Absence of Blood Parasites in Griffon Vultures from Spain

Apparent absence of blood parasites in Winter Wrens in British Columbia

“…Our results add to a growing body of literature documenting the apparent absence of blood parasites in species (Engstrom et al 2000), regions (Stewart et al 1997, Jovani et al 2002, or populations (Blanco et al 1998, Masello et al 2006). Two factors suggest a possible population-level effect.…”

Redescription of Babesia moshkovskii (Schurenkova) from the griffon vulture Gyps fulvus (Hablizl)

“…Infection in adult birds may be concomitant with other disease agents (Samour and Peirce, 1996;Blanco et al, 1997). Surprisingly, a recent report from the same study area did not nd any haematozoa in griVon vultures (Blanco et al, 1998) even though the young birds sampled exhibited similar clinical conditions to those in the present study.…”

Blood parasites of birds: a plea for more cautious terminology

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There is currently much interest in parasites of birds and the possible significance of certain of these parasites in host survival and productivity (Cooper 1989). Many studies have concentrated on blood parasites, such as Huemoproteus and Leucocytozoon, and a number of relevant papers have appeared in Ibis and elsewhere.We have noted an increasing tendency for authors who have examined blood smears of birds and failed to find parasites to state that haematozoa were 'absent' in the samples or, sometimes, even to suggest that the negative findings indicate a population that is free of such parasites (Blancou et al 1998, Merino & Minguez 1998.We should like to make a plea that great caution is exercised when interpreting apparently negative findings during parasitological examination of the blood of birds.We suggest that failure to find parasites does not necessarily indicate that they are absent. We base this claim on the following points.

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