Why should ducks, geese, and swans not be fed?
Three good reasons for not feeding the birds include: • it may propagate swimmer’s itch in the area where the birds are being fed • it may make the birds dependent on humans for survival • feeding the birds may stimulate fecal deposits at the feeding site. How do you determine which birds are carrying the schistosomes that are causing swimmer’s itch on a particular lake? Birds can be checked for avian schistosomes by hatching the miracidia from parasite eggs in the hosts’ feces. If hatch-year (young birds) that can’t fly are positive for avian schistosomes, then it must be concluded that they contacted the parasite on that specific lake. Not only can the bird species of dermatitis-producing parasite be isolated, but it is possible to determine the level of infection. This is done by weighing the fecal content and then counting the number of miracidia that hatch from one gram of feces. It is important not only to know what bird species serve(s) as hosts, but also the level of infection.
