Waterfowl helminth manuscript near comple- 

 tion. — Tim bibliography of references to water- 

 fowl helminths was brought to current status an<l 

 will be ready for publication as soon as the typing 

 of the manuscript is completed. During the year, 

 150 references were added, bringing the total to 

 about 2,400. About .'500 books and papers were 

 abstracted in the course of surveying the 

 literature. 



The checklist of helminths of waterfowl, now 

 totaling 844, was brought up to date. Descrip- 

 tions of 27 species, "21 of which were translated 

 from the Russian, were added to the list, and keys 

 for the identification of nematodes, aeanthoce- 

 phala, and cestodes of waterfowl were revised as 

 descriptions of forms were obtained. There still 

 remain 2(i species for which descriptions are not 

 available. 



Fowl choli ra low in 1963. — Although no major 

 losses from fowl cholera in waterfowl are known 

 to have occurred in the western United States 

 during the year, several isolated cases were en- 

 countered in the course of routine diagnostic ex- 

 aminations. Two whistling swans, a Canada 

 goose, and a cackling goose from western national 

 wildlife refuges were shown by bacteriological 

 examination to have died from the disease. Be- 

 cause of the constant danger of fowl cholera in 

 waterfowl, about 85 Canada geese of a captive 

 flock on the Monte Vista Refuge were immunized 

 with a commercially prepared bacterin in 

 November. 



Triuii />, I, r swan eygnets show lower mortal- 

 ity. — Studies of the causes of mortality in trum- 

 peter swan cygnets on the Red Rock Lakes Refuge 

 were continued from the previous year. Of 24 

 cygnets in 6 broods regularly observed on Lower 

 Lake, 8 died or were unaccounted for, a mortality 

 of 33.3 percent. Of 19 vy<rnets in 7 broods ob- 

 served in 1002 on Lower Lake, 13 were lost, a 

 mortality of 68.4 percent. 



These figures seem representative of the Red 

 Rock Lakes Refuge as a whole since the 1963 na- 

 tional aerial trumpeter swan survey for 1963 re- 

 vealed 127 cygnet son the refuge, as compared with 

 .">•'! in 1962. This is the largest number reported 

 since the first census was taken in 1032. 



Miliaria infections in watt rfowl, — Studies at the 

 Seney National Wildlife Refuge in L963 indicated 

 the presence of at least (i species of blackflies 

 (S; in alia m) breeding in the area. At least 1 



serves as a vector for Leucocytozoon. a malaria- 

 like organism which occurs in the Canada geese. 

 Breeding habits of this fly are being studied in the 

 hope of developing control methods that can be 

 incorporated into the management schedule for 

 waterfowl impoundments. Gulls, found to be 

 highly susceptible to a Plasmodium (mosquito- 

 borne malaria) recently isolated from Canada 

 geese, were used, along with young ducks and 

 geese, in surveying the prevalence of this blood 

 parasite in the Seney goose population. Evidence 

 of infection was determined in over 50 percent of 

 the ir^H' sampled. The specific mosquito vector 

 of the infection is not yet known. 



Throat disease in mourning doves. — Surveil- 

 lance of trichomoniasis, a throat disease of mourn- 

 ing doves, was continued during 1963 by the 

 collaboration of many State game personnel. 

 Infection rates appeared higher in many areas 

 than in previous years, but no alarming losses were 

 reported. A definite and rapid reduction of in- 

 cidence was noted in July. 



Nematodes in relation to merganser losses. — 

 Diagnostic services of the laboratory at the 

 Patuxent Center led to evidence that a nematode 

 worm parasite {Eustrongylides sp.), for which 

 fish serve as an intermediate host, was a contribut- 

 ing factor to losses of mergansers in the Rack Ray, 

 Ya., area. 



Type E botulism in birds. — At year's end a large 

 die-off of loons and gulls on Lake Michigan indi- 

 cated a relation to the type E botulism recently 

 evident in processed fish. This implication has 

 initiated research activity on type E botulism in 

 hi rds and collaboration with other agencies, pari ie- 

 ularly the Rureau of Commercial Fisheries and 

 the Michigan Conservation Department. 



Tissue damage from pesticides. — In an effort to 

 clarify the mechanism of certain neurological 

 signs in experimental ducks treated with Kepone, 

 histological sections of various tissues of the cen- 

 tral nervous system were studied without uncover- 

 ing any attributable lesions or changes. Active 

 sperm formation was found in the testes of male 

 mallards and pheasants exposed to various dosages 

 of Kepone, thus contradicting our earlier findings 

 in which degenerative changes in the testes of 

 male pheasants were reported. 



Ring-necked pheasant. — Rlood samples from 

 1.1(17 pheasants from 44 Iowa game farms have 

 been collected by the Iowa Unit Rapid plate 



52 



