Large termitaria act as refugia for tall trees, deadwood and cavity-using birds in a miombo woodland

TLDR: Large termitaria appear to play an important role in maintaining functionally important components of the avifauna in heavily impacted Miombo woodlands and contributed to the resilience of bird communities through high on-mound densities of trees with deadwood.

Abstract: Landscape heterogeneity can play an important role in providing refugia and sustaining biodiversity in disturbed landscapes. Large Macrotermes (Isoptera) termite mounds in miombo woodlands form nutrient rich islands that sustain a different suite of woody plant species relative to the woodland matrix. We investigated the role of termitaria in providing habitat for cavity-using birds in miombo woodlands that had been greatly impacted by elephants and fire, by comparing the availability of habitat favored by cavity-using birds (tall trees, trees with deadwood, and cavities) on and off mounds, and then testing its effect on species richness and abundance of cavity-using birds. We surveyed 48 termitaria paired with 48 woodland matrix sites in the breeding season; and 54 matrix-termitarium pairs in the non-breeding season in Chizarira National Park, Zimbabwe. Generalized linear mixed-effects models showed that termitaria harboured significantly higher densities (ha−1) of habitat components considered important for cavity nesting birds. Density of trees >6 m in height and incidence of trees with deadwood was nearly 10 times greater on mounds than in the matrix, and the density of cavities was nine times higher on mounds compared to the matrix. A model selection procedure showed that termitaria provided refugia for cavity-using birds and contributed to the resilience of bird communities through high on-mound densities of trees with deadwood. Large termitaria thus appear to play an important role in maintaining functionally important components of the avifauna in heavily impacted Miombo woodlands.