Storks have re-established themselves in Charente Maritime department since returning in 1978 after a 10-year absence – in part because of an invasive American crawfish which now forms a large part of their diets.
The Nouvelle-Aquitaine department recorded more than 900 baby birds in 2020, the highest rate of reproduction for the graceful birds - who are attracted by the favourable climate, and abundance of food and marshes in which to nest.
Habitats such as the 11,000-hectare marais de Brouage are ideal breeding grounds for storks. Spotters with the Ligue pour la protection des oiseaux (LPO) recorded some 630 stork nests across the department in 2020, and counted 942 hatched young.
"The stork is a protected species and the LPO has carried out annual monitoring of populations in the department since the 1960s. At the time, there were between one and three pairs," a spokesperson for the LPO told France 3 Nouvelle Aquitaine.
"It disappeared for 10 years but returned naturally to nest in 1978."
Unlike parts of Spain and in Alsace in the east of France, where storks nest on the same buildings or church spires year after year, the storks in the area often choose nesting sites away from towns and villages, but close to the marshes which cover a significant part of the region.
For an increasing number of Charente storks, their favourite sites are now electricity pylons – in spite of the risk of electrocution or accidents from flying into lines.
“We work closely with Enerdis and RTE who run the distribution networks to make sure they are disturbed as little as possible,” said Nicolas Gendre of the Ligue pour la Protection des Oiseaux (LPO), who has been following the storks for years.
“They are more at risk of electrocution on the medium tension lines, where the lines are closer together, but when they see a pylon they very often see a good nesting site and feel safe on them.”
High tension lines are usually checked by helicopters every couple of years but the storks, unlike most birds, do not seem to mind - “They are very calm most of the time,” said Mr Gendre.
Marshes in the Charente are often crossed by high tension lines, distributing power from the nuclear power stations at Blaye in Gironde and Civaux in Vienne.
This year too, for the first time two couples have built nests on pillars of the emblematic Tonnay-Charente suspension bridge.
With the introduction of modern farming and the use of chemical pesticides like DDT, numbers of storks declined sharply after the Second World War to the point that surveys in the 1960s by the LPO showed there were only two or three breeding couples.
They disappeared totally for 10 years between 1968 and 1978 before a breeding couple were again sighted, and were then joined by others.
Storks are protected and the LPO, started a programme of monitoring the birds and encouraging their nesting by building nesting platforms in trees and on special pylons installed with help of Enedis.
“In 2020 we now had 630 couples who managed to raise 940 young,” said Mr Gendre.
“Part of their success is due to their diet, which over the last couple of years has included more and more American crawfish, an invasive species, as well as their normal diet of voles, crickets and grasshoppers.”
The 2020 figure for successfully raising young is lower thanin some previous years, with the explanation being a period of cold and stormy weather in early May when the young were vulnerable.
Eating the crawfish has had an effect on the colouring of the storks, although not as great as with pink flamingos who get their pink colour from the shrimp they eat.
“Young birds typically have black beaks which turn red when they are adults. With the crawfish diet, the beaks often go through a yellow or orange stage before turning red.”
Most of the storks in the area are migratory, flying to overwinter in Spain, North Africa or the Sahel region south of the Sahara desert but north of the Equator.
But in recent years a significant number, around 130 couples, have stayed in the Charente Maritime.
“They can cope with cold spells in winter of up to about a week, and in the Charente that is usually the length of any cold spells we have,” said Mr Gendre.
“Generally he Charente Maritime has a gentle, sunny climate, ideal for storks.”
He said that for lovers of nature, the return of the storks was a good thing: “They have been part of the eco-system for a long time and it is encouraging to see them come back after disappearing for so long.”