The occurrence of Great Black- 
headed Gulls in Bahrain in winter of 
1989/90 
Erik Hirschf eld 
Not much is known of the migration pattern of Great Black-headed 
Gulls Larus ichthyaetus in Arabia. Nightingale and Hill (in prep) state 
that they are late migrants in Bahrain, seldom seen before mid- 
December, increasing in January to peak in mid-February, whereafter 
they decrease until most are gone by mid- April. In some springs, an 
increase has been recorded in mid-March, presumably of migrants 
that have wintered farther south and which pass Bahrain on their 
return migration. Bundy et al. (1989) mention it as a fairly regular 
visitor in coastal waters of eastern Saudi Arabia from December 
through to March, when their numbers reach a peak. 
During more than 50 days in the field in Bahrain from December 1989 
to April 1990, 1 recorded and aged 1,047 individuals between 8 
December and 19 April. Peak numbers, of 98 and 115, were recorded 
on 23 and 24 February respectively. The first flock numbering more 
than 30 was seen on 30 January (35), while the last was recorded on 27 
March (40). 
In figure 1, 1 have calculated the mean number of Great Black-headed 
Gulls observed per excursion during 10-day periods. This should 
negate large fluctuations in numbers resulting from the variation of the 
intensity of my activities. Counts were made between one and five 
times per 10-day period, the lower number during March and April 
when passerine migration also attracted my attention. 
