Normal period of occurrence generally applies to non pelagic seabirds for 

 which hundreds of sightings from Maryland recorded during the past century 

 have been analyzed and reported by Stewart and Robbins (1958). Earliest and 

 latest records are those I recorded at sea. 



COMMON LOON ( Gavia immer) 



Status . Common spring and fall transient and winter visitant within 50 km 

 of shore, becoming less common toward the edge of the Continental Shelf 

 (Fig. 3). 



Normal period of o ccurrence . --Mid-September to late May. 



Earliest fall record . --19 October 1974. 



Latest spring r ecord .-- 1 June 1975. 



Maximum counts. --FALL: 



85 in 8 h, 2-20 km from shore, 19 November 1972; 

 2 h, 2-60 km from shore, 3 December 1977. SPRING: 240 in 6 h, 2-90 km 



102 in 6 h, 2-90 km from shore, 27 April 1974; 97 

 WINTER: 23 in 3 h, 2-20 km from 



64 in 



from shore, 30 April 1977; 



in 11 h, 2-177 km from shore, 11 April 1976 



shore, 12 January 1975; 26 in 4 h, 2-90 km from shore, 1 February 1975 



Remarks. — During fall and winter, most common loons were solitary, but 

 during the height of the spring migration (mid-April to early May), they were 

 occasionally seen in rafts of up to 100. Migrating loons were most conspic- 

 uous during the first three hours of daylight, and to a lesser extent, during 

 the last two hours of the day. All loons generally avoided the vessels and 

 showed no interest in chum. 



MAMJJASOND 



month 



1=0.1-1.0 1=1.1-5.0 B=5.1-10.0 HB=10.1-12.0 



MEAN NUMBER OF INDIVIDUALS OBSERVED PER HOUR 



X = ZONE NOT SAMPLED IN THIS MONTH 



Figure 3. Seasonal abundance and seaward patterns of the common loon in the 

 northern Chesapeake Bight, 1971-1977. 



9 



