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A new species of Leucocytozoon with gametocytes in fusiform host cells is described from the Bukharan great tit Parus bokharensis. It represents the first leucocytozoid in which the host cell nucleus is split into 2 more or less symmetrical portions, each located at an end of the host cell within its elongated fusiform processes. This species appears to be restricted with respect to geography and host.

Blood parasites of the protozoan suborder Haemosporina include Plasmodium, Leucocytozoon, and Haemoproteus. Because life cycles of these parasites often lead to matings between individuals of the same genetic lineage (clones), selection for female-biased sex ratios should occur. Accordingly, sex ratios of populations of Plasmodium and Leucocytozoon closely matched expectations for probable rates of outbreeding. However, sex ratios of Haemoproteus populations were similar across a wide range of inferred outbreeding rates. Of several hypotheses we consider to explain this disparity, there are three we favour. The first is that the interaction among host immunity, parasite pathogenicity, and clone longevity differs among genera, so that on average more Haemoproteus clones coexist within hosts, thus reducing selection for female-biased sex ratios in that genus. The second hypothesis posits that hosts of the Haemoproteus populations we analysed had greater dispersal than did host of Plasmodium and Leucocytozoon. A consequence of this might be greater temporal and spatial variability 111 Haemoproteus outbreeding rates so that Haemoproteus populations were presented from achieving ideal sex ratios for the situation in which they found themselves. The third hypothesis is that Haemoproteus is vectored by relatively small midges so that biased parasite sex ratios in blood can result in too few gametes of one sex in a vector Each hypothesis has its merits and each could contribute to the patterns we observed. Our objective here is to stimulate further interest in the disparity.

We investigated whether the blood parasite Leucocytozoon simondi could slow mallard (Anas platyrhynchos) population growth in the east that has been associated with American black duck (A. rubripes; hereafter black duck) population decline. Susceptibility to parasites was compared among F1 ducklings produced from crosses between mallard and black ducks from areas of Leucocytozoon endemicity (Ontario), and between mallards from an area free of Leucocytozoon (Saskatchewan). We produced 6 types of ducklings: Ontario black duck x Ontario black duck (OB x OB), Ontario black duck x Ontario mallard (OB x OM), Ontario black duck x Saskatchewan mallard (OB x SM), OM x OM, OM x SM, and SM x SM. We predicted that because of probable coevolution of black ducks and Leucocytozoon, black duck ducklings would have resistance to the parasite. We also predicted that Ontario genes would confer some resistance to ducklings because these ducklings' parents had survived exposure to Leucocytozoon. In contrast, we predicted that mallard and Saskatchewan genes would not confer resistance, i.e., OB x OB ducklings would have greatest resistance to Leucocytozoon, SM x SM ducklings would have least, and remaining duckling types would have intermediate resistance. Of 169 ducklings exposed in 2 years in 3 geographically separate locales, none died, showed noticeable symptoms, or otherwise behaved abnormally. Nonetheless, weekly blood smears indicated that 91% of ducklings became infected, and many developed intense parasitemias. However, infection intensities were not different among the 6 duckling types. In addition, hematocrits were not lowered by intense infections. These results suggest that the effects of Leucocytozoon on wild waterfowl populations have been overestimated, and that Leucocytozoon will not prevent further range expansion of mallards.

The effect of different genera of blood parasites on female Great Tits Parus major was studied in central Sweden. Haemoproteus, Leucocytozoon, Hepatozoon, Plasmodium and Trypanosoma were found, but ...

Three Fenno-Scandian populations of Pied Flycatchers Ficedula hypoleuca were sampled for their haematozoan parasites over the period 1989-1992. Pied Flycatchers from the environs of Uppsala, Sweden had lower prevalence and intensities of infections than those from Meltaus, Finland. In addition, birds from Uppsala were not parasitized by leucocytozoids and were virtually free from trypanosomes; conversely, birds from Meltaus were heavily parasitized by both groups. Birds from Konnevesi, Finland, showed an intermediate prevalence and intensity of parasitism. This study clearly shows the role of ecologically diverse conditions in determining the composition, transmission and prevalence of a blood parasite fauna presumably through their effect on vector composition and population density.

1. The influence of reproductive effort on host susceptibility to parasitism was examined in great tits, Parus major, by comparing the prevalence of haematozoan parasites with respect to clutch size in male and female parents. 2. Observational and experimental studies were conducted. Observational studies documented the relationship between clutch size and parasite prevalence in males and females in unmanipulated nests. Reproductive effort was manipulated by exchanging complete clutches between pairs of nests during incubation. Parents experienced a maximum manipulation of ± 5 eggs. 3. Observational studies showed that the prevalence of parasites was higher in females than males. The prevalence of parasites in males increased with both increasing clutch size and increasing age

Parasite-host interactions are important in the study of evolutionary biology, but the direct fitness consequences of blood parasites have not been well studied. Blood was sampled from 48 female and 37 male Tengmalm's owls (Aegolius funereus) in 1991 and from 49 females and 48 males in 1992. The samples were randomly selected from between 93 and 128 breeding pairs trapped in western Finland. The avian haematozoas found in the blood films were Haemoproteus noctuae (prevalence 3% for females and 2% for males), H. syrnii (10% and 1%), Leucocytozoon ziemanni (97% and 94%) and Plasmodium circumflexum (0% and 1%). Leucocytozoon ziemanni reduced clutch size of females in 1991 when the abundance of the main food (voles) was intermediate, but had no apparent detrimental effect in 1992 when food abundance peaked

Blood smears were examined from 935 individuals of 19 migrant and resident bird species collected in Louisiana. Of these, 320 (34.2%) harbored hematozoa. The prevalences of parasites were as follows: Haemoproteus spp. 22.8%, Trypanosoma spp. 6.9%, unidentified microfilariae 5.0%, Plasmodium spp. 3.4%, and Leucocytozoon spp. 1.3%. These data are consistent with other reports from the region. Infections were observed in 33% of the individuals in the 13 migrant species sampled and 33% of the individuals in the 6 resident species.

Development of Leucocytozoon ziemanni ( = L. danilewskyi) was studied in its simuliid vectors and in saw-whet owls, Aegolius acadica. Sporogony was completed in Simulium aureum, S. latipes, and Prosimulium decemarticulatum within 5 to 7 days at 21 C after gametocytes were ingested. Sporozoites were inoculated into 4 owls and hepatic biopsies were performed at intervals thereafter. Four types of schizonts were observed: (a) hepatic forms in parenchymal cells, (b) renal forms in tubular cells, (c) megaloschizonts in endothelial cells lining the walls of blood vessels in spleen, liver, kidney, heart, intestine, gonad, and bone marrow, and (d) small, "wormlike" schizonts in endothelial cells of the lung. None was observed in the brain. Sporozoites developed in hepatic parenchymal and renal tubular cells. Following completion of primary schizogony in 4 days, merozoites penetrated polychromatic erythrocytes and matured about 2 days after as round gametocytes. Megaloschizonts were seen from 5 days and matured 3 days onwards. Appearance of elongating gametocytes from 8 days postinjection coincided with the rupture of the megaloschizonts. Merozoites from the latter developed in erythroblasts and lymphocytes and matured about 2 days later as fusiform gametocytes. The life cycle shows similarities to that of L. simondi with the sequential appearance of hepatic and megaloschizonts and the associated round and fusiform gametocytes. Gametocytes of species of Leucocytozoon have been reported from owls from different regions of the world: in Europe by Danilewsky (1889, 1890), Ziemann (1898), Laveran (1902, 1903), Berestnev (1904), Cardamatis (1911), Franca (1912), Moldovan (1913), and Franchini (1923); in Asia by Ogawa (1911); in Africa by Kerandel (1913), Leger and Leger (1914), Fantham (1926), and Gaud and Petitot (1945); in the Americas by Carini (1920), Coatney and Roudabush (1937), Bennett and Fallis (1960), and Khan and Fallis (1970a); and in Australia by MacKerras and MacKerras (1960). Round and fusiform gametocytes have been observed but whether they arise from different schizogonic cycles as in L. simondi (Desser, 1967; Yang et al., 1971) is unknown. Observations pertaining to this follow. MATERIALS AND METHODS Six adult, saw-whet owls, Aegolius acadica, trapped at Toronto Island in October 1967, were held over winter in an animal house in Toronto. Examination of centrifuged as well as regular blood smears from these owls (once or twice weekly) over an 8-month period revealed no paraReceived for publication 14 June 1973. * This study was done during the author's tenure as a postgraduate student at the University of Toronto. Support from the Medical Research Council of Canada Grant M2998 to Dr. A. M. Fallis, Professor Emeritus and Special Lecturer, Department of Parasitology, School of Hygiene, University of Toronto, is gratefully acknowledged. sites in 4 birds while the 2 others harbored chronic infections of L. ziemanni (status of this species to be discussed by Bennett, Laird, Khan, and Herman, in litt. ). In the spring of 1968 the owls were taken to the field station at Algonquin Park, Ontario, where they were subsequently held in cages in an animal house. Wild-caught simuliids were used in these experiments. They were collected from late May 1968, in the manner described by Bennett (1960), after feeding on the 2 naturally infected owls, and were subsequently retained in containers at about 21 C (Khan and Fallis, 1970b). Unfed flies collected at the same time served as controls; none of 22 was infected. Engorged flies were dissected daily to follow the sporogonic development. Midguts and salivary glands were dissected and spread thinly prior to fixation with methanol and staining with Giemsa. To determine the time of appearance of the gametocytes and the pattern of schizogony, 4 owls were experimentally infected with sporozoites. The methods of preparation and inoculation of the latter have been reported previously (Khan and Fallis, 1970b). Blood smears were prepared daily from all birds following injection. Biopsies were performed at intervals thereafter and the birds were necropsied subsequently. Blood smears and tissue imprints were air-dried before fixing with methanol and staining with Giemsa. Tissues were fixed in Carnoy's and sections, cut at 4 ,u, were stained by the Giemsa-Colophonium method. Photomicrographs were made with a Zeiss photomicroscope. Measurements are in microns.

Birds from south-central Cameroon, western Africa, were surveyed for blood parasites from August to October 1986. Of 331 birds examined, representing 65 species of 15 families and 6 orders (mostly passerines), 55 (17%) were found to be infected with 1 or more genera of hemotropic parasites. These included: Haemoproteus spp. (11% prevalence), Leucocytozoon spp. (3%), Plasmodium spp. (2%), Trypanosoma spp. (1%), and microfilariae of filariid nematodes (1%). Several new host-parasite associations were identified.

Blood films from 475 band-tailed pigeons (Columba fasciata) from Colorado (364), California (105), and Mexico (6) were examined for hematozoa. Bone marrow from 18 Colorado birds was examined for trypanosomes. Eighty-six percent of the pigeons from Colorado, 51 percent from California, and all from Mexico showed some parasitemia. Parasites identified were: Haemoproteus columbae, H. sacharovi, Leucocytozoon marchouxi, Trypanosoma avium, and microfilaria. T. avium is a new record for the band-tailed pigeon. Significant differences in infection (P < 0.05) were found between adults and immatures in Colorado, between adult males and adult females in California, and between adults of each population. Band-tailed pigeons from Colorado were more heavily parasitized than those from California; Haemoproteus columbae and Trypanosoma avium were not found in birds from California. A limited sample from Mexico revealed parasite burdens similar to those reported for Colorado. J. WILDL. MANAGE. 41(1):128-130 Band-tailed pigeons occur in two distinct populations in western North America (Braun et al. 1975), with the Coastal population (C. f. monilis) being a major game species with annual harvests in excess of 500,000 birds in some years (Jeffrey 1976). Despite the wide distribution of this pigeon and its importance as a game species, little information is available concerning its parasite burden. This paper reports the results of examination of blood films from pigeons sampled in Colorado, California, and Mexico. Wood and Herman (1943) examined one pigeon each from Arizona (C. f. fasciata) and California (C. f. monilis) and reported Haemoproteus and Leucocytozoon, respectively. Stabler et al. (1950) and Stabler and Holt (1961) reported on the hematozoa from 109 pigeons captured north of Colorado Springs, Colorado. Parasites reported in these two papers were Haemoproteus columbae, H. sacharovi, Leucocytozoon marchouxi, and microfilaria. Due to the paucity of data from pigeons outside of east central Colorado, efforts were made to collect adequate samples of blood films from a variety of locations. This study was supported in part by Colorado Federal Aid to Wildlife Restoration Project W-88-R. The assistance of J. A. White in making blood films from birds in Colorado and California, and of F. J. Ward in making California pigeons available is gratefully acknowledged. Appreciation is expressed to D. C. Bowden, Department of Statistics, Colorado State University, for conducting statistical analyses. METHODS AND MATERIALS Pigeons in Colorado were sampled from May into September, in Mexico from December and April, and in California from January into March. Most pigeons sampled were captured in cannon nets (Colorado) and drop traps (California). Those from Mexico were shot. In all, blood films were available from 475 pigeons: 364 from Colorado, 105 from California, and 6 from the Durango-Sinaloa border in Mexico. Blood films from Colorado were from 8 of at least 19 subpopulations (Braun 1976) and were well distributed within the state. The California films were from Pebble Beach within the winter and breeding ranges of the Coastal population. The few samples from Mexico were from within the winter range of the Interior population (Braun et al. 1975). Bone marrow from 18 of the Colorado birds was examined in saline for try128 J. Wildl. Manage. 41(1):1977 This content downloaded from 207.46.13.172 on Sat, 15 Oct 2016 04:21:23 UTC All use subject to http://about.jstor.org/terms BLOOD PARASITES FROM BAND-TAILED PIGEONS ' Stabler et al. 129 Table 1. Blood parasites of band-tailed pigeons from Colorado and California.a

Leucocytozoon grusi sp. n. from a sandhill crane, Grus canadensis (L.), is described, and the species compared with similar forms in the literature. Potentially useful new characters for the separation of species of the Leucocytozoidae are suggested; these include the area of the parasite, area of host cell nucleus and ratios comparing the area of the normal erythrocyte with the area of the parasite and the area of the host cell-parasite complex. There are few reports of hematozoa from the avian order Gruiformes and only one recorded case of Leucocytozoon infection. Rodhain et al. (1913) noted this parasite in Balaeniceps rex from the Congo and provided a brief description of it, although not designating a specific name. Recently, a series of blood films from sandhill cranes were referred to us for analysis of the hematozoon infections. Several films contained gametocytes of a species of Leucocytozoon whose morphological parameters bore little relationship to other described species of the genus. The species was therefore considered to be new and designated as Leucocytozoon grusi. Concurrent infections of an unknown hemoproteid were also noted in these films. Gametocytes of the Leucocytozoidae are generally difficult to identify, apart from their hosts, on purely morphological grounds. Furthermore, as Fallis and Bennett (1966) and Khan and Fallis (1970) have demonstrated, species of Leucocytozoon from one avian order or family are not normally infective, even under experimental conditions, to members of another order. Some 77 species of Leucocytozoon have been described (Berson, 1960), usually on the basis of the "one host-one parasite" philosophy prevalent in the late 19th and early 20th centuries (Bennett and Laird, 1973). The measurements included in these species descriptions (if measurements were included at all) were the mean and the range-data which are statistically limited and present little information about the normal parasite populaReceived for publication 26 April 1973. * Department of Biology and WHO International Reference Center for Avian Malaria Parasites, Memorial University of Newfoundland, St. John's, Newfoundland, Canada. tion. These facts pose obvious taxonomic problems towards the solution of which certain parameters, previously employed only for the Haemoproteidae by Bennett and Campbell (1972), could be significant. Such parameters include the area of the parasite, the area of the distorted host cell nucleus, and the length and breadth of the distorted host cell nucleus. Certain ratios have also been calculated and these ratios (herein termed indices) are the host nucleus index, the parasite index, and the host-parasite index. These parameters and indices have been obtained for L. grusi and are presented as part of the species descrip

Early oocysts of Leucocytozoon tawaki Fallis, Bisset and Allison were located between the basal lamina and the midgut epithelium of the vector, Austrosimulium ungulatum. The spherical oocysts were surrounded by an amorphous, electron-dense wall and contained a large, central core of closely spaced dense particles, the crystalloid inclusion. Around the latter were many concentrically arranged cisternae of granular endoplasmic reticulum. A few large, poorly defined nuclei, some of which contained spindle apparatus, were seen. Sporozoite formation occurred around the peripheral cytoplasm of maturing oocysts. The sporozoite pellicle was subtended by 30 microtubules which appeared to originate from the most posterior of 3 dense, polar rings. Each forming sporozoite contained a central nucleus, mitochondrion, and a crystalloid inclusion both anterior and posterior to the nucleus. The nature and significance of the crystalloid in Leucocytozoan species and other apicomplexans is discussed with special reference to similar viruslike inclusions in the sporogonic stages of certain species of Plasmodium.

Leucocytozoon sp., L. lovati and Haemoproteus mansoni infections in captive blue grouse (Dendragapus obscurus) were monitored weekly throughout primary and relapse periods. Chicks developed primary infections with L. lovati and Leucocytozoon sp. during 5- 9 wk of natural exposure, whereas H. mansoni was transmitted during a 2-3-wk period. Relapse infections of Leucocytozoon sp. and L. lovati in wild blue grouse had constant monthly prevalences (percent infected) and intensities (mean number of parasites). In contrast, prev- alence and intensity increased throughout the relapse period for H. mansoni. The patent period in infrapopulations (within one host) of H. mansoni was 5-11 wk for primary, and 11-26 wk for relapse infections. Likewise, peak intensities appeared 1-4 wk after the start of patency for primary and 5-11 wk for relapse infections. No differences were detected in the Leucocytozoon spp. Precise timing and peak intensity was selected for in H. mansoni which had a short transmission period, but not in Leucocytozoon with long transmission periods. Gametocyte production occurs for a longer period during relapse than during the primary period. This satisfies constraints imposed by a pulse vector on parasite transmission to vertebrate hosts. A model is proposed to explain the evolution of the complex intensity patterns observed in H. mansoni.

A new species of Leucocytozoon with elongate gametocytes and unique morphology is described from a Thailand thrush, Zoothera marginata, and represents the first fusiform leucocytozoid named from a passeriform. This species appears to be restricted with respect to geography and host.

The type, paratype, and reference material of avian hematozoa in the reference collection of the International Reference Centre for Avian Haematozoa is listed. This material includes one species of Atoxoplasma, 41 species of Haemoproteus, one species of Hepatozoon, two species of Lankesterella, 15 species of Leucocytozoon, 31 species of Plamodium, one species of Spirogregarina, and three species of Trypanosoma.

In an effort to establish comparative data within the genus Leucocytozoon, elongate gametocytes of L. ziemanni from naturally infected great horned owls (Bubo virginianus) were exam- ined by electron microscopy. Micro- and macrogametocytes proved to be easily distinguishable at the electron microscopic level due to dramatic dimorphism at maturity and cytoplasmic and nuclear morphology. The parasite membrane architecture, number and type of cytoplasmic ribosomes of both micro- and macrogametocytes, presence and arrangement of osmiophilic bodies and electron dense spheres, mitochondrial morphology, endoplasmic reticulum cisternae morphology, mitochondria con- taining pocket infoldings of the nuclear membrane of the microgametocytes, and cytostome and food vacuole formation compare favorably with available information on L. simondi and L. smithi. Com- parative variations exist only in that L. ziemanni gametocytes apparently lack compartmentalization of the cytoplasm by aligned unit membranes and parasite induced separations of the host cell nu- cleus as reported for L. simondi. The ultrastructure of gametocytes of vari

One of the most noteworthy contributions in its time to the study of the life cycles of protozoa was Schaudinn's famous memoir on the life cycles of the parasites of Athene noctua. Even though Schaudinn's conclusions proved erroneous, at least they served as an impetus for renewed attention to the morphology and life history of hematozoa. My recent discovery of a focus of Leucocytozoon infection in Minnesota and North Dakota should therefore prove of general interest to American protozoologists. The counties involved were Clay (Minn.), Cass (N. Dak.), and Pembina (N. Dak.), all the infected areas being in the Red River valley, the basin of a glacier lake (Lake Agassiz) in prehistoric times. The Leucocytozoon I have encountered there is Leucocytozoon smithi, Laveran et Lucet 1905, parasitic in the domestic turkey. This parasite was discovered by Theobald Smith in 1895 in the Eastern United States; it has also been reported by Laveran and Lucet in 1905 from France, by Wickware in 1922 from Eastern Canada, by Stephan in 1922 from Germany, by Knuth and Magdeburg in 1924 from Germany, by Yakimoff and Rastegaieff in 1927 from the Crimean peninsula, and by Knuth and David in 1928 from Germany. The absence of a description of L. smithi in the American parasitological literature, the extreme scarcity of observations of Leucocytozoa in domestic birds, and the strange fact that L. smithi, in these 35 years following its discovery, has never been reported from the United States, prompted me to record my observations on this parasite. In the present paper I confine myself to the sexual stage of the parasite as seen in the peripheral blood. For observations smears from the freshly drawn blood were used. The stain used was Wright's stain without previous alcoholic fixation of the blood film. This method seemed to give the most satisfactory contrast. The parasite stains blue, the host cell nucleus or its parts bright pink in contrast to the normal red blood cell whose nucleus stains blue. If the invaded cell is an erythrocyte, then this deviation from the normal staining affinity seems rather startling. It may be assumed that the staining affinity of the nucleus is altered by changes in the internal oxydation reduction potential due to the karyorhexis and karyolysis, undoubtedly brought about by the katabolism of the parasite. The nature of the host cell is still disputed, though it is the consensus of the majority of the later observers that it is an immature red blood cell and that other mononuclear blood

This study deals with the protozoan genera Haemoproteus, Leucocytozoon, Plasmodium, and Trypanosoma. The material was collected for the most part in the vicinity of Peru, Nebraska, during the spring and summer of 1937. Altogether eighty-four different birds were examined, comprising nineteen families. Fifteen species, out of the thiry-five examined, were found to be infected with one or more genera of blood parasites.

An opportunity to examine wild waterfowl in Maine for blood parasites was presented during the summer of 1939 by the Maine Pittman-Robertson Wildlife Restoration Project. A major objective of the survey was to determine the prevalence of the blood protozoan Leucocytozoon. This parasite was shown by O'Roke2 (1934) to be responsible for heavy losses among wild ducks in Michigan. O'Roke found it occurring widely in ducks from other central, and also from western and southern, states. In addition, Herman (1938) reported Leucocytozoon in wild ducks on Cape Cod, Massachusetts. Previous to the present survey we had some evidence that this parasite is present in the waterfowl of Maine. One outbreak occurred in 1935 in a flock of domestic ducks near the town of Orono. The ducks had been brought in from Massachusetts about a month earlier. The owner, not being familiar with the malady, brought specimens to Dr. J. F. Witter, Animal Pathologist at the University of Maine. It was not certain that the parasites had been acquired after their arrival in this state. In June 1938 blood smears obtained by the Wildlife Research Department of the University of Maine, from two wild black ducks near Orono, revealed Leucocytozoon. One of the birds, a duckling, was examined, banded, and released. It survived the infection and was caught late the following fall near Orono in a muskrat trap. Other ducks examined that summer, one golden-eye and two ring-neck ducks, were negative for blood parasites. In the summer of 1939 banding and other operations in connection with the project mentioned gave the desired opportunity for the collection of blood smears from waterfowl. Study of the smears has produced a number of new host records for species of parasites already described as well as for some possibly undescribed parasites. In addition, some information was obtained in the comparative prevalence of infections in adult and young birds and in different species of ducks. Since no previous survey of this type has been made in the region it seems desirable at this time to present the findings.

Fifty-eight chickens showing an avian malaria-like syndrome came from 32 poultry farms in 8 Central Luzon provinces, Philippines, and were found positive for Leucocytozoon caulleryi. Young chickens were more susceptible than adults. The parasite invaded and destroyed the red blood cells, resulting in severe anemia, extreme leg weakness, greenish-white or greenish-yellow diarrhea, anorexia, loss of weight, and decreased egg production. Hemoptysis was common in severely infected chickens. Not all infected chickens died. The significant pathological lesions were enlarged spleen and liver. Petechial hemorrhages were usual in liver, lungs, pancreas, kidneys, intestines, and muscles. Blood clots were frequent in thoracic and abdominal cavities of chickens that suddenly died. Stages of gametogony were seldom seen all at one time in the blood smear. Either ring forms or mature gametocytes without host cell nucleus were common in the peripheral circulation. Blood became free of parasites 10 to 14 days after appearance of the initial stages.

Of 38 Pekin ducklings infected with L. simondi by 24-hr exposures or intraperitoneal injection of ground-up black flies, 94.3% showed prepatencies of 7 days (? 24 hr). Most of the naturally infected ducks showed two peaks of gametocyte density, the first on the 10th day postexposure composed entirely of round forms, and the second on the 14th to 16th days postexposure composed of approximately 90% elongate forms. Elongate gametocytes appeared on the 11th day postexposure in 30 ducks, the 12th day in four ducks, and four did not show elongate forms. Eight ducks infected by injection of black flies died within 48 hr of the first appearance of elongate gametocytes, and ten ducks infected the same way showed a sharp increase in gametocyte density following the appearance of the elongate forms. The length of the prepatent period of Leucocytozoon simondi given by O'Roke (1934) and Fallis et al. (1951) is between 6 and 14 days. Several investigators have described the length of the initial infection to be about 30 days (O'Roke, 1934; Chernin, 1952b; Fallis et al., 1951). O'Roke (1934), Huff (1942), and Fallis et al. (1951, 1956) reported that the gametocyte population rose to a maximum density early, decreasing gradually into latency, and Chernin (1952a) pointed out that if there was any mortality the ducks died between 10 and 19 days postexposure. The pleomorphic gametocytes of L. simondi have been described by Fallis et al. (1951) and Chernin (1952b), who noted that round forms are most prominent early in patency while elongate or spindle forms predominate as the infection progresses. Chernin's (1952b) differential counts on the two forms show that the round form reaches a maximum density earlier than the elongate form. Chernin and Sadun (1949) thought that there might be a cyclic variation in the gametocyte density in primary infections, but Chernin (1952b) later refuted this. It is our intention to describe the occurrence and timing of the prepatent period, the appearance of elongate gametocytes, gametocyte density fluctuation, and mortality. Received for publication 14 March 1966. * Contribution Number 116 from the W. K. Kellogg Biological Station, Michigan State University. 962 MATERIALS AND METHODS Ducks were infected by exposure to black flies for 24 hr or sporozoites were inoculated intraperitoneally, thus allowing all sporozoite development to begin at approximately the same time. Thirty-eight white Pekin ducks ranging from 2 to 3 weeks of age were used as hosts for L. simondi. Group 1 consisted of 20 ducks exposed to black flies at Indian River, Michigan for 24 hr on 16 July 1964. Group 2 consisted of 18 ducks, of which ten were infected on 6 June 1965 by intraperitoneal injection of ground-up black flies collected at the Fox River in Seney, Michigan, on 3 June 1965, and eight were infected the salme way with black flies collected at the same location on 13 July 1965. All ducks were maintained in outdoor pens at the W. K. Kellogg Biological Station near Kalamazoo, Michigan, an area where L. simondi is not transmitted (Kocan and Clark, 1965). The naturally infected ducks of Group 1 were examined for parasites by thin blood films taken daily beginning with the day following exposure to black flies. Gametocyte densities were recorded every other day beginning with the 8th day postexposure. Ducks in Group 2 were sampled for gametocyte density daily. Blood for a slide and an erythrocyte count was obtained from a web vein puncture. Erythrocyte counts were done on a hemocytometer with blood diluted in a standard RBC diluting pipette, using Hayem's fluid as a diluent. All blood films were stained with Giemsa. Parasite counts were recorded as gametocytes per mm3 of venous blood. This was done by counting the mean number of gametocytes per 1 000 RBC's and the number of RBC's per mmm of blood. These values were used in the equation gametocytes _ RBC per mm3 gametocytes per mm" 1,000 per 1,000 RBC's thus giving gametocytes per mm3 of blood. DifThis content downloaded from 157.55.39.120 on Sun, 04 Dec 2016 04:52:30 UTC All use subject to http://about.jstor.org/terms KOCAN AND CLARK-PREPATENT PERIOD AND PARASITEMIA IN LEUCOCYTOZOON TABLE I. Number of birds becoming patent and showing first elongate gametocytes on nth day postexposure. * Days postexposure 6 7 8 9 10 11 12

Hematozoa are reported from 1,361 members of the Passeriformes representing 101 species and 22 families, all from Colorado. Some parasitemia was observed in 693 birds (51%). The parasites and their incidences were: Plasmodium (all species), 43 (3%); Haemoproteus, 229 (17%); Leucocytozoon, 273 (20%); Trypanosoma, 401 (29%); Haemogregarines sensu lato (Hepatozoon and Lankesterella), 40 (2.9%); microfilaria, 174 (13%). Seventy-one new host-parasite associations were encountered. Two papers on the hematozoa of Colorado birds have been published by Stabler and Holt (1963, 1965). This third in the series deals with 1,361 members of the Passeriformes, representing 101 species and 22 families. MATERIALS AND METHODS All birds were from Colorado, the majority being from east of the Continental Divide. The period of collection extended from 1948 to 1969. Blood from those captured alive was obtained from a snipped toenail and from the body cavity of those which were shot. Following staining with Giemsa, the blood films were first scanned under low dry magnification (150 X ) and then searched under oil immersion (1,455 X) until we felt that all hematozoan types had probably been detected. The femoral marrow from many of the dead birds was examined in physiological saline for trypanosomes. RESULTS The results are summarized in Table I. Of the 1,361 birds examined, 693 (51%) showed some parasitemia. The parasites and their incidences were: Plasmodium (all species), 43 Received for publication 22 July 1969. (3%); Haemoproteus, 229 (17%); Leucocytozoon, 273 (20%); Trypanosoma, 401 (29%); Haemogregarines sensu lato (Hepatozoon and Lankesterella), 40 (2.9%); microfilaria, 174 (13%). Of the 401 infections with Trypanosoma, only 91 had the organism in the circulating blood. Seventy-one new host-parasite associations were encountered. The common redpoll appears to have been examined parasitologically for the first time. DISCUSSION The complete hematological picture of some of the 1,361 passeriforms has already been published (Stabler, 1961). These birds constitute less than 10% of the total, are all magpies, and are included here for the sake of completeness. Table I bears a column headed "Hg sensu lato" (Haemogregarines sensu lato). It includes parasites similar to those described by Wood and Herman (1943) and Clark and Swinehart (1966) as Hepatozoon (32 cliff swallows, 1 plain titmouse, and 1 western blueTABLE I. Hematozoa from Colorado Passeriformes. Hg sensu Bird Total No.+ Pr Pc Pr-c Pp Pv Pn Ph H L T lato M Tyrannidae Eastern kingbird 10 4 2 2 1 Tyrannus tyrannus Western kingbird 16 9 1* 1' 2 7* Tyrannus verticalis Ash-throated flycatcher 2 1 1* Myiarchus cinerascens Say's phoebe 10 2 1* 1 Sayornis saya Western flycatcher 4 4 2* 4 Empidonax difficilis Western wood pewee 9 5 4 1* Contopus sordidulus Vermillion flycatcher 1 0 Pyrocephalus rubinus Genera and species names are listed according to the fifth (1957) edition of the AOU Check-list. Abbreviations: Pr, Plasmodium relictum; Pc, P. cathemerium; Pr-c, P. relictum-cathemerium; Pp, P. polare; Pv, P. vaughani; Pn, P. nucleophilum; Ph, P. hexamerium; H. Haemoproteus; L, Leucocytozoon; T, Trypanosoma; Hg sensu lato, Haemogregarines sensu lato; M, Microfilaria; *, New host-parasite records. 12 This content downloaded from 207.46.13.71 on Sat, 22 Oct 2016 06:17:57 UTC All use subject to http://about.jstor.org/terms STABLER AND KITZMILLER-HEMATOZOA FROM COLORADO PASSERIFORMES 13

Young ducks were brought to the University of Michigan Biological Station in the summer of 1927. These were not infected upon arrival but plainly showed Leucocytozoon anatis after being kept ten days near other ducks infected with this parasite. During this time blood samples were taken daily. Since the manner and time of infection were not determined, it was not possible to be accurate in giving the age of any parasite subsequently found. However, from the daily samples it was found possible to work out the various developmental stages and to assign ages which appear correct to within not more than three days. The earliest parasites found were in young red blood cells (Figs. 3-5), and appeared similar to young stages of bird malaria. The parasite possesses a cytoplasm which with tetrachrome stain distinctly stains blue, and a nucleus which stains red. The normal young red blood corpuscle has a larger and less compact nucleus than the older cell; the cytoplasm takes more azur stain and less eosin than do the mature red cells.

A 2-year epidemiological study of Plasmodium hexamerium in meadowlarks and starlings of the Cheyenne Bottoms Waterfowl Management Area, Barton County, Kansas, revealed that seasonal infection incidence varied significantly in the meadowlark, being highest in the early spring and lowest in the winter, but did not vary significantly in the starling. Both host species became infected at an early age, the meadowlark in the nest and the starling soon after leaving it. In concurrent vector studies: (1) Culex tarsalis was infected with P. hexamerium in the laboratory; (2) C. tarsalis, Aedes nigromaculis, and A. sollicitans were exceedingly abundant and fed regularly on small birds in the field, therefore all are considered potential vectors with C. tarsalis the most likely; (3) mosquito populations were not high until June when annual transmission probably begins; (4) populations of probable vectors are too low during March and April to account for the observed increase in malaria incidence in meadowlarks collected at that time. Overall differences in the epidemiological patterns of P. hexamerium in the meadowlark and starling are credited principally to differences in migratory habitats of the two birds and degree of ecological association with vectors. The natural transmission of avian malaria is one of the most poorly understood aspects of the biology of Plasmodium. Herman's (1938) study of malaria in the redwing (Agelaius phoeniceus (L.)) is a classic and has been supplemented only recently by the work of Fallis and others on Leucocytozoon (Fallis, Anderson, and Bennett, 1956; Fallis and Bennett, 1963; Fallis, Davies, and Vickers, 1951; Fallis, Pearson, and Bennett, 1954). Growing interest in the ecology of the encephalitis viruses, along with the suggestion that bird malaria studies may shed light on this problem (Herman et al., 1954), makes further work on the epidemiology of avian malaria desirable. The present survey was part of a general study of animal parasites and viruses in central Kansas which began in February 1963 and is still in progress. The meadowlarks (Sturnella magna (L.) and S. neglecta Aud.) and European starling (Sturnus vulgaris L.) were studied because both were found to harbor Plasmodium hexamerium Huff. Thus, variations in epidemioReceived for publication 15 October 1965. * Taken from a dissertation submitted to Graduate College in partial fulfillment of requirements for degree of Doctor of Philosophy. Supported in part by NIH Grant AI-05232-02 which provided many of the facilities used. t Present address: Department of Zoology, Rutgers University, New Brunswick, New Jersey. logical patterns of this parasite in its different hosts might be manifestations of factors which generally affect avian malaria epidemiology.

This survey was conducted in an experimental area in Clarendon County, South Carolina, where several types of data concerned with human malaria have been collected for a number of years. Despite the continued absence of any blood-positive cases of human malaria in the area for the 2 years since February 1949, wild-caught anophelines, upon dissection, are still found with oocysts and sporozoites. Both Anopheles quadrimaculatus and Anopheles crucians are involved. This survey was one of the investigations undertaken to locate the source of the malaria-like infections in the mosquitoes. Since practically all the anophelines for dissection are collected in stables and chicken houses, beneath dwellings, and about other farm buildings, domestic animals logically seemed to be possible hosts. From Asia there are some reports in the literature of blood parasites belonging to the genus Leucocytozoon that were found in the domestic chicken. However, no records of such organisms occurring in this host outside the Eastern Hemisphere were located.

In a large proportion of Boa constrictor taken in the vicinity of Colima, Mexico, hemogregarines were visible in erythrocytes of the peripheral circulation. One characteristic of a majority of these infections was the marked fusiform or spindle shape of many infected red blood cells. Such cells closely resembled certain avian blood cells parasitized by Leucocytozoon. Developmental stages in the blood, and schizogony in the tissues are described. Schizogony occurs primarily in the endothelial cells of lung capillaries but may occur in this type of cell in other organs. The spindle shape of the infected erythrocytes is so distinctive that the organisms are placed in a new species, Hepatozoon fusifex. Culex tarsalis or Aedes togoi, biting B. constrictor with certain types of hemogregarines in their blood developed mature sporozoites in their hemocoels. Similar stages were found in a tick, Amblyomma dissimile, removed from a boa. The hemogregarines were transmitted to clean B. constrictor by feeding them infective C. tarsalis or A. dissimile. It has not been established with certainty whether these sporogonic stages are part of the life history of H. fusifex or belong to a separate hemogregarine species. Hemogregarine parasites frequently produce considerable hypertrophy of the infected blood cells. Marked changes in the morphology of the host cells apart from those associated with hypertrophy are less common. Wenyon (1908) reported that in Haemogregarina gracilis from Mabuya quinquetaeniata, the parasite had the property of pushing out the infected host cell at either end and thus elongating it considerably. In the same paper, Wenyon noted that another sporozoan blood parasite of African snakes, Haemocystidium najae, from Naja haje and from Naja nigricollis, altered the shape of the infected erythrocyte so that the latter came to resemble the fusiform shape of a red cell of the guinea fowl infected by Leucocytozoon. Laveran and Salimbeni (1909) pictured hypertrophied erythrocytes of a Brazilian lizard, Tupinambis teguixin, infected with Haemogregarina tupinambis. Some of these red cells reached a length of 35 yt and became spindleshaped. Other investigators have reported Leucocytozoon-like parasites in the blood of reptiles. However, this designation has been based Received for publication 7 March 1969. * Aided by Grants GB 414 and 7069 from the NSF, Training Grant E-70, U. S. Public Health Service, Grant Zoology 254, University of California, and Sigma Xi-RESA Grant in Aid of Research, 1963. t Present address: Gorgas Memorial Laboratory, P. 0. Box 2016, Balboa Heights, Canal Zone. either on the shape of the parasite or on its presence in leukocytes (Leger and Mouzels, 1917) and in no case did the infected blood cell show a spindle or fusiform shape. Yonge (1966) found round Leucocytozoon-like gametocytes in differentiating blood cells of Natrix sipedon sipedon infected with Cytotoddia. Arcay de Peraza (1968) erected a new genus and species, Paraleucocytozoon lainsoni, for a leukocyte-inhibiting sporozoan of Iguana iguana iguana; and Lainson and Shaw (1969) reported a leucocytozoid with round to oval gametocytes in blood cells of the Brazilian lizard Tupinambis nigropunctatus. The parasite described in the present communication produced much greater elongation of the infected host erythrocyte than was observed by previous investigators, and much more modification in the shape of the parasitized cell than has been noted for other hemogregarine infections. MATERIALS AND METHODS Fifty-five of 57 adult or subadult boas (Boa constrictor)* taken from 1963 through the spring * The host has been placed in either the genus Constrictor or Boa in recent herpetological papers. Our previous report used the designation C. constrictor (Ball, Chao, and Telford, 1967). The use of the generic name Boa instead of Constrictor now seems to be accepted by most herpetologists (Underwood, 1967) and therefore we are using this designation in the present paper.

The following observations on the protozoan genera Haemoproteus, Leucocytozoon, Plasmodium, and Trypanosoma, with notes on the immature nematode group Microfilaria, are based for the most part on material collected at Peru, Nebraska, during the spring and summer of 1935 and 1936. Eightynine different birds were examined representing nineteen families and fortyfour species. Of this group twenty-six were found to harbor one or more genera of blood parasites.

