Aspects of the nonbreeding ecology of the Tree Pipit Anthus trivialis in and around Amurum Forest Reserve, Jos Plateau, Nigeria

Abstract

To advance our knowledge about the nonbreeding ecology of the Tree Pipit Anthus trivialis, this study investigated its population dynamics, habitat utilisation and foraging behaviour, from October to December 2018, in and around the Amurum Forest Reserve, located in the guinea savannah zone of Nigeria, West Africa. The study area comprises four main habitat types: gallery forest, rocky outcrop, savannah and farmland. Distance sampling along six transect lines (total length ∼14.2 km) were used to estimate Tree Pipit abundance and density, while habitat utilisation and foraging behaviour were determined from 222 focal observations. Tree Pipit density in the study area averaged about 1 ind. ha-1 and differed significantly between habitats, being highest in savannah, followed by rocky outcrop, farmland and gallery forest. The vegetation characteristics percentage of grass cover, fruiting and flowering plants, and shrubs, as well as insect abundance, significantly influenced the distribution of Tree Pipits in the reserve. Tree Pipits were seen capturing their prey using two foraging techniques, of which gleaning on the ground was the most frequently observed. Variation in Tree Pipit abundance across the three-month study period suggests that many may have been on passage, with relatively few individuals remaining in the area as winter residents.