Towards integrated frameworks for assessing bird species richness using citizen science and geospatial data

Abstract

Citizen science has become increasingly essential for assessing species population trends and guiding conservation strategies. However, integrating citizen science input and datasets with spatial analysis remains underutilized, despite its critical potential to enhance ecological understanding and inform targeted conservation efforts. This study utilized bird data from the Kenya Bird Map initiative (January 2019–December 2023), combining with satellite imagery processed through Google Earth Engine (GEE) over the same period, to investigate the environmental factors that influenced species richness in Nairobi National Park and its surrounding buffer zone. Our methodology incorporated multiple satellite-derived datasets, selecting key environmental variables based on their ecological relevance, spatial resolution, and temporal consistency. We focused on vegetation productivity and climatic factors as critical determinants of species richness, using NDVI and EVI to assess vegetation cover and evaluating the roles of precipitation, soil moisture, and temperature in shaping species distribution and habitat quality. A Generalized Linear Model (GLM) was applied to analyze the relationship between species richness and these environmental covariates. NDVI exhibited a significant positive association with species richness (0.280 ± 0.052, P < 0.001), indicating that higher vegetation productivity supports greater bird diversity. Precipitation also had a positive effect (0.165 ± 0.056, P = 0.003), whereas soil moisture negatively influenced species richness (−0.159 ± 0.052, P = 0.002), suggesting that excessively wet conditions may reduce habitat suitability. Temperature did not exhibit a significant relationship (0.016 ± 0.043, P = 0.717). Nonlinear trends were observed, with intermediate levels of NDVI and soil moisture maximizing species richness. Interaction effects revealed that vegetation, precipitation, and soil moisture collectively influenced richness, highlighting the complexity of species-habitat associations. These findings emphasize the importance of sustainable land-use practices that align with conservation priorities to safeguard biodiversity in rapidly changing environments.