Sonic-tagged flannelmouth suckers made long distance and local movements; 12.5% of fish moved ≥ 98 km downstream and 40% stayed within Glen Canyon. Motivation for long distance movements could be spawning or food related. A controlled flood of 1,274 m³/sec did not displace flannelmouth suckers downstream or interrupt spawning. The majority (62%) of fish moved into the impounded mouth of the Paria River. Spawning occurred as evidenced by capture of adults over spawning areas and collection of young-of-year (YOY) in spring and summer. From May-September 1996, YOY flannel mouth suckers were captured in the impounded mouth of the Paria River. Successful rearing of YOY fish was attributed to the presence of a warm, slackwater area in the mouth. Formation of this area is dependent upon antecedent Colorado and Paria river flows and their effect on sediment deposition in the mouth of the Paria River.

The ideas for this thesis were conceived as a result of the author's work on a cooperative agreement between the National Park Service and the Landscape Architecture Program in the School of Renewable Natural Resources, wherein the changes that have occurred on the cultural landscapes of four prehistoric or historic sites were documented. Historic cultural landscapes, especially those associated with vernacular sites have been largely overlooked in interpretive efforts. Readings revealed that vernacular cultural landscapes may serve as a form of historic documentation. These landscapes may provide additional clues regarding the history of our country to visitors of historic sites if the information is interpreted in an interesting, sensitive, and factual manner. The Blankenship/Dos Lomitas Ranch, an early 20th century cattle ranch located within the boundaries of Organ Pipe Cactus National Monument, is a vernacular historic site with remnants of the associated landscape intact. This landscape may hold valuable information regarding a major westward migration of American cattle ranchers during the mid to latter 19th century that had a profound effect on the ecology and culture of the Sonoran desert in southern Arizona. As a result of readings, visits to historic sites, and interviews with professionals in the field of interpretation, recommendations are made to present the story of the vernacular landscape of this pioneer cattle ranch to visitors of Organ Pipe Cactus National Monument.

I studied Trichomonas gallinae, a flagellated protozoan that is the causative agent of the avian disease trichomoniasis. The purpose of my study was to assess (1) the incidence of trichomonads in wild birds, (2) the prevalence of trichomonads in water sources utilized by wild birds, and (3) possible methods to control the transmission of trichomonads in water sources utilized by wild birds. I trapped 403 birds during 1994 and 1995. Approximately 1/3 of these birds tested positive for T. gallinae, however, none exhibited any signs of lesions. I collected water samples from 10 bird baths, isolating flagellated protozoa from 2 of them. I could not identify the species of flagellated protozoa. I determined that high temperatures (50°C), near ultra-violet radiation, and natural sunlight are effective against trichomonads. In addition, the highest effective dilutions of Chlorox, Nolvasan, and distilled white vinegar active against trichomonads were determined.

I studied bat use of 3 isolated water developments on the Cabeza Prieta National Wildlife Refuge in southwestern Arizona between May 1995 and August 1997. I recorded bat echolocation calls to measure overall activity, videotaped bat behavior and identified aquatic insects to determine whether bats were feeding or drinking, mist netted to assess visitation patterns with respect to season, sex, and reproductive condition for each of 4 species captured, studied movements of banded individuals, and monitored roosts of the California leaf-nosed bat (Macrotus californicus) in nearby mines. Echolocation activity was much higher at water than in nearby dry desert washes and was greater in dry washes than at random sites away from water. Bats visited water in all seasons, visiting primarily to drink, not to feed on insects. The California leaf-nosed bat constituted 41% of more than 1,000 captures. I concluded that in my study area this species made extensive use of water developments for drinking, particularly during lactation.

In 1995, Squaw and Flash creeks were renovated with Antimycin-A to eradicate non-native fish. After renovation, 129 Apache trout from Flash Creek were introduced into Squaw Creek. Two years later, all size classes were present. Apache trout above a natural barrier on Flash Creek were allowed to repopulate the renovated section. Three years later, 45 Apache trout were found below the natural barrier. In both streams, adults selected deep, slow moving areas. Juveniles selected shallow areas with fast currents. Both size classes selected open areas exposed to sunlight with surface turbulence and other forms of instream cover. Apache and Gila trout were experimentally PIT-tagged in the: (1) pelvic girdle; (2) abdominal cavity; and (3) dorsal musculature to determine the best tagging location. Fish tagged in the dorsal musculature had 0% tag loss and 98% survival. The minimum size Apache and Gila trout could be tagged was 90 mm TL.

The southernmost known North American stand of corkbark fir ( Abies lasiocarpa var. arizonica (Merriam) Lemm.) is found in the Santa Catalina Mountains just north of Tucson, Arizona. Climate response, age distribution, and fire history were studied in this small corkbark fir stand to provide baseline information for future management. Response function analysis indicated April--June precipitation from the current growing season, April--June temperature from the current growing season, November--March precipitation prior to the growing season, and August--October precipitation from the previous growing season as the most highly correlated factor with ring-width variance. Age distribution appeared to be steady state. A fire chronology developed for the corkbark fir site was used to test synchroneity of fire events with previously developed chronologies from nearby sites. Chi-squared analyses indicated significant association of fire years for all sites but not spread of fire from one site to another.

The tropical forest of Guatemala's 21,130 square kilometer Maya Biosphere Reserve and buffer zone is being impacted by deforestation due to an increase of the local population and establishment of over 200 new settlements over the last 20 years. Existing geographic information system databases and remote sensing data were used to determine how much of the observed deforestation could be explained by three factors: roads, human settlements, and soil quality. Each factor was analyzed separately using spatial and statistical analysis methods. These factors were then combined to create a final deforestation risk model. The deterministic model enables policy makers, as well as managers, to create scenarios that assess the impact of their actions on the forest on a regional scale.

I conducted a management assessment for the conservation of benthic resources harvested by small-scale hookah divers in the northern Gulf of California (NG), Mexico, and analyzed the reproductive ecology of the black murex snail. Open access to the fisheries, combined with national and international market pressure, fishing methods, and the timing of fishing activities have caused an evident decline in production, the use of new fishing zones, and a shift of fishing effort towards deeper areas. However, the organization of the diving sector and its initiatives to establish forms of regulation provide an opportunity to alleviate this situation. I conclude that comanagement has the potential to be an effective management system for the benthic resources of the NG, a system that could be facilitated by the sedentary and semisedentary nature of these resources. An informal type of co-management arena is already in place with the possibility of being formalized and solidified.

The purpose of my research was to determine if landowners in the Colorado River delta were interested in participating in a program for restoring wetlands on their lands. I interviewed 30 landowners along the river and 16 on the marginal areas of the delta Results show that wetland restoration in private and ejido lands is feasible in the Colorado River delta, Mexico. This restoration could be embraced and enhanced by the participation of local communities. Although, interviewed farmers are willing to contribute with land and water, the water they can provide will not be enough to main existing riparian habitats. Farmers stated that they would not pump out any water delivered to the delta for environmental purposes because it would make their crops unprofitable. Thus, a binational agreement allocating in-stream flows for environmental purposes to the delta needs to be addressed and will be respected by Mexican farmers.