Changes in the gull populations of SW Wales

Pathogenic microorganisms associated with gulls and terns (Laridae)

“…Declines of breeding numbers in gull populations, attributable to large die-off due to botulism, have been observed in the UK. (Smith 1982, Sutcliffe 1986, Worrall 1987, Austria (Grüll & Rauer 2000: C. ridibundus), Czech Republic (Chytil & Macháček 2000: C. ridibundus) and elsewhere (Shutt et al 2014: L. marinus). Smith (1977) noted the following larid species involved in outbreaks of botulism: C. ridibundus, L.…”

“…chicken carcasses, fish remains, etc. : Gophen et al 1991, Ortiz & Smith 1994b, Lloyd 1996, Gourreau et al 1998; iii) feeding on maggots: fly larvae living in intoxicated avian cadavers might contain very high concentrations of type C toxin (Sutcliffe 1986, Brand et al 1988, Gophen et al 1991, Hubálek & Halouzka 1991, Lloyd 1996, Wobeser 1997, Gourreau et al 1998. Soos & Wobeser (2006) found that hatch-year L. pipixcan carcasses were the primary source of toxin-laden maggots prior to outbreaks of botulism in local waterfowl, and thus a major initiating factor for avian botulism outbreaks in Saskatchewan (Canada) at least in the years 1999-2001.…”

Re-Evaluation of the Role of Landfills and Culling in the Historic Changes in the Herring Gull (Larus argentatus) Population in Great Britain

“…Initially, the symptoms are a characteristic flaccid paralysis that results in dehydration and then eventual death. There have been an increasing number of reports of botulism in Herring Gulls throughout Britain and in Northern Ireland and the Republic of Ireland in recent years (e.g., Macdonald and Standring 1978;Sutcliffe 1986: Lloyd et al 1991Mitchell et al 2004), and confirmed deaths have been reported in every month of the year. Certain diagnosis of botulism in gulls found dead is difficult, because it requires a blood sample taken from the individual while still alive (Macdonald and Standring 1978), but death from botulism is often attributed to birds that show paralysis or are found dead with partially extended wings.…”

Use of Lethal Control to Reduce Habituation to Blank Rounds by Scavenging Birds

“…The presence of large numbers of these birds often leads to conflict with humans. Gulls and corvids are known carriers of human pathogens such as Salmonella, Escherichia coli, and avian botulism, and they have the potential to transfer disease to water storage reservoirs (Benton et al 1983, Butterfield et al 1983, Ortiz and Smith 1984, Monaghan et al 1985, Sutcliffe 1986). Concentrations of scavenging birds cause considerable nuisance, and their defecation is detrimental to amenity areas and increases health risks to local residents (Fasham 2000).…”