Aspects of chick growth in Gull-billed Terns in coastal Virginia
Aspects of chick growth in Gull-billed Terns in coastal Virginia
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DOI：
10.2307/1521992
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发表时间：
1999-01-01
期刊：
影响因子：
0.3
通讯作者：
Hatfield, JS
中科院分区：
文献类型：
--
作者：
Erwin, RM;Eyler, TB;Hatfield, JS
Because of concerns about apparent population declines and low productivity of Cull-billed Terns (Sterna nilotica) along the coast of Virginia, we investigated whether food limitations may result in retarded growth rates of young. Several colonies of Gull-billed Terns were monitored from May to July each year from 1994 to 1996 on both sandy barrier islands and marsh/shellpile islands in coastal Virginia. Nests were visited one to three times a week to monitor clutch size and hatching success, and enclosures were installed around selected nests to monitor chick growth from hatching to at least two weeks of age. When comparing chick growth, we found significant year, habitat and hatch order effects. Chicks from marsh shellpiles had higher mass and culmen growth rates than did those from barrier islands, and first-hatched chicks had significantly higher culmen growth rates than did second-hatched chicks. Year effects were only found for mass growth rates. Growth rates of Gull-billed Terms in these Virginia colonies seem to be low relative to those of six other North American tern species from other geographic areas. These findings suggest that growth rates of young Gull-billed Terns, as well as other reproductive parameters, need to be examined in detail in other coastal areas such as Texas, where the species is more abundant, to determine whether our growth results are species- or region-specific.
