Sinharaja lowland wet rainforest ecology: Dipterocarp endemism and mixed-species bird waves?

Sinharaja Forest Reserve is Sri Lanka’s last remaining contiguous tract of primary lowland tropical rainforest, declared a UNESCO World Heritage Site in 1988. The forest is dominated by massive Dipterocarpaceae trees (such as Hora, Doona, and Mesua) reaching 45 meters in height, exhibiting over 60% endemism among trees, woody climbers, and orchids. The forest structure displays distinct vertical stratification: emergent canopy, closed sub-canopy, shady understory, and a damp ground layer rich in ferns and terrestrial leeches. This dense primary ecosystem sustains rare endemic fauna, including leopards, purple-faced langurs, and mixed-species bird flocks.