To establish the presence of selected infectious diseases in a "healthy" wild waterfowl population, a serologic and parasitologic study was initiated. Sera from 123 Canada geese (primarily Branta canadensis interior) and 179 mallards (Anas platyrhynchos) were screened for antibodies against six arboviruses. There was no neutralizing antibody detected against western viral encephalitis, eastern viral encephalitis, St. Louis viral encephalitis, Venezuelan viral encephalitis, California viral encephalitis, or vesicular stomatitis. Sera from 55 ducks and 12 geese were negative for agglutinating antibodies to Salmonella pullorum, Salmonella typhimurium, and Mycoplasma gallisepticum. Fifty-five duck sera and 11 goose sera were negative for complement-fixing antibodies of ornithosis. The most significant serologic finding was the presence of Newcastle disease antibody. Forty (17 percent) of 236 Canada geese were positive for Newcastle disease antibody. Thirty-seven (14 percent) of 267 mallard ducks had antibody titers for Newcastle disease virus. A limited study of parasitism revealed a low prevalence of Haemoproteus, Leucocytozoon, and microfilariae in both geese and mallards as well as Plasmodium in wild geese. The significance of the serological and parasitological findings is discussed. The occurrence of infectious disease in waterfowl has been well documented (Halloran 1955:332-348, Quortrup et al. 1957, Sciple 1953, Rosen and Bischoff 1950, O'Roke 1931). Most reports of disease in waterfowl have been concerned with spectacular epizootics, individual mortality, an extension of host or geographic range, or a survey of an easily sampled species as part of a domestic animal or human disease problem. While there can be no doubt of the value of these types of reports, they lack continuity and contribute little to understanding the significance of disease in wild populations. This is a report on the initial phase of an infectious disease investigation of selected wa erfowl populations in the Mississippi flyway. Its aim is to establish the presence, prevalence, and significance of infectious disease in this apparently "healthy" waterfowl population. Previous experience of the birds with disease was determined by the presence of antibodies against a select This study was supported and conducted cooperatively by the University of Wisconsin, Department of Veterinary Science, and the Wisconsin Conservation Department, Division of Research and Planning. Published with the approval of the Director of the Wisconsin Agricultural Experiment Station as Veterinary Science paper N.S. 499. This content downloaded from 157.55.39.148 on Fri, 16 Dec 2016 07:41:45 UTC All use subject to http://about.jstor.org/terms DISEASES OF WATERFOWL * Bradshaw and Trainer 571 number of antigens, or by the identification of protozoan parasites in blood smears. The diseases selected for study were chosen because of a history of waterfowl susceptibility or because of potential opportunity for

Examination of blood films from wood ducks (Aix spo7ssa) from several northeastern states revealed Haemovproteus, Leucocytozoon, Plasmodium and a trypanosome. Haemoproteus occurred in all areas sampled and birds of the year from Massachusetts demonstrated the highest incidence during the last 2 weeks in August. Leucocytozoon was most prevalent in more northern areas. P. circllmflexllm and a trypanosome are reported for the first time from this host. BLOOD PARASITES OF WOOD DUCKS * Herman et al . 119 and to urinary lead exeretion. Am. J. Clin. Pathol. 50 ( 3 ): 291-301. ROSEN, M. N., AND R. A. BANKOWSKI. 1960. A diagnostic technique and treatment for lead poisoning in swans. California Fish and Game 46( 1 ) :81-90. WATSON, R. JANET, ELIZABETH DECKER, AND H. C. LICHTMAN. 1958. Hematologic studies of children with lead poisoning. Pediatrics 21(1): 4056. WHITAKER, JO ANNE, AND TERESA J. VIETTI. 1959. Fluorescence of the erythrocytes in lead poisoning in children: an aid to rapid diagnosis. Pediatrics 24 ( 4 ): 734-738. WOBESER, G. 1969. Apparent favourable response of lead poisoning in a duck to treatment svith a chelating agent. Wildl. Disease Assoc. Bull. S(2 ) :120. Received for publication March 31, 1970. Plasmodium, Leucocytozoon, and Haemoproteus, occurring in the blood of birds, have also been reported from the wood duck ( Herman 1963 ) . This report extends our knowledge of the prevalence of these parasites in this host species. The authors are indebted to William L. Miller, David Grice, Clark G. Webster, William C. Good, Frank McCilvrey, David Hickok, and Terry W. Johnson, who supplied blood smears, or otherwise cooperated in obtaining specimens that formed the basis for this report. MATERIAL AND METHODS Most blood films were obtained by the puncture of a vein in the wing or toe and were stained with Giemsa's stain. Approximately 20,000 red blood cells (RBC) on each film were examined microscopically with the oil immersion objective (970 x ). Samples included 3S5 blood films from 230 birds from Massachusetts in 1952, and one film from each of the following: 128 and 198 birds, 1952 and 1953, respectively, Vermont; 13 birds, Maine, 1956; 35, Ohio, 1964; 173, New York, 1965; and 114, Patuxent Wildlife Research Center, Maryland, 1965. In addition, blood samples from seven adult wood ducks captured in their nest boxes at the Patuxent Wildlife Research Center on April 21 and A4ay l and 2, 1952, were inoculated into duck embryos following the technique of McChee ( 1949, as in Eichorn 1940). During the summer of 1965, blood samples were obtained from 42 wood ducks at the Patuxent Center and subinoculated, intramuscularly, into mallard ducklings ranging in age from a few days to several weeks. Blood films were taken from the mallards three times a week for at least 60 days following injection, and examined for evidence of Plusmodium. This content downloaded from 157.55.39.135 on Sun, 03 Jul 2016 05:46:00 UTC All use subject to http://about.jstor.org/terms Table 1. Blood parasites from wood ducks. NO. BIRDS H or LOCATION EXAMINED H Sb 12 S0 P P T Maine 1956 13 11 85 9 69 (} O O Massachusetts 1952 230 88 38 1 18 6 0 Vermont 1952 128 18 14 0 3 1 1 Vermont 1953 198 48 24 0 2 0 0 New York 196S 16 0 0 0 0 0 New York 1965 157 13 8 0 0 0 0 Ohio 1964 35 15 43 1 0 0 0 Patuxent Center 1965 114 13 11 0 0 0 0 120 Jo?lrnal of Wildltfe Management, Vol. 35, No. 1, January 1971 from 4, and six from 1 bird. Although these multiple films were obtained at intervals throughout the period, a number of ducks including the bird from which sis films were made, remained negative. Several birds were negative in one or more examinations axld positive in others, either beconing infected during the interim or losing the parasitemia. Some birds were positive at each examination, the longest duration being a month from first to last sample. Plasmodium was observed only in smears of birds from Massachusetts and Vermont. Eighteen of the ducks from Massachusetts were infected. In addition, six birds had young parasites that could not be differentiated from Haemoproteus and may have been P1usmodium. On only one of the birds from Massachusetts was a specific diagnosis possible. Round, mature schizonts, svith 12 merozoites, together with the characteristic round gametocytes displacing the hostcell rlucleus, led us to classify this infection as P. relictum. In the other 17 infections, developing segmenters were observed but insufficient forms were present to pernit a species diagnosis. Many of these wood ducks were also infected with Haemoproteus, which has gametocytes very similar to those of P. circumflexum. However, without the confirming evidence of mature schizonts, diagnosis as P. circumfilexum sras not justified. Plasmodillm was not observed in more than one film of a bird when additional smears were made on other dates. The bird with P. relictum was positive on July 16. Most infections were observed in late August or early September. Irlfections were low level7 with less than 10 parasites per 10,000 RBC. Of the five infections with Plusmodium observed in birds from Vermont, orle was diagnosed as P. relictum, three as P. circumflexum, and one as P. sp. The elongate a = June. b = August-September. H = Haemoproteus, L diu771, T = trypanosomes. Leucocytozoorw, P

