News records of parasitation of nestling kestrels Falco t. tinnunculus by the blood-sucking fly Carnus hemapterus (Insecta: Milichiidae: Diptera)

Parasitation of nestling Kestrels by the blood-sucking fly Carnus hemapterus was studied during the years 1996[long dash]2009 in several regions of Germany. A total of 1.336 nestlings four of 302 broods were carefully checked for parasites. Results are analysed separately for three categories of nests: nest- boxes in or associated with human buildings, open nests in towns and suburban settlements and open nests outside human settlements. Rates of parasitation were similar between the latter two categories, but twice as high in nest-boxes in areas of human settlement. On average, a Kesrel nestling up to the age of 35 days carried 7.1 adult C. hemapterus flies. No parasitation was recorded at older ages. There seemed to be a negative relationship of parasitation rates with body mass: relatively light nestlings had more parasites than heavier siblings or nestlings of the same age from other broods. Causes of variation in parasitation rates are discussed. Nest-boxes seem to provide bet-ter microclimate for the survival of C. hemapterus pupae, which results in earlier and heavier infection of nestlings in the following season.