, Volume 1, Issue 4, pp 362–373 | Cite as

Leukocyte Profiles in Wild House Finches with and without Mycoplasmal Conjunctivitis, a Recently Emerged Bacterial Disease

  • Andrew K. Davis
  • Katherine C. Cook
  • Sonia Altizer
Original Contributions


Leukocyte profiles (relative numbers of white blood cell types) have been used by a growing number of ecological studies to assess immune function and stress in wild birds. House Finches (Carpodacus mexicanus) in eastern North America are susceptible to an eye disease caused by the bacterium Mycoplasma gallisepticum, providing the opportunity to examine whether leukocyte profiles are associated with infection status and other host characteristics. In this study, we compared blood smears from 297 wild House Finches with and without conjunctivitis to examine whether leukocyte profiles were associated with the presence and severity of mycoplasmal conjunctivitis. We also evaluated the influence of age, sex, and molt on leukocyte profiles in both diseased and nondiseased birds. Of 243 House Finches of known age and sex sampled, 30% showed clinical signs of mycoplasmal conjunctivitis. House Finches with conjunctivitis had significantly higher heterophil to lymphocyte (H/L) ratios and harbored greater numbers and proportions of heterophils and monocytes than nondiseased birds. Leukocyte profiles of noninfected birds did not differ significantly with respect to sex, but young birds had significantly greater numbers of lymphocytes and total white blood cells than adults. Molting birds had significantly more eosinophils than nonmolting birds. Finally, House Finches with the most severe outward signs of conjunctivitis showed the most dramatic leukocyte changes relative to noninfected individuals, and increasing H/L ratios and monocytes in diseased birds were paralleled in a subset of birds that were recaptured during the study period. These results are consistent with patterns observed in domestic poultry and suggest that understanding patterns of leukocyte differentials in this host-pathogen system could improve our understanding of innate immunity and infectious disease risk in other wild passerines.


Mycoplasma gallisepticum Carpodacus mexicanus white blood cells innate immunity heterophils lymphocytes monocytes 



We thank Carol Reap, Rusty Pritchard, and Sonha Payne for access to trapping sites at backyard feeding stations. We acknowledge David Toplon for initiating white blood cell counts in House Finches at Emory University as part of an undergraduate thesis. David Ley provided results from clinical tests of MG presence in a subset of birds. Barry Hartup and Wesley Hochachka provided useful discussion and comments on an early draft of the manuscript. Part of this work was supported by the National Science Foundation (under grant no. DEB-0094456 to André Dhondt) and by a University Research Committee Award from Emory University to Sonia Altizer.


