Global relationships between tree-cavity excavators and forest bird richness

Area of Science:

• Ecology
• Biodiversity Science
• Conservation Biology

Background:

• Tree-cavity excavators, primarily woodpeckers (Picidae), serve as key indicators of forest ecosystem health and avian diversity.
• Their role extends to facilitating other species by creating nesting sites, linking their presence to broader forest bird communities.

Purpose of the Study:

• To investigate if the positive correlation between tree-cavity excavators and other forest birds extends to broad geographical scales.
• To assess the global applicability of excavators as indicators for forest bird diversity.

Main Methods:

• Utilized global distribution maps to estimate richness of tree-cavity nesting and forest-associated birds across zoogeographic regions.
• Employed generalized least-squares models to analyze the relationships between excavator richness and other forest bird groups.

Main Results:

• Demonstrated a significant positive correlation between the richness of tree-cavity excavating birds and that of secondary cavity nesters and other forest birds (generalists and specialists) globally.
• Observed variations in these correlations across different zoogeographic regions.

Conclusions:

• Tree-cavity excavators are effective biodiversity indicators across multiple spatial and geographical scales, particularly in tropical ecosystems.
• Their ease of detection, keystone roles, and suitability as management targets support their use in global biodiversity monitoring efforts.