Welsh Journals

SKOKHOLM BIRD OBSERVATORY, 1956 PETER DAVIS, Warden THE 1956 season was one of the longest and certainly the busiest in the 23 years of the observatory's existence. We opened on 5th February, and closed down on 26th October. In that time, visitors had stayed on the island for a total of 271 unit weeks 43 more than in the record season of 1954. After two years as cook, Pauline Ralphs served most efficiently as Assistant Warden, whilst Ann Challis cooked excellently. My wife played a full part in the activities of the observatory, in addition to pursuing her own studies. A very able young Swiss ornithologist, Francois Veuilleumier, proved a valuable supernumerary during six weeks of the summer. The ornithological work progressed steadily along the es- tablished lines. Migration was disappointing in May and August, but there were periods of great interest at other times, and we had our share of rarities, which will be detailed in the Skokholm Bird Observatory annual report and in British Birds magazine. With 123 species seen in the year, the record of 1955 was equalled. Over 7,300 birds were ringed, covering 69 species. A fall in the number of shearwaters ringed, due to the increasing proportion of recaptures, was compensated by advances in the totals for other sea-birds, notably puffins. The shearwatering programme was reorganized. The location of each bird is now recorded and all recaptures, including those in the year of ringing, are now entered in the files. This has entailed more paper work, but will make future analyses far more valuable. For the first time we tried rings of magnesium-aluminium and of monel in the effort to combat ring-loss in the sea-birds. Pauline Ralphs continued her shearwater studies and was able to cover the entire pre-egg stage. She weighed adults regularly in the burrows, and later another series of chicks. She successfully used the technique of sexing by cloacal examination discovered by the Australian zoologist, D. L. Serventy, and later I was able to apply this to the 18 breeding pairs of Storm Petrels in my own study-burrows. This technique, applicable only at the time of egg-laying, led me to the unexpected discovery that male Storm Petrels usually take the first incubation shift. This has reversed my earlier assump- tions, but fortunately most of the 1956 breeding birds were the same as in the two previous seasons, and the new data can be applied to earlier results. Periods of inclement weather from late July onwards had interesting, if sometimes disastrous, consequences, affecting both hatching success and the feeding rate. They were directly responsible for the failure of four or five pairs, and for the longest incubation period (50 days) and the longest fledging period (73 days) in my records.