  1. Altizer, S, Hochachka, WM, Dhondt, AA 2004aSeasonal dynamics of mycoplasmal conjunctivitis in eastern North American house finchesJournal of Animal Ecology73309322CrossRefGoogle Scholar
  2. Altizer, S, Davis, AK, Cook, KC, Cherry, JJ  2004bAge, sex, and season affect the risk of mycoplasmal conjunctivitis in a southeastern house finch populationCanadian Journal of Zoology82755763CrossRefGoogle Scholar
  3. Bortolotti, GR, Dawson, RD, Murza, GL 2002Stress during feather development predicts fitness potentialJournal of Animal Ecology71333342CrossRefGoogle Scholar
  4. Branton, SL, May, JD, Lott, BD, Maslin, WR 1997Various blood parameters in commercial hens acutely and chronically infected with Mycoplasma gallisepticum and Mycoplasma synoviaeAvian Diseases41540547PubMedGoogle Scholar
  5. Brawner, WR, Hill, GE, Sundermann, CA 2000Effects of coccidial and mycoplasmal infections on carotenoid-based plumage pigmentation in male house finchesAuk117952963Google Scholar
  6. Campbell, TW 1995Avian hematology and cytology, 2nd ed.Iowa State University PressAmes, IAGoogle Scholar
  7. Campo, JL, Gil, MG, Torres, O, Davila, SG 2000Association between plumage condition and fear and stress levels in five breeds of chickensPoultry Science80549552Google Scholar
  8. Dhondt, AA, Tessaglia, DL, Slothower, RL 1998Epidemic mycoplasmal conjunctivitis in house finches from eastern North AmericaJournal of Wildlife Diseases34265280PubMedGoogle Scholar
  9. Elston, JJ, Beck, M, Alodan, MA, Vega-Murillo, V 2000Laying hen behavior 2. Cage type preference and heterophil to lymphocyte ratiosPoultry Science79477482PubMedGoogle Scholar
  10. Ewenson, EL, Zann, RA, Flannery, GR 2001Body condition and immune response in wild Zebra Finches: effects of capture, confinement and captive-rearingJournal of Comparative Physiology88391394CrossRefGoogle Scholar
  11. Figuerola, J, Munoz, E, Gutierrez, R, Ferrer, D 1999Blood parasites, leucocytes and plumage brightness in the cirl bunting, Emberiza cirlusFunctional Ecology13594601CrossRefGoogle Scholar
  12. Fudge, AM 1994Blood testing artifacts: interpretation and preventionSeminars in Avian and Exotic Pet Medicine324Google Scholar
  13. Gross, WB, Siegel, HS 1983Evaluation of the heterophil/lymphocyte ratio as a measure of stress in chickensAvian Diseases27972979PubMedGoogle Scholar
  14. Harmon, BG 1998Avian heterophils in inflammation and disease resistancePoultry Science77972977PubMedGoogle Scholar
  15. Hartup, BK, Bickal, JM, Dhondt, AA, Ley, DH, Kollias, GV 2001aDynamics of conjunctivitis and Mycoplasma gallisepticum infections in house finchesAuk118327333Google Scholar
  16. Hartup, BK, Dhondt, AA, Sydenstricker, KV, Hochachka, WM, Kollias, GV 2001bHost range and dynamics of mycoplasmal conjunctivitis among birds in North AmericaJournal of Wildlife Diseases377281Google Scholar
  17. Hauptmanova, K, Literak, I, Bartova, E 2002Haematology and leukocytozoonosis of great tits (Parus major L.) during winterActa Veterinaria Brno71199204Google Scholar
  18. Hemborg, C, Lundberg, A 1998Costs of overlapping reproduction and moult in passerine birds: an experiment with the pied flycatcherBehavioral Ecology and Sociobiology431923CrossRefGoogle Scholar
  19. Hill GE (1993) House finch (Carpodacus mexicanus). In: Poole A, Gill F (editors), Birds of North America, No. 46, Academy of Natural Sciences, Philadelphia, and American Ornithologists’ Union, Washington, DCGoogle Scholar
  20. Hill, GE 2002A Red Bird in a Brown Bag. The Function and Evolution of Colorful Plumage in the House FinchOxford University PressNew YorkGoogle Scholar
  21. Hochachka, WM, Dhondt, AA 2000Density-dependent decline of host abundance resulting from a new infectious diseaseProceedings of the National Academy of Sciences9753035306CrossRefGoogle Scholar
  22. Horak, P, Saks, L, Ots, I, Kollist, H 2002Repeatability of condition indices in captive greenfinches (Carduelis chloris)Canadian Journal of Zoology80636643CrossRefGoogle Scholar
  23. Kollias, GV, Sydenstricker, KV, Kollias, HW, Ley, DH, Hosseini, PR, Connolly, V,  et al. 2004Experimental infection of individually caged house finches with Mycoplasma gallisepticumJournal of Wildlife Diseases407986PubMedGoogle Scholar
