26 Nov 2008

27th November 1988 - Briere

Briere

Our journey had taken us through several areas designated Parc Natural Regional. Basically these were special land management zones (equivalent to British National Parks), where the aim was to ensure the safe‑keeping of the country's natural heritage while permitting the develop­ment of compatible economic activities ‑ recreation, farming, non‑polluting industry, environmental education, etc. Within these zones there may be areas of wildlife interest, eg the vast marshes and reedbeds of Briere, which were protected against drainage and other development, but where shoot­ing was still allowed.
From the map and one of our books we knew the Parc Regional Natural de Briere consisted of wet­land and farmland with a few towns and villages. At the centre of the area was la Grande Briere, totalling some 7000 ha of marshes and lagoons, one of the largest such areas in inland France.
The basin containing the marsh was formed by earth movements which caused the underlying rocks to sink. Over millions of years the sea has occasionally flooded the basin, laying down deposisits of sediment. Then about eleven million years ago the basin was completely cut off from the sea by the formation of a littoral bar. The landscape has been subjected to human activities such as fishing, reed‑cutting, grazing and hay making ‑ preventing the drier bits of land becoming woodland. Instead there is wet heath merging into boggy meadow. At the end of the summer the fields are reputed to be blue with heath lobelia. Many birds are known to breed in the park, including bearded tit, cettis, savis and grasshapper warblers, bluethroat, garganey and bittern. In the winter wild duck and geese visit the flooded areas.
What we have seen so far of the wetland is vast areas of phragmites cut by drainage channels and with patches of willow scrub developing on drier ground. We stopped at a pic­nic site hoping to find footpaths or tracks but with no luck. There were, however, some punts padlocked to their mooring and that form of trans­port could prove most interesting. The place was deserted except for a few fishermen and hunters ‑ one hopes that in a place of this size wildlife could find some refuge from such activities.
Where there are reedbeds one expects to find marsh harriers and we were not disappointed. There were up to four birds in view at a time and the show was almost continuous. Mostly they were brown birds but there was at least one adult male. In contrast to the flying displays we were watching a couple of days ago, most of these birds were get­ting down to business - hunting.
As their name suggest, marsh harriers show a preference for shallow fresh or brackish water, fringed or extensively invaded by tall standing reeds, reed mace and other similar vegetation without too many trees. Briere must look like heaven to them.
The harriers quarter the reeds in a low lei­surely flight, flapping steadily in today's calm weather but gliding slowly forwards in a strong wind. All the while they scan the herbage beneath for any sign of movement and, when a victim is located, the harrier checks its flight, sometimes almost turning over, before plunging vertically with legs out­stretched. We have not seen them fly out of the reeds with prey, so presumably they consume the victim immed­iate­ly on the ground.
Twice we saw birds carrying vegetation. On the first occasion the vegetation was dropped as another bird approached and they called to each other; they came together several times, twisted and turned once or twice each time then parted. On the second occasion the same type of interac­tion continued for some time and the bird with the vegetation kept hold of it for longer. The birds often called when they were coming together, a shrill weak version of the courtship call. This out of season activity is thought to be play, or young birds practising for the spring.
At last we caught up with short‑toed tree­creep­er. A bird with a strange call flew over our heads and landed on a nearby willow tree. We could see clearly the buffish flanks and the longer bill which distinguish it from the ordinary treecreeper.
A bearded reedling bounced out of the reeds and called attention to himself, others were heard but not seen. Two Cetti's warblers had a dispute about fifty metres behind us, they shouted chewey­‑chewey‑­chew‑chew at each other ‑ in the fading light visual identification was impossible. Other distinctive sounds came from water rails; silhou­ettes of water voles crossed the channels and a merlin zoomed over the reeds.

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