Differentiation in foraging ecology between three sympatric woodpeckar species of the Atlantic Forest in Argentina

LAMMERTINK M; FERNANDEZ JM; ARETA JI

Congreso; Ornithological Congress of the Americas; 2017

The Helmeted Woodpecker (Celeus galeatus), a threatened species endemic to theAtlantic Forest, co-exists with two other woodpecker species of similar appearance: theLineated Woodpecker (Dryocopus lineatus) and the Robust Woodpecker (Campephilusrobustus). These are the three largest woodpecker species in the Atlantic Forest andthey show a notable convergence in the colors and patterns of their plumages. However,Lineated Woodpecker (210 g) and Robust Woodpecker (261 g) are considerably heavierthan Helmeted Woodpecker (130 g). We compared the foraging ecology of the threespecies in forests with and without selective logging. Out of 315 foraging observations,257 observations came from 19 radio-tagged woodpeckers. Foraging substratediameter was similar between Helmeted and Lineated Woodpeckers, but averagedmore than double in Robust Woodpecker. Lineated and Robust Woodpeckers usedtrees of similar diameter at breast height whereas Helmeted Woodpeckers used treeswith trunks that were significantly more slender. In foraging height, RobustWoodpecker foraged highest up followed by Lineated and then Helmeted Woodpecker.Helmeted Woodpecker foraged more on dead substrates. Helmeted Woodpeckerincluded bamboos (Guadua trinii and Merostachys claussenii) as foraging substrateswhereas only Lineated and Robust Woodpeckers were seen foraging on Paraná Pines(Araucaria angustifolia).In all, the three woodpecker species are welldifferentiated in foraging ecology. We will apply our findings of this foragingdifferentiation in upcoming works on species co-existence and plumage convergence,and on differentiation in responses to selective logging.