Patuxent Wildlife Research Center (PWRC) Migratory Bird Research (MBR) Comments/FAQ(comments)
We also provide some estimates of mean trend and a ranking of species from most extreme decline to most extreme increase, using the procedures given in Link and Sauer (1996). These results adjust estimates for relative precision, and you can estimate:
These results are based on hierarchical model trend estimates (Link and Sauer 2002).
We group birds based on attributes such as breeding habitat, nest type, migration status, and nest location. If species in the group show consistent trends, and differ from species not in the groups, it suggests that the common feature could be influencing population change for the group. For more discussion on this, click here. For a listing of the species in each guild, click here
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