Acta Zoologica Cracoviensia, 41(1) 1998

Issue:

VOL 41(1) 1998

Keywords:

Urban birds, daily activity of birds, influence of weather conditions

Download PDF

Share this article:

The influence of weather factors on the daily activity of urban populations of birds at their common roosts in Słupsk

• Ewa GÓRSKA

Abstract:

Under conditions of heavy cloudiness and during rains the activity phase of Streptopelia decaocto, Passer domesticus, Turdus merula, Sturnus vulgaris, Pica pica and Corvus monedula underwent a shortening - the morning departures from the roosts happened later and the evening arrivals earlier by about a dozen to several dozen minutes than on cloudless and rainless days (statistically significant differences). On days with morning temperatures below 0°С the Collared Doves, House Sparrows and Jackdaws left the roosting sites about a dozen to several dozen minutes earlier than they did on days with morning air temperatures above 0°C, when extended the activity phase of these birds. Un­der the conditions of persisting cloudiness and rainfall the species under study started and finished their daily activity at an illumination lower than that on fine days. On the other hand, when short-lived bright intervals and breaks in rainfall occurred at the time of morn­ing departures from the roost and during evening arrivals, the beginning and end of daily activity took place at a higher illumination than on cloudless and rainless days.