O. humilis 92 14 Reo Guanacol, Smi. E Nitterker May 2 Wrens singing commonly in the afternoon, often heard one sing while the other of the pair trilled. We are located along a dry sandy river bed 30 yds. wide, There is a line of big guanacaste trees along the river, backed with an open understory of the type at Rio Agua Dulce but more open (see beyond, plants collected). Wrens occur in the understory and in patches of low vegetation in areas where no large trees are present. Color & legs & feet of specimens today ranged from dull blue-slate to slate with a bluish-green cast. Several specimens were moderately fat, especially in the interclavicular area. Local name: Pocholito, May 3 Photos in Color: 6. "Spina" with guanacaste in background a bit taller, C. humilis here. Plants B-1, B-2 are there. 7. View across road showing good habitat & "Spina", BHA, x guanache. 8. Nest in BHA 10 feet up. B-3 plant B-4 small bush 2 feet high beneath spinas - not important for wrens B-5 other spina B-6 dry tree 25-30 feet along road. Photos Plants B-1 is dominant tree in the region.