Wing feather mite infestations on passerine birds : season and ambient air temperature influence the distribution of Proctophyllodes stylifer across the wings of blue tits (Parus caeruleus).

Wiles, R. and Cameron, J. and Behnke, J. M. and Hartley, Ian R. and Gilbert, F. S. and McGregor, P. K. (2000) Wing feather mite infestations on passerine birds : season and ambient air temperature influence the distribution of Proctophyllodes stylifer across the wings of blue tits (Parus caeruleus). Canadian Journal of Zoology, 78 (8). pp. 1397-1407. ISSN 0008-4301

Abstract

Changes in the distribution of the wing-feather mite Proctophyllodes stylifer (Buckholz 1869) on the flight feathers of blue tits (Parus caeruleus) were studied throughout the seasons and in relation to ambient air temperature at three combinations of study sites (Lancashire, West Midlands, and South Midlands). We tested the hypotheses that the distribution of mites is influenced in part by season and ambient air temperature. In the winter months mites clustered predominantly on the tertiary feathers, whereas in late spring, summer, and autumn, mite-infestation scores were higher on the proximal primary and secondary feathers. Three approaches were employed to determine whether this seasonal redistribution of mites arose as a response to changes in microclimate, probably ambient air temperature, rather than to season per se. Firstly, meteorological data for the Lancashire study sites, and our own monitoring of the precise air temperature at the time of handling and inspection at the West Midlands study sites, enabled us to establish a link between distribution pattern and ambient temperature. Secondly, limited observations on the distribution of mites on birds recaptured when ambient air temperatures differed by 5°C or more between first and second nettings, one temperature being below 10°C and the other above, supported the idea that the change in distribution was associated with air temperature. Finally, the results of a small experiment in which heavily infested birds caught on a day when air temperatures ranged from 9 to 11°C were taken indoors and temporarily subjected to a higher ambient air temperature (20 min) prior to re-inspection and release also confirmed that mite movement was associated with the temperature of their environment. We conclude that the seasonal changes in distribution were driven by microclimatic changes, in part by temperature.