Illera J.C. & Atienza J.C. (1997) Blue tits Parus caeruleus exploiting Gum Cistus capsules Cistus ladanifer as sources of arthropod food. ARDEA 85 (2): 279-281

The foraging behaviour of Blue Tit Parus caeruleus was studied in detail during the postbreeding period, and in this period they used Gum Cistus capsules quite intensively. We found arthropods in 57% of the examined capsules. The use of the capsules of this shrub demonstrates once again how ably Blue Tits cue in on localized plentiful but temporary food supplies.