Factors Influencing the Faunal Recolonization of Restored Thornscrub Forest Habitats

Tamaulipan thornscrub forests (thornforests) have high ecological and economic values, yet over 90% of these forests have been lost, and they remain threatened, making them a conservation hotspot. For decades, federal, state, NGO, and corporate entities have been acquiring land and actively or passively restoring these forests, but results have been mixed and seldom monitored. This study characterized and quantified faunal communities of restored thornforest habitats in south Texas and examined the relationships between restored faunal communities and key site characteristics and environmental factors. We surveyed and analyzed mammal, bird, Lepidoptera, and herptile communities within 12 restored sites in the Lower Rio Grande Valley of southernmost Texas, USA. The site and environmental factors that influenced animal community composition, richness, diversity, and abundance varied widely among taxa. Time since restoration began and method of restoration influenced many community metrics, whereas patch size and extent of isolation influenced few. Several aspects of restored plant communities were influential, especially ground layer diversity, and high invasive plant cover negatively impacted many animal community metrics. If actively restoring a site, efforts to control invasive plants, foster native plant diversity, and provide a nearby water source are likely the most effective ways to promote faunal recolonization.