Phloem sap in fire-damaged Scots pine provides instant foraging opportunities for Three-toed Woodpeckers Picoides tridactylus

Abstract

Three-toed Woodpeckers Picoides tridactylus are known to use phloem sap of conifer trees as a food resource mostly in springtime. A local pair instantly began to forage sap of Scots pine Pinus sylvestris trees that were damaged in a prescribed forest burning; before the fire they had used phloem sap elsewhere in their territory. During three weeks after the fire, the pair intensively used sap of Scots pines which were exposed to fire. The woodpeckers were probably attracted by nutrients induced by damage reaction of the burned pines. Rapid sap use of newly burned trees has not been described before, and it indicates behavioural plasticity how this woodpecker species can use resources in disturbance driven, dynamic forest environments.