Lesser Woodcreepers excavate nest cavities in trees

• Autores: Cockle, Kristina Louise; Gomez, Milka R.; Ferreyra, Carlos A.; Di Sallo, Facundo Gabriel; Bodrati, Alejandro
• Año de publicación: 2024
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: dendrocolaptinae; excavation behavior; facultative excavation; tree cavity
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

To understand the evolution, life-history tradeoffs, and population ecology of cavity nesters, it is critical to identify the avian lineages and circumstances in which birds excavate tree cavities. Woodcreepers (Furnariidae: Dendrocolaptinae; 56 species) are considered non-excavatorsdependent on existing cavities. We overturn this assumption by providing definitive evidence that the Lesser Woodcreeper (Xiphorhynchus fuscus, 23 g) is a facultative tree-cavity excavator. From 2007 to 2022 in the Atlantic forest of Misiones, Argentina, Lesser Woodcreepers nestedin preexisting tree crevices (4 nests), or excavated cavities in trunks of large-diameter trees in advanced stages of decay (mean diameter: 58 cm, range: 22–121 cm, 22 nests). Nest entrances were vertically elongated and chambers were usually pocket like, excavated in the exterior ofthe trees (sapwood), with floors that curved along the trees’ circumference. Excavating woodcreepers pulled out elongated pieces of spongy, fibrous decayed wood, tapping only when inside cavities. Published and online photographs of nests of Xiphorhynchus species suggest thatexcavation may be widespread in the genus. Our observations that woodcreepers tore out elongated pieces of spongy wood (rather than hammering) are consistent with the idea that their long, thin bills are more resistant to torsion and less resistant to impact compared to the stouterbills of other excavators in Passeriformes and Piciformes. Research has tended to focus on birds with chisel-shaped bills, perforating harder sapwood to create nesting chambers in the center of heartrot-infected trees (resulting in typical woodpecker cavities, with circular floors). Wehypothesize that Lesser Woodcreepers have adopted an alternative strategy, selecting large trunks with soft outer wood (sapwood), stopping their excavation radially if they reach harder wood, and then expanding the nest chamber laterally. Furnariidae may offer a useful model family forunderstanding ecological and evolutionary factors that influence cavity excavation.
Fil: Cockle, Kristina Louise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; Argentina
Fil: Gomez, Milka R.. No especifíca;
Fil: Ferreyra, Carlos A.. No especifíca;
Fil: Di Sallo, Facundo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; Argentina
Fil: Bodrati, Alejandro. No especifíca;