Discovering the common tern in the Gulf of Morbihan

Discovering the common tern in the Gulf of Morbihan

“Kritt, kritt, kriiitt.” As soon as the zodiac approaches the pontoon moored off L ocmariaquer (Morbihan), a swarm of terns let out their shrill cry, gathering above our heads in a simulacrum of attack. A new version of Hitchcock’s Birds? A shiver of fear runs through us, the photographer and me. Then, we are struck by the beauty of the scene: five feet above us vibrate the immaculate whiteness of their wings, their vermilion red beak and legs, and that forked tail which has earned them the name of sea swallows. .

With his head protected by a hood, David Lédan climbs onto the pontoon dedicated to the nesting of tern colonies. Responsible for the protection of natural environments in the regional natural park of the Gulf of Morbihan, he rushes to count eggs and chicks, carried out four times a season. These balls of down on legs spin to take refuge under the edge of the wooden cladding.

“Five minutes, not one more, so as not to disturb them too much”, he says once back in the zodiac. Result: 58 nests. “What matters is the number of young that will eventually fly away. Here we have a reproduction rate of between 1 and 1.2 per pair of terns, while the average in Brittany is 0.54”, welcomes the fifties, who has been working for nearly twenty years to promote their reproduction. “With the increase in human disturbances, and the presence of rats and gulls that eat their eggs or chicks, the numbers of common terns fell sharply in the gulf in the early 2000s, he recalls. These pontoons made it possible to ‘reverse.”

What would summer be in the Gulf of Morbihan without the presence of this bird above the water and the beaches? In the evening, it often accompanies swimmers, in search of small fish to feed its brood. Some confuse it with the seagull. But his black brigand cap in which the eyes of the same color are camouflaged, his wings deployed in a circumflex accent or his gracefully jerky turns during his fishing trips sign his species from afar. Arriving in Brittany in mid-May to reproduce, the common tern leaves from mid-August to Africa to join its winter resort. A less ambitious journey than that of its cousin, the arctic tern, which performs a record migration between the two poles. During the summer, the stone bird will have been part of Breton heritage, as surely as the megaliths and castles that dot the bay.

As the salt here mixes with the water, the human monuments blend into the natural heritage. A few wing strokes from the tern pontoon, we are on the island of Gavrinis. The highest point of the bay at… 24 meters high, it offers a breathtaking view of the entrance to the gulf, a passage of barely 900 meters separating Arzon from Locmariaquer.

Archaeological remains

Above all, the island conceals a Neolithic gem hidden under a cairn (dry stone construction). A flashlight in hand, the visitor enters the corridor of the dolmen which led to the burial of important people. The beam of light then reveals the striking spectacle of walls engraved six thousand years ago: a series of interlocking curves like huge fingerprints. Unless they are circles in the water? “These patterns are called radial arches, explains Perrine Foulon, guide on the cairn of Gavrinis. penetrates the land. According to the latest hypotheses of the researchers, they would form representations of water or the ocean.

To the east of Gavrinis, the islet of Er Lannic has also yielded numerous archaeological remains, in particular ax blades, flints and pottery. From the boat, we admire its enclosure of megaliths in an arc, half submerged. Cormorants and gulls like to land on the menhirs of this unusual islet which is also an ornithological reserve. But is it due to the presence of the enemy gull, predator of its offspring? Here, no sea swallows. To find them: head for the Rhuys peninsula, on the other side of the gulf.

In Sarzeau, in the salt marsh of Truscat, awaits them a “five-star hotel” fitted out by a salt worker crazy about birds. In its mudflat, the first basin of the saltworks, Olivier Chenelle has thus created three islets for them. He surrounded them with an electric fence to prevent the intrusion of the fox, and clears them in winter in order to offer the terns the best comfort for laying eggs as soon as they arrive in Brittany. The terns appreciate the place: more than 200 nests have been counted there this year by David Lédan. They are not the only birds welcomed here. In the carnations (last basins of the saline) at low water level, several families of elegant avocets trot and feed in June. “For me, the cultivation of salt is a way to sustain biodiversity. Here, there is at least as much life as in a nature reserve!” pleads, amazed, this hard worker who has rehabilitated with his hands the only two saltworks currently in operation in the Gulf of Morbihan.

Discovery trails

Salt… a wealth long reserved for monks and nobles. Abundant in the past in the gulf, the white gold notably made it possible to build the castle of Suscinio, whose round towers emerge in the middle of a vast landscape of water, reed beds and dunes. Residence-fortress of the Dukes of Brittany, owned by the department since 1965, it has been renovated in the spirit of the 15th century, and has come back to life since last April thanks to the many activities on offer. Three discovery trails allow you to cross the forests and the old saltworks, which have become sensitive natural areas, which surround it. In any season, it is possible to listen to and observe a wide variety of birds: little egret, Eurasian spoonbill, dunlin, kingfisher, plover, wood sandpiper, redshank, etc. “The Suscinio marsh is very popular, because located between the gulf and the ocean, it is the last stage for migrants before Spain”, comments David Lédan during the ornithological visit he leads on the site. In September and October, the common terns will also leave their Morbihan resort. Carrying on their wings the last memories of summer.

On the Loup

In the clay of the saline live surprising residents: bees. These wild foragers dig small holes that we risk crushing and blocking by walking on the edges of the basins. However, this is where these solitary bees collect provisions (nectar and pollen) to feed their larvae. The entrance to their burrows is no larger than an inch in diameter. The whole has the effect of a building where everyone lives side by side, but separately…

naturalist sheet

The common tern is a member of the laridae family, which also includes gulls and gulls. Four types of terns can be observed in France: dwarf, common, sandwich and roseate.

The chicks are fed shrimp and fish for about twenty days. After about three weeks, they take their first flying lesson, then their first fishing lesson. Once independent, they leave their parents.

The tern nests in colonies in open spaces, often on stony ground (pierregarin, old slang “to nest in the stone”). The space between the nests is very small but each of them is defended by a pair which recognizes the call of its chicks.

After 22 to 26 days of brooding, 2 to 3 chicks are born per pair of terns. Their down is mimetic to blend in with the environment. They are semi-nidifuge, that is, they stay close to the nest where they are fed by their parents.

Address Book

Ask about

  • For information on accommodation, restaurants or visits in the Gulf of Morbihan, contact the Vannes tourist office on 02 97 47 24 34 or consult the website

To visit

  • Ornithological discovery with David Lédan at the Suscinio marsh: every Tuesday during school holidays, then from April to October every other Tuesday. €8, registration with the Sarzeau tourist information office on 02 97 53 69 69. To join one of the 150 free nature tours offered by the Morbihan department:
  • Oyster farms (2h30) by electric boat departing from Baden, information on 02 97 57 00 19 or (€45/adult; family package for 4 people at €120).
  • Salt marsh of Saint-Armel with the salt worker Nathalie Krone. Nine visits per week are organized in the summer, from Monday to Friday. Info. on 06 81 22 43 52 or on
  • Château de Suscinio, with many family activities. Information and reservation of daytime or evening tickets (night show on Tuesdays and Thursdays in July-August) on The castle also offers 45-minute ornithological walks. Tel.: 02 97 41 91 91.
  • Gavrinis Cairn (boat crossing with mandatory guided tour) from many ports in the Gulf in summer. Info. on 02 97 57 19 38 or on

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