Center revealed no infection with this organism. 



Xutritional dejicienci/ in Canad<i gene. — In 

 May and June 1964. a severe loss of young Canada 

 geese occurred in the Fish Springs National Wild- 

 life Refuge. Twenty-nine of 41 birds of the year 

 died, and 3 survivors were sacrificed in July and 

 August for funher study. Examination of five 

 birds at the Bear River Research Siatiwi showed 

 that perosis was at least a contributing cause of 

 death. 



Perosis results from a deficiency of manganese 

 or of certain vitamins in the diet. Manganese de- 

 ficiency is the most conmion cause in poultry, but 

 inadequate levels of choline, biotin. niacin, or folic 

 acid may be responsible. High levels of calcium 

 or phosphorus increase the requirement for 

 manganese. 



Waterfo'xl parasite manujseripts completed. — 

 The waterfowl family (ducks, geese, and swans) 

 is worldwide in distribution, and many of its 

 parasites have a similar worldwide occurrence. 

 Parasitological research is being performed in 



many different countries, and several abstract and 

 bibliographic publications on waterfowl parasites 

 are available. However, none of these gives com- 

 pilations of the accumulated knowledge. 



The study of waterfowl parasites in progress at 

 the Bear River Research Station requires the use 

 of a large number of references for the identifica- 

 tion of parasites, indications of pathogenic import- 

 ance, comparison of results, better understanding 

 of the ecology, and planning future studies. In 

 the absence of such a summary, one was prepared, 

 along with a bibliography, during the period 

 1959-64. The result is an annotated bibliography 

 of about 2,300 references on helminths of water- 

 fowl, now in press. Also, in press is a catalog of 

 helminths of waterfowl of the world, giving for 

 each of S45 reported species its importance as a 

 waterfowl parasite, synonymy, summary of life 

 history, hosts, habitat, distribution, and biblio- 

 graphic citations for these items. These publica- 

 tions will provide useful references to waterfowl 

 parasites throughout the world. 



Mule deer at watering tank cm the Arizona desert. The two "hues" on the buck are cholla cactus "claws." (Photo 



by J. B. Elder) 



56 



