Honors Projects for Zoology
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ItemControl of Jackson’s chameleons using decoys(University of Hawaii at Manoa, 2015-05)The Jackson’s chameleon is an invasive east African species that was released on the island of Oahu as well as the other main Hawaiian Islands. This species poses a direct threat via predation to already-endangered native invertebrates, which are integral to the maintenance of healthy forest ecosystems. Current population management strategies are ineffective at best, requiring extensive, labor-intensive manual removal. This project endeavored to determine whether decoys of female Jackson’s chameleons deployed in the field would visually attract males in their arboreal habitat, concentrating them and making them more easily accessible for removal by resource managers. This hypothesis was tested by producing a number of female decoys of varying size and deploying them in the field; effectiveness was assessed via proximity to decoys. However, during this experiment, I failed to observe an increase in the number of male chameleons in the area immediately surrounding the decoys. These results are not prohibitive, as the experimental design used did not allow for absolutely certainty of chameleon presence or absence. Additional trials coupled with a modified experiment design may yet produce the desired response. If successful, the use of decoys in the field could provide a scalable, cost-effective solution to controlling Jackson’s chameleon populations, ultimately helping to protect sensitive native ecosystems in Hawaii and other areas where non-native Jackson’s chameleons have become established.
ItemThe Use of the Effluent from Marine Shrimp Culture to Grow Microalgae in Support of Oyster Growth in a Simulated Closed Microcosm Recirculating Aquaculture System(University of Hawaii at Manoa, 2014-09-26)The Pacific white shrimp, Litopenaeus vannamei, is an important species of shrimp due to their ability to survive in low salinities. They are typically found in the Pacific, from Mexico to Peru, in areas that have lower salinities than the typical ocean, making them a beneficial species for aquaculture farming. Shrimp excrete ammonia, a nitrogenous compound, which can build up in aquaculture farms. The goal of my project is to investigate the effects of nitrogenous pollutants on the growth rate of these shrimp. Tanks will be created to simulate normal, medium and highly nitrogenous conditions. Five tanks will be used as the controls and will have normal amounts of nutrients, no nitrogenous pollutants and a normal density. Five other tanks will have 50% and five more tanks will have a 100% increase of nitrogen levels above the control to simulate an aquaculture environment. The water conditions such as pH, temperature, salinity, dissolved oxygen, and total nitrate in the tanks will be monitored daily. The number of larvae in each stage in each tank will be recorded daily and the time between each molt will indicate the growth rate. It is expected that the shrimp in the high nutrient tanks will have a higher growth rate initially, but will decline after a certain level. This research could be beneficial because the threshold for nitrogen levels for Pacific white shrimp cultivation can be determined.
ItemResurveying Of The Marine Environment Of KauaʻI: Views From The Perspective Of Locals And KūPuna(University of Hawaii at Manoa, 2014-09-26)In 1983, an initial coastal inventory was produced on Kauaʻi that included an atlas and a narrative inventory report sponsored by the Army Corps of Engineers. This inventory included field surveys at 77 marine and coastal sites around Kauaʻi in 1981 and information on the recreational and historical practices on the coastline perimeter of the island. In addition to recreational uses, status and location of coral and other marine organisms were recorded. Since this date, there has been no island-wide survey of the status of the coastal ecosystems of Kaua‘i. The study is a qualitative investigation of the current status and health of these resources based on interviews with local participants. Eventually, field re-surveys of the island will be accomplished. In addition, the narrative provides cultural features of the areas. It was hypothesized that anthropogenic activities have caused changes in the marine environment based on the perspective of local people, scientists, and na kānaka maoli (Native Hawaiians). Interviews and observational information from locals were collected and analyzed to understand problematic areas. The new interviews and the old narrative were used to collaboratively create newly updated information that would be available to the public. Areas of high priority and changes were highlighted, based on the issues that were revealed during the interviews. Eventually, field teams will use the new narrative for the next phase of the project, which is to conduct surveys at the originally surveyed 77 sites. Furthermore, additional sites will likely be surveyed based on important feedback from the Kauaʻi elders, locals, and scientists. The interviews are an independent but important component of the coastal inventory, and will supplement the marine and coastal surveys in order to gain a better understanding and verify the current status of Kauaʻi coral reefs, beaches and water quality.
