Article Abstract:
A novel procedure for obtaining estimates of molt duration for birds captured once within a molten period is presented. This method, called Residual Raggedness Value (RRV), is compared with estimates obtained from the regression method and recaptures using a data set of Willow Warblers. A positive correlation was found between molt stage and the wing raggedness value, which measures the amount of missing feather in bird wings. A high correlation was also obtained between recaptured birds' molt speed and the RRV at the first capture. Estimates obtained using the RRV technique were close to those calculated from recaptured individuals.
User Contributions:
Comment about this article or add new information about this topic:
Article Abstract:
Distribution atlases of bird populations are becoming increasingly common. A new study assesses the ability of such data to develop inductive wildlife-habitat relationship (WHR) models for seven species of woodpecker in the Jura, France: the Black Woodpecker, Great Spotted Woodpecker, Middle Spotted Woodpecker, Wryneck, Green Woodpecker, Grey-Headed Woodpecker and the Lesser Spotted Woodpecker. The study shows that using woodpecker distribution data from a breeding bird atlas, combined with habitat variables, is a simple way of building WHRs.
User Contributions:
Comment about this article or add new information about this topic:
Article Abstract:
The speed of migration of the juvenile reed warblers (Acrocephalus scirpaceus) and sedge warblers (A. schoenobaenus) were examined. The results showed that sedge warblers have higher migration speed than reed warblers. Sedge warblers have departed with lower fat deposition than reed warblers, but may have encountered stopover sites which offered higher relative fat deposition rates farther down south. The amount of visible fat at the time of banding has been found to be related to migration speed.
User Contributions:
Comment about this article or add new information about this topic: