Birds and Their Ticks in Northwestern California: Minimal Contribution to Borrelia Burgdorferi Enzootiology

• Published in: The Journal of parasitology 2001-08, Vol.87 (4), p.755-761
• Main Authors: Slowik, Ted J, Lane, Robert S
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Biological and medical sciences; Birds; Birds - parasitology; Borrelia burgdorferi; California - epidemiology; Chaparral; Disease Vectors; Ecology; ECTOPARASITOLOGY; Fundamental and applied biological sciences. Psychology; Infections; Lizards; Lizards - parasitology; Lyme disease; Lyme Disease - epidemiology; Medically important nuisances and vectors, pests of stored products and materials: population survey and control; Parasitism; Synecology; Terrestrial ecosystems; Tick Infestations - veterinary; Ticks; Vectors. Intermediate hosts; Wildlife habitats; Woodlands
• ISSN: 0022-3395; 1937-2345
• DOI: 10.1645/0022-3395(2001)087[0755:BATTIN]2.0.CO;2

Birds and their attendant ticks were surveyed for infection with the Lyme disease spirochete Borrelia burgdorferi, in chaparral and woodland-grass habitats in northwestern California from March to July, 1998 to 1999. In total, 234 birds were captured and recaptured (15%); nearly 2.5 times more birds were captured in chaparral than in woodland-grass. Overall, 34 species representing 15 families were collected during this study; of these, 24 species were caught in chaparral, 19 in woodland-grass, and 9 in both vegetational types. The most frequently captured birds were sage sparrows (Amphispiza belli) in chaparral, and American robins (Turdus migratorius) and oak titmice (Baelophus inornatus) in woodland-grass. Birds hosted 35 Ixodes pacificus (15 larvae, 20 nymphs) and 9 Haemaphysalis leporispalustris (3 larvae, 5 nymphs, 1 adult) ticks, of which 32 were removed from chaparral birds and 12 from woodland birds. The prevalence of tick infestation was 13% (21/167) in chaparral and 5% (3/67) in woodland-grass, but the relative and mean tick intensities of 0.19 and 1.5 for chaparral birds, and 0.18 and 4.0 for woodland birds, respectively, did not differ significantly by habitat. Spirochetes were not detected in either bird-blood or tick-tissue samples when tested by culture, immunofluorescence, or Giemsa-staining. In contrast, over 90% (86/94) of western fence lizards (Sceloporus occidentalis) collected in June or July were infested with an average of 6.9 and 8.9 immature I. pacificus in chaparral and woodland-grass, respectively. We conclude that birds contribute little to the enzootiology of B. burgdorferi in chaparral and woodland-grass habitats in northwestern California because of their limited parasitism by tick vectors and lack of detectable spirochetemias.