Dynamics of Campylobacter colonization of a natural host, Sturnus vulgaris (European starling).

Wild European Starlings (Sturnus vulgaris) shed Campylobacter at high rates, suggesting that they may be a source of human and farm animal infection. A survey of Campylobacter shedding of 957 wild starlings was undertaken by culture of faecal specimens and genetic analysis of the campylobacters isolated: shedding rates were 30.6% for Campylobacter jejuni, 0.6% for C. coli and 6.3% for C. lari. Genotyping by multilocus sequence typing (MLST) and antigen sequence typing established that these bacteria were distinct from poultry or human disease isolates with the ST-177 and ST-682 clonal complexes possibly representing starling-adapted genotypes. There was seasonal variation in both shedding rate and genotypic diversity, both exhibiting a maximum during the late spring/early summer. Host age also affected Campylobacter shedding, which was higher in younger birds, and turnover was rapid with no evidence of cross-immunity among Campylobacter species or genotypes. In nestlings, C. jejuni shedding was evident from 9 days of age but siblings were not readily co-infected. The dynamics of Campylobacter infection of starlings differed from that observed in commercial poultry and consequently there was no evidence that wild starlings represent a major source of Campylobacter infections of food animals or humans.

Preliminary investigations of ultraviolet-induced markings on domestic turkey chicks and a possible role in injurious pecking.

Several gallinaceous species including domestic turkeys have the capacity for ultraviolet (UV) vision. This might function in signalling between birds, for example in individual recognition, which would suggest the presence of plumage markings visible under UV radiation. Between 1 and 22 d of age, the plumage of 17 male turkey poults (BIG6) was examined. When viewed under a conventional fluorescent white luminaire (which emits minimal UV) the birds were a uniform yellow or white according to the stage of feather emergence. However, when viewed under a lamp emitting radiation with peaks in the UV spectrum, distinct fluorescent and non-fluorescent patches were observable on several parts of the body including the wings, tail, shoulders, thighs, neck, breast and dorsal surface. This paper describes the changes in incidence, size, location and qualitative aspects of these UV-visible markings. The age at which UV-visible markings were first observed on the wings and tail corresponded closely with the age at which injuries to these sites were first caused by pecking, as reported previously. It is suggested that the 'unnatural' appearance of these markings under conventional lighting, which emits minimal UV radiation, might attract or protract injurious pecking from conspecifics.