Duck Species Co-occurrence in Hunter Daily Bags

作者：Haugen Matthew T^*; Vrtiska Mark P; Powell Larkin A

来源：WILDLIFE SOCIETY BULLETIN, 2015, 39(1): 70-78.

DOI：10.1002/wsb.515

• Central Flyway
• harvest
• multi-species management
• Parts Collection Survey
• waterfowl regulations

As multi-species harvest management gains support among waterfowl managers, increased understanding of duck species relationships during harvest is needed. We used U.S. Fish and Wildlife Service's Parts Collection Survey data from 2002 to 2011 to develop a matrix defining relationships among duck species harvested in the Central Flyway. We calculated conditional probabilities of co-occurrence in a hunter's daily bag (i.e., P(B vertical bar A), the probability that species B was in a hunter bag, given that species A was in the same bag). We then performed 12 scenarios of hypothetical changes to species-specific regulations. We used Central Flyway harvest estimates from 2011 and probabilities of co-occurrence to predict the effects of regulatory changes on harvest. Hunters were more likely to harvest 2 species of diving ducks (P(Diving vertical bar Diving)=0.37) than to harvest a diving duck given that a dabbling duck was also harvested the daily bag (P(Diving vertical bar Dabbling)=0.12). Hunters also were more likely to harvest 2 ducks of the same species (and sex in the case of mallards [Anas platyrhynchos]) within a daily bag (mean P(A vertical bar A)=0.31) than 2 ducks of different species (mean P(B vertical bar A)=0.13). Traditionally, managers have focused on single-species assessments when considering regulatory changes, but harvest regulation changes may affect multiple duck species if harvest is redistributed to other species. Our data show a range of co-occurrence patterns of species commonly or rarely harvested together. Examination of the relationships among duck species during harvest provides critical insight for the development of appropriate regulations for multi-species management.

• 出版日期2015-3