http://www.rssboard.org/rss-specification 720 https://escholarship.org/uc/wrca_moorea/rss Recent eScholarship items from Student Research Papers, Fall 2006 Fri, 19 Jun 2026 21:13:46 +0000 https://escholarship.org/uc/item/52v27033 <p>Wood-decaying macrofungi are an important component of forest ecosystems because they are the major decomposers of dead woody debris and are crucial for nutrient cycling. This is especially true in the tropics where biomass is high. However, most studies to date have focused on temperate forests in the northern hemisphere. Little is known about wood-inhabiting fungi in French Polynesia. In fact, no identification materials exist. The following study seeks to fill this gap in knowledge. First, a general survey was done of the wood-fungi occurring in the mountains of Moorea. Next, in a pilot study, all Hibiscus tiliaceus dead wood (&gt;1cm) was measured and surveyed for fungi using 10, 25-meter line transects. The aim of this phase was to determine if wood with fungi has different characteristics than wood without. Fungi were found on 61% of wood surveyed, but larger logs, and wood of intermediate decay were more likely to have at least one species. An additional 20 transects... https://escholarship.org/uc/item/52v27033 Tue, 6 Mar 2007 00:00:00 +0000 Wheaton, Felicia https://escholarship.org/uc/item/1fz795cf <p>The effects of human activities on the earth’s environment have gained increasing attention in recent years. With coral reefs declining worldwide, efficient tools for assessing reef health are more important than ever. The species of larger foraminifera known as Peneroplis pertusus share key characteristics with reef building corals. By examining the populations’ natural distribution along with the abiotic factors affecting bleaching, a better understanding of reef systems as a whole is achieved. In this study, P. pertusus was collected from ten different sites on a fringing reef in Moorea, French Polynesia. Collected from coral rubble at one, two, and three meters depths, they were analyzed for abundance, size, and extent of bleaching. Light experiments were used in the laboratory to determine response to increased solar radiation. One-way statistical analysis, along with the Wilcoxon test found no strong correlation between depth and percent bleaching. A difference... https://escholarship.org/uc/item/1fz795cf Tue, 6 Mar 2007 00:00:00 +0000 Ellison, Aimee https://escholarship.org/uc/item/8hk9852g <p>Octopuses are known for the advanced behaviors and elaborate displays used in predator avoidance. Although studies have provided anecdotal evidence on the defense mechanisms of these animals, whether these behaviors vary under light and dark conditions is unknown. This study investigated the diurnal and nocturnal predator defense mechanism s of Octopus bocki (Adams, 1941) in Moorea, French Polynesia. Seven behaviors were identified as primary defense mechanisms for protection from fish predators during daylight and nighttime hours. Rates of occurrence and durations for defense behaviors significantly differed between diurnal and nocturnal conditions, as O. bocki frequently Crawled during the daylight hours , but sat still and Curled during the nighttime hours. Results indicate that O. bocki modifies predator defense behaviors for survival under light and dark conditions.</p> https://escholarship.org/uc/item/8hk9852g Mon, 26 Feb 2007 00:00:00 +0000 Valencia, Natalie https://escholarship.org/uc/item/9pz5690t <p>The study of microorganisms and filamentous blue-green algae holds great ecological and geological importance; such microbial communities to be on of the first forms of life as well as the initial source of atmospheric oxygen. In Moorea, an island in the South Pacific, the microbial communities found on the intertidal mudflats have been widely studied and characterized. However, little is known about the marine mats that are consistently covered with seawater. This study surveyed the algal communities present in the shallow lagoon formed at Temae Beach, a public sand beach located on the northeast tip of Moorea. Seven morphologically different mats were observed and their distributions determined and mapped throughout two regions: the littoral (intertidal and sub-tidal) and back reef. The majority of mats were found within the sub-tidal while none were seen within the intertidal and very few observed within the back reef region. A common trend observed within this distribution... https://escholarship.org/uc/item/9pz5690t Tue, 20 Feb 2007 00:00:00 +0000 Chang, Carol https://escholarship.org/uc/item/7b94s417 <p>Previous studies of the feeding biology of Culcita novaeguineae Muller &amp; Troschel