High Genetic Connectivity and Weak Structure Shape Australian White Ibis Metapopulation Dynamics Across an Urban Coastal Landscape

ABSTRACT Urbanisation reshapes habitat structure, resource availability, and movement pathways for many wildlife species, often creating novel selective pressures and management challenges. The Australian white ibis ( Threskiornis molucca ) has rapidly expanded from its historic range into eastern Australian cities, causing some conflicts with people, yet the genetic and demographic processes underpinning this shift remain poorly understood. We used SNP‐based genomic data from 184 individuals sampled across 15 colonies in the Moreton Bay City region of Southeast Queensland to investigate population structure, genetic diversity, inbreeding, dispersal, and landscape resistance. Genetic diversity was moderate across colonies ( H e 0.134–0.166; H o 0.084–0.145), and pairwise F ST values were uniformly low (< 0.14), consistent with widespread gene flow, though two colonies exhibited elevated inbreeding ( F IS ≤ 0.28), suggesting local dispersal constraints. Kinship analyses confirmed both within‐ and cross‐colony sibling and parental relatedness, providing direct evidence of recent interbreeding and movement. We found a balanced sex ratio and no evidence of sex‐biased dispersal. Landscape resistance models revealed that genetic differentiation was only weakly associated with habitat variables, a striking contrast to many urban adaptation studies where anthropogenic features typically fragment populations. This suggests that urban development may paradoxically facilitate connectivity for this species by creating a network of resource‐rich foraging and breeding colonies that promote movement. Together, these results demonstrate that ibis in this region form a single, interconnected population with high gene flow and demographic resilience, rather than a classic metapopulation. Management seeking to minimise human‐ibis conflict therefore requires coordinated, landscape‐scale strategies addressing resource availability and inter‐site movement, rather than colony‐specific approaches alone.