Nocturnal field use by wintering Skylark Alauda arvensis on intensive farmlands

Few studies investigate ecological requirements of wintering Skylark Alauda arvensis, most dealing with diet or diurnal field occupancy. This paper presents original data about the nocturnal field use by wintering Skylarks on intensive farmlands in western France. In December 2000 and January 2001, bird abundance and flock size were estimated in 119 fields using the line transect method and a 100 watts searchlight. In each field, variables such as crop type, vegetation height and ground cover were recorded. Crop types included stubbles, winter cereals, ryegrass, set-aside, legumes, oilseed rape and bare ground. We used General Linear Models with Poisson error term to fit models describing skylark abundance according to these variables. 458 Skylarks were counted along 42.42 km. Results showed significant effects of crop type, vegetation height and ground cover on abundance of birds. Skylarks were more abundant in stubble fields. When considering all crop types, skylarks were more abundant where vegetation height ranged from 1 to 10 cm and ground cover from 10 to 75%. Fields without vegetation were avoided. Large flocks were never recorded. 47.1% of the contacts were single birds and 5.1% were flocks of more than 10 birds. These results are discussed in relation to present knowledge of the diurnal field use and nocturnal flocking behaviourPeu de travaux abordent l'écologie de l'Alouette des champs (Alauda arvensis) en hiver et ceux disponibles ont trait au régime alimentaire ou à l'occupation diurne de l'espace agricole. Cet article présente des données originales sur l'utilisation nocturne des parcelles par les oiseaux hivernants dans les plaines cultivées de l'Ouest de la France. Au cours de l'hiver 2000-2001, l'abondance des alouettes et la taille des groupes ont été estimées pour 119 parcelles de cultures à l'aide d'un phare portatif et selon la méthodologie des transects linéaires. Dans chaque parcelle, nous avons enregistré les variables relatives au type de culture (chaumes, céréales d'hiver, ray-grass, jachères, légumineuses, colza, terre nue), à la hauteur et au recouvrement de la végétation. Nous avons utilisé des modèles linéaires généralisés pour tester l'effet de ces variables sur l'abondance de l'Alouette des champs. 458 alouettes ont été dénombrées sur un total de 42,42 km de transect. Les résultats de l'analyse soulignent un effet significatif du type de culture, de la hauteur et du recouvrement de la végétation sur l'abondance des oiseaux. Les Alouettes des champs étaient plus abondantes sur les parcelles de chaumes, lorsque la hauteur de végétation était comprise entre 1 et 10 cm et lorsque le recouvrement de la végétation était compris entre 10 et 75 %. Les parcelles dénuées de végétation étaient évitées. Nous n'avons contacté aucun groupe d'alouettes de grande taille. 41,7 % des contacts ne concernaient qu'un seul oiseau et seulement 5,1 % étaient des groupes constitués de plus de 10 oiseaux. L'ensemble de ces résultats sont discutés à la lumière des connaissances actuelles sur l'utilisation diurne de l'espace agricole et le comportement nocturne des alouettes

