Long-term bird population trends based on accumulated ratios (proportional change) sometimes give a very misleading view of population change. Alternate methods of representing population change, based on the weighted means for the individual years, avoid the dangers of using ratios. Some advantages and disadvantages of various weighting techniques are discussed.
Additional Publication Details
Techniques and results of nongame bird monitoring in North America
Dachverband Deutscher Avifaunisten
Gottingen, West Germany
Patuxent Wildlife Research Center
Larger Work Type:
Larger Work Subtype:
Other Government Series
Larger Work Title:
Bird Census Work and Nature Conservation. Proceedings VI of the International Conference on Bird Census Work.