DAYTIME HABITAT SELECTION BY COTTONTAILS IN CENTRAL PENNSYLVANIA

Information on behavioral responses of wildlife to habitat alterations is needed to allow restoration and maintenance of suitable habitats f or a variety of vertebrate species. We studied the use by radio-tagged eastern cottontail rabbits (Sylvilagus floridanus) of habitats within a terrestrial ecosystem scheduled to be used for disposing secondaril y-treated effluent (domestic wastewater) in central Pennsylvania. Cott ontails selected old-fields and shrublands for daytime use, but cropla nds were used when oats and corn matured during summer and fall. Above ground bedding sites (forms) were associated with relatively dense cov er, indicating that cottontails recognized variations in microhabitat within habitat types, Females frequently used underground burrows when air temperature was less than 0 C, whereas males seldom used burrows except when air temperature was less than -5 C during winter. Cottonta ils encountered a wide range of microclimates at forms. Air temperatur e, net radiation, and wind speed extremes were greater -7.1 to 38 C, - 21 to 70 W/m(2), and 0.0 to 11.3 cm/sec. Air temperature, net radiatio n, and wind speed were greater at open sites than those at forms used by cottontails during each season. Cottontails selected micro-environm ents in which the insulating effect of dense cover may allow conservat ion of metabolic energy or reduction of heat loss. Provision of dense herbaceous and shrub cover is essential to management of cottontail ha bitat because it allows the animal to maintain a positive energy balan ce as well as avoid predators. Typically, cottontails occupied a form from sunrise to sunset. Thus, the structure of vegetation associated w ith forms may be a key indicator of suitable cottontail habitat. Shrub -woodland habitat appeared to be especially important to cottontails d uring late winter and early spring because of increased cover associat ed with early leaf-out of shrubs.