28 Loomis on Birds of Chester County, South Carolina. \ J y^ 



They kept well away from the land. None were seen nearer 

 than a mile, most were out beyond two miles. At midday, 

 over several square miles, a few solitary individuals were seen 

 on the water. All the others had disappeared, had passed over 

 without stopping. On the ioth a second and apparently greater 

 flight began, reaching its height on the 12th. As before, all flew 

 steadily southward along the line of the shore. They came 

 nearer to the land, however, on the day of greatest abundance, 

 a heavy fog having set in. When it lifted it was seen that 

 the inshore edge of the movement was within five hundred 

 yards of the surf at Point Pinos — a sort of local shifting having 

 transpired. The flocks were quite noisy as they passed onward 

 through the fog. The constant utterance of their call notes not 

 improbably aided those further out to keep their course. No 

 stragglers were noticed on the water during the fog or after it. 

 All had passed over. From the 15th onward there were feeble 

 movements along, but no rushes. The birds were inclined to 

 approach the shore nearer than at first, and loiterers were found 

 quite numerously upon the water. Perhaps these later birds were 

 not the tired ones that had dropped by the way and resumed 

 their journey, nor those that had been delayed in starting, but 

 arrivals from stations further north, the advance guard of others 

 that subsequently followed, as I was informed, and made the Bay 

 a resting place. 



On land such a migration as described would readily have 

 escaped notice in its earlier stages. The concealment afforded 

 by the vegetation would cause stragglers to be overlooked, and 

 the greater perils and the artificial and natural obstructions would 

 necessitate a higher flight being maintained. 



To summarize: When a smaller land species is habitually rare 

 or absent in this locality through the whole course of either move- 

 ment, it is held, aside from the influences of environment, that 

 the cause lies in the shifting of the line of flight to the eastward 

 or westward, not in a continual passing over of successive waves. 



Erratic Variability. — Lateness of arrival, unusual scarcity or 

 absence, exceptional abundance or occurrence, exemplify erratic 

 variability- These irregularities of migration may reasonably be 

 attributed to variableness in the location of isolated communities, 

 variation, eastward or westward, of starting point bringing about 



