Comparison of nesting ecology of three co-existing Atlantic Forest woodpeckers reveals narrow specialization in the Helmeted Woodpecker Celeus galeatus.

LAMMERTINK, MARTJAN; FERNANDEZ, JUAN MANUEL; COCKLE, KRISTINA L.

ACTA ORNITHOLOGICA

MUSEUM & INST ZOOLOGY

Lugar: Warszawa, POLAND; Año: 2020

0001-6454

The Atlantic Forestin southeastern South America is a biodiversity hotspot with high speciesrichness and high forest loss. Three large to medium-sized woodpecker species(Robust Woodpecker Campephilus robustus, Lineated Woodpecker Dryocopuslineatus, and theglobally threatened Helmeted Woodpecker Celeus galeatus,) coexist in the south of theecoregion, and show remarkable convergence in plumage patterns and colouration,possibly driven by interspecific interactions. We assessed differentiation in nest tree species, nestsubstrates, and timing of breeding and evaluated whether nesting ecology may bea factor explaining an association with mature forests in the HelmetedWoodpecker. Robust and Lineated Woodpeckers excavated cavities in nine and eight nest treespecies, respectively, whereas Helmeted Woodpeckers specialized narrowlyon laurel trees (88% of nest cavities in two species in genus Nectandraof 52±14 cm DBH).Helmeted Woodpecker is further distinguished by a more frequent use of living,partially decayed treesand by more frequent re-use of nest cavities. When nesting in selectivelylogged forest (vs. old-growth), Robust and Lineated Woodpeckers used trees with smaller DBH and Robust Woodpeckers excavated lower in trees. Helmeted Woodpeckers selected nest treeswith similar dimensions in both environments, indicating lesser flexibility. Helmeted Woodpeckers bred 20?23 dayslater in the year than Lineated and RobustWoodpeckers, potentially allowing them to avoid nesting near the two larger species. The narrow specialization ofHelmeted Woodpecker on nesting in Nectandratrees of large sizes at the onset of decay is a possible factor in makingit sensitive to selective logging effects. To stop declines of Helmeted Woodpecker we recommend the sparing fromselective logging of large Nectandratrees, as well as large trees of species used for roosting, and restoring moreforested areas to mature forest conditions.