Although hummingbirds are considered the major bromeliad pollinators, different species may contribute differently to pollination. This study analyses the importance of different hummingbirds to pollination of Vriesea rodigasiana (Bromeliaceae), based on visitation frequency (a quantity component) and germinated pollen load per visit (a quality component) in the Atlantic rainforest of southeastern Brazil. This bromeliad flowers for 3-4 months with a peak in March. Its yellow, tubular flowers last about 13 h and demonstrate approach herkogamy. During flowering peak, Thalurania glaucopis visited more flowers than Ramphodon naevius, whereas by the end of the flowering season the latter visited more. Differences in hummingbird bill length resulted in different pollen placement and stigma contact. The short-billed T. glaucopis received pollen on the top of its head, depositing it on the center of the stigma, while the long-billed R. naevius received it on the proximal part of its bill, depositing it on the lower lobe of the stigma. Flowers visited by T. glaucopis had six times more pollen tubes than those visited by R. naevius. Our results suggest that this functional group of hummingbirds may be split into even smaller groups, namely short-billed and long-billed hummingbirds, based on different sites of pollen placement. Although both species were pollen vectors of V. rodigasiana, the short-billed T. glaucopis was its most effective pollinator in the area supporting Stebbin's principle, linking floral features and good pollinators. © 2012 Springer-Verlag.299197105Araujo, A.C., Fischer, E.A., Sazima, M., Floração seqüencial e polinização de três espécies de Vriesea (Bromeliaceae) na região da Juréia, sudeste do Brasil (1994) Rev Bras Bot, 17, pp. 113-118Arizmendi, M.C., Dominguez, C.A., Dirzo, R., The role of an avian nectar robber and of hummingbird pollinators in the reproduction of two plant species (1996) Funct Ecol, 10, pp. 119-127Bawa, K.S., Plant-pollinator interactions in Tropical Rain Forests (1990) Ann Rev Ecol Evol Syst, 21, pp. 399-422Begon, M., Townsend, C.R., Harper, J.L., (2006) Ecology-from Individuals to Ecosystems, , Oxford: Blackwell PublishingBenzing, D.H., (2000) Bromeliaceae: Profile of an Adaptative Radiation, , Cambridge: Cambridge University PressBuzato, S., Sazima, M., Sazima, I., Hummingbird-pollinated floras at three Atlantic forest sites (2000) Biotropica, 32, pp. 824-841Campbell, D.R., Waser, N.M., Price, M.V., Lynch, E.A., Mitchell, R.J., Components of phenotypic selection: pollen export and flower corolla width in Ipomopsis aggregata (1991) Evolution, 45, pp. 1458-1467Canela, M.B.F., Sazima, M., Aechmea pectinata: a hummingbird-dependent bromeliad with inconspicuous flowers from the rain forest in Southeastern Brazil (2002) Ann Bot, 92, pp. 731-737Dafni, A., (1992) Pollination Ecology-a Practical Approach, , Oxford: Oxford University PressEndress, P.K., Syncarpy and alternative modes of escaping disadvantages of apocarpy in angiosperms (1982) Taxon, 31, pp. 48-52Endress, P.K., (1994) Diversity and Evolutionary Biology of Tropical Flowers, , Cambridge: Cambridge University PressEngel, E.C., Irwin, R.E., Linking pollinator visitation rate and pollen receipt (2003) Am J Bot, 90, pp. 1612-1618Faegri, K., van der Pijl, L., (1979) The Principles of Pollination Ecology, , 3rd edn., