Yahiaoui K.,University of Abderrahmane Mira de Bejaia |
Yahiaoui K.,University of Boumerdes |
Arab K.,University of Boumerdes |
Belhamra M.,University Mohamed Khider of Biskra |
And 3 more authors.
Revue d'Ecologie (La Terre et la Vie) | Year: 2014
Depending on the resulting habitat mosaic, that is created, habitat loss can reduce the abundance and diversity of birds. Turtle Dove (Streptopelia turtur) is particularly likely to suffer from such pressure, yet few studies have been performed to evaluate its conservation status in Algeria. The information on breeding habitat requirements for turtle dove is important for managing remnant woodlots and shrub land used by this species. To address this issue we surveyed the species in a suburban area of 1087 ha situated in the Isser Valley in Boumerdes (northern Algeria). In order to determine past and predicted future trends in habitat availability we compared landscape types in 2006 with those present in the 1960s and found that nine of the 11 habitats surveyed were occupied by turtle doves in 2006-07. The mean density of turtle doves across our study area was 0.79 pairs/ha during 2006 and 2007. Hatching success was 36.5% and post-fledging nesting success reached 67.7%. A comparison of habitat diversity between the 1960s and 2006 showed an increase of forest- related habitats, which tends to favour turtle doves' persistence, and could possibly reduce the effect of the landscape homogenization related to anthropogenic land use practices. Being classified as a habitat specialist, the Turtle Dove is likely to decline in the Isser Valley under continuing habitat changes.
Guillemain M.,CNERA Avifaune migratrice |
Green A.J.,CSIC - Donana Biological Station
Journal of Ornithology | Year: 2013
Few studies have considered how body condition changes over time in individual birds, and most of these concerned long-lived breeding birds. We used a large database of Common Teal Anas crecca ringed and recaptured while wintering in the Camargue to study inter-annual persistence in wing length and body condition. Winter body condition may be a major determinant of survival during that season, and may further be related to breeding success. Indices of condition were compared for individual Teal between the moments of ringing and of recapture the following winter, analyzing each sex and age class (adult or juvenile) separately. Wing length was highly repeatable between years, though some limited annual variation was also recorded in adult males. Using scaled mass index as an index of body condition, we observed that condition at ringing was the strongest predictor of body condition at recapture for males and juvenile females, although inter- and intra-annual variation was also significant in most cases. The value of the slope for the relationship between individual body condition indices at ringing and recapture did not differ from 1 for males and for adults, whereas, for juvenile females, the slope was significantly greater than 1, indicating that individual differences in condition became more exaggerated over time. When analyses were repeated using crude body mass instead of a condition index, results were generally similar. Birds recaptured the following winter had a greater body condition at ringing that those that were not recaptured, supporting the hypothesis of a link between winter body condition and return probability. Our results demonstrate the importance of a head start in Teal, given persistent effects of obtaining better condition in the first winter, and suggest specific age and sex effects. They also underline the value of condition indices as a long-term predictor of individual quality in birds, even during the non-breeding season and for such a relatively short-lived species. © 2013 Dt. Ornithologen-Gesellschaft e.V.
Glrard O.,CNERA Avifaune migratrice
Alauda | Year: 2011
From 1994 to 2009, 7 816 dead birds belonging to 92 species were sampled on roads in Atlantic France mainly in the Vendee region. Barn Owl, Common Moorhen, Blackbird and House Sparrow were the most involved species. The highest mortality rate was found in June and December and the lowest in April-May and July-August. More of 50 % of the corpses have been found along hedge-lined roads.The influence of weather conditions on road mortality is difficult to assess, except for a few species (Robin, Thrushes, Chaffinch) whose mortality was higher during cold spells.About 55 % of birds were killed during daytime. We tried to estimate the annual road mortality in birds for the whole of France by using three approaches. Thus it is likely that at least some 30 millions of birds are killed each year by road traffic in France. Besides predation by cats, road traffic may be considered as the second most important non-natural cause of bird mortality in that country.
Valery L.,French Natural History Museum |
Schricke V.,CNERA Avifaune migratrice
Wildfowl | Year: 2013
Trends in abundance, the timing of arrival and departure, and the number of goosedays at internationally important sites, are presented for Dark-bellied Brent Geese Branta bernicla bernicla wintering in France during 1982-2012 inclusive. Numbers wintering in France increased more rapidly than the increase in the population as a whole: c. 30% of the world population occurred in France in 1982 and just over half in 2012. Throughout the past 30 years, c. 75% of Brent Geese wintering in France have concentrated at just six sites. Two of them (Bassin d'Arcachon and Golfe du Morbihan) have shown a sharp rise in numbers in mid-January, most notably a fivefold increase in 30 years at the Bassin d'Arcachon, which now accounts for c. 43% of the total in France (compared with c. 21% in 1982) and c. 22% of the world population (c. 5% in 1982). Wintering phenology at the six main sites, determined from the dates on which 50% of the annual peak count had arrived and departed, has varied over time. At five of the sites, this proportion of Brent Geese now arrives 3-4 weeks earlier than 30 years ago. The total number of goose-days has increased almost fivefold at Bassin d'Arcachon and doubled in Baie de Bourgneuf, although the reasons for these changes remain unclear. In particular, the increase at Bassin d'Arcachon merits investigation, given a long-term decline in eelgrass Zostera sp. abundance at this site. © Wildfowl and Wetlands Trust.
Nilsson L.,Lund University |
Follestad A.,Norwegian Institute for Nature Research |
Guillemain M.,CNERA Avifaune migratrice |
Schricke V.,CNERA Avifaune migratrice |
Voslamber B.,Sovon Dutch Center for Field Ornithology
Wildfowl | Year: 2013
France is traditionally a staging area for Greylag Geese Anser anser migrating from northwest Europe to wintering sites in Spain, though increasing numbers have wintered in France over the last three decades. This paper considers sightings within France of neck-banded individuals marked elsewhere in Europe since the 1980s, to determine the origin of Greylag Geese staging and now wintering in the country. The geese included in this study were all caught in summer during the annual moult, either as family groups or in non-breeding flocks. Most sightings of neck-banded geese were from western France, and most birds identified were from breeding areas in the Nordic countries or to a lesser extent in the Netherlands. The Lac du Der area in northeast France was found to be a wintering area for an introduced population of Greylags established southwest of Stockholm in Sweden, and the geese wintering on the Camargue in southern France were recruited mainly from central Europe. Numbers wintering in France have increased in line with the general increase in the European Greylag Goose population, whereas numbers on passage in France have not increased in the same way, possibly due to a northward shift in the winter distribution of Greylags across Europe. The numbers wintering in France are, however, still small compared to other areas along the flyway. © Wildfowl & Wetlands Trust.