Population monitoring at Jomfruland and Lista Bird Observatories in 2015
Figur 1 (klikk på bildet) Forekomsten av fuglekonge i den standardiserte nettfangsten ved fuglestasjonene på Jomfruland og Lista var veldig høy høsten 2015, og antallet ved begge fuglestasjonene var det høyeste siden 1993.
Figur 2 (klikk på bildet) Om våren kommer rødstjert 9 dager tidligere enn det gjorde i 1990.
The new annual report from Jomfruland and Lista bird observatories is published. The full report (in Norwegian) can be downloaded:
Many species that overwinter in tropical areas (especially Willow Warblers and Whitethroat), and some species that winter in Europe and North Africa (as Blackbird and Fieldfare), were caught in low numbers in 2015. Some sedentary and irruptive species, such as Blue tit and Great tit, were also caught in low numbers. This is due to the poor breeding season, as the spring was dominated by high rainfall and low temperatures in May and June.
The annual ringing results were, however, somehow compensated by a record incidence of Goldcrest. This species is generally the most abundant ringed species during autumn at Jomfruland Bird Observatory. In 2015, the number of Goldcrests ringed at Jomfruland and Lista was the highest since 1993. The species occurrence has been increasing since 2009 (see Figure 1).
The report also shows that most of the passerines studied on this report arrive earlier in the spring than they did in 1990, probably due to climate change. On Figure 2, it is possible to see the changes in arrival (blue) and departure (orange) for Redstart, using Julian dates (1=1 January, 110=20 April, 270=27 September).
Temperature, rainfall and wind speed is expected to increase in Norway during the next years. Arrival and departure times in spring and autumn are for many bird species directly linked to food availability, temperature and access to nesting sites. Therefore, changes in the arrival and departure times also change the time of nesting, breeding success, survival, distribution and population size of many bird species.