in Hawai’i have shown that the cushion star prefers to prey on coral species of the genus Pocillopora over the genus Porites. Distribution and feeding biology studies of C. novaeguineae in Cook’s Bay on the island of Mo’orea, French Polynesia have shown that it habitats near Porites spp. coral in areas where Porites spp. coral is sparse, and prefers to prey on Acropora spp. coral. The purpose of this study was to further examine coral prey preference of C. novaeguineae in Mo’orea, using specimens from four areas on the island for better representation of its feeding ecology on Mo’orea, French Polynesia. My studies showed that C. novaeguineae in Mo’orea prefers Acropora spp. and Pocillopora spp., over Porites spp. (p=0.0046), and showed no preference for Acropora spp., over Pocillopora spp.. The study further determined that C. novaeguineae primarily feeds nocturnally, and moves persistently... https://escholarship.org/uc/item/7b94s417 Mon, 12 Feb 2007 00:00:00 +0000 Hawkins, Sigrid V. https://escholarship.org/uc/item/6vt6p2w8 <p>Ferns present an interesting case in island biogeography because of their unusually high dispersal ability. A general survey of the filmy ferns (Hymenophyllaceae) of Moorea, French Polynesia was undertaken by observing distribution in the field, conducting tests of desiccation tolerance, and inferring a phylogeny based on morphological characters. A total of 12 filmy fern species (including three species previously unreported in the literature for Moorea) were found to occur in moist, wellcovered habitats throughout the island, with distinct sets of high elevation and low elevation species. Five species were included in an experiment to determine relative degree of desiccation tolerance; results indicate that terrestrial species have lower desiccation tolerance than epiphytic or epipetric species. In order to place the Moorea filmy ferns in the larger archipelago context, eight additional Society Island species were included in the phylogeny for a total of 20 taxa based on... https://escholarship.org/uc/item/6vt6p2w8 Fri, 9 Feb 2007 00:00:00 +0000 Nitta, Joel H. https://escholarship.org/uc/item/8xx4w41z <p>The objective of this study was to determine if the distribution of insect species and presence of herbivory differed between native and non-native plants in the coastal region of Mo'orea, French Polynesia. Therefore, four native plant species (Barringtonia asiatica, Hibiscus tiliaceus, Terminalia catappa, Thespesia populnea) and four non-native plant species (Carica papaya, Mangifera spp., Morinda citrifolia, Musa spp.) were sampled. Each collected insect was tested for herbivory, and placed in a cup with a 2X1in. piece of undamaged leaf from the tree it was found and frequently checked for damage. Significantly greater insect species abundance was found on native plants compared to non-native plants (p=0.0431). No significant difference was found in richness (p=0.6409) or diversity (p=0.8451) between native and non-native plants. Significantly more herbivory damage was observed on the whole tree in native plants (p=0.0001). The herbivory trials found more cases of herbivory... https://escholarship.org/uc/item/8xx4w41z Thu, 8 Feb 2007 00:00:00 +0000 Prado, Erin M. https://escholarship.org/uc/item/7fq439n2 <p>While water striders (Hemiptera: Gerridae) have a global distribution different species have adapted to very different habitat types. Freshwater water striders such as Limnogonus luctuosus live in areas along streams and rivers with little to no flow. Marine water striders, such as coastal species Halobates hawaiiensis, have adapted to life on the surface of the ocean. Since these types of water striders live in such different habitats, and face different environmental factors their food preference and behavior can be quite different. In this study, average density of L. luctuosus individuals was measured along the Opunohu River. Also, food preference, behavior, and the effects of increased density were tested in the laboratory for both L. luctuosus and H. hawaiiensis. Response time and frequency of approach to mobile and immobile prey items were recorded for H. hawaiiensis and L. luctuosus. H. hawaiiensis preferred immobile prey while L. luctuosus preferred mobile prey.... https://escholarship.org/uc/item/7fq439n2 Thu, 8 Feb 2007 00:00:00 +0000 Riley, Melissa K. https://escholarship.org/uc/item/12t2697d <p>Spirobranchus giganteus Pallas 1766 is an obligate associate of coral. This study focused on the distribution of five branchial crown colormorphs (Blue, Brown, Marigold, Purple, and White) on eight coral species (Acropora I, Acropora II, Porites I, Porites II, Porites III, Porites IV, Porites