The moist, silty soil beneath the willow grove is covered with a dense mat of low vegetation including giant ragweed, carpenter's square, dayflower, and rice cutgrass. Short-tailed shrews, house mice (_Mus musculus_), harvest mice and cotton rats thrive in this habitat. Red-winged blackbirds (_Agelaius phoeniceus_), yellow-billed cuckoos (_Coccyzus americanus_), red-eyed vireos (_Vireo olivaceus_), catbirds (_Dumetella carolinensis_) and Kentucky warblers (_Oporornis formosus_) use it for nesting. The high humidity and dense vegetation in this grove render it favorable habitat for recently metamorphosed frogs and toads, especially the tree frog, which is sometimes extremely abundant there in summer. #Populus deltoides.#--Cottonwood is one of the less common trees on the area, but it attains a larger size than any of the other kinds. The larger of the two creeks on the Reservation is lined with mature cottonwoods along the lower part of its course. Along the smaller creek large cottonwoods are also present but they are more widely spaced. A few cottonwoods are present at well scattered points on slopes and hilltops, usually in forest edge situations or in woodland where other trees are sparse. By far the largest tree on the Reservation is a cottonwood of 15-foot circumference (Plate 1), growing on a hilltop near the south boundary of the Reservation, at the edge of woodland adjacent to a cultivated field. The heavy rainfall of 1951 resulted in the establishment of hundreds of cottonwood seedlings, mostly in places remote from the mature trees. So far as observed, all these were in recent silt deposits. Many of them have survived the drought of 1952-1954.