Chaillé-les-Marais, France
Chaillé-les-Marais, France

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Boileau N.,Les Marais | Bretagnolle V.,CNRS Chizé Center for Biological Studies
Journal of Raptor Research | Year: 2014

The post-fledging dependence period (PDP) of 25 Eurasian Kestrel (Falco tinnunculus) fledglings was studied in a coastal marsh in western France in 2002 and 2003. Body condition at fledging was the only parameter that had a positive effect on the length of the PDP, which averaged 18 d (range 3-31 d). Mean daily distance from the nest increased 15 m per day until independence, and mean area used during the PDP was 7.3 ha. Male kestrels provided food for fledglings during the PDP (though decreasing their delivery rate with time). Females stopped feeding their young 3 d after they fledged. First fledglings received more food than others and food per fledgling decreased with brood size. © 2014 The Raptor Research Foundation, Inc.

Common Kestrels have been monitored from 1973 to 2012 on the same sample of 41 breeding sites in Côte d'Or, in an area of 1600 km2 (tab. 1). From 1992 to 2012, a 20 km2 area was exhaustively monitored (fig. 2): breeding pairs range between 2 and 11. We conclude that breeding population of Kestrels in the area was stable, despite fluctuations, over the last 40 days and discussed the importance of long term survey for estimating accurate trends of breeding Kestrel population in France.

In France, the number of attacks (physical contact between the species and men) on humans by the Common Buzzard from 2007 to 2014 was of 48 at 37 different sites (a mean of 6 more or less 3.5 attacks/year). Over the studied period, those attacks have significantly increased, partly due to a better knowledge and a greater publicity. These attacks however remain marginal in relation to other problems due to wild animals on human health and must be treated with caution rather than by persecution.

The effects of nest type on breeding success of Kestrels living in rural areas were studied over a period of 21 years (1992-2012) in Burgundy (East France). Five nest types (n = 35 different nests) were used by the species: cavity in domestic buildings, nest-box, cliff cavity, nesting in old crow nest and on the top of agricultural silo. Based on a sample of 123 breeding records, laying date, clutch size, brood size at hatching, and number of fledglings per pair were not significantly affected by nest type. Nest desertion (due to food shortage or infertile eggs) accounted for 60 % in nest failures. The nest prédation rate was low in all nest types. In fact, individual quality of birds may play the crucial role in breeding success.

A field survey ot a Common Kestrel population was carried out in Burgundy (France) from 1992 to 2005 using individual colourmarked birds captured with bal-chatri traps. Thus 402 individuals have been , marked on 937 attempts. Main results are: sex-ratio and age-ratio varied according to annual cycle of the species. Age-ratio was biased towards adults. Males are much more prone to be recaptured than females, particularly the more they are old and light. Handling stress is low with only 6.9 % of stressed birds. After their release, birds often behave as before their capture. Bias in age-ratio is due to young birds which show less developed hunting techniques (especially with respect to mammals) and field knowledge. This study appears to be the first conducted in Europe that presents detailed results about bal-chatri trapping as a sampling method to study Common Kestrel.

Boileau N.,Les Marais | Delaporte P.,Ligue pour la Protection des Oiseaux LPO
Alauda | Year: 2012

This behaviour was observed during three winters in mudflats of the Marennes-Oléron bay (Western France). Kleptorasitism attempts (n = 44) occurred in 5% of captured preys (n = 878) and involved gulls (65%; Chroicocephalus ridibundus, Larus canus, Laws argentatus) but also Curlew (35%). Successful attempts were higher in gulls (62%) compared to curlews (26%). Worms were the major prey type stolen with handling time significantly higher in those prey types. No differences were observed in attack durations and vigilance time of attacked birds between curlews and gulls and kleptoparasitism rates did not differ among six different mudflats of the bay.

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