Topic
Nectarinia
About: Nectarinia is a research topic. Over the lifetime, 80 publications have been published within this topic receiving 1807 citations.
Papers published on a yearly basis
Papers
TL;DR: In general, sunbirds feeding at Leonotis responded less to reward levels by differential turning and movement than some other organisms, possibly reflecting different prey distributions or boundary constraints on their foraging.
Abstract: Sunbirds (Nectarinia spp.) feeding at the East African mint Leonotis nepetifolia en- counter great variations in the nectar contents of flowers blooming in dense fields. The dispersion patterns of nectar are attributable to nectar removal from some flowers by the sunbirds themselves in earlier foraging and also to intrinsic floral variations. The problem facing the foraging sunbird is to increase its foraging efficiency (net energy gain per unit time) by avoiding recently visited, empty flowers and by visiting flowers with greater than average nectar volumes. Sunbirds patterned their foraging in 3 major ways. First, they used initial flowers probed on an inflorescence as an assay of what the rest of the flowers in that inflorescence contained and they rejected inflorescences with little nectar. Such rejection increased nectar intake per flower by as much as 15%. Second, territorial sunbirds preferentially fed at unvisited inflorescences, increasing nectar intake 25% relative to random foraging. This was accomplished at least in part by foraging at different heights on successive foraging bouts. Third, flight distances to the next flower changed in response to immediate reward levels in some species but not in others. In general, sunbirds feeding at Leonotis responded less to reward levels by differential turning and movement than some other organisms, possibly reflecting different prey distributions or boundary constraints on their foraging.
211 citations
TL;DR: The overall pattern of sunbird radiation across Indian Ocean islands indicates that these birds disperse across ocean barriers with relative ease, but that their subsequent evolutionary success probably depends on a variety of factors including prior island occupation by competing species.
126 citations
TL;DR: The impact of urbanization on a guild of nectar-feeding birds in a biodiversity hotspot at the Cape of Africa is studied, finding that urbanization reduces the functional diversity of the nectarivore guild.
Abstract: Urbanization is a widespread and rapidly growing threat to biodiversity, therefore we need a predictive understanding of its effects on species and ecosystem processes. In this paper we study the impact of urbanization on a guild of nectar-feeding birds in a biodiversity hotspot at the Cape of Africa. The guild of four bird species provides important ecosystem services by pollinating 320 plant species in the Cape Floral Region. Functional diversity within the guild is related to differences in bill length. The long-billed Malachite Sunbird (Nectarinia famosa) plays an irreplaceable role as the exclusive pollinator of plant species with long nectar tubes. We analyzed the composition of the guild in suburban gardens of Cape Town along a gradient of increasing distance from the nearest natural habitat. Urbanization reduces the functional diversity of the nectarivore guild. Malachite Sunbirds did not penetrate more than 1 km into the city, whereas only the short-billed Southern Double-collared Sunbirds (Cinnyris chalybea) occurred throughout the urbanization gradient. The lack of data precludes conclusions regarding the detailed responses of Orange-breasted Sunbirds (Anthobaphes violacea) and Sugarbirds (Promerops cafer), however their absence across the entire gradient is suggestive of high sensitivity. The functional diversity of this guild of pollinators can potentially be restored, but the pros and cons of this conservation action need to be considered.
125 citations
TL;DR: The results show that P. roupelliae is largely dependent on birds for pollination, and thus confirm the utility of floral syndromes for generating hypotheses about the ecology of pollination systems.
Abstract: We investigated whether the “ornithophilous” floral syndrome exhibited in an African sugarbush, Protea roupelliae (Proteaceae), reflects ecological specialization for bird-pollination A breeding system experiment established that the species is self-compatible, but dependent on visits by pollinators for seed set The cup-shaped inflorescences were visited by a wide range of insect and bird species; however inflorescences from which birds, but not insects, were excluded by wire cages set few seeds relative to open-pollinated controls One species, the malachite sunbird (Nectarinia famosa), accounted for more than 80% of all birds captured in P roupelliae stands and carried the largest protea pollen loads A single visit by this sunbird species was enough to increase seed set considerably over unvisited, bagged inflorescences Our results show that P roupelliae is largely dependent on birds for pollination, and thus confirm the utility of floral syndromes for generating hypotheses about the ecology of pollination systems
102 citations
TL;DR: It is found that floral tube length has a bimodal distribution with 37 Cape species potentially dependent on pollination by Malachite Sunbirds, a pollination service irreplaceable by the more abundant, short-billed sunbird species.
101 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2022 | 1 |
| 2019 | 1 |
| 2018 | 1 |
| 2017 | 1 |
| 2016 | 6 |
| 2015 | 1 |