Nocturnal field use by wintering Skylarks Alauda arvensis on intensive farmlands

Few studies investigate ecological requirements of wintering Skylark Alauda arvensis, most dealing with diet or diurnal field occupancy. This paper presents original data about the nocturnal field use by wintering Skylarks on intensive farmlands in western France. In December 2000 and January 2001, bird abundance and flock size were estimated in 119 fields using the line transect method and a 100 watts searchlight. In each field, variables such as crop type, vegetation height and ground cover were recorded. Crop types included stubbles, winter cereals, ryegrass, set-aside, legumes, oilseed rape and bare ground. We used General Linear Models with Poisson error term to fit models describing skylark abundance according to these variables. 458 Skylarks were counted along 42.42 km. Results showed significant effects of crop type, vegetation height and ground cover on abundance of birds. Skylarks were more abundant in stubble fields. When considering all crop types, skylarks were more abundant where vegetation height ranged from 1 to 10 cm and ground cover from 10 to 75%. Fields without vegetation were avoided. Large flocks were never recorded. 47.1% of the contacts were single birds and 5.1% were flocks of more than 10 birds. These results are discussed in relation to present knowledge of the diurnal field use and nocturnal flocking behaviour.Peu de travaux abordent l’écologie de l’Alouette des champs (Alauda arvensis) en hiver et ceux disponibles ont trait au régime alimentaire ou à l’occupation diurne de l’espace agricole. Cet article présente des données originales sur l’utilisation nocturne des parcelles par les oiseaux hivernants dans les plaines cultivées de l’Ouest de la France. Au cours de l’hiver 2000-2001, l’abondance des alouettes et la taille des groupes ont été estimées pour 119 parcelles de cultures à l’aide d’un phare portatif et selon la méthodologie des transects linéaires. Dans chaque parcelle, nous avons enregistré les variables relatives au type de culture (chaumes, céréales d’hiver, ray-grass, jachères, légumineuses, colza, terre nue), à la hauteur et au recouvrement de la végétation. Nous avons utilisé des modèles linéaires généralisés pour tester l’effet de ces variables sur l’abondance de l’Alouette des champs. 458 alouettes ont été dénombrées sur un total de 42,42 km de transect. Les résultats de l’analyse soulignent un effet significatif du type de culture, de la hauteur et du recouvrement de la végétation sur l’abondance des oiseaux. Les Alouettes des champs étaient plus abondantes sur les parcelles de chaumes, lorsque la hauteur de végétation était comprise entre 1 et 10 cm et lorsque le recouvrement de la végétation était compris entre 10 et 75 %. Les parcelles dénuées de végétation étaient évitées. Nous n’avons contacté aucun groupe d’alouettes de grande taille. 41,7 % des contacts ne concernaient qu’un seul oiseau et seulement 5,1 % étaient des groupes constitués de plus de 10 oiseaux. L’ensemble de ces résultats sont discutés à la lumière des connaissances actuelles sur l’utilisation diurne de l’espace agricole et le comportement nocturne des alouettes.Eraud Cyril, Corda Eve. Nocturnal field use by wintering Skylarks Alauda arvensis on intensive farmlands. In: Revue d'Écologie (La Terre et La Vie), tome 59, n°4, 2004. pp. 581-589

Habitat selection of the Eurasian woodcock in winter in relation to earthworms availability

12 pagesInternational audienceThe Eurasian woodcock (Scolopax rusticola) is a game species experiencing high hunting pressure, long-term modifications of its habitats, and with questions regarding its current conservation status. Winter is a season of highest concentration of birds and hunting pressure but woodcock precise habitat requirements are poorly known. It is crucial to assess threats and to develop sustainable management options for the conservation of woodcock populations. During three consecutive winters, we monitored 65 individual woodcocks fitted with radio-tags in Brittany, France. Habitat selection was analysed using GIS and compositional analysis, in relation to vegetation types, soil variables (humus types) and the abundance of their main prey (earthworms). Woodcocks used different habitats diurnally and nocturnally, generally preferring areas with high earthworm biomass. Diurnal habitat selection in forests was associated with humus type (preference for mulls, rich in earthworms) and dense shrub strata (better protection). Hedges with a high density of trees and shrub were also important habitat. At night, grazed meadows were the preferred habitat, containing five times higher biomass of earthworms compared to cultivated fields. Sustainable management of populations requires protection and management of habitats that incorporates food and cover. Forestry practices should preserve rich humus types and coppices by choosing tree species that ameliorate the soil and soil tilling. Changes in landscapes and intensive agricultural practices are current threats to woodcock populations: destruction of hedges, decrease of permanent grazed meadows, impoverishment of soils fauna biomasses from ploughing and chemical applications. However, woodcocks may benefit from the recent development of set-asides, grass field-borders and simplified farm practices (no-tillage and direct sowing)

Are ARID5B and IKZF1 polymorphisms also associated with childhood acute myeloblastic leukemia: the ESCALE study (SFCE)?

International audienceOf the average 470 new cases of acute leukemia (AL) registered annually in France among children aged <15 years,1 |[sim]|90 are cases of acute myeloblastic leukemia (AML). Down|[rsquo]|s syndrome and other inheritable predisposing diseases explain only a small proportion of AML

Familial melanoma: Clinical factors associated with germline CDKN2A mutations according to the number of patients affected by melanoma in a family

International audienc

Effect of 17q21 variants and smoking exposure in early-onset asthma.

