Dates of arrival of the Eurasian golden oriole (Oriolus oriolus L.) in decidious forest in relation to increase of local air temperature in NW Croatia

Abstract

Numerous regions worldwide are affected by Earth climate warming. Most studies of bird phenology in relation to global and regional climate change have focused on trends in arrival dates and breeding dates. The study investigates the results of phenological spring migration research on Eurasian Golden Oriole during a period of 26 years (1991–2016) in relation to average spring air temperatures (April–May) and year in deciduous forests (northwestern Croatia). Data is available for spring arrivals detected by the first song. Arrival date advanced significantly during the research period. According to the linear regression slopes, models suggested that in Eurasian Golden Oriole arrival date has advanced 6 days in period 1991–2016. Furthermore, average spring air temperatures (April–May) increased significantly during the study period. Furthermore, date of arrival was significantly negative correlated with average spring temperatures. My results provide evidence that warms spring has impacted spring migration arrival dates of Eurasian golden oriole of the deciduous forests in northwestern Croatia.