Käser J, Amrhein V & Hänggi A
Spinnen (Arachnida, Araneae) im Winter - kleinräumige Unterschiede als Folge tageszeitlicher Temperaturschwankungen
Spiders (Arachnida, Araneae) in winter - differences in the appearance of species in small-scale spaces as a response to daily temperature fluctuations
Pitfall traps were positioned for the investigation of the spider fauna at the northern and southern slopes of three mountain ridges (Chilchberg, Riedberg, and Buechenberg, municipalities Nunningen and Zullwil, canton Solothurn, Switzerland) within the Swiss Jura Mountains. The temperature in the upper litter was measured at three hour intervals. Independent of the weather more or less clear differences between northern and southern slopes could be observed. Maximum day temperature fluctuations of 15.8 °C were measured.
There were no significant differences in spider communities based on quantitative comparison methods. However, a qualitative analysis showed major differences in species composition. More than 50% of all species per investigation area showed clear preferences for the northern or the southern slope, with more then two thirds of the individuals only found on either the north or south slopes.
appearance of adults; daily temperature; forests; Jura mountains; Switzerland; winter fauna