© Copyright: Images: Jari Peltomäki, Jouko Lehmuskallio, Simo Mikkonen, Kari Pihlaviita, M. & W. von Wright (Kansalliskirjasto, The National Library of Finland). Recording: Jan-Erik Bruun. All rights reserved.
- Name also: Common Treeceeper, Eurasian Treecreeper
- Family: Treecreepers – Certhiidae
- Appearance: A small bird, well camouflaged on the bark of tree trunks with its brown back streaked with black and white markings. Underparts white, particularly throat and chest. Distinctive longish curved beak.
- Size: Length 12.5–14 cm, weight 7–10 g.
- Nest: Between loose bark and tree trunk, in specially designed nest-boxes, in gaps between the planks of wooden buildings, or in log piles. Built on a base of spruce twigs, bowl made of decaying bark fragments, juniper bark and feathers.
- Breeding: Lays 3–8 eggs April–May. Only females incubate, for 14–15 days. Fledglings remain in nest for 13–18 days.
- Distribution: breeds in old spruce stands and mixed forest in Southern Finland, declining further north but may be observed as far north Southern Lapland. Finnish breeding population estimated at 150,000–250,000 pairs.
- Migration: Some birds migrate, by night. Migrants fly south in September–October, returning in March–April. Winters in neighbouring regions, though some birds may migrate as far as Central Europe.
- Diet: Invertebrates.
- Calls: A chirpy “sri”; song clear with short phrases, not unlike song of Willow Warbler in melody.
The only member of its family and genus found in Finland. Back and wings mainly brown with white and black streaks. Underparts white, particularly bright on chin and breast. Tail long and sturdy with tapering end, shaped like a woodpecker’s tail. Legs brownish yellow. Long downturned beak dark brown with pinkish lower mandible. Irises brown.
Treecreepers climb up tree trunks in search of food from ground level to about halfway up the tree, before fluttering downwards towards the base of the trunk of the next tree they want to search. Their bright white chins reflect light onto the tree trunk like a mirror to help them spot their invertebrate prey in holes and crevasses in the bark.