Ecological Archives M075-022-A3

Robert E. Ricklefs, Bethany L. Swanson, Sylvia M. Fallon, Alejandro Martínez-Abraín, Alexander Scheuerlein, Julia Gray, and Steven C. Latta. 2005. Community relationships of avian malaria parasites in southern Missouri. Ecological Monographs 75:543–559.

Appendix C. Comparisons of malaria parasite prevalence among different locations in North America based on reports in the literature.

Based on studies surveyed by Greiner et al. (1975) , in which prevalence was determined by visual inspection of blood smears, we compiled a table of sampled and infected individuals from several original studies in other areas in North America. We included only those host species that were common in our study area in the Missouri Ozarks and were represented elsewhere by samples mostly exceeding 20 individuals. An ANOVA on arcsin-transformed prevalence weighted by the square root of sample size for individual species in each study revealed a significant study effect (F = 4.03, df = 9,13, P = 0.012) and a significant species effect (F = 3.49, df = 10,13, P = 0.019; overall model, F = 4.68, df = 19,13, P = 0.0034, R2 = 0.872). Among studies represented by two or more species in this comparison, the one by Love et al. (1953) and the present study reported high prevalence overall (arcsin prev = 0.68, 0.65). The studies of Collins et al. (1966) , Bennett et al. (1975) , and Bennett and Fallis (1960) (0.37, 0.37, 0.17), as well as the combined data for North America in Greiner et al. (1975) (0.26), reported low prevalence (Table C1). Among studies focusing on a single species, high prevalence was found only among Northern Cardinals (Cardinalis cardinalis), which had a high infection rate in the Missouri Ozarks (6 of 13 individuals), as well as 18/25 in one study in Georgia (Jordan 1943) and 8/9 in another study in South Carolina (Hunninen and Young 1950) .

In these comparisons, one cannot determine whether differences between studies represent geographic effects, habitat effects, the particular interval over which the study was conducted, or the methods employed in each study. Except for the present study, which used PCR screening to detect parasitism, prevalence was determined by visual examination of blood smears, which is fairly standardized (McClure et al. 1978, Godfrey et al. 1987, Weatherhead and Bennett 1992) although perhaps not uniformly applied. The difficulty in comparing prevalence among studies is highlighted by the following examples. For the Prairie Warbler Dendroica discolor, Greiner et al. (1975) reported no parasitized individuals in their compilation of North American studies. Using PCR screening, we determined that six of 17 birds were parasitized, but inspection of slides in 1999 revealed zero infections out of five examined, although three of these individuals had malaria parasites. For the Black-and-White Warbler Mniotilta varia, Greiner et al. (1975) reported three infected individuals out of 123 smears examined. We detected 11 of 50 infected individuals by PCR screening; smears read in 1999 revealed zero of 22 infections, although seven of the individuals had malaria parasites in their peripheral circulation.

Table C1. Results of statistical tests of heterogeneity in the prevalence of malaria parasites infecting a particular host species across studies. Significance of deviations from the overall mean prevalence was determined by partitioned G test.

Study

VOL

VRG

IVI

WCI

MVA

PCY

PAM

SAU

DDI

TLU

CCA

1

L

     

L

           

2

ns

     

ns

 

L

       

3

ns

ns

 

ns

   

ns

 

L

ns

L

4

   

ns

   

L

L

L

     

5

                   

H

6

                   

ns

7

                   

H

8

                 

ns

ns

9

                   

ns

10

H

ns

ns

ns

H

H

ns

H

H

ns

ns

   Note: Host species are VOL = Vireo olivaceus, VGR = Vireo griseus, IVI = Icteria virens, WCI = Wilsonia citrina, MVA = Mniotilta varia, PCY = Passerina cyanea, PAM = Parula americana, SAU = Seiurus aurocapillus, DDI = Dendroica discolor, TLU = Thryothorus ludovicianus, and CCA = Cardinalis cardinalis.

ns = not significantly different from mean prevalence over all studies combined; L = prevalence significantly lower than mean in partitioned G test (not adjusted); H = prevalence significantly higher than mean in partitioned G test (not adjusted).

 

TABLE C2. References for studies used to compile Table C1.

Study

Reference

Location

Months

Habitat

1

(Bennett and Fallis 1960)

Ontario, Algonquin

summer

Mixed woods and lakeshore

2

(Bennett et al. 1975)

New Brunswick

May-Aug

Marsh, lakeshore

3

(Collins et al. 1966)

South Carolina

Mar-Nov

Pine plantation and marsh

4

(Greiner et al. 1975)

North America

All

All

5

(Hunninen and Young 1950)

South Carolina

June-Aug

Hospital grounds

6

(Jochen 1966)

New Jersey

All year

Game farm; coastal second growth

7

(Jordan 1943)

Georgia

May-Oct

University of Georgia campus

8

(Love et al. 1953)

Georgia

All year

Mixed

9

(Wetmore 1941)

Maryland

Mostly summer

Suburban mixed

10

This study

Missouri

July

Forest

   Note: Durations of studies were 1 year (6), 2 years (3, 7, 9), 3 years (1, 2, 5), 4 years (10), and 5 years (8).

 

LITERATURE CITED

Bennett, G. F., M. F. Cameron, and E. White. 1975. Hematozoa of the passeriforms of the Tantramar Marshes, New Brunswick. Canadian Journal of Zoology 53:1432–1442.

Bennett, G. F., and A. M. Fallis. 1960. Blood parasites of birds in Algonquin Park, Canada, and a discussion of their transmission. Canadian Journal of Zoology 38:261–273.

Collins, W. E., G. M. Jeffery, J. C. Skinner, A. J. Harrison, and F. Arnold. 1966. Blood parasites of birds at Wateree, South Carolina. Journal of Parasitology 52:671–673.

Godfrey, R. D. J., A. M. Fedynich, and D. B. Pence. 1987. Quantification of hematozoa in blood smears. Journal of Wildlife Diseases 23:558–565.

Greiner, E. C., G. F. Bennett, E. M. White, and R. F. Coombs. 1975. Distribution of the avian hematozoa of North America. Canadian Journal of Zoology 53:1762–1787.

Hunninen, A. V., and M. D. Young. 1950. Blood protozoa of birds at Columbia, South Carolina. Journal of Parasitology 36:258–260.

Jochen, R. F. 1966. Research note: blood parasites of birds trapped in the New Jersey coastal region. Avian Diseases 10:405–407.

Jordan, H. B. 1943. Blood protozoa of birds trapped at Athens, Georgia. Journal of Parasitology 29:260–263.

Love, G. J., S. A. Wilkin, and M. H. Goodwin, Jr. 1953. Incidence of blood parasites in birds collected in southwestern Georgia. Journal of Parasitology 39:52–57.

McClure, H. E., P. Poonswad, E. C. Greiner, and M. Laird. 1978. Haematozoa in the Birds of Eastern and Southern Asia. Memorial University of Newfoundland, St. John's, Newfoundland.

Weatherhead, P. J., and G. F. Bennett. 1992. Ecology of parasitism of brown-headed cowbirds by haematozoa. Canadian Journal of Zoology 70:1–7.

Wetmore, P. A. 1941. Blood parasites of birds of the District of Columbia and Patuxent Research Refuge vicinity. Journal of Parasitology 27:379–393.



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