The effects of several forms of agricultural use of native fescue (Festuca scabrella) grasslands upon populations of native passerine birds were studied in the Hand Hills of southern Alberta in 1970.Censuses of avian populations were carried out on twelve 40-acre (16.2 ha) study plots as well as on two 10-mi (16.1 km) long roadside routes. The vegetation on the study plots and along the roadside routes was described.Native fescue grasslands, undisturbed for 3 years, supported a passerine community consisting of Baird's sparrow (Ammodramus bairdii), Sprague's pipit (Anthus spragueii), savannah sparrow (Passerculus sandwichensis), clay-colored sparrow (Spizella pallida), and western meadowlark (Sturnella neglecta). Incomplete disturbance of fescue grasslands, by mowing for hay or grazing by cattle, reduced or eliminated Baird's sparrow and Sprague's pipit but permitted the ingress of horned lark (Eremophila alpestris) and chestnut-collared longspur (Calcarius ornatus). Total elimination of the native grassland, by ploughing and cultivation for cereal crops, eliminated all passerine species except the horned lark. Peripheral disturbed areas resulting from cultivation, such as held boundaries and roadside ditches, may have benefited several species that tend to occur in ecotonal habitats: savannah sparrow, clay-colored sparrow, and vesper sparrow (Pooecetes gramineus).

Summary Observations were made with radar from the Shetland Isles in 1960. During the late autumn a regular broad‐front movement passed westwards over Shetland from Scandinavia about midnight. Its front evidently extended by dawn from the Outer Hebrides towards the Faeroe Islands. The movement consisted of fast‐moving bright radar responses. During the later hours of the night the responses from the overnight passage movement generally, though not invariably, almost totally disappeared. Their disappearance seems to have been due to the birds having descended below the radar beam. The radar display always filled up again with rather faint, evenly distributed, responses in a short period around dawn, over a wide area of the south Norwegian Sea. The evidence indicates that these responses were from the same species as those observed on overnight passage, and that the sudden reappearance of responses around dawn was due to a sudden gain of altitude by these birds. The responses then assumed directions of movement which were not randomly distributed around the compass. Continuation of flight southwestwards or westwards on the overnight heading was infrequent, even in southeasterly winds. Movement in directions between W. and N.N.W. was very rare after dawn. Off Shetland three main directions of movement were recorded, E.S.E.–S.E., N.–N.N.E. and S.–S.S.W. Ascents at dawn and re‐orientation behaviour have been established as taking place over both the northeastern Atlantic Ocean and the North Sea. Ascents with at least one direction of reorientation have been observed also off the Outer Hebrides, off eastern Scotland and north of East Anglia. Overnight passage was recorded from Shetland on 22 out of 48 nights and the dawn ascent was recorded on 33 mornings. Directions of movement after dawn were determined on 26 mornings, on only two of which were the directions random. On 15 of the 24 mornings when re‐orientation occurred the wind at 900 m. above Lerwick was not greater than 15 knots. In 1961 ascent, without re‐orientation, was recorded from Iceland Redwings and Wheatears off the Outer Hebrides by Lee (1963). The possibility that birds of Icelandic origin were responsible for any of the southeastward directions of movement observed around Shetland in 1960 could be excluded for a combination of reasons. The possibility that warblers, flycatchers, chats, or finches drifted to Fair Isle and Shetland could have been responsible for the dawn ascents and re‐orientation off Shetland was also excluded. The radar responses, the detailed analysis of the radar data, the correlation of radar observations with field observations on Fair Isle and North Rona and other circumstantial evidence have strongly suggested that thrushes of the genus Turdus (especially Turdus musicus and probably T. merula and T. pilaris) were responsible for the overnight passage movements, dawn ascents and re‐orientation behaviour after dawn. It is shown that Shetland falls within the regular migratory path of Scandinavian thrushes in the autumn. Neither da...

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Shearwaters, Puffinus spp., were studied off the west coast of Canada from 1975 to 1978. Sooty shearwaters, P. griseus, were the most abundant shearwaters off British Columbia in both May and September–October. Pink-footed shearwaters, P. creatopus, also occurred in both spring and fall. Flesh-footed shearwaters, P. carneipes, were found only in May. Buller's shearwaters, P. bulleri, were encountered in June and July during cruises across the Gulf of Alaska and in September and October off British Columbia. The recent increase of Buller's shearwater in the North Pacific is documented. A review of records of the short-tailed shearwater, P. tenuirostris, shows that it is usually rare and irregular off the coast of British Columbia. One black-vented shearwater, P. opisthomelas, was seen in the Gulf of Alaska. Sooty shearwaters occur off British Columbia in far lower numbers than off northern California, Oregon or Washington State. The manner in which sooty shearwaters migrate is described. The relationship between shearwater distributions and depths of water over the continental shelf are examined.