The Ecological Role Of Traditional Home Gardens In Facilitating Bird Movement In Human-Modified Tropical Landscapes

Abstract

Habitat loss and fragmentation are major threats to biodiversity, particularly in tropical agricultural landscapes, where natural forests persist as small and isolated patches. Identifying how human-managed habitats contribute to functional connectivity is essential to understanding species persistence in these landscapes. Agroforestry systems, particularly traditional home gardens (THG), support rural well-being by providing tangible products and enhancing landscape functional connectivity. This study evaluated whether THG facilitates bird movements between forest fragments in a mountainous region of Mexico. We recorded the arrival and departure directions of birds visiting THG and analyzed movement orientation using circular statistics. Then, we compared the directions observed in the sampling with hypothetical directions measured from a hypothetical route that birds may use, defined from the spatial arrangement of THG cover in the village, the surrounding forest fragments, and the location of the sampled THG. Our results show that most birds departed in the opposite direction from which they arrived, suggesting that THG act as biological stepping stones, forming corridors that enhance connectivity between fragmented habitats. This pattern was consistent when analyzing the complete assembly and across most trophic guilds, except for granivorous birds. Comparing observed arrival and departure directions with hypothetical directions shows that birds move through the THG along routes connecting the forest fragments surrounding the village. These findings highlight the potential of THG to enhance functional connectivity and support ecological flows in fragmented tropical landscapes. Thus, conserving and managing THG within broader landscape networks can safeguard biodiversity and ecological processes in human-modified environments.