flying on migration is one of the most moving and spectacular phenomena of the bird world. Many East African wintering cranes migrate via Israel. Autumn migration south is from August to October, and then north to breed from February to early March. Cranes are omnivorous foragers, eating a wide range of food from roots and seeds to small mammals and birds. They particularly like maize and frogs. Small numbers of cranes over-winter on a maize farm c. 40 km from our place in Aquitaine where they glean un-harvested seeds. Cranes are well known for their courtship dances with much strutting and head bobbing. Cranes pair for life, but if one dies, the other may repair with a new partner. The normal annual clutch is 2 blotchy brown eggs taking about 30 days to incubate before hatching. Crane eggs are often preyed upon by members of the crow family and foxes among others, but adults put up a strong defence. Removed eggs are often replaced within a few weeks. The precocial hatchlings develop rapidly, running around with their parents and swimming within about 24 hours. Breeding begins at the age of 3-6 years and life expectancy is up to 30 to 40 years, but in practice, most wild cranes are thought to live from just 5 – 12 years.