The material herein reported is a continuation of studies made by Beltran (1939) on the blood protozoa of native birds from Mexico City and its environs. In his first report (1939) the above author examined 276 birds obtained from street markets, and in a later paper (1940) results are given from 85 birds, many of which were obtained in some of the suburban districts surrounding Mexico City (Texcoco, Xochimilco), and Toluca. Infections with Plasmodium, Haemoproteus, and Leucocytozoon were found. Sixty-one birds from which peripheral blood examinations had been previously made by Beltran were given by him to the writer for more extended examination, and the remaining 33 birds included in the present paper were obtained from markets in Mexico City.

Blood smears of 284 wild birds and 263 domestic birds of 'Columbus, Ohio, were examined for parasites. None of the domestic birds was infected, while 61 (21.5%) of wild birds harbored one or more species as follows: Haemoproteus (42 birds), Leucocytozoon (15), Plasmodium (8), microfilaria (1). Mixed infections were observed in 5 wild ducks and 2 Mourning Doves.

The ornithophilic Simuliidae that feed on waterfowl were studied in northern Michigan. With the exception of one Cnephia sp., only Simulium rugglesi (Nicholson and Mickel) were collected attacking birds in Michigan during the study period from 15 April 1959 to 21 August 1962. The number of flies trapped in Michigan was never comparable to similar collections in Canada and Wisconsin. Nevertheless, a high incidence of Leucocytozoon infection was observed in both Cheboygan and Presque Isle Counties near streams, in contrast to substantially lower incidences of infection and fatality on the lake front at the University of Michigan Biological Station and at Riggsville (both in Cheboygan Co. and both away from streams). Host preference studies were made by exposing mallard ducks and 14 other species of birds. New host feeding records for S. rugglesi included black terns, herring gulls, black crown night herons, sandpipers, robin fledglings, and blackbird fledglings. S. rugglesi preferred ducks over all other birds except gulls and blackbirds, colored ducks and ducklings over white ducklings and over goslings of all colors. They preferred colored ducklings and large white ducklings over goslings. S. rugglesi transmits Leucocytozoon among summer resident birds rather than the birds migrating through this region of Michigan. Epizootic conditions here are therefore significantly different from those in areas with larger and earlier appearing S. rugglesi populations farther north.

Leucocytozoon, Haemoproteus, Plasmodium, and Trypanosoma spp., as well as microfilaria, have been found in peripheral blood of wild waterfowl from the United States by one or another of the following authors: Herman (1938, 1951), Nelson and Gashwiler (1941), Wetmore (1941), Wood and Herman (1943), and Levine and Hanson (1953). Clarke (1946) has reported Leucocytozoon in a black duck (Anas rubripes) from Ontario. This is the only record found in the literature concerning the occurrence of these parasites in wild waterfowl from Canada.

Blood parasites are reported from 274 blue grouse, Dendragapus obscurus, from western Montana. These are the first such observations on this bird from the United States. Eighty-eight per cent showed some parasitemia. The parasites found were: Leucocytozoon (231), Haemoproteus (137), Trypanosoma (146), Plasmodium (1), and microfilaria (93). The blue grouse represents a new host record for Plasmodium. There have been no reports of hematozoa from the blue grouse (Dendragapus obscurus) of the United States. Stabler et al. (1966) found no trypanosomes in the bone marrow of one Colorado blue grouse. Of the five studies on the blood parasites of this bird, four (Fowle, 1946; Adams and Bendell, 1953; Bendell, 1955; Woo, 1964) were on Vancouver Island grouse and the fifth was on birds from southwestern Alberta (Holmes and Boag, 1965), all in Canada. This report is on the hematozoa in 274 of these birds from

Of 603 birds collected at Wateree, South Carolina, 22.7% were infected with one or more blood parasites. The most prevalent infection was with Haemoproteus sp. followed by Plasmodium sp., microfilaria, Leucocytozoon sp., and Trypanosoma sp. The blood parasites of birds in South Carolina have been studied by Hart (1949) and by Hunninen and Young (1950). Hart examined a total of 323 English sparrows and 64 various other birds from 1946 to 1947. Hunninen and Young examined 737 birds collected on the grounds of the State Hospital at Columbia, South Carolina from 1947 to 1949. In the present investigation, birds were collected as part of a program to investigate the incidence of Plasmodium and virus infections in birds and mosquitoes in a selected area of South Carolina. Reported here are the results of this study in regard to prevalence of blood parasites in birds collected during a period of approximately 11 months. MATERIALS AND METHODS The study area selected was in the southeastern corner of Richland County, South Carolina. The area was approximately 6 miles long, running along U. S. Highway 601 from the Southern Railroad crossing in Wateree, South Carolina to the Wateree River. Collections were made on both sides of the road in an area approximately 2 miles wide. The area consisted of extensive pine plantings with intermixed areas of freshwater swamp. At the Wateree end of the area was located a farm on which were raised chickens, cattle, and horses. Birds were collected in Japanese nylon mist nets or were shot, the latter proving to be the most effective method in the very dense areas and for several species of birds such as woodpeckers. Blood smears were made from the blood samples collected by cardiac puncture, the latter being used for purposes other than those discussed in this paper. Two blood slides were made from each bird. The slides were air dried, fixed with methyl alcohol, and stained with Giemsa. The slides were studied under low power (100 X) for the detecReceived for publication 20 January 1966. * Address: Assistant Chief, Laboratory of Parasite Chemotherapy, NIAID, NIH, Bethesda, Maryland. t Address: State Entomologist, South Carolina Department of Health, Columbia, South Carolina. tion of the microfilariae and under oil immersion (970 X) for the detection of the other parasites. A minimum of 100 fields were examined before a smear was considered negative. The presence of Plasmodium sp., Leucocytozoon sp., Haemoproteuis sp., Trypanosoma sp., and microfilaria was recorded. The collection periods were from 5 June 1962 to 14 November 1962, and from 12 March 1963 to 16 April 1963.