But, from these three colors, you can mix all colors found in the spectrum. Selecting Three Primaries. Probably the best way to choose primary colors is to browse through various art instruction books until you find an artist that sees, and interprets, color in the same way as you do. Deciding on which three primary watercolors to begin with can seem quite daunting, especially if you are new to watercolor.
144 Field Manual of Wildlife Diseases: Birds Figure 16.4 During the 1973 outbreakof duck plague at Lake Andes NationalWildlife Refuge in South Dakota, morethan 40,000 mallards died. Photo by Milton Friend from adjacent Flanders Bay, apparently as a result of diseasetransmission from white Pekin ducks.ittle is known about the response of wild water-fowl to strain differences.Duck plague outbreaks are thought to be caused whenbirds that carry the virus shed it through fecal or oral dis-charge, thus releasing the virus into food and water withwhich susceptible birds may have contact.
Domesticated birds (chickens, turkeys, etc.) may become infected with avian influenza A viruses through direct contact with infected waterfowl or other infected poultry, or through contact with surfaces that have been contaminated with the viruses.oth HPAI and LPAI viruses can spread rapidly through flocks of poultry. HPAI virus infection in poultry (such as with HPAI H5 or HPAI H7 viruses) can cause disease that affects multiple internal organs with mortality up to 90% to 100%, often within 48 hours. Some ducks can be infected without any signs of illness.