University campuses as urban biodiversity refugia: butterfly diversity and community turnover in Northern Mindanao, Philippines

Butterflies are widely used as bioindicators of environmental quality, yet their diversity patterns within institutional landscapes remain poorly documented in the Philippines. This study assessed butterfly diversity across eight campuses of the University of Science and Technology of Southern Philippines (USTP) in Northern Mindanao using presence–absence data derived from standardized point counts. Species richness, Shannon diversity, and community composition were examined using Jaccard-based nonmetric multidimensional scaling (NMDS), descriptive permutational multivariate analysis of variance (PERMANOVA), and beta diversity partitioning. Butterfly assemblages varied markedly among campuses, with less urbanized and more heterogeneous campuses supporting higher richness and diversity. NMDS revealed clear compositional differentiation among campuses, while beta diversity partitioning showed that intercampus variation was dominated by species turnover rather than nestedness. These results indicate that campuses host distinct butterfly assemblages rather than subsets of a single regional community. Overall, the findings highlight the ecological value of university campuses as components of urban and periurban biodiversity networks and underscore their potential role in conserving insect diversity within human-dominated landscapes.