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Influence of edge effects on common vole population abundance in an agricultural landscape of eastern France

100%

Delattre P., Morellet N., Codreanu P., Miot S., Quere J. P., Sennedot F., Baudry J.

Acta Theriologica

2009

tom 54

nr 1

51-60

Vole demographics are often modified close to wooded environments. Population monitoring in such settings reveals substantial edge effects, although these have seldom been quantified. This study compares the abundance of common voleMicrotus arvalis (Pallas, 1778) populations at various distances from three types of wooded environment (hedgerow, copse and forest) and in two types of habitat (temporary and permanent grassland). In temporary grassland, substantial edge effects were detected along the boundaries of forests and hedgerows. At 100 m from the forest edge, voles were twice more abundant than at 50 m, four times more than at 25 m and eight times more than at 5 m. In permanent grassland, the edge effect was such that voles were practically absent up to 100 m from the forest edge. For both types of grassland, the edge effect was more pronounced for forest habitat than for hedgerows, that is, for elements with a large surface area of wooded environment. Our results suggest that landscape context may greatly affect the local abundance of voles. Given the considerable damage done byM. arvalis, the presence of wooded patches in grassland areas leads to lower vole densities in adjacent areas and this might be an alternative method to controlM. arvalis as a pest species.

Estimation of water vole abundance by using surface indices

100%

Giraudoux P., Pradier B., Delattre P., Deblay S., Salvi D., Defaut R.

Acta Theriologica

1995

tom 40

nr 1

A method to estimate the abundance of the fossorial form of the water vole Arvicola terrestris scherman (Shaw, 1801) has been developed, by using surface indices. Results are compared to the standard method of estimation using trap lines. These results show quantitatively that it is possible to differentiate reliably mole indices from water vole indices. Moreover, the two species are inclined to exclude each other. Even though water voles share the same galleries as moles, specific surface indices of the water vole occur for any density exceeding 2 ind/trap line (over 20 ind/ha). Several models of abundance estimation are put forward, all of them using linear multiple regressions. Correlations between the estimations from indices and the estimations from trap lines exceed 0.8 and the limits of using abundance classes are tested. Other limits are developed in the discussion. One of them is that the sampling intervals are saturated for densities exceeding 400 ind/ha. The index method, which is easy to carry out, offers the definite advantage of being suitable to space and time scales otherwise incompatible with estimations from trap lines. For instance, it allows distribution maps from wide transects about areas of more than 25 km2 to be drawn, in less than two days.

Distribution of small mammals along a deforestation gradient in southern Gansu, central China

84%

Giraudoux P., Quere J. P., Delattre P., Bao G., Wang X., Shi D., Vuitton D., Craig P. S.

Acta Theriologica

1998

tom 43

nr 4

Small mammals were surveyed along a deforestation gradient in southern Gansu, China (2300-2600 m altitude), a high endemicity area for human alveolar echinococcosis. Rodent distribution was assessed using removal trapping in six habitat types from timbered forest to farmland and villages, by index transects, and by the collection of specimens by local people, Species captured were 2 shrews: Anourosorex squamipes, Sorex sinalis-, 12 rodents: Eozapus setchuanus, Microtus limnophilus, Cricetulus long/- caudatus, Tscherskia triton, Apodemus agrarius, Apodemus draco, Apodemus penin- sulae, Micromys minutus, Mus muscitlus, Rattus noruegicus, Niviventer confucianus, Myospalax fontanieri\ and 1 lagomorph Ockotona thibetana. On the basis of trap success four rodent assemblages were recognized. Species richness decreases after deforestation, especially in the intermediate stage (scrubland-grassland).

Ograniczanie wyników

3 Acta Theriologica

3 Delattre P.

2 Giraudoux P.

2 Quere J. P.

1 Bao G.

1 Baudry J.

1 Codreanu P.

1 Craig P. S.

1 Deblay S.

1 Defaut R.

1 Miot S.

1 Morellet N.

1 Pradier B.

1 Salvi D.

1 Sennedot F.

1 Shi D.

1 Vuitton D.

1 Wang X.

1 2009

1 1998

1 1995

Wyniki wyszukiwania

Influence of edge effects on common vole population abundance in an agricultural landscape of eastern France

Estimation of water vole abundance by using surface indices

Distribution of small mammals along a deforestation gradient in southern Gansu, central China