Haematology and Leucocytozoonosis of Great Tits (Parus major L.) During Winter

Abstract

Only a few studies about partial haematological examination of great tits have been published so far. We performed a haematological examination of 81 great tits (Parus major) from Brno, Czech Republic, in winter 2000/2001. The examination of 80 healthy birds yielded the following results: 5.89 ± 1.36 × 106/μl erythrocytes, haemoglobin content 173.2 ± 29.9 g/l, packed cells volume 45 ± 4 %, and 4.06 ± 2.40 × 103/μl leucocytes (68.5% lymphocytes, 19.6% heterophils, 5.6% eosinophils, 5.6% basophils and 1.0% monocytes). In the blood of an injured great tit having its leg amputated, we found anaemia and leucocytosis. The blood smears were tested also for the incidence of blood parasites. In three healthy birds (3.9%, n=77) we distinguished the blood parasites of Leucocytozoon genus and in one case (1.3%, n=77) also some microfilariae (in all cases 1 parasite per 105 erythrocytes). The injured great tit suffered from the infection with blood parasite Leucocytozoon dubreuili. We assume that the enfeeblement of organism by the trauma resulted in immunity decrease allowing the reactivation of latent infection L. dubreuili.