Hylophilus decurtatus Lake Oronga, 200'; lip St. San Miguel, El Salvador Feb. 23, 1942. Saw two birds about 30' up in a tree, one chasing the other, and both uttering short, sharp "fee" notes. They flew about adjacent treetops, never going out of sight. Finally the pursuing bird caught the other, and both fell out of the tree some 30 feet to the ground. It appeared as though the two were firmly attached, though how I could not see. Each bird had one wing outstretched, motionless. The pair floated slowly down, spinning slowly round and round as they fell, like a double maple samara. Upon hitting the ground the pair separated & copulation then ensued. I attempted to catch them on the ground during copulation, but they flew at my approach, one up into a nearby tree, the other about 8' off the ground in a low shrub about 20' away. I collected the latter bird (1291). It is a male. Testes were small.