Interactive effects of elevation and newly paved road on avian community composition in a scientific reserve, Bioko Island, Equatorial Guinea

Understanding interactive effects between anthropogenic disturbance and abiotic factors on species turnover can help to identify and prioritize conservation of potentially vulnerable tropical bird communities. We investigated the potential factors influencing avian understory community composition along with a recently constructed road across three elevations (300, 800, and 1200 m), each with two sampling sites (road edge vs. interior forest), over a four‐year period on Bioko Island, Equatorial Guinea. Insectivorous species were the most abundant guild‐sampled accounting for 55% of total species diversity within the dataset followed by frequent mixed‐flock followers (48%). Habitat associated with elevation was the most significant factor influencing the composition of avian communities. Additionally, we identified species with clear statistical associations for each elevation: the yellow‐lored bristlebill (Bleda notatus), olive sunbird (Cyanomitra obscura), and white‐tailed warbler (Poliolias lopezi). We found evidence for significant community differences between the disturbance edge and interior forest transects at 300 m only. Likewise, understory insectivores were found at higher numbers within the interior forest transect at this elevation. Based on the data presented here, we suggest low elevation avian understory insectivores should be considered focal species for future assessment studies in this area. Furthermore, since many traditional protected areas focus on upland habitat containing high species endemism, our findings emphasize the importance of equally conserving lowland elevations as they may house commonly overlooked, yet important and diverse segments of the bird community. in Spanish is available with online material. Resumen Comprender los efectos interactivos entre la perturbación antropogénica y los factores abióticos en el recambio de especies puede ayudar an identificar y priorizar la conservación de comunidades de aves tropicales potencialmente vulnerables. Investigamos los factores potenciales que influyen en la composición de la comunidad del sotobosque de aves a lo largo de una carretera recientemente construida a lo largo de tres elevaciones (300, 800 y 1200 m), cada una con dos sitios de muestreo (borde de la carretera vs bosque interior), durante un período de cuatro años en la isla de Bioko, Ecuatorial Guinea. Las especies insectívoras fueron el gremio más abundante muestreado y representaron el 55% de la diversidad total de e