The periodicity of isosporan oocyst discharge in the greenfinch (Carduelischloris)

Over a five-month period 404 faecal samples from greenfinches (Carduelis ch loris L.) from Corby, Northants were examined for coccidian oocysts. Of the se, 101 were positive for isosporan oocysts. By recording the time that eac h sample was taken the daily periodicity of oocyst discharge was shown. Onl y one of the 133 samples was positive from 7 am to noon, whereas 100 of 271 (37%) were positive from noon to 6 pm, the peak being between 2 pm and 5 p m when 71.5% of the samples contained oocysts.