  24. Ley, DH, Berkhoff, JE, Mclaren, JM 1996Mycoplasma gallisepticum isolated from house finches (Carpodacus mexicanus) with conjunctivitisAvian Diseases40480483PubMedGoogle Scholar
  25. Luttrell, MP, Fischer, JR, Stallknecht, DE, Kleven, SH 1996Field investigation of Mycoplasma gallisepticum infections in house finches (Carpodacus mexicanus) from Maryland and GeorgiaAvian Diseases40335341PubMedGoogle Scholar
  26. Luttrell, MP, Stallknecht, DE, Fischer, JR, Sewell, CT, Kleven, SH 1998Natural Mycoplasma gallisepticum infection in a captive flock of house finchesJournal of Wildlife Diseases34289296PubMedGoogle Scholar
  27. Mazerolle, DF, Hobson, KA 2002Physiological ramifications of habitat selection in territorial male ovenbirds: consequences of landscape fragmentationOecologia130356363CrossRefGoogle Scholar
  28. Messonnier, S 2000Counting white blood cellsExotic Pet Practice52Google Scholar
  29. Michener, H, Michener, JR 1940The molt of house finches of the Pasadena region, CaliforniaCondor42140153Google Scholar
  30. Møller, AP, Dufva, R, Erritzoe, J 1998Host immune function and sexual selection in birdsJournal of Evolutionary Biology11703719CrossRefGoogle Scholar
  31. Nava, MP, Veiga, JP, Puerta, ML 2001White blood cell counts in house sparrows (Passer domesticus) before and after moult and after testosterone treatmentCanadian Journal of Zoology79145148CrossRefGoogle Scholar
  32. Nolan, PM, Hill, GE, Stoehr, AM 1998Sex, size, and plumage redness predict house finch survival in an epidemicProceedings of the Royal Society of London. Series B265961965CrossRefGoogle Scholar
  33. Norris, K, Evans, MR 2000Ecological immunology: life history trade-offs and immune defense in birdsBehavioral Ecology111926CrossRefGoogle Scholar
  34. Nunn, CL 2002A comparative study of leukocyte counts and disease risk in primatesEvolution56177190PubMedGoogle Scholar
  35. Nunn, CL, Gittleman, JL, Antonovics, J 2000Promiscuity and the primate immune systemScience29011681170CrossRefPubMedGoogle Scholar
  36. Pyle, P 1997Identification Guide to North American Birds. Part 1Slate Creek PressBolinas, CAGoogle Scholar
  37. Qureshi, MA 1998Role of macrophages in avian health and diseasePoultry Science77978982PubMedGoogle Scholar
  38. Roberts, SR, Nolan, PM, Hill, GE 2001aCharacterization of Mycoplasma gallisepticum infection in captive house finches (Carpodacus mexicanus) in 1998Avian Diseases457075Google Scholar
  39. Roberts, SR, Nolan, PM, Lauerman, LH, Li, L-Q, Hill, GE 2001bCharacterization of the mycoplasmal conjunctivitis epizootic in a house finch population in the southeastern USAJournal of Wildlife Diseases378288Google Scholar
  40. Roitt, I, Brostoff, J, Male, D 2001Immunology, 6th ed.HarcourtNew YorkGoogle Scholar
  41. Ruiz, G, Rosenmann, M, Novoa, FF, Sabat, P 2002Hematological parameters and stress index in rufous-collared sparrows dwelling in the urban environmentsCondor104162166Google Scholar
  42. SPSS (2002) Version 11.5.1, Chicago: SPSS, IncGoogle Scholar
  43. Stangel, PW 1985Incomplete first prebasic molt of Massachusetts house finchesJournal of Field Ornithology5618Google Scholar
  44. Svensson, E, Skarstein, F 1997The meeting of two cultures: bridging the gap between ecology and immunologyTrends in Ecology and Evolution129293CrossRefGoogle Scholar
  45. Vleck, CM, Vertalino, N, Vleck, D, Bucher, TL 2000Stress, corticosterone, and heterophil to lymphocyte ratios in free-living Adelie penguinsCondor102392400Google Scholar
  46. Wakelin, D 1996Immunity to Parasites: How Parasitic Infections Are ControlledCambridge University PressCambridge, UKGoogle Scholar
  47. Walberg, J 2001White blood cell counting techniques in birdsSeminars in Avian and Exotic Pet Medicine107276Google Scholar
  48. Zulkifli, I, Norma, MTC, Chong, CH, Loh, TC 1999Heterophil to lymphocyte ratio and tonic immobility reactions to preslaughter handling in broiler chickens treated with ascorbic acidPoultry Science79402406Google Scholar

Copyright information

© EcoHealth Journal Consortium 2004

Authors and Affiliations

  • Andrew K. Davis
    • 1
  • Katherine C. Cook
    • 1
  • Sonia Altizer
    • 1
  1. 1.Department of Environmental StudiesEmory UniversityAtlanta

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