The prevalence and source of plastic incorporated into nests of five seabird species on a small offshore island.

There is little evidence documenting the prevalence of plastic nest incorporation for different seabird species and populations, and even less detailing the source of such debris as nesting material. This study presents a baseline dataset on the presence of plastic in the nests of five seabird species on Lady Isle, Scotland using a novel and repeatable methodology for quantifying plastic incorporated into nests. Plastic was found in 24.5% to 80% of nests of all species. We analysed pellets of regurgitated material and the spatial distribution of herring gull nests containing plastic in the context of the tide and nesting habitat. Differences in the types of plastic found in pellets and nests suggests that plastic incorporated into herring gull nests was not derived at foraging sites and likely collected from the local environment. Targeted beach cleans before the breeding season could help minimise the quantity of plastic available to herring gulls.

Haemoproteus minutus is highly virulent for Australasian and South American parrots.

BACKGROUND: Haemoproteus and Plasmodium species are widespread avian blood parasites. Several Plasmodium species are known for their high virulence and have caused significant declines in naïve bird populations. The impact of closely related Haemoproteus parasites is largely unknown. Recently we reported a lethal disease in two parrot aviaries caused by Haemoproteus parasites. RESULTS: Here we show that the causative pathogen Haemoproteus minutus is responsible for further 17 lethal outbreaks in parrot aviaries in Denmark, Germany and Great Britain. All affected parrots are endemic to Australasia and South America. We sequenced the cytochrome b gene from megalomeront-infected muscle tissue of 21 parrots and identified the two lineages TUPHI01 and TURDUS2 as causative agents, commonly naturally infecting the common blackbird (Turdus merula) and the song thrush (Turdus philomelos), respectively, in the Palaearctic. No intraerythrocytic parasite stages were found in any of the parrots. We failed to detect H. minutus in invasive Indian ring-necked parakeets (Psittacula krameri) in Germany. Together this suggests that abortive infections with two virulent lineages of H. minutus are lethal for naïve parrot species from Australasia and South America. We asked whether we could detect H. minutus in New Zealand, where its Turdus hosts were introduced in the 1800s. We therefore tested invasive blackbirds and song thrushes, and the co-existing endemic red-fronted parakeet (Cyanoramphus novaezelandiae) population on three New Zealand islands. No Haemoproteus spp. DNA was detected in all blood samples, indicating absence of transmission. CONCLUSIONS: The results of this study show that captive parrots in Europe are threatened by two lineages of an otherwise benign parasite of Turdus spp. Aviary collections of parrots should be protected from Culicoides spp. vectors in Europe. Animal trade and climate changes extending the current vector and parasite distribution have to be considered as potential risk factors for the introduction of the disease in naïve parrot populations.

The emergence and spread of finch trichomonosis in the British Isles.

Finch trichomonosis, caused by the protozoal parasite Trichomonas gallinae, was first recognized as an emerging infectious disease of British passerines in 2005. The first year of seasonal epidemic mortality occurred in 2006 with significant declines of greenfinch Carduelis chloris and chaffinch Fringilla coelebs populations. Here, we demonstrate that large-scale mortality, principally of greenfinch, continued in subsequent years, 2007-2009, with a shifting geographical distribution across the British Isles over time. Consequent to the emergence of finch trichomonosis, the breeding greenfinch population in Great Britain has declined from ca 4.3 million to ca 2.8 million birds and the maximum mean number of greenfinches (a proxy for flock size) visiting gardens has declined by 50 per cent. The annual rate of decline of the breeding greenfinch population within England has exceeded 7 per cent since the initial epidemic. Although initially chaffinch populations were regionally diminished by the disease, this has not continued. Retrospective analyses of disease surveillance data showed a rapid, widespread emergence of finch trichomonosis across Great Britain in 2005 and we hypothesize that the disease emerged by T. gallinae jumping from columbiforms to passeriforms. Further investigation is required to determine the continuing impact of finch trichomonosis and to develop our understanding of how protozoal diseases jump host species.