International audienceBACKGROUND: A genomewide association study has shown an association between variants at chromosome 17q21 and an increased risk of asthma. To elucidate the relationship between this locus and disease, we examined a large, family-based data set that included extensive phenotypic and environmental data from the Epidemiological Study on the Genetics and Environment of Asthma. METHODS: We tested 36 single-nucleotide polymorphisms (SNPs) in the 17q21 region in 1511 subjects from 372 families for an association with asthma. We also tested for genetic heterogeneity according to the age at the onset of asthma and exposure to environmental tobacco smoke in early life. RESULTS: Eleven SNPs were significantly associated with asthma (P<0.01), of which three (rs8069176, rs2305480, and rs4795400) were strongly associated (P<0.001). Ordered-subset regression analysis led us to select an onset at 4 years of age or younger to classify patients as having early-onset asthma. Association with early-onset asthma was highly significant (P<10(-5) for four SNPs), whereas no association was found with late-onset asthma. With respect to exposure to environmental tobacco smoke in early life, we observed a significant association with early-onset asthma only in exposed subjects (P<5x10(-5) for six SNPs). Under the best-fitting recessive model, homozygous status (GG) at the most strongly associated SNP (rs8069176) conferred an increase in risk by a factor of 2.9, as compared with other genotypes (AG and AA) in the group exposed to environmental tobacco smoke (P=2.8x10(-6); P=0.006 for the test for heterogeneity of the SNP effect on early-onset asthma between groups with tobacco exposure and those without such exposure). CONCLUSIONS: This study shows that the increased risk of asthma conferred by 17q21 genetic variants is restricted to early-onset asthma and that the risk is further increased by early-life exposure to environmental tobacco smoke. These findings provide a greater understanding of the functional role of the 17q21 variants in the pathophysiology of asthma

A SUMOylation-defective MITF germline mutation predisposes to melanoma and renal carcinoma

So far, no common environmental and/or phenotypic factor has been associated with melanoma and renal cell carcinoma (RCC). The known risk factors for melanoma include sun exposure, pigmentation and nevus phenotypes(1); risk factors associated with RCC include smoking, obesity and hypertension(2). A recent study of coexisting melanoma and RCC in the same patients supports a genetic predisposition underlying the association between these two cancers(3). The microphthalmia-associated transcription factor (MITF) has been proposed to act as a melanoma oncogene(4); it also stimulates the transcription of hypoxia inducible factor(5) (HIF1A), the pathway of which is targeted by kidney cancer susceptibility genes(6). We therefore proposed that MITF might have a role in conferring a genetic predisposition to co-occurring melanoma and RCC. Here we identify a germline missense substitution in MITF (Mi-E318K) that occurred at a significantly higher frequency in genetically enriched patients affected with melanoma, RCC or both cancers, when compared with controls. Overall, Mi-E318K carriers had a higher than fivefold increased risk of developing melanoma, RCC or both cancers. Codon 318 is located in a small-ubiquitin-like modifier (SUMO) consensus site (Psi KXE) and Mi-E318K severely impaired SUMOylation of MITF. Mi-E318K enhanced MITF protein binding to the HIF1A promoter and increased its transcriptional activity compared to wild-type MITF. Further, we observed a global increase in Mi-E318K occupied loci. In an RCC cell line, gene expression profiling identified a Mi-E318K signature related to cell growth, proliferation and inflammation. Lastly, the mutant protein enhanced melanocytic and renal cell clonogenicity, migration and invasion, consistent with a gain-of-function role in tumorigenesis. Our data provide insights into the link between SUMOylation, transcription and cancer

A SUMOylation-defective MITF germline mutation predisposes to melanoma and renal carcinoma.

International audienceSo far, no common environmental and/or phenotypic factor has been associated with melanoma and renal cell carcinoma (RCC). The known risk factors for melanoma include sun exposure, pigmentation and nevus phenotypes; risk factors associated with RCC include smoking, obesity and hypertension. A recent study of coexisting melanoma and RCC in the same patients supports a genetic predisposition underlying the association between these two cancers. The microphthalmia-associated transcription factor (MITF) has been proposed to act as a melanoma oncogene; it also stimulates the transcription of hypoxia inducible factor (HIF1A), the pathway of which is targeted by kidney cancer susceptibility genes. We therefore proposed that MITF might have a role in conferring a genetic predisposition to co-occurring melanoma and RCC. Here we identify a germline missense substitution in MITF (Mi-E318K) that occurred at a significantly higher frequency in genetically enriched patients affected with melanoma, RCC or both cancers, when compared with controls. Overall, Mi-E318K carriers had a higher than fivefold increased risk of developing melanoma, RCC or both cancers. Codon 318 is located in a small-ubiquitin-like modifier (SUMO) consensus site (ΨKXE) and Mi-E318K severely impaired SUMOylation of MITF. Mi-E318K enhanced MITF protein binding to the HIF1A promoter and increased its transcriptional activity compared to wild-type MITF. Further, we observed a global increase in Mi-E318K-occupied loci. In an RCC cell line, gene expression profiling identified a Mi-E318K signature related to cell growth, proliferation and inflammation. Lastly, the mutant protein enhanced melanocytic and renal cell clonogenicity, migration and invasion, consistent with a gain-of-function role in tumorigenesis. Our data provide insights into the link between SUMOylation, transcription and cancer