Volume 12, Number 7—July 2006
Research
Migratory Passerine Birds as Reservoirs of Lyme Borreliosis in Europe
Table 1
Infestation of migratory birds by Ixodes ricinus ticks and tick infection with Lyme borreliosis group spirochetes, Ottenby Bird Observatory study, Sweden, 2001
| Bird species* | No. birds | No. ticks | No. (%) birds infested | Mean no. ticks/ infested bird | No. (%) birds with infected ticks | No. larvae | No. (%) positive larvae | No. nymphs | No. (%) positive nymphs | |
|---|---|---|---|---|---|---|---|---|---|---|
| Ground foraging | ||||||||||
| Erithacus rubecula | 3,939 | 446 | 185 (5) | 2.4 | 20 (11) | 296 | 6 (2) | 150 | 15 (10) | |
| Luscina luscinia | 32 | 9 | 4 (13) | 2.3 | 2 (50) | 5 | 0 | 4 | 2 (50) | |
| Luscina svecica | 85 | 8 | 5 (6) | 1.6 | 1 (20) | 0 | 0 | 8 | 1 (13) | |
| Turdus philomelus | 261 | 141 | 24 (9) | 5.9 | 10 (42) | 88 | 14 (16) | 53 | 17 (32) | |
| Turdus iliacus | 51 | 22 | 9 (18) | 2.4 | 2 (22) | 5 | 0 | 17 | 4 (24) | |
| Turdus merula | 193 | 170 | 44 (23) | 3.9 | 15 (34) | 36 | 11 (31) | 134 | 28 (21) | |
| Turdus pilaris | 23 | 6 | 3 (13) | 2 | 1 (33) | 3 | 1 (33) | 3 | 1 (33) | |
| Sturnus vulgaris | 30 | 18 | 9 (30) | 2 | 2 (22) | 7 | 3 (43) | 11 | 4 (36) | |
| Prunella modularis | 64 | 9 | 4 (6) | 2.3 | 1 (25) | 2 | 0 | 7 | 1 (14) | |
| Anthus trivialis | 61 | 29 | 11 (18) | 2.6 | 6 (55) | 17 | 8 (47) | 12 | 6 (50) | |
| Aluada arvensis | 1 | 6 | 1 (100) | 6 | 1 (100) | 6 | 1 (17) | 0 | 0 | |
| Fringilla coelebs | 122 | 9 | 2 (2) | 4.5 | 1 (50) | 8 | 8 (100) | 1 | 0 | |
| Carduelis flammea | 441 | 1 | 1 (0.2) | 1 | 0 | 1 | 0 | 0 | 0 | |
| Carduelis spinus | 79 | 1 | 1 (1) | 1 | 0 | 0 | 0 | 1 | 0 | |
| Pyrrhula pyrrhula | 55 | 8 | 5 (9) | 1.6 | 2 (40) | 1 | 0 | 7 | 2 (29) | |
| Carduelis chloris | 73 | 5 | 5 (7) | 1 | 0 | 1 | 0 | 4 | 0 | |
| Carduelis cannabina | 26 | 1 | 1 (4) | 1 | 0 | 0 | 0 | 1 | 0 | |
| Carpodacus erythrinus | 55 | 1 | 1 (2) | 1 | 0 | 0 | 0 | 1 | 0 | |
| Emberiza schoeniclus | 54 | 1 | 1 (2) | 1 | 0 | 1 | 0 | 0 | 0 | |
| Troglodytes troglodytes | 500 | 33 | 17 (3) | 1.9 | 0 | 25 | 0 | 8 | 0 | |
| Acrocephalus palustris | 30 | 1 | 1 (3) | 1 | 0 | 0 | 0 | 1 | 0 | |
| Other | ||||||||||
| Accipiter nisus | 54 | 2 | 1 (2) | 2 | 0 | 0 | 0 | 2 | 0 | |
| Lanius collurio | 169 | 7 | 2 (1) | 3.5 | 0 | 4 | 0 | 3 | 0 | |
| Dendrocopus major | 83 | 8 | 1 (1) | 8 | 1 (100) | 2 | 0 | 6 | 4 (67) | |
| Hippolais icterina | 87 | 15 | 2 (2) | 7.5 | 0 | 15 | 0 | 0 | 0 | |
| Sylvia atricapilla | 170 | 8 | 7 (4) | 1.1 | 0 | 4 | 0 | 4 | 0 | |
| Sylvia borin | 194 | 1 | 1 (0.5) | 1 | 0 | 0 | 0 | 1 | 0 | |
| Sylvia curruca | 621 | 11 | 8 (1) | 1.4 | 2 (25) | 4 | 0 | 7 | 2 (29) | |
| Sylvia nisoria | 13 | 4 | 3 (23) | 1.3 | 0 | 1 | 0 | 3 | 0 | |
| Phylloscopus sibilatrix | 65 | 1 | 1 (2) | 1 | 0 | 1 | 0 | 0 | 0 | |
| Phylloscopus trochilus | 2,116 | 21 | 19 (1) | 1.1 | 1 (5) | 9 | 0 | 12 | 1 (8) | |
| Regulus regulus | 2,212 | 1 | 1 (0.1) | 1 | 0 | 0 | 0 | 1 | 0 | |
| Parus major | 132 | 35 | 19 (14) | 1.8 | 9 (47) | 22 | 6 (27) | 13 | 5 (39) | |
| Parus caeruleus | 541 | 9 | 6 (1) | 1.5 | 0 | 1 | 0 | 8 | 0 | |
| Certhia familiaris | 37 | 1 | 1 (3) | 1 | 0 | 0 | 0 | 1 | 0 | |
| Phoenicurus phoenicurus | 341 | 23 | 12 (4) | 1.9 | 2 (17) | 12 | 0 | 11 | 2 (18) | |
| Sylvia communis | 220 | 47 | 18 (8) | 2.6 | 3 (17) | 29 | 3 (10) | 18 | 4 (22) | |
| Acrocephalus scirpaceus | 30 | 1 | 1 (3) | 1 | 0 | 0 | 0 | 1 | 0 | |
| Total | 13,260 | 1,120 | 437 (3) | 2.6 | 82 (19) | 606 | 61 (10) | 514 | 99 (19) | |
*Ground-foraging species include invertebrate feeders (Erithacus rubecula through Sturnus vulgaris), insectivores (Prunella modularis and Anthus trivialis), granivores (Aluada arvensis through Emberiza schoeniclus), and herbaceous plant–foraging insectivores (Troglodytes troglodytes and Acrocephalus palustris). Other species include raptors (Accipiter nisus and Lanius collurio), arboreal insectivores (Dendrocopus major through Phoenicurus phoenicurus), and reed-foraging insectivores (Sylvia communis and Acrocephalus scirpaceus). The common names of the 38 bird species listed (from top to bottom) are European robin, thrush nightingale, bluethroat, song thrush, redwing thrush, blackbird, fieldfare, starling, dunnock, tree pipit, skylark, chaffinch, redpoll, siskin, bull finch, green finch, linnet, scarlet rosefinch, reed bunting, wren, marsh warbler, sparrow hawk, red-backed shrike, great spotted woodpecker, icterine warbler, blackcap, garden warbler, lesser whitethroat, barred warbler, wood warbler, willow warbler, goldcrest, great tit, blue tit, tree creeper, redstart, whitethroat, and reed warbler.