ItemNosema ceranae climate and seasonal prevalence in honeybees in Hawaii(University of Hawaii at Manoa, 2014-01-15)Honeybees have a great influence on humans, not only because of honey production, but also, and more importantly, because of their role as pollinators. It has been estimated that one in every three bites of the food people consume is the result of pollinating activities of honeybees. According to the USDA, approximately 80% of the crops grown in the United States are a result of honeybee pollination (Moisset & Buchmann, 2011). They not only pollinate crops that humans consume, but they also pollinate crops that are utilized as feed for livestock. Given the importance of honeybees for food production, sustainability and health of managed colonies is a priority, not only in our own society, but also the world.
ItemBehavioral Ecology and Evolution of Hawaii's Endemic Carnivorous Caterpillars (Lepidoptera: Cosmopterigidae Hyposmocoma spp.)(University of Hawaii at Manoa, 2013-07-16)The endemic Hawaiian moth genus Hyposmocoma includes hundreds of species, providing dramatic examples of explosive radiation and ecological specialization. Many of these species exhibit typical caterpillar feeding ecology, consuming plant material, including aquatic algae-grazing and fern stem-boring. However, one clade deviates from this norm and has developed carnivorous behavior, an extremely rare trait in Lepidoptera worldwide. These species demonstrate behavior ranging from simple scavenging to molluscivorous prey capture, and their behavioral ecology and morphology reflects this. Here I investigate the degree of specialization and variation in behavior and morphology of several species of carnivorous Hyposmocoma, including both described and undescribed species. Observations and analyses are focused on prey preference of the carnivorous, "cigar" case clade, and mandible morphology within this and other Hyposmocoma groups. My results demonstrate that prey preference varies among species within the carnivorous clade, and ranges from arthropod scavenging to specialized snail capture behavior. The genus Hyposmocoma exhibits extraordinary diversity in terms of: number of species, caterpillar case morphology, feeding behavior (from algae eaters in streams to obligate snail eaters in native forests) and preferred habitat (from dry lowland forests to upper elevation cloud forest, to streams). This study set out to investigate whether similar levels of polymorphism exist in mandible microstructure. My hypothesis was that with so many vastly different natural history traits, a feature with critical adaptive function such as mandible morphology will reflect this dramatic level of variation. However, an unexpectedly low level of variation was observed. Mandible microstructure was found to be highly conserved, whether preferred feeding type included wood boring or snail feeding. Possible reasons for mandible structure conservation include recent speciation events, and the possibility that the structure observed across the genus is versatile enough such that it is functionally effective in diverse settings. Continued analyses of Hyposmocoma ecology, behavior, and morphology will prove useful in phylogenetic inference, and warrants continued study alongside ongoing molecular research.
ItemBehavioral Response of the O’ahu ‘amakihi to Experimental Infection with Avian Malaria(University of Hawaii at Manoa, 2010-05-11)Avian malaria (Plasmodium relictum), like other introduced diseases, is considered one of the greatest threats to the recovery of Hawaiian forest birds. Most bird species survive only at high elevations. The O’ahu ‘amakihi (Hemignathus flavus) is one of few species that has stable and widespread populations in low elevation forest habitat. This study is part of a larger project that experimentally infected O’ahu ‘amakihi with avian malaria to determine how they deal with this disease at low elevation. My objective is to determine if behavioral changes during the course of infection could be used to document tolerance to the disease. The study used four experimentally infected birds as the treatment group, and four uninfected birds as a control group. All bird activity was recorded and processed using the data analysis program BEAST (Student Version 1.0) and analyzed with respect to changes in parasitemia (percentage of infected erythrocytes). Behavioral variation was tested using a mixed model analysis of variance (ANOVA), which could identify differences between infected and control groups as well as between time periods. Focused contrasts could test effects of different time periods. Percent of observation time spent sitting was the only behavior that differed significantly between infected and control birds. Sitting varied with degree of infection, climaxing during the crisis phase and returning to pre-infection levels, indicating recovery. There was no loss of mass or signficant decline in nectar consumption. The O’ahu ‘amakihi thus shows low morbidity, which may account for their continued survival in low elevation forest habitats where avian malaria is prevalent.