One of the greatest of natural sights in France and other places in Europe including parts of Southern England happens twice every year. Heralding the onset of spring and the colder weather of autumn it is a source of great excitement amongst local residents and we get very excited as we anticipate when and where it is going to happen. In a mildly competitive way we all want to be the first to catch the beginning of the event, taking great pleasure in telling friends and neighbours what they have seen. It starts an almost infectious habit of rubber necking or craning, (excuse the pun), of necks to spot them. News of sightings travels fast here in the Charente. Yet, its timing means that many holiday visitors to France will never witness the sight of what must be one of nature’s most incredible spectacles.
The Grus Grus Migrations
It is the migration of Eurasian Cranes, (Grus Grus or common cranes), arriving from, or leaving to go, to their breeding grounds. Flying in huge flocks of hundreds, or often thousands, in ever widening V-shape formations. These are the largest birds in Europe with wingspans of up to 2 metres and weighing in at a meaty 4-6kg. This is not something new. The Grus has been around on this Earth for over 50 million years. They can fly as high as 9000 metres as they use the thermals as much as possible to conserve energy and carry them over their incredibly journey of thousands of miles.
As they reduce altitude to around 1-2000 metres and lose the benefit of these thermals or wind assistance they will flap their enormous wings in a stately and almost synchronised fashion powering their way onward. In spring they arrive around the end of February to the middle of March leaving us, depending on weather conditions, around October time.
Listen out, their coming!
You will hear them long before you see them, often from thousands of metres away, high up min the sky. Possibly in small formations at first. A bark like trumpeting sound can be heard in the distance which gets louder and more significant as they approach. Then you could see the tip of a dark arrow shaped formation in the sky, either fins of this arrow may be equal in length as a perfect V-shape or short on one side and elongated on the other with the centre space open or followed by others in a similar formation. They are not flying together as social units; they group together purely for safety and to collectively find the best roosting sites. On leading at the point.
Look at the spectacle
As the sight of these magnificent birds gets closer you will note the elegant outstretched neck and pointed, duck like beak, giving line of sight to their destination, the enormous wide wings and black flight feathers and their pale breast. The leading bird will drop back as it tires and immediately another will take its place. What drives this huge momentum is the cranes sensitivity to changes of light and temperature and once the migration has started most of the birds will follow.
Where do they come from?
There are approximately 400, 000 cranes split into 3 migratory directions. Over 130,000 will make the westerly trip to/from the breeding grounds in the warmer climes of Spain, Portugal and North Africa to Northern France. Around 140,000 will journey to/from their preferred grounds in Scandinavia, Russia and the Baltic States, Italy and Germany to over-winter in Africa and the rest, as such uncounted, use a more easterly route to/from Estonia, Russia via Turkey and North Africa for Ethiopia. Not all make it. The weaker ones will stop and rest maybe never to start again. The cold will catch up with them. They breed in swamps, forests, wetlands and bogs but always near water. Their diet consists of plant foods, roots, pond weed, tubers and berries. When breeding they will eat animal foods, mainly insects but also mice and small birds. They are friends of the farmer in that, although they can eat crops, they prefer to look for waste grain in harvested fields cleaning them up for future planting.
The grus grus, or common crane, is mostly monogamous usually pairing for life. If a partner dies they often will seek a new mate. They will usually lay two eggs around May; incubation takes 30 days mainly by the female. Chicks can run at 24 hours old and by 9 weeks can fly short distances. Parent birds go into a post breeding moult whilst caring for the young which makes them unable to fly for up to 6 weeks. Survival rate, (in Spain), is around 50% by the winter. This specie of crane can live for 30-40 years. They are a very demonstrative bird with aggressive courtship and defensive rituals and are able to utilise over 90 sounds and gestures including bows and pirouettes. If attacked they will go into a distraction display but will physically attack some ground predators.
For Susan and me these are events not to be missed. Maybe it is because we are in a valley with the river or just lucky enough to be situated on the cranes popular migration route we have been very fortunate with our sightings. Not just the awesome, piercing flypast but, on a number of years, the cranes have taken to flying around in circles above the Mill. We do not know whether the birds are just getting their bearings or waiting for other flocks to catch up with them. Possibly it is a bit of both because other flocks do seem to join them before they settle on a direction and continue their journey. Last autumn, (2015), we had hardly seen any and we were quite disappointed. One evening we were sitting on our terrace, enjoying the view and sipping something cold and refreshing when Susan mentioned the lack of cranes we had seen. While she was talking I noticed the tell tale tip of the dark arrow in the sky quite far away but approaching us.
I knew straight away what is was. It was the Grus! It was a lovely evening with a clear sky. Susan had her back to their approach. I suggested that maybe they were returning late that year and they could be along any time soon.
I could not hide that wonderful sound from her when the first V-formation flew over us. To our delight there followed another, then another and yet more, they just kept coming. We had never seen so many in one sighting. There were thousands of them. How long we had sat there we do not know but dusk was close when the last had passed by. Of course many people must have seen them but to us it was an incredibly lucky omen. It was personal and it made our year.