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Knowledge of the habitat requirements of the Ozark big-eared bat (Plecotus townsendii ingens) is limited but is critcally important to recovery objectives for this endangered subspecies. We studied habitat use and foraging activity by P t. ingens during October 1991 and August and September 1992. Fourteen females and six males were fitted with radiotransmitters. Intraand intersexual comparisons showed no differences in median distances to foraging areas, median size of foraging areas, or number of foraging sites per bat. Late emergence times and frequent periods of inactivity during October 1991 may have been due to cold weather. Females traveled shorter distances to foraging sites and used smaller foraging areas than females previously studied during the maternity season. Females used habitats in proportion to their availability, but males used forest habitat more than expected in September. Habitat use likely was determined by prey distribution because P t. ingens has high flight maneuverability and thus would not be restricted in its use of habitat types. Our results suggest that recovery efforts that include habitat conservation should focus on areas within a radius of 8 km from caves used by P t. ingens, but additional research on movements and habitat use at other times of the year are needed to assure recovery biologists that all critical habitats are identified.

A search of 4600 ha of the McCurtain County Wilderness Area (MCWA), Oklahoma, in 1989-1990 yielded 15 groups of red-cockaded woodpeckers (Picoides borealis). The number of groups and number of individuals in a 3795-ha area that was surveyed in 1977 and 1989-1990 declined by 62% and 75%, respectively. The productivity of the population was low during 1989-1990; 0.69 young were fledged per nesting attempt. To assess the adequacy of foraging habitat, forest structure was measured in an area with a high density of groups (1.95/km2) in 1990 and in an area where the group density had declined from 2.92 groups/km2 in 1977 to 0.74 groups/km2 in 1990. Forest structure in both areas was adequate but approached the limits recommended in the Red-cockaded Woodpecker Recovery Plan. To determine if isolation of groups was related to population decline, we estimated nearest neighbor distances from cluster locations (a cluster is the cavity trees used by a group of woodpeckers) in 1977 and 1990. Cluster sites had longer nearest neighbor distances in 1977 than in 1990, which may indicate that isolation by distance reduces the influx of dispersing breeders from elsewhere in the population. Periodic fires occur naturally in the MCWA but have been suppressed since 1926. Re-establishment of a fire regime is important in maintaining the integrity of the MCWA and may be beneficial to its red-cockaded woodpecker population.

Northern bobwhite (Colinus virginianus) populations fluctuate widely in den- sity, which may be due to changing nutritional conditions. High requirements for protein in the diet of bobwhites for reproduction and growth and the low quality of protein in many cereal grains led us to hypothesize that dietary limitations in certain essential amino acids may occur in wild bobwhite populations in western Oklahoma. We explored this hypothesis by examining seasonal changes in the amino acid composition of bobwhite diets and com- paring observed levels in their diets to known requirements of a closely related species, Japanese quail (Coturnix coturnix japonica). Bobwhites were harvested seasonally (summer, autumn, winter 1989-1990) on three ranches from supplementally fed ( 900 m from supplemental food). Bobwhites used supplemental food for >15% of their diet in only 1 of 6 seasons. Supplemental food did not appreciably influence body condition indices (body mass, organ masses, carcass com- position), but did influence the diets of bobwhites, as evidenced by significant differences in concentrations of fat and essential amino acids in crop digesta. Although crude protein requirements apparently were met in all seasons, levels of ?one essential amino acid in diets of reference and supplemented bobwhites were below recommended levels for growth or breeding in Japanese quail. The sulfur-containing amino acids, methionine + cystine, were consistently the most limiting nutrients in the diet, with seasonal means ranging from 0- 53% below recommended levels for growth or breeding in Japanese quail. These observa- tions support our hypothesis that selected essential amino acids may be seasonally limiting in diets of bobwhites. Dietary requirements of bobwhite for suspected limiting amino acids should be determined in feeding trials to identify more accurately the magnitude of these apparent deficiencies.

We evaluated diets of eastern woodrats (Neotomafloridana) on Cross Timbers rangeland subjected to experimental brush manipulation. Treatments were tebuthiuron and triclopyr herbicides, applied with and without annual prescribed burning. Untreated ref- erence sites also were evaluated. Microhistological techniques were used to estimate relative percent composition of plant species in diets. A total of 23 plant species were found in diets from summer and winter samples. Eastern woodrats exhibited seasonal variation in diet selection, consuming mostly forbs in summer and browse in winter. Pokeweed (Phytolacca americana) and eastern redcedar (Juniperus virginiana) comprised the greatest percentages of diets in summer and winter, respectively. Experimental brush treatment also influenced diet composition. We hypothesized that eastern woodrats would exhibit opportunistic for- aging behavior and use food types in proportion to their availability. Forb and browse diet classes were used in accordance with availability except for forbs on burned tebuthiuron sites. Eastern woodrats generally followed an opportunistic foraging strategy although oc- casions of selective foraging were observed, presumably in response to increased palatability and/or nutritional quality of available forage.

We examined the influence of four experimental brush treatments on relative population density, reproduction and body condition of eastern woodrat (Neotomafioridana) populations on Cross Timbers rangeland in Oklahoma. Experimental brush treatments were tebuthiuron and triclopyr herbicides, applied with and without annual prescribed burning. Untreated reference sites also were evaluated. A total of 333 eastern woodrats were collected from March 1986 through December 1988. Relative population density varied among seasons and experimental treatments. Maximum summer peaks in density were observed each year on triclopyr treatments. Density was similar between populations on tebuthiuron treatments and reference sites. Reproductive activity of females varied among seasons but not among experimental treatments; peaks occurred in spring and autumn 1986 and summer 1987. Percentage of reproductively active males, as evidenced by spermatogenesis, was less than expected in winter. Mean body weights and condition scores were highest in autumn and spring but were not influenced by experimental treatments. Mean stomach content weight did not differ among seasons or experimental brush treatments.

Birds were counted during autumn and winter from October 1987 through February 1989 on sites in Cross Timbers in central Oklahoma 5 and 6 yr after herbicide treatments. We censused two replications of tebuthiuron-treated, triclopyr-treated, and untreated reference sites with a modification of the point-count method. Thirty-five species were documented during the entire census period; 16 species were observed only on herbicidetreated sites and two species only on reference sites. During autumn and winter, more birds and more species were found on sites treated with herbicides than on reference sites. Tebuthiuronand triclopyr-treated sites supported similar numbers of species during both seasons. Herbicide-treated sites had the highest species richness, but untreated areas were needed to maintain interior woodland species.