Exploitation of Britain as a wintering area is believed to have been a gradual process, but how well is this reflected by ringing recoveries?

SUMMARY The number of gulls wintering inland has steadily increased throughout the twentieth century and it is apparent that this has been achieved by exploiting man's activities. Gulls in the area under study were shown to be mainly of Continental origin. They roosted on reservoirs and the directions of their daily dispersals were dictated by the disposition of refuse tips, their principal feeding sites. Individuals showed tendencies to return to the London area and use the same flightlines and feeding areas, including tips, in successive years. As man-made environmental changes continue, and are apparently not yet fully exploited by gulls, there exists a potential for further expansion of the gull population and consequent aggravation of the problems it presents.

From an analysis of ringing recoveries, body measurements, timing of primary moult and of arrival and departure, it is suggested that the Herring Gulls wintering inland in south-east England originate from breeding colonies in Arctic Norway and Russia.

The study showed that straw mulching decreased the basic seedlings and tillers of winter wheat and the leaf area index (LAI) at earlier growth stage, but increased the LAI at latter growth stage. Straw mulching and irrigation reduced the transmittance and reflectance of PAR, resulting in the increase of PAR capture ratio mainly at the height of 40-60 cm. The solar energy utilization ratio of grain was decreased by straw mulching, while that of stem and leaf was increased. The total solar energy utilization efficiency of winter wheat could also be increased by straw mulching.