Patterns in Avian nest predation in North-Central Nigeria: An experimental study

Abstract

This study investigated the nest predator community and factors contributing to avian nest predation in the Amurum Forest Reserve and some surrounding farmlands, north-central Nigeria, May 2015. A total of 240 artificial nests were randomly and equally placed; elevated in shrubs and on ground vegetation within different habitats. Of this total, 160 nests were visited every third day (visited nests) while 80 nests were only visited on the last day of the experiment to determine their fate (unvisited nests). We tested the effect of vegetation parameters on the Daily Survival Rate (DSR) of visited nests as well as the influence of visitation on the predation probability of the two groups of nests. Overall, 69% of the artificial nests were predated and the potential predators captured on camera traps were the African Giant Pouched Rat Cricetomys gambianus, Tantalus Monkey Chlorocebus tantalus and Black Rat Rattus rattus. DSR was significantly influenced by nest position only in the rocky outcrop and savannah, although it seemed higher for the elevated nests in all the habitats. We found no significant effect of the vegetation parameters on DSR. The significantly lower predation probability recorded for visited compared to unvisited nests suggests that nest predators in the study area tend to avoid areas that are frequently visited by humans, an indication of anthropogenic impacts and anti-predation strategy. The findings of this study can enhance our understanding of potential nest predators in the study area as well as how nesting behaviour of bird species can influence predation risk.

Key words: Daily Survival Rate, nest predation, model egg, camera trap, predation probability