Adams, Ralph M.

The effects of human presence on displacement behavior and time-activity budgets of free-ranging manatees (Trichechus manatus) are poorly known. The congregation of manatees and human tourists in the warm waters of Crystal River, Florida, during the winter months offered a unique opportunity to study these effects. Focal animal sampling was used to gather behavioral data on manatees during randomly selected daylight sampling periods. Frequencies of displacement were correlated with numbers of humans to determine if incidences of displacement were increased. Displacement increased with human presence. Maintenance and sexual behaviors decreased as human presence increased.

Free-ranging manatees wintering in the warm water of Kings Spring, Crystal River, Florida, were studied to determine the relationships between human presence and their sexual behaviors. The manatees of Crystal River are unique because of frequent exposure to large numbers of snorkelers and divers. Quantitative knowledge of such relationships are becoming increasingly important as preservation measures are reviewed to ensure that the human activity at the Spring does not pose a threat to manatee reproduction. Focal animal sampling provided sexual behavioral data of manatees during randomly selected 30 min sampling periods. Frequencies of four of the eight observed sexual behaviors increased significantly in the presence of humans. Differences were also found between the types of sexual behaviors manatees exhibited while interacting with conspecifics, and the behaviors displayed with humans. Manatees appeared to be hyperstimulated in the presence of humans. No conclusions could be made about the effects of human interaction on manatee reproductive success because of the relatively short duration of the study.

Gradual salinity acclimatization and growth studies were performed on fry of the spotted tilapia, Tilapia mariae. First, fry were successfully brought to a salinity of 40%. in 8 weeks by gradual weekly increments of 5 %.. Second, fry were exposed separately for nine weeks to salinities of 0, 5, 10, 20, 25, and 30 %.. Fish grew best at 5 and 10 %. (p < 0.05) and least at 30 %.. At nine weeks, fish at 0, 5, 10, 20, 25, and 30%. appeared to be osmoregulating, as indicated by osmolarities of their inner body fluids. These results suggest that Tilapia mariae may become a competitive threat to fishes in native estuarine environments in southern Florida.

The reproductive success of White Ibises, Eudocimus albus (L.) was studied during the 1988 and 1989 nesting seasons at a wading bird colony in Florida. Evidence suggests that the diets of both adult and nestling Ibises included garbage from a nearby dump. The mean clutch size was 2.5 +- 0.72 in 1988 and 2.6 +- 0.72 in 1989. The probability of a nest surviving to produce at least one 10-day-old nestling was 45.8% and 54.1% for 1988 and 1989, respectively. Success was higher for nests on islands at the periphery of the colony than on islands more centrally located. This resulted from reduced interactions between nesting Ibises and Cattle Egrets (Bubulcus ibis) and, reduced egg predation by grackles (Quiscalus spp.) at the periphery of the colony. Both clutch size and reproductive success were within the ranges previously reported for Ibises at other colonies that did not supplement their diets with garbage.

The history of the public high school is discussed including
characterization of the slow learner, the culturally
disadvantaged and the problem student. Two identical groups
of students participated in the experiment; one group actively
and physically involved in the educational process;
the other less actively and physically involved. The raw
score data were statistically analyzed. The mean, median
and ninety-five percent confidence interval were similar
for both groups. Thus, attempts to physically involve
these students will not increase their achievement. The
current methods of teaching, curricula and building designs
are discussed.