Table 2.
Pathogens in domestic chickens on San Cristobal and Santa Cruz Islands from 2001 to 2003, known pathogenicity to wild birds, and risk to Galápagos bird species
| Pathogen | Disease type | Wild bird species affected | Virulence | Citation | Galápagos bird species at risk |
|---|---|---|---|---|---|
| Avian paramyxovirus type I (Newcastle disease) | Virus | Double-crested cormorants, white pelicans, mallard ducks; Gulls, USA, and Canada | Moderate to high | Wobeser et al., 1993, Banerjee et al., 1994, Docherty and Friend, 1999 | Flightless cormorant, brown pelican, Galápagos penguin, lava gull, Galápagos finches mockingbirds, Galápagos pintail |
| Avian encephalomyelitis (picornavirus) | Virus | Pheasant, quail, turkeys | Unknown | Van Steenis, 1971, Calnek, 2003 | Unknown: antibodies reported in waved albatross (Padilla et al., 2003) |
| Infectious bursal disease (birnavirus) | Virus | Herring gull | High | http://w3.vet.cornell.edu/nst/ | Lava gull |
| Marek’s disease (herpesvirus) | Virus | Suggestive lesions of Marek’s disease in a great-horned owl | Unknown | Halliwell (1971) | Barn owl, short-eared owl, Galápagos penguin |
| Avian adenovirus type I | Virus | Turkeys, pigeons, mallard ducks, guineafowl, pheasants, geese | Unknown | Gerlach (1999) | Fightless cormorants, waved albatross (Padilla et al., 2003), boobies, white-cheeked pintail, lava gull, terns |
| Infectious bronchitis virus (coronavirus) | Virus | Racing pigeons | Moderate | Barr et al. (1988) | Galápagos doves |
| Fowlpox (poxvirus) | Virus | Galliformes | Low to high | Gerlach, 1999, Thiel et al., 2005 | Galápagos passerines (recombination with passerine strains possible, canarypox-like isolate identified) |
| Infectious tenosynovitis (reovirus) | Virus | Muscovy ducks | Low | Wobeser (1997) | White-cheeked pintail |
| M. gallisepticum (Mycoplasma sp.) | Bacteria | House finch, American goldfinch, house sparrow, many species of Passeriformes, Piciforms, Apodiformes, and Columbiformes, USA Wild turkeys, USA | Moderate to high | Davidson et al., 1982, Jessup et al., 1983, Friend, 1999, Hartup et al., 2001, Luttrell et al., 2001, Forrester and Spalding, 2003 | Darwin’s finches, mockingbirds Galápagos doves, dark-billed cuckoos, yellow warbler |
| Dispharynx sp. | Nematode parasite | Many passerines: Brown-headed cowbird, boat-tailed grackle, American crows, blue jay, northern mockingbird, Northern cardinal, Carolina wren, wild turkey | Moderate to high (depends on intensity of infection) | Rickard, 1985, Forrester and Spalding, 2003 | Dark-billed cuckoos, Darwin’s finches, mockingbirds, yellow warbler, Galápagos flycatcher, Vermillion flycatcher |
| Capillaria spp. | Nematode parasite | C. contorta and C. annulata (poultry capillaria): turkey, goose, pheasant, guinea fowl, peafowl, black-crowned night heron, double-crested cormorant | Low to moderate | McDougald, 2003, Forrester and Spalding, 2003 | Flightless cormorant, yellow-crowned night heron, lava heron |
| T. gondii | Protozoa | Members of Accipitiriformes, Anseriformes, Galliformes, Gruiformes, Charadriiformes, Columbiformes, Strigiformes, Passerifomes | Moderate to high | Dubey, 2002 | Any wild bird species in contact with feral or domestic cat feces |
| Megabacteria (Macrorhabdus sp.) | Fungus | Canaries | Moderate | Uyttebroek and Ducatelle, 1990, Lumeij, 1999, Tomaszewski et al., 2003 | Darwin’s finches, yellow warblers, mockingbirds, yellow-billed cuckoo, Galápagos and Vermillion flycatchers |