V, Porites VI) by quadrat sampling method. White was the most abundant colormorph, representing 24.0% of the total. Blue was the least abundant colormorph at 9.5% of the total. There were no significant differences in Shannon-Weiner Diversity Index (H’) of colormorphs between coral species. Also, relative colormorph abundance did not differ significantly between coral species or between the Front and Back positions. Only Blue and Marigold differed significantly in relative abundance between Top, Midde, and Bottom positions. Findings support a colormorph distribution of colormorphs. There are two possible explanations: 1) mortality and selection effects on distribution and 2)... https://escholarship.org/uc/item/12t2697d Thu, 8 Feb 2007 00:00:00 +0000 Song, Daniel S. https://escholarship.org/uc/item/9s6740fr <p>The defensive behaviors of four opisthobranchs (Glossodoris cincta, Risbecia imperials, Stylochelius striatus, and Dolabrifera dolabrifera) were observed and categorized. The displays studied were mantle flexation, mucus production, mantle secretion, inking, and rearing. Members of each species were placed in two laboratory situations containing two different antagonists. The antagonists (Dardanus lagopodes and Lutjanus fulvus) were chosen because they were carnivorous, abundant, and found in the same ecology as the opisthobranchs studied. Additionally, they were chosen because they differed phylogenetically, physiologically, and behaviorally and, therefore, represented two very different predators. In some cases, individuals exhibited different defensive behaviors in the presence of different antagonists. Differential responses could reflect physiological, biological, or phylogenetic differences between the four observed opisthobranch species. In some instances, defensive... https://escholarship.org/uc/item/9s6740fr Wed, 7 Feb 2007 00:00:00 +0000 Ghazali, Sameen R. https://escholarship.org/uc/item/9jm2351g <p>Autotomy and regeneration are widespread in many groups of invertebrates and vertebrates, such as annelids, crustaceans, amphibians, and reptiles. Regeneration is common in all classes of Echinodermata and prevalent in ophiuroid brittle stars. Moorea, French Polynesia was surveyed for species of brittle stars living on coastal areas of the island in different habitats.</p><p>Ophiuroid populations were sampled in habitats such as a mangrove marsh, a sandy beach with coral rubble and a jetty with coral rubble and conglomerate coral to determine percentages with regenerating arms. Macrophiothix longipeda (Lamarck 1816) from the mangrove marsh and two populations of Ophiocoma scolopendrina (Lamarck 1816) from the beach and jetty were studied to determine if there were differences in experimental rates of arm regeneration after induced autotomization. Each habitat was colonized by distict ophiuriod assemblages and had different percentages of regenerating individuals; M. longipeda... https://escholarship.org/uc/item/9jm2351g Wed, 7 Feb 2007 00:00:00 +0000 Chinn, Sarah https://escholarship.org/uc/item/93n6h93r <p>Epiphytes are important in forest ecosystems because they contribute to species diversity and aid in nutrient cycling. Despite this, the ecology of tropical epiphytes, particularly nonvascular species, is not well understood. This study compared epiphyte richness, cover, diversity, and species distributions to host tree diameter, canopy cover, aspect, and height on the trunk. Thirty-two Metrosideros collina trees were sampled for epiphyte species every 0.5 centimeters along circumferential transects at 0, 0.75, and 1.5 meters off the ground. Host tree diameter at 0.5 meters was measured, as well as canopy cover at North, South, East, and West. Epiphyte cover was lowest at the bottom of the trunk and highest at 1.5 meters. Richness correlated positively with diameter and canopy cover, but it did not vary significantly with height or aspect, according to the Wilcoxon and Tukey tests. Epiphyte cover correlated positively with canopy cover, but it did not vary significantly with... https://escholarship.org/uc/item/93n6h93r Wed, 7 Feb 2007 00:00:00 +0000 Dobbs, April M. https://escholarship.org/uc/item/7vq7s0xw <p>Environmental Science Policy and Management, University of California, Berkeley, California 94720 USA Abstract. Interspecific mutualisms between ant and scale insect species have been well documented as symbiotic relationships that merit resource acquisition in exchange for protection. In this study, insect removal experiments were preformed on the branches of Psidium guajava in order to measure the effects that insect populations have on one another. Five ant removal, five scale removal and five control