PRESENT STATUS AND TRENDS OF SEABIRDS IN NORWAY 



295 



Table 5. Status of the common murre (Uria aalge) in Norway (cf. Fig. 2). 



mortality figures given above is 34%: 

 m x = (1-P)/1 X = 0.66/0.35 = 0.17 



For equal sex ratio, breeding success is 2 

 times m x = 0.34. 



A British ringed gannet from Ailsa Craig 

 (5512'N, 507'W) was found nesting when 4 

 years old in the Nordmjele colony in 1970 

 (Brun 1972), giving direct evidence that immi- 

 gration from colonies in Great Britain (Scot- 

 land) still takes place. 



Estimates of Total Seabird 

 Population in Norway 



In addition to the more detailed censuses of 



the cliff-breeding species dealt with so far, 

 notes have been made on all seabirds observed 

 during numerous flights along the Norwegian 

 coast. Although a first attempt at putting a 

 figure to all seabird species in Norway may be 

 somewhat premature, it is believed that even 

 an extrapolation combined with an educated 

 guess is of some value until more accurate 

 censuses covering the whole coast can be 

 made. Although the data (Table 1) are 

 arranged in the same way as the results from 

 "Operation Seafarer" in the British Isles 

 (Cramp et al. 1974), it must be stressed that 

 the accuracy of the Norwegian figures, at 

 least for the noncliff-breeding birds, is far in- 

 ferior to the very fine British data. The table 

 includes data for two petrels (Hydrobates 

 pelagicus, Oceanodroma leucorrhoa), which in 



