Epizootiology of Leucocytozoon in Canada geese (Branta canadensis)

Journal of Parasitology
By: , and 



Studies have been conducted over the past 20 years, mainly at the Seney National Wildlife Refuge in northern Michigan. Losses in goslings occur every year. Every fourth year these losses are severe, approaching 80% of the gosling crop. Lesser losses occur during the fifth year, in 1969 these losses were about 50%. In the two intervening years losses were in the range of 17 to 27%. It is assumed that the losses in these off-years are due to predation, weather, and other habitat-related factors. In the years of severe losses we attribute the cause largely to Leucocytozoon. Although most of the goslings sampled each year demonstrate a parasitemia with Leucocytozoon, in the years of severe losses the parasitemia is much higher and accompanying characteristic pathological findings are much in evidence. The main vector of Leucocytozoon in ducks in the area is Simulium rugglesi which has been implicated in the transmission in ducks in Wisconsin and Ontario as well as in Michigan. However, the losses in the geese occur in early June before S. ruggIesi makes its appearance in any numbers. Field and laboratory studies implicate S. innocens as the most important vector in early transmission to the geese. This species of fly is most abundant in late May when the geese are hatching. Adult geese have been observed to have a relapse of parasitemia when they arrive at the nesting area in late April and during the egg-laying period. Experiments on captive birds indicate relapse parasitemia can be increased by various stress factors. It is hyposthesized that unattached adults, which remain more aggressive during the nesting season, are the chief source of parasites for the vector blackflies.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Epizootiology of Leucocytozoon in Canada geese (Branta canadensis)
Series title Journal of Parasitology
Volume 56
Issue 4, Section II, part
Year Published 1970
Language English
Contributing office(s) Patuxent Wildlife Research Center
Description 143-144 (abstract)
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Journal of Parasitology
First page 143
Last page 144(abs)