An Eco-immunological Study of Chesapeake Bay Waterfowl

Science Center Objects

The Challenge: The health of the abundant waterfowl species of Chesapeake Bay has become a major concern due to the spread of Avian Influenza (AI) across North America and the role of waterfowl as a vector of AI. For decades, the health of the Bay’s waterfowl has been affected by the degradation of water quality and food supply due to industrial contaminants,agricultural run-off, pollution from human settlements, and loss of marsh habitat. Measuring immune system function is a more precise way to evaluate wildlife health than noting abundance and population trends. Characterization of immune function in local waterfowl species will assist public health officers and wildlife managers in predicting the probability and dynamics of an outbreak of avian influenza in Chesapeake Bay.

The Science: The black duck, an iconic, formerly abundant Chesapeake Bay species is a focal species in the restoration of a healthy Chesapeake Bay ecosystem. We are assessing the black duck’s innate immune function, since that innate immunity is the critical arm of the immune system that serves as the first line of defense against invading pathogens. We are assaying the effectiveness of oxidative burst and degranulation, two cellular level immune responses responsible for controlling infection quickly. We will compare the relative functional effectiveness of degranulation and oxidative burst in the black duck vs a closely-related species, the mallard duck (Anas platyrhynchos). Mallard populations have increased in abundance in the Chesapeake during the decades when black ducks declined, and a comparison of the relative immune responses of the two species can serve to quantify the relative capacity of the two species to cope with local environmental stressors.

The Future: We will utilize the Patuxent Wildlife Research Center Waterfowl Complex which houses 9 species of ducks representing the full continuum of North American ducks, including dabbling ducks, sea ducks, and diving ducks. This will be the first comprehensive comparison of innate immune responses among species of the 3 major groups of ducks, which differ in life history, habitat use, and diet. An assessment of immune system health of waterfowl species in the Chesapeake Bay will support the efforts to restore the Chesapeake Bay ecosystem and serve as a major indicator of the impact of pollutants and contaminants on human health.