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Frequent Visitors (frequent + visitor)
Selected AbstractsFrequent Visitors to the School Nurse at Two Middle SchoolsJOURNAL OF SCHOOL HEALTH, Issue 9 2000James F. Sweeney No abstract is available for this article. [source] Pollination ecology of Isoglossa woodii, a long-lived, synchronously monocarpic herb from coastal forests in South AfricaPLANT BIOLOGY, Issue 3 2010M. E. Griffiths Abstract Synchronous monocarpy in long-lived plants is often associated with pollination by wind, in part because infrequent mass flowering may satiate pollinators. Selfing in synchronous monocarps may provide reproductive assurance but conflict with the benefits of outcrossing, a key evolutionary driver of synchrony. We predicted that animal-pollinated species with synchronous flowering would have unspecialised flowers and attract abundant generalised pollinators, but predictions for selfing and outcrossing frequencies were not obvious. We examined the pollination biology of Isoglossa woodii (Acanthaceae), an insect-pollinated, monocarpic herb that flowers synchronously at 4,7-year intervals. The most frequent visitor to I. woodii flowers was the African honeybee, Apis mellifera adansonii. Hand-pollination failed to enhance seed production, indicating that the pollinators were not saturated. No seed was set in the absence of pollinators. Seed set was similar among selfed and outcrossed flowers, demonstrating a geitonogamous mixed-mating strategy with no direct evidence of preferential outcrossing. Flowers contained four ovules, but most fruits only developed one seed, raising the possibility that preferential outcrossing occurs by post-pollination processes. We argue that a number of the theoretical concerns about geitonogamous selfing as a form of reproductive assurance do not apply to a long-lived synchronous monocarp such as I. woodii. [source] Insect flower visitors, foraging behaviour and their effectiveness as pollinators of Persoonia virgata R. Br. (Proteaceae)AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 1 2002Helen M Wallace Abstract Leioproctus species are frequent flower visitors to Proteaceae and have been inferred as pollinators of many species of Persoonia. This study investigated frequency of flower visitors, their behaviour and the breeding system of Persoonia virgata. The two most frequent visitors were the native bees Trigona carbonaria Smith (Hymenoptera: Apidae) and females of Leioproctus (Cladocerapis) speculiferus Cockerell (Hymenoptera: Colletidae). These species have different foraging strategies on the flowers of P. virgata and, on the basis of more frequent stigma contact, L. speculiferus was found to be the most effective pollinator. Pollination studies indicated that fruit set of bagged flowers (0.5% and 9.2%) was significantly less (P < 0.001) than fruit set of control flowers left open to visitors (24.0% and 48.9%) in two experiments, respectively. Furthermore, flowers that were bagged and cross-pollinated set significantly (P < 0.001) more fruit (43.8%) than flowers that were bagged and self-pollinated (6.6%), suggesting partial self-incompatibility. No significant difference in fruit set was found between control flowers and cross-pollinated flowers, indicating that flower visitors of P. virgata were efficient vectors of cross-pollen from plant to plant. [source] Bird Assemblage and Visitation Pattern at Fruiting Elmerrillia tsiampaca (Magnoliaceae) Trees in Papua New GuineaBIOTROPICA, Issue 2 2010Steffen Oppel ABSTRACT Most tropical trees produce fleshy fruits that attract frugivores that disperse their seeds. Early demography and distribution for these tree species depend on the effects of frugivores and their behavior. Anthropogenic changes that affect frugivore communities could ultimately result in changes in tree distribution and population demography. We studied the frugivore assemblage at 38 fruiting Elmerrillia tsiampaca, a rain forest canopy tree species in Papua New Guinea. Elmerrillia tsiampaca is an important resource for frugivorous birds at our study site because it produces abundant lipid-rich fruits at a time of low fruit availability. We classified avian frugivores into functional disperser groups and quantified visitation rates and behavior at trees during 56 canopy and 35 ground observation periods. We tested predictions derived from other studies of plant,frugivore interactions with this little-studied frugivore assemblage in an undisturbed rain forest. Elmerrillia tsiampaca fruits were consumed by 26 bird species, but most seeds were removed by eight species. The most important visitors (Columbidae, Paradisaeidae and Rhyticeros plicatus) were of a larger size than predicted based on diaspore size. Columbidae efficiently exploited the structurally protected fruit, which was inconsistent with other studies in New Guinea where structurally protected fruits were predominantly consumed by Paradisaeidae. Birds vulnerable to predation foraged for short time periods, consistent with the hypothesis that predator avoidance enhances seed dispersal. We identified seven functional disperser groups, indicating there is little redundancy in disperser groups among the regular and frequent visitors to this tropical rain forest tree species. [source] | ||||||||||