The secretarybird or secretary bird is a large bird of prey that is endemic to Africa. It is mostly terrestrial, spending most of its time on the ground, and is usually found in the open grasslands and savanna of the sub-Saharan region. John Frederick Miller described the species in 1779. A member of the order Accipitriformes, which also includes many other diurnal birds of prey such as eagles, hawks, kites, vultures, and harriers, it is placed in its own family, Sagittariidae.

Woody plant encroachment is a natural phenomenon characterised by the increase in density of woody plants, bushes and shrubs, at the expense of the herbaceous layer, grasses and forbs. It predominantly occurs in grasslands, savannas and woodlands and can cause regime shifts from open grasslands and savannas to closed woodlands. The term bush encroachment refers to the expansion of native plants and not the spread of alien invasive species. It is thus defined by plant density, not species. Woody encroachment is often considered interpreted as a symptom of land degradation. The phenomenon is observed across different ecosystems and with different characteristics and intensities globally.