CHARACTERISTICS OF NATURALLY ACQUIRED PLASMODIUM-RELICTUM CAPISTRANOAE INFECTIONS IN NAIVE HAWAIIAN CROWS (CORVUS HAWAIIENSIS) IN HAWAII

Indigenous to Hawaii, the Hawaiian crow (Corvus hawaiiensis) is the wo rld's most severely endangered species with only 3 reproductively acti ve pairs remaining in the wild. Seven captive-reared, avian malaria-na ive C. hawaiiensis were exposed in an outdoor aviary and hematological ly and serologically monitored for 9 wk. Three birds showed Plasmodium relictum capistranoae parasitemia (6.35%, 2.15%, and 0.60%). All bird s were seroconverted for malaria on week 7 as determined by enzyme-lin ked immunosorbent assay (ELISA). Malaria IgG levels of exposed parasit emic birds did not differ from those of exposed nonparasitemic C. hawa iiensis and were not significantly correlated with the level of parasi temia. Four of 9 hematological parameters, e.g., white blood cell coun t (WBC), relative and absolute lymphocytosis, and total solids (TS), s howed significant increases related to ELISA-determined malarial infec tion. The sensitivity, specificity, and the positive predictive values of these 4 parameters for malarial infections in C. hawaiiensis were higher than 66%, with the WBC and TS sensitivity reaching 100%. The re ference range of 9 hematological parameters was established based on u ninfected, clinically healthy C. hawaiiensis. Seven birds were success fully treated and released, increasing the total wild C. hawaiiensis w orld population by approximately 50%.