Digital Commons Network^™

The Effects Of Photoperiod On The Prolactin Cells Of Notropis Cornutus (Mitchell), Matthew Kevin Hettinger

Masters Theses

Three groups of the common shiner (Notropis cornutus, Mitchell) were adapted to three different photoperiods. These photoperiods were 16L:8D (summer), 12L:12D (controls), and 8L:16D (winter). The prolactin cells were studied histologically and morphologically with respect to staining characteristics, cell and nuclear morphology, nuclear size, and cellular density. The prolactin cells of those fish under the long photoperiod exhibited greater cellular activity than the controls as evidenced by an increase in nuclear size, cellular density, and by becoming more circular. The prolactin cells of those fish under the short photoperiod exhibited the same characteristics as those in the long photoperiod. The …

Habitat Utilization And Seasonal Movements Of Black Bears In The Great Smoky Mountains National Park, Patrick C. Carr

Masters Theses

A radiotelemetry study to determine seasonal movements and habitat utilization of black bears (Ursus americanus) in the Great Smoky Mountains National Park was undertaken from June 1980 to May 1982. Annual home range size in a year of poor hard mast production was 119 km² and 13 km² for males and females, respectively, and 36 km² and 6 km² in a year of good hard mast production. Bear movements were governed by seasonal food availability. Bears exhibited an affinity to summer home ranges but traveled to widely dispersed fall ranges. Seasonal range shifts were more evident …

Habitat Utilization And Movement Ecology Of Black Bears In Cherokee National Forest, R. Steven Garris

Masters Theses

Home range, movements, and habitat use of black bears in the Cherokee National Forest were monitored from June 1980 through December 1981.

In 1980, home range sizes averaged 192 km² for male bears and 23 km² for females, whereas the average range in 1981 for males was 60 km² and 15 km² for females. Larger ranges for males likely reflect a social structure that enhances reproduction. Differences in home range sizes between years was attributed to the availability and abundance of hard mast, especially acorns. Both sexes exhibited seasonal shifts in range use between summer and …

Reproduction And Denning Of Black Bears In The Great Smoky Mountains, William Gregory Wathen

Masters Theses

The reproductive biology and denning ecology of black bears were studied in the Great Smoky Mountains National Park and Cherokee National Forest. The majority of information was collected from 36 radio-instrumented females monitored from June 1980 to May 1982.

Females entered dens from 21 November to 16 January (x=20 December, n=38), and emerged from 18 March to 4 May (x=10 April, n=41), for an average denning period of 113 days. Females with newborn cubs denned significantly longer (P< 0.001) than other females. Tree denning females emerged later and remained in dens longer than others.

Twenty-five ground dens and 33 tree dens were examined. Significant differences (P< 0.005) in den utilization were observed between winters, with more tree dens being utilized during the winter of 1980-81 (79.3%) than in the winter of 1981-82 (34.5%).

Females in estrus were captured from 22 June to 12 …

Observed Changes In The Largemouth Bass Population Since Construction Of A New Pump Storage Reservoir At Charleston, Illinois, Lawrence B. Durham

Masters Theses

Lake Charleston, Illinois was electrofished to determine the status of the largemouth bass (Micropterus salmoides, Lacepede) population after its reconstruction into a pump storage reservoir. The changes observed were an increased rate of growth of the initial year class, increased average growth increment of older bass, and a more abundant bass population. Factors which may have influenced increased growth were decreased turbidity, alkalinity, and increased water level. There is a possibility the increase in water level led to an increase in terrestrial invertebrates as a food source, and increased spawning substrate and cover due to submerged terrestrial vegetation. …

The Effect Of Repeated Spermiation On Sperm Density In The American Toad (Bufo Americanus), Michael A. Kriz

Masters Theses

Bufo americanus (American toad) responds to LH-RF injections by releasing sperm into the cloaca. An ANOVA test (repeated measures) was used to determine that spermiation number and body size but not frequency of injection affected sperm density. The affects of body size on sperm density were that large toads produced the highest sperm densities, followed by the medium and then the small toads. Sperm density decreased with repeated spermiations which could correlate with the explosive breeding pattern of the American toad.