Nesting ecology of Yellow Rails in southcentral Oregon

From 1995-1998 we studied the breeding ecology of Yellow Rails (Coturnicops noveboracensis) in southcentral Oregon. We found 34 Yellow Rail nests; 26 had either hatched or failed when found, and eight were active (seven of th ese hatched). These nests were the first found in Oregon in 65 years and fu rther substantiate recent findings that a small, disjunct population of bre eding Yellow Rails persists west of the Rocky Mountains. Nests hatched betw een 8 June and 9 August with a mean clutch size of eight eggs (SD = 1.1). W e measured vegetation in 1-m(2) plots around each nest. Total live vegetati on cover averaged 48.7% +/- 10.9, and Carer simulata dominated at 26.1% +/- 12.3. Other vegetative species characterizing Yellow Rail nest sites were: C. utriculata, C. vesicria, Eleocharis palustris, Juncus balticus, and J. nevadensis. Dead or senescent vegetation from the previous year provided 49 .7% cover. Water depths at active nests were 0.5-5.0 cm. A canopy of senesc ent vegetation or a dome of live vegetation was present above every nest, o ften concealing the nests from view.