Parts Collection Surveys
The HIP Waterfowl Survey (U.S.) and Harvest Questionnaire Survey (Canada) are used to generate estimates of total duck and goose harvest for each country, but that's only half of the process. Each country has a two-tier harvest system, and the second part of the harvest estimation process involves Parts Collection Surveys. Each year the U.S. Fish and Wildlife Service and Canadian Wildlife Service asks a sample of hunters to send in one wing from each duck that they shoot, and the wing tips and tail feathers from each goose. Before the start of every hunting season, survey participants are provided with postage-paid, "wing envelopes" for them to send in their waterfowl parts. In the U.S. these wing envelopes are addressed to one of the four collection points, one in each flyway. In Canada, all the wing envelopes are sent to one centralized location.
Different species of ducks often have distinct color patterns on their wing feathers that biologists can use to identify the species of each wing. For example, Mallards have an easily recognizable purple speculum bordered by two white bars (Fig. 1). In contrast, male Northern Pintails have a partly iridescent green speculum, and females have a dull bronze speculum (Fig. 2). Most wings can easily be identified to species by learning wing feather coloration. Similarly, the species of a goose can be determined from the size and the color of its tail feathers.
Results from the Parts Collection Surveys are combined with the diary surveys to generate species-specific harvest estimates. For example, if the estimated total duck harvest for a state was 750,000 and 35 percent of the wing sample consisted of mallards, then that state's estimated mallard harvest would be 35 percent of 750,000, or 262,500.
Just as a spelling bee is an event where people gather to try to correctly identify the spelling of words, a wing bee is an event where waterfowl biologists gather to try to correctly identify the species, age, and sex of each duck wing and goose tail submitted by hunters. At the end of the hunting season, state and federal biologists gather at annual wing bees and examine all the waterfowl parts submitted by hunters. In the U.S., the USFWS receives about 90,000 duck wings and 20,000 goose tails and wing tips annually. The annual sample size for Canada's survey is about 20,000 duck wings and 8,000 goose tails. Wing bees are held in each flyway every January and February, and biologists from all over North America attend and help out.
The primary reference for duck wing identification is "Species, Age and Sex Identification of Ducks Using Wing Plumage," by Sam Carney.