Techniques for dispersing birds in cities

Public Health Significance of Urban Pests Birds 263 262 effective decontamination of the soil under communal roosts infected with sapronotic fungi H. capsulatum is possible by repeated 3–4 times use of 3 formaldehyde Tosh et al., 1967; • reducing the number of nest boxes available for starlings; • trapping birds in nets or various bird traps and euthanizing the captured birds, if per- mitted; and • sterilizing birds chemically, with a treated grain bait, if permitted. These activities should be carried out in an integrated approach to bird management, since individual steps alone do not produce success. Furthermore, inspection and control measures must be performed by, or under the supervision of, veterinary public health agencies – and only when they are substantiated and necessary. Ornithologists, wildlife managers and citizen representatives such as consumers should be involved in imple- menting the control measures. The integrated approach to bird management also needs a public education component media and a legal regulatory component – that is, poli- tical support – as necessary parts of the process. Finally, a risk–benefit analysis should also be performed.

8.4.4. Techniques for dispersing birds in cities

Birds can be dispersed by various techniques Frings Jumber, 1954; Bickerton Chapple, 1961; Schmitt, 1962; Brough, 1969; Gorenzel Salmon, 1992, 1993. Briefly, they include the use of: • tape strips; • airport strobe lights and flashlights; • fireworks, rockets and shell crackers cartridges that contain no lead shot against approaching flocks which, although effective, are less acceptable in cities; • shooting, pistols, explosives and screamers; • tape-recorded distress or scary calls of birds such as those of owls; • falcons and other trained raptors; • water-mist sprayers; • plastic netting; and monitoring of avian populations and surveillance for associated zoonoses and saprono- ses. The majority of the public health problems caused by wild birds are associated with feral pigeons, gulls, blackbirds, grackles, starlings, corvids and house sparrows. For instance, at least 800 reported transmissions of a pathogen mostly C. psittaci from feral pigeons to people have been found Sixl, 1975; Pospíˇsil et al., 1988; Glünder, 1989; Haag- Wackernagel Moch, 2004, this probably being only the so-called tip of the iceberg. Similarly, hundreds of cases of histoplasmosis in people have been acquired via the air- borne route during, or after, work on communal roosts of birds in urban areas in North America Furcolow et al., 1961; Murdock et al., 1962; Ajello, 1964; D’Alessio et al., 1965; Dodge, Ajello Engelke, 1965; Tosh et al., 1966, 1970; Younglove et al., 1968; Latham et al., 1980; Storch et al., 1980; Waldman et al., 1983; Chamany et al., 2004. Public health surveillance should involve both a passive and active monitoring approach, the former based mainly on reports of disease, while the latter also includes serological surveys of urban birds and city dwellers, further microbiological examination of compe- tent haematophagous invertebrate vectors and avian hosts their infection rate, and inves- tigations of habitats as sources of disease. Monitoring population density of the avian hosts and invertebrate vectors, and their spatial mapping and temporal seasonal distribu- tion, is also necessary. Management priorities should then be established and objectives defined for prevention and control of bird-related infections.

8.4.3. Control of wild and feral birds in urban areas