National Migratory Bird Harvest Survey

We learn about individual species with the Parts Collection Survey

The Parts Collection Survey asks hunters to send in wings and/or tail feathers from their harvested birds.

Wings identify the sex of birds

Migratory bird reproduction is important to sustain populations. Reproduction is dependent upon the relative number of male and female birds in the population. A sex ratio is the average number of male birds for every female bird. We use sex ratios to understand a species' capacity for reproduction.

Wings and tail feathers identify the age of birds

If we identify a lot of immature birds, then we know that many adult birds are successfully reproducing. We can estimate reproduction rates from the ratio of the harvest of immature birds to adult birds. However, since immature birds are more vulnerable, we use banded bird recovery data to "correct" for the greater number of immature birds that are harvested when calculating the proportion of immature birds in the population.

In the graph below, you can compare different species' age ratios by year.

Consistent rates of reproduction ensure that waterfowl are abundant enough for hunting. By providing us with accurate survey results, we calculate better estimates, and hunters improve hunting opportunities for future generations. Learn more about how wings are identified to species. The more hunters that participate, the more accurate our estimates will be!

The Parts Collection Survey helps us understand trends

Some years, when bird populations are high, harvest is high and vice versa. Managers are more concerned about harvest rate than total harvest. Harvest rate is the proportion of a species' total population that is harvested. We calculate harvest rates from bird banding data.
Adult breeding Mallards and fall adult harvest estimates often follow similar patterns

US Fish and Wildlife Service Division of Migratory Bird Management
Web content created by Emma Chan and Abby Walter