In a Black Skimmer Colony 83 



The male aids in incubation. 



Earliest positive date for yonng in nest, May 13. 



For at least two to three Aveeks before the commence- 

 ment of nest bnilding the birds spend the greater part of 

 clear days awny from the boxes, returning to them towards 

 sunset. During rainy or extra cold days they do not so 

 generally depart from the boxes at such times. 



All the birds forsake the boxes two to three weeks 

 after the young first fly. Prior thereto they may be absent 

 during the greater part of the day but usually return to the 

 boxes at night. 



- Latest dates when seen September 20 to October 2 for 

 different years. 



TWENTY-FOUR HOURS IN A BLACK SKIMMER 

 COLONY 



BY P>. R. BALES^ M.D. 



A day and a night spent in the midst of a densely poj)- 

 ulated sea bird colony is an experience never to be forgot- 

 ten. Such was my experience on June 23, 1917. The col- 

 ony was one of the Black Skimmer {Rhynchops nigra), and 

 was located on a small island about fifteen miles off the 

 Virginia coast. 



The island is composed entirely of fine sand, and is 

 barely above high tide, in fact, it is so slightly elevated 

 that high tides in 101(5 swept over the island drowning all 

 the young birds with the exception of a few which took 

 refuge on several slight elevations. A thin growth of salt 

 water grass covers these elevated portions, but the rest of 

 the island is destitute of vegetation. 



The colony, a conservative estimate of whicli, would 

 number the breeding birds at 1000 pairs, is about one mile 

 long and several hundred yards wide. It is like a city, 

 being more thickly populated at some parts than at oth- 

 ers; at one place, without moving, 26 nests could be seen, 

 at another place 14, and at another 10. The similarity to 

 a great city is further carried out by the small detached 