Evidence of spread of the emerging infectious disease, finch trichomonosis, by migrating birds.

Finch trichomonosis emerged in Great Britain in 2005 and led to epidemic mortality and a significant population decline of greenfinches, Carduelis chloris and chaffinches, Fringilla coelebs, in the central and western counties of England and Wales in the autumn of 2006. In this article, we show continued epidemic spread of the disease with a pronounced shift in geographical distribution towards eastern England in 2007. This was followed by international spread to southern Fennoscandia where cases were confirmed at multiple sites in the summer of 2008. Sequence data of the ITS1/5.8S/ITS2 ribosomal region and part of the small subunit (SSU) rRNA gene showed no variation between the British and Fennoscandian parasite strains of Trichomonas gallinae. Epidemiological and historical ring return data support bird migration as a plausible mechanism for the observed pattern of disease spread, and suggest the chaffinch as the most likely primary vector. This finding is novel since, although intuitive, confirmed disease spread by migratory birds is very rare and, when it has been recognised, this has generally been for diseases caused by viral pathogens. We believe this to be the first documented case of the spread of a protozoal emerging infectious disease by migrating birds.

Acute necrotising pneumonitis associated with Suttonella ornithocola infection in tits (Paridae).

Suttonella ornithocola, first isolated from the lungs of British tit species in 1996, was found to be a novel bacterium belonging to the family Cardiobacteriaceae. Comprehensive surveillance of garden bird mortality across Great Britain between April 2005 and April 2009 involved post mortem and microbiological examination of 82 tits (Paridae; multiple species) and six long-tailed tits (Aegithalidae; Aegithalos caudatus). S. ornithocola was isolated from six birds submitted from six incidents of morbidity and mortality involving Paridae and Aegithalidae species with a wide geographical distribution. The mortality incidents occurred sporadically at low incidence throughout the study period, which suggested that the infection is endemic in native bird populations, with a seasonal peak during early spring. Histopathological examination showed multiple foci of acute pulmonary necrosis associated with gram-negative cocco-bacillary bacteria. These findings supported the hypothesis that S. ornithocola is a primary pathogen of tits in Great Britain.

Emerging infectious disease leads to rapid population declines of common British birds.

Emerging infectious diseases are increasingly cited as threats to wildlife, livestock and humans alike. They can threaten geographically isolated or critically endangered wildlife populations; however, relatively few studies have clearly demonstrated the extent to which emerging diseases can impact populations of common wildlife species. Here, we report the impact of an emerging protozoal disease on British populations of greenfinch Carduelis chloris and chaffinch Fringilla coelebs, two of the most common birds in Britain. Morphological and molecular analyses showed this to be due to Trichomonas gallinae. Trichomonosis emerged as a novel fatal disease of finches in Britain in 2005 and rapidly became epidemic within greenfinch, and to a lesser extent chaffinch, populations in 2006. By 2007, breeding populations of greenfinches and chaffinches in the geographic region of highest disease incidence had decreased by 35% and 21% respectively, representing mortality in excess of half a million birds. In contrast, declines were less pronounced or absent in these species in regions where the disease was found in intermediate or low incidence. Also, populations of dunnock Prunella modularis, which similarly feeds in gardens, but in which T. gallinae was rarely recorded, did not decline. This is the first trichomonosis epidemic reported in the scientific literature to negatively impact populations of free-ranging non-columbiform species, and such levels of mortality and decline due to an emerging infectious disease are unprecedented in British wild bird populations. This disease emergence event demonstrates the potential for a protozoan parasite to jump avian host taxonomic groups with dramatic effect over a short time period.

Analysis of feces samples collected from a wild-bird garden feeding station in Scotland for the presence of verocytotoxin-producing Escherichia coli O157.

Composite wild bird feces collected at regular intervals from a garden feeding station in southwest Scotland over a 3-year period were examined for verocytotoxin-producing Escherichia coli O157. One sample was positive for Escherichia coli O157. The isolate belonged to phage type 21/28 and possessed vtx2, eaeA, and enterohemorrhagic E. coli hlyA genes.