Modelling Climate Change Impacts on the Distribution and Phenology of Insectivorous Bats in the Guinea Savanna Zone of Nigeria: An Original Conservation Projection

This dissertation develops an original modelling framework for projecting climate change impacts on the spatial distribution and seasonal phenology of insectivorous bats in the guinea savanna zone of Nigeria, covering Plateau, Benue, Kogi, Nassarawa, and Niger States in the North Central geopolitical zone. Insectivorous bats provide economically important pest regulation and pollination ecosystem services, and understanding how climate change will shift their distributions and alter their phenological timing is critical for maintaining these services under future conditions. The dissertation employs a five-year empirical base dataset generated through monthly acoustic monitoring at 40 sites using automated bat detectors, combined with roost-level emergence count phenology data from 15 monitored roost sites. Distribution models are constructed using ensemble species distribution modelling under two CMIP6 climate scenarios (SSP2-4.5 and SSP4-6.0) at 2050 and 2080 time horizons. A phenological change model links emergence timing to temperature and rainfall onset predictors using dynamic linear models fitted to the time series. Echolocation call libraries are built for 22 guinea savanna species to enable automated acoustic identification. Modelling results project range contractions exceeding 25 percent for 14 of 22 species under SSP4-6.0 by 2080, with cave-roosting specialists showing the greatest vulnerability. Phenological advancement of emergence and parturition timing averages 12 days per degree of warming. The dissertation delivers an original climate vulnerability ranking framework for Nigerian insectivorous bats and identifies 18 roost sites as priority conservation investments under all modelled scenarios. Keywords: climate change, insectivorous bats, distribution modelling, phenology, guinea savanna Nigeria.