Sheila M. Macdonald

Growth in Otter (Lutra lutra) Populations in the UK as Shown by Long-term Monitoring

Abstract European otters declined dramatically from the 1950s, disappearing from many rivers. We report here on longterm monitoring (from 1977) in 3 catchments in western Britain that were recolonized naturally and in 2 catchments in eastern England that were reinforced by captive-bred otters. A minimum of 16-years data was collected on each river until 2002. At a series of sites in each study river, the percentages which were positive for otters and the number of spraints per sprainting site were recorded and combined to produce an annual index of population. One western river, naturally recolonized, showed rapid early population growth for 5 years, followed by slower growth, while growth was steadier in 2 catchments which already held some otters at the beginning of the study. Colonization on the eastern rivers was slower, with greater fluctuations over time. Annual population growth rates were estimated at 1–7%, higher in the earlier years. A strategy for annual monitoring of otters is recommended.

Responses of ground flora to coppice management in an English woodland – a study using permanent quadrats

Changes in the ground flora in sweet chestnut (Castaneasativa) woodland were studied over 11 years usingpermanent quadrats in two coppiced plots and one plot in a ride widened by treeremoval. Light and temperature were also recorded. The temperature range wasgreater in the ride than in the coppice plots. Light reaching the woodland floorin summer fell to less than 1% of incident radiation at later stages of thecoppice cycle. Species richness peaked in the second and third year aftercoppicing and then declined in both the coppice plots and the ride. A similarpattern was seen in total percentage frequency of cover. The dominant species,Anemone nemorosa, showed little response to the coppicecycle in terms of frequency, but showed a fourfold increase in floweringintensity in the second and third year following coppicing. Other speciesgenerally declined in frequency through the coppice cycle, and flowering waslargely suppressed in the later stages. The results are discussed in relation toalternative methods of woodland management.

Otters in Morocco

That otter numbers have declined in northern Europe is well known and the Vincent Wildlife Trust is attempting to discover how far this is also true in the southern part the otters range. Healthy populations have been found in Portugal, Greece and northern Tunisia but declines have occurred in other Mediterranean countries. Here the authors describe the results of a survey in Morocco.

Winter bird numbers and land-use preferences in an arable landscape in eastern England

The winter bird assemblage and habitat preferences were studied in a largely arable landscape, dominated by winter cereals, in eastern England in one winter. A total of species was recorded on 70 l-km transects but 11% of transects had no birds. Overall densities were low, Skylark Alauda arvensis being the most abundant species. Bird was highest in the first winter period (October-December). Species richness varied proportion to the available habitat in the first winter period but there was a preference for stubble, grass and tilled land (harrow) in the second winter period (January-February) Skylarks preferred stubbles in the first winter period and stubbles and grass in the second winter period. Some 34% of all birds fed on winter cereals despite a lack of preference for this habitat, while 94% of seed specialists (finches and buntings) were recorded on stubbles. The areas of preferred habitats (stubbles, grass) were probably too limited to allow more than small populations to persist. Only by the widespread adoption of agricultural extensification and/or farming some of the land specifically for conservation benefits can the declines in bird populations on intensively managed arable farmland be reversed.

A survey for otters in Israel

The results of a field survey for otters in Israel suggest that the species is close to extinction in the coastal plain, where many rivers are grossly polluted. Signs of the animal were found throughout the Jordan catchment, but, because the total area occupied is very small, even this population seems vulnerable.