Compte rendu ornithologique camarguais pour les années 1982 et 1983

Résumé En

This ornithological report covering the years 1982 and 1983 follows on from a series begun in 1950. It deals mainly with the results of the long-term monitoring of several bird communities in the Camargue and lists a few species which are accidental in the area. The baseline for inclusion of unusual observations is provided by the Guide des Oiseaux de Camargue (Blondel & Isenmann, 1981) which gives the status and phenology of the 337 species recorded in the Camargue, the Crau and the Alpilles. Now that a rare birds committee has been established in France only those observations accepted by this committee will in future be published here. The present report, however, was written before the committee had given a verdict on some of the observations submitted. The meteorological report shows that 1982 was a dry year with a mild winter and a hot summer. The autumn was mild and characterised by a freak storm from the S.E. on the 7-8 November. 1983 was also a dry year ; the spring was dominated by frequent and strong S.E. winds and the summer was hot. Cormorants have been censused for the 3rd and 4th consecutive winters and their numbers have peaked at between 4 000 and 6 000 (Fig. 1). The recent increase in numbers can perhaps be related to the increase of the breeding populations of Denmark and Holland, since ringed birds from Holland have been sighted in the Camargue. Reed-nesting herons are censused annually by aerial photography over the major part of the south coast of France. The Grey heron continues to increase in number and to extend its range (Table I). Purple heron numbers have increased since 1981, but unlike the Grey, the major colonies of this species are not situated within the Camargue proper but to the East and West of the two main arms of the river. Tree-nesting herons have also been censused annually since 1968. Their numbers are given in Table II, from which it can be seen that the Cattle egret population has practically stopped increasing and now fluctuates at around 400 pairs. Both Little and Cattle egrets have also been censused at the winter roosts (Table III). Breeding Bitterns were also censused and 54 «booming» males were located in the greater Camargue area in 1983 ; the number found in the Camargue proper (24) being the same as in 1982. Both years produced record numbers of flamingos breeding in the delta : 10 500 pairs raised 6 825 chicks in 1982 and 14 400 pairs raised 7 200 chicks in 1983, the latter being the only colony established throughout the western Mediterranean. The ringing programme started in 1977 was continued and 652 and 720 chicks respectively were marked the two years. These birds are individually recogniseable in the field and there have now been over 19 000 contacts from a total of 4 688 colour-ringed flamingos (56 % of the sample). Sightings are from the Western Mediterranean in particular, but with a few birds in Senegal, Mauritania and Libya. Following the strong S.E. winds of early November 1982, small groups of flamingos were sighted well inland in France. One ringed bird is known to have returned to the Camargue after being seen on the River Isère (Drôme), 185 km up the Rhône valley. In spite of the large numbers of flamingos in the Camargue these two springs the problem of these birds feeding in the rice-paddies has not worsened. On the contrary, the scaring campaings have paid off and no subsequent damage was reported by the farmers (even though the area under rice cultivation has increased). The wintering Bewick’s Swan population peaked at 55-60 in 1981-82 and 68 in 1982-83, rather lower than the peaks of 85 and 82 individuals recorded in the past. Over the past six years the number of Shelducks recorded along the south coast of France prior to breeding has been around 1 400 individuals. About 500 pairs breed in the area, mainly in the salines of the Camargue and Petite Camargue. The colour-ringing programme was continued and a further 69 birds were marked, bringing the total of individually recogniseable Shelducks ringed since 1978 to 316. Sightings of these birds on the «Grosser Knechtsand» have shown that birds from the south of France join the vast majority of birds from North Western Europe for the annual moult in the German Waddenzee (see Table IV). Following the cold spell in N. Europe in winter 1981-82, a record number of 2 060 Shelducks were counted in S. France, most of these (1 876) being in the Camargue and Petite Camargue. Results of the monthly winter censuses of other Anatidae species, carried out by the C.N.R.S. since 1964-65, are summarised in Table V and VI, prepared and commented upon by A. Tamisier. During the winter of 1982-83 total duck numbers peaked at only 100 000. This is lower than usual and may be attributed to two factors mainly : the S.E. storm of early November and the gradual loss of good habitat (disturbance by hunting and fishing has increased). In order to emphasize the importance of disturbance-free areas the numbers of ducks recorded on the St Seren marsh located in the centre of the Tour du Valat Reserve are given in Table VII. Regarding the larger raptors there has been no change in the status of the Egyptian vulture and Eagle owl in the Alpilles, but the two pairs of Bonelli’s eagles have had very poor breeding seasons with only 2 young raised in two years. In the Camargue there has been no detectable change in the Marsh harrier population, an estimated 84 occupied nest sites being located in 1982. In the Crau the wintering population of Little bustards has remained relatively stable over the past ten years at around 1 000 individuals (max. 1 283 in Dec. 1982). Amongst the waders on passage unusually high numbers of Marsh sandpipers, up to 15-16 together, have been recorded each autumn, a Terek sandpiper was shot locally in Sept. 1983 and there are two further May records of Wilson’s phalarope, a species now observed almost annually. The 1982 census of breeding laro-limicolae revealed 26 pairs of Slender-billed gulls but these failed to raise any chicks. In 1983, however, a similar number of pairs raised 60 young, by far the most successful season on record for this species. Mediterranean gulls also had two good seasons with a record 13 pairs in 1982 and 14 young raised in 1983 by 5-6 pairs (incomplete census). Whiskered terns, on the other hand, did not breed in 1982 and failed in their attempt in 1983 (200 + pairs). Amongst the passerines a Desert wheatear was recorded in the Crau in February 1983. This bird, the second recorded from the Crau in 3 years, has been accepted by the rareties committee. Finally, an event which has either been overlooked in the past or is a new development, is the importance of a Carrion crow roost near Le Sambuc where 950 were recorded in December 1983.