Article Abstract:
A ten-year autumn stopover pattern study between 1983 and 1992 of migratory passerines on Appledore Island, Maine, indicates that young birds predominate among the captured birds in all species. Recapture rate is higher for younger than older birds. Young Northern Waterthrushes stop significantly longer compared to adults. The young birds are leaner than the adults in a number of species. The birds show an increase in fat content and mass during stopovers. Differences in fat increase and in mass between age groups and between sexes are insignificant for all species examined. Species differences are an important factor in stopover biology.
User Contributions:
Comment about this article or add new information about this topic:
Article Abstract:
The utility of four nondestructive condition indices are evaluated to predict the levels of fat in migratory passerines. Wood thrushes, Swainson's thrushes and summer tanagers are studied in terms of their body mass, body mass scaled by wing chord length, fat scoring and the total body electrical conductivity method. Results show that body mass is the best predictor of total body fat in the passerines Hylocichla mustelina, Catharus ustulatus and Piranga rubra.
User Contributions:
Comment about this article or add new information about this topic:
Article Abstract:
The abundance of seven species of cavity-nesting birds and the Northern Parula in a bottomland hardwood forest associated with the Atchafalaya River in Louisiana remained unaffected by Hurricane Andrew. The density of understory vegetation and the number of snags increased with the damage, following the hurricane. Their low abundance may be associated with the loss of canopy foraging habitat or of Spanish moss, that is one of its major nesting sites.
User Contributions:
Comment about this article or add new information about this topic: