Surveys and Monitoring Waterfowl Population Surveys Migration Surveys
| Migration Surveys |
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Some population surveys are conducted during the spring and autumn migrations, such as the mid-continent sandhill crane survey, which is undertaken in late March. Nearly the entire population of cranes gathers in Nebraska’s Platte River Valley during spring migration. A pilot-biologist and observer count birds along established transect lines. Aerial photography of a sub-sample of crane flocks is used to quantify errors and develop correction factors to obtain a more accurate population estimate. A Coordinated Spring Survey of Mid-Continent Sandhill Cranes report is produced each year. Another example of a migration survey is the Fall Inventory of Greater White-Fronted Geese that is conducted every September in the Canadian prairie, where the population gathers during the southward autumn migration. |