trees were treated. Data was taken daily over the course of 18 days. Ant activity was measured using a one-minute, unidirectional, point count and the number of scales per branch was determined by photographing a sample of five leaves per branch. Wilcoxon rank-sum tests found that ant populations differ significantly to that of controls in the absence of scale insects. Scale insect populations were not significantly affected by the removal of ants. Observational ant behavior... https://escholarship.org/uc/item/7vq7s0xw Wed, 7 Feb 2007 00:00:00 +0000 Almarez, Maya https://escholarship.org/uc/item/7320c2dz <p>Crab chelae are a model system for studying the relationship between the biomechanics of an organism’s structure and its ecolgical role. This study investigated how chelae dimorphism may correlate with specialization in function in the land crab Cardisoma carnifx (Herbst 1791). This was achieved by comparing field observations of preferential claw usage during diurnal activities to a mechanical model drived from anatomical claw measurements, claw closing effort of captured specimens, and calculations of expected closing force. Behavior, mechanical scaling, and effort were also compared between males and females. Foraging, eating, and lead claw entering burrow showed significant differences in claw use frequency. It was also found that the major and minor claws scaled differently with respect to carapace length, with the major claw displaying positively allometric scaling and the minor claw displaying near-isometric scaling. Measurement of claw closing effort with respect... https://escholarship.org/uc/item/7320c2dz Wed, 7 Feb 2007 00:00:00 +0000 Hata, Tom https://escholarship.org/uc/item/71g4k00t <p>Tahitian legend states Fagraea berteriana is a gift of repentance from the god, Tane. The scientific community knows little more about this tree than its inter-island distribution in the South Pacific. I surveyed the island of Moorea to map an intra-island distribution of F. berteriana and quantify environmental characteristics surrounding the tree’s growth. I tested dispersal hypotheses by collecting bird observations and conducting seed germination experiments that included a numer of seed scarification treatments. The tree occurred in densities ranging from 44 to 244 trees/hectare and at elevations spanning from approximately 300 to 900 m. Density differed with significance between two sites, Tohiea and the Cross Island Trail. Tree density increased with greater elevations and more southerly aspects. Ninety-five percent of the trees sampled grew on slopes greater than 80%. There was no correlation between tree density and slope or between density and tree height.... https://escholarship.org/uc/item/71g4k00t Wed, 7 Feb 2007 00:00:00 +0000 Hanna, Zachary R. https://escholarship.org/uc/item/6db9m25g <p>The River Continuum Concept (RCC) predicts that as the form of particulate organic matter available in streams and rivers varies longitudinally, so will the functional feeding groups (FFGs) of benthic macroinvertebrates. The RCC was developed based on data from continental streams; therefore, its applicability to the unique ecology of island streams is virtually untested. The purpose of this study was to discover if the RCC works in the small streams of Moorea, French Polynesia. Three sites along an elevational gradient were sampled for benthic macroinvertebrates in five streams of similar catchment size. Each sample was sorted and all taxa were assigned to a FFG. Species richness and FFG variation along a longitudinal gradient were compared to RCC predictions. Patterns in the longitudinal variation of crustacean/mollusc species richness and shredder, grazer, and predator percent composition were found to match RCC predictions. However, total species richness, insect species... https://escholarship.org/uc/item/6db9m25g Wed, 7 Feb 2007 00:00:00 +0000 Groff, Margaret H. https://escholarship.org/uc/item/67j9641r <p>Environmental variables change over elevational gradients and can isolate plant populations. Three varieties of Hibiscus tiliaceus L. exist on an elevational gradient in Moorea, French Polynesia. These variety’s morphological and chemical characteristics are associated with the differences between their environments. Leaf and flower morphological data were collected and analyzed and found significant differences in petal width and length, anther count, burgundy center color, and leaf width and length between the varieties, particularly between the coastal and mountain types. The increased rainfall and lower temperatures of the high mountains lowered net primary production for the mountain variety as compared to the coastal