Year: 1976
Type: article
Abstract: It has been commonly reported, but rarely described in detail, that storms may inflict heavy direct mortality on eggs and young of•colonial birds nesting along shores in salt marshes, sand beaches, and loxv rocky coasts.High tides and strong winds have killed eggs and chicks of Least Terns, Sterna albifrons (Hagar, 1937), Black Guillemots, Cepphus grylle (Winn, 1950), Roseate Terns, Sterna dougallii (Robertson, 1964), Common Terns, Sterna hirundo (H.Hays, pcrs.comm.), and Laughing Gulls, Larus atricilla (J.Berger, pcrs.comm.).Storms may also indirectly increase mortality of chicks by adversely affecting feeding conditions for adults.This effect is little studied in seabirds, but has been documented for aerial feeders such as swifts, whose food supply is reduced by cold, rainy weather (c.g, Lack and Lack, 1951).In June, 1972 Ricklefs and White were studying the energetics of nestling growth in Sooty Terns (Sterna fuscata) at the Dry Tortugas, located in the Gulf of Mexico 70 miles west of Key West, Florida, when hurricane Agnes passed west of the area.High winds, heavy rain, rough seas, and low temperatures prevailed for more than a week.Robertson worked in the colony from 28 June, about a week after the storm subsided, to 6 July.We report here the effects of hurricane Agnes on the growth and survival of young Sooty Terns and Brown Noddies (Anous stolidus).WEATHER National Weather Service records (Simpson and Hebert, 1973) show that a barometric pressure trough began to move from Yucatan to southern Florida and the western Bahamas on 11 June 1972.On 14 June, a strong localized depression developed near Cozumcl Island, Yucatan, and it moved east on 15 June.Winds reached tropical storm strength overnight and Agnes was named on 16 June.By 18 June xvhcn the center of the storm was passing 175 miles W of Dry Tortugas, Agnes had reached hurricane status.Agnes was a relatively weak hurricane, but she had an exceptionally large circulation envelope, about 1,000 nautical miles in diameter.Disturbed weather patterns were seen in satellite photographs up to 2,000 miles from the center of the storm.The Dry Tortugas had fair weather until 11 June, after which increasing rain, winds, and rough seas prevailed.The disturbance lasted about 10 days.We could not obtain weather records from the Dry Tortugas, but Key West records illustrate the degree of disturbance (Fig. 1).The mean temperature during June at Key West between 1832 and 1922 was 81.9 ø F (Clayton, 1944).Between 12 and 20 June 1972, temperatures at Key West were unscasonally low, with daily maxima at or below the mean temperature on 6 days.Winds recorded at Key West increased during the storm and 54
Source: Bird-Banding
DOI: 10.2307/4512192
Authors: S. C. White, W. B. Robertson, Jr., R. E. Ricklefs
Language: English
Topic: Avian ecology and behavior
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2800594288