Cavities provide suitable microhabitats for various organisms. Therefore, cavity excavators are important species in forest environments. We observed large differences in both persistence and occupancy of the cavities of Grey-headed Woodpecker Picus canus monitored during the whole cavity lifespan in a 33-year study in southern Finland. Of a total of 80 cavities studied, the median persistence time was 17 years, but this varied from a median lifespan of 29 years for cavities in living trees to only 9 years for cavities in dead trees. The expected number of life-span nests of forest bird species per old cavity was 4.2 in living, and only 1.6 in dead trees. Ten bird species utilised the old cavities (most frequently Great Tit Parus major, Grey-headed Woodpecker and Pied Flycatcher Ficedula hypoleuca). The results show that both suitable living and dead trees should be available for cavity excavators such as the Grey-headed Woodpecker, and that living and dead trees may have different, but important ecological roles for cavity-nesting birds in boreal forests.
How to translate text using browser tools
18 March 2022
Dynamics of the Cavities of Grey-Headed Woodpeckers Picus canus Reveal Their Long- and Short-Term Ecological Roles in Boreal Forests
Timo Pakkala,
Juha Tiainen,
Heikki Pakkala,
Markus Piha,
Jari Kouki
ACCESS THE FULL ARTICLE
Acta Ornithologica
Vol. 56 • No. 2
Winter 2021
Vol. 56 • No. 2
Winter 2021
cavity
cavity occupancy
cavity persistence
cavity trees
cavity-nesting birds
dead trees
grey-headed woodpecker