and mid-mountain varieties. The mid-mountain variety was found to have greater competition for light than the other varieties. These can be linked to the significant size differences in leaves and inflorescence. Chemical differences were analyzed... https://escholarship.org/uc/item/67j9641r Wed, 7 Feb 2007 00:00:00 +0000 Bell, Thomas W. https://escholarship.org/uc/item/4gb4v3zk <p>Organisms experience physiological and ecological changes during ontogenesis, and studies have shown that such changes have an impact on behavior over the life cycle. However, little is known about how octopus behavior changes during ontogeny. The pygmy octopus, Octopus bocki (Adam 1941), expresses differences in chromatophore development and mantle length between developmental stages. These changes may be important in predator defense, therefore I hypothesized that predator response behavior also changes over the life cycle. Timed interactions between an octopus and a fish predator were used to compare the behaviors and color displays exhibited by three different size categories of O. bocki; juvenile, sub-adult, and adult. Color display diversity was analyzed using the Shannon-Weiner diversity index. The analysis revealed a negative correlation between color display diversity and size during predator interactions, supporting the hypothesis that behavior changes over the life... https://escholarship.org/uc/item/4gb4v3zk Wed, 7 Feb 2007 00:00:00 +0000 Himes, Julie E. https://escholarship.org/uc/item/3fb344vf <p>Shorebirds often feed in multispecies groups that display interesting niche dynamics. On Moorea, French Polynesia, the Wandering Tattler (Tringa incana) and Pacific Golden Plover (Pluvialis fulva) are the dominant shorebird species during the northern winter. These species’ feeding behavior was observed at the Temae estuary on the northeast side of the island. Relative abundance of the two species was determined using transect counts at the estuary and an adjacent beach. T. incana displayed more striking and sprinting behavior, while P. fulva displayed more picking and walking behavior. T. incana also consumed more crabs than P. fulva. The two species existed in relatively equal abundance in the estuary; T. incana was more common on the beach. Though these data suggest some differences in feeding niche, a great deal of overlap was observed. The degree of niche partitioning appears to be greater in this study than in similar studies conducted on these species’ breeding grounds.</p> https://escholarship.org/uc/item/3fb344vf Wed, 7 Feb 2007 00:00:00 +0000 Greene, Andrew D. https://escholarship.org/uc/item/355702bs <p>The various predator defense mechanisms possessed by shallow water sea cucumbers were surveyed in twelve different species and morphs. While many defense mechanisms such as the presence of Cuverian tubules, toxic secretions, and unpalatability have been identified in holothurians, I hypothesized that the possession of these traits as well as the degree to which they are utilized varies from species to species. The observed defense mechanisms were compared against a previously-derived phylogeny of the sea cucumbers of Moorea. Furthermore, I hypothesized that while the presence of such structures is most likely a result of the species’ placement on a phylogenetic tree, the degree to which they utilize such structures and their physical behavior are influenced by their individual ecologies. The presence of a red liquid secretion was restricted to individuals of the genus Holothuria (Linnaeus 1767) however not all members of the genus exhibited this trait. With the exception of... https://escholarship.org/uc/item/355702bs Wed, 7 Feb 2007 00:00:00 +0000 Castillo, Jessica A. https://escholarship.org/uc/item/2f74g3hp <p>French Polynesia’s indigenous tamanu Tree (Calophyllum inophyllum) is an important natural resource harvested for lumber, resin, and oil. Being a marine-seed dispersed species it self-propagates and can be found growing along the coastline of Moorea. Development and harvest patterns on Moorea may be slowing the natural reproductive rate of the species. Fifty years ago it was recommended as a species to include in management programs as it had been noted to be in decline due to its slow growth and high use rates. Interviews with elders, carvers and healers indicated that the range has indeed diminished. A total island survey was performed and the resulting map of C. Inophyllum’s distribution indicates that the range is healthy- but it will continue to compete with human development for the diminishing resource of coastal terrain.</p> https://escholarship.org/uc/item/2f74g3hp Wed, 7 Feb 2007 00:00:00 +0000 Howell, Valerie B.