Key Factors Influencing Breeding Seasons of Insectivorous African Passerines in a Guinea Savanna Habitat, Central Nigeria

Abstract

Food and weather variables are known to be important factors influencing life history activities such as breeding in organisms. Studies that highlight these interactions are particularly needed in rapidly changing ecosystems due to anthropogenic activities. Our study determined breeding seasons of insectivorous African passerines in relation to insect prey abundance and diversity, temperature, rainfall and relative humidity in Pandam Game Reserve (PGR), (08°40’N 09°03’E) central Nigeria. Breeding seasons of insectivorous African passerines were determined by observing for brood patches in birds from five constant effort bird trapping sites and breeding behaviours on five line transects of 1000 m. Aerial insects were collected from 50 points at 100 m sections on the five line transects using sweep net of 35 cm diameter and pore size of 1mm². Monthly records of temperature, rainfall and relative humidity were also collected. Mean number of breeding insectivorous African passerines per month were compared using one sample T-test. Effects of insect abundance and diversity, temperature, rainfall and relative humidity on breeding insectivorous African passerines were tested using Generalised Linear Model (GLM). Results showed significant difference in mean number of breeding insectivorous African passerines per month. Highest breeding activities were observed between June and October with peak in October; this mirrored the trend of insect abundance across months. Temperature and humidity had significant effects on insect abundance and diversity respectively, highest insect diversity index (H) was recorded in January. The study concludes that insectivorous African passerines probably breed all year round in PGR, however, breeding of many of the species peak in the wet season between June and October. This is likely influenced by high insect prey abundance in wet season indirectly affected by temperature and humidity two important factors determining habitat productivity.

Keywords: Breeding season, Insectivorous African Passerine, Breeding behavior, Pandam Game Reserve

DOI: 10.7176/JNSR/16-2-02

Publication date: July 30^th 2025