The French version of MIQ-RS is a valid and reliable instrument in French-speaking population and therefore useful as a measure for motor imagery ability.

1. Colonization in a reintroduced population of European beavers in the Loire Valley was studied between 1974 and 1999. It followed a discontinuous remoteness model and a scattered distribution, beavers occupying only 25% of the river system over the 2800 km explored. 2. After 5 years, the colonization rate reached 104.2% year–1 of new sites occupied (SD 75% year–1), before dropping over the next 20 years. Nevertheless, the number of new colonies per km (0.125) remained stable throughout the years. 3. Populus nigra, Salix alba and Fraxinus angustifolia were the dominant woody species in beaver sites, often associated with some herbaceous species. 4. The length of willow grove dominated by S. alba and P. nigra (x) was the best predictor of beaver home range (y), fitting the equation y=−0.742x + 5.9. Long‐term maintenance of the population requires a minimum of 1.79‐km of willows per colony. 5. In cutting tree trunks, beavers stimulate shoot development from the remaining stumps. They rejuvenate riparian forests, increase the number of tree stems and help stabilize the banks. Their effect on woody plant morphogenesis may have consequences for the helophyte communities used as food or habitat by other aquatic species.

Populations of threatened species, especially predators at the top of the food chain, may be affected by anthropic pressures. The endangered western population of European mink Mustela lutreola has shown a large decline over 50% of its natural range. M. lutreola disappeared from northwestern France between 1984 and 1997, and the decline was associated with an increase in mustelid trapping, changes in watercourse quality, and habitat modifications due to agricultural practices. The pattern of decline showed a fragmentation restricting the minks into very small areas. Trapping was the first known cause of mortality. Although feral American mink Mustela vison may compete with autochthonous carnivores, M. lutreola had disappeared from streams before the introduction of the American species, suggesting that competitive interactions were not responsible. Furthermore, American mink has never been found or has remained rare in 62.4% of the area from which M. lutreola has disappeared. During the past 25 years, permanent grassland surfaces were reduced by 40%, whereas fodder culture increased by 470%, causing considerable habitat changes. Furthermore, 55.7% of water courses were classified as being of bad quality or polluted. Therefore, our data suggests that a conjunction of intensive trapping, alterations in water quality and habitat modification was critical for the European mink's decline. Although there are difficulties in ascribing specific cause to distribution changes in a top predator, this decline can be regarded as an indication for anthropic pressures on natural habitats.

Selection and use of woody plants in beaver (Castor fiber) lodge construction on the Loire River are poorly understood. We investigated woody species used by beaver for construction and analysed the efficiency of the tree-cutting technique used. We observed that beavers used branches of Salicaceae of large diameter (approx. 4.5 cm) to build the frames of their lodges, even in sites where these were scarce. They then cut small branches of the more abundant species in any given site (Salix fragilis, S. alba, Fraxinus angustifolia, Ulmus minor) to cover the lodge. The shapes of cut tree sections depended on diameter at the cut, and orientation was related to bank slope. Most cut trees (55%) fell into the water, where they were more easily exploited than those that fell in other directions. We conclude that beavers of the Loire River need Salicaceae for construction, even where they are scarce. The tree-cutting technique is efficient for exploiting fallen trees, but leads to changes in plant morphology. Repeated use by beaver creates shrubby re-growth that is too small for use in lodge construction.

Invasive species represent a major threat to biodiversity, and the understanding of their population genetics is one of the most important goals in conservation biology. Recently, it has been proposed that methods using molecular tools could help define efficient eradication strategies and should be a preliminary step in the management process. The American mink was introduced in Europe for fur farming purposes in the 1920s, and, due to escapees, several feral populations have been mentioned in the last decades. In France, feral mink have been observed since the 1970s, and the largest population, located in Brittany, is considered to be still expanding. We investigated the genetic variability and population structure of 149 feral mink and 21 farmed mink from this area using six microsatellite loci. Our results showed three genetically distinct population units at the regional scale. A pattern of isolation by distance was observed for the whole sample. In our case we explain this pattern by recent admixture of the three genetic units. Our findings suggest that populations have recently met and started to homogenise.

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The location of Hen and Montagu’s Harriers nests was studied from 1970 to 1982 in a conifer plantation and in surrounding moors of heath and thorn-broom in Maine-et-Loire, near Saumur, France. The Hen Harrier prefers to nest in conifers and uses places where trees are 4 to 27 years old. Montagu’s is more frequent on moors and nests in younger pine plantations. The decrease of the Montagu’s Harrier population from 22 pairs in 1972 to 8 in 1982 cannot be explained entirely by the increase in height of the Pine trees. Other factors might interfere, particularly competition between the two species as far as the nesting area is concerned.