Ornis Hungarica. vol.8 Suppl. 1.. (1998) p.69-77.
Moult dynamics and its allometry in the Tree Sparrow (Passer montanus)
The dynamics of the body moult in Hungarian and Romanian tree sparrows populations in the Carpathian Basin (Ã“csa) and in Dobrudia (Istria) was examined. Snow's moult index was calculated using data taken from 2762 birds captured between 1986 and 1991 Individual moulting rates were established from the changes of moult indices of birds captured several times. Population moulting rates were calculated from the changes of average indices. The dynamics of the moult could be described with a sigmoid curve. Threre was a significant between-year difference between the steepest parts of the curves. This variation was markedly different for immature birds. Moult in adults birds was both faste rand more synchronous. Istrian birds also moulted faster. No difference between the moulting of the birds in the two regions could be shown by examining moulting allometry. In both regions, moulting of secondaries and tail feathers was highly synchronous and started during the first third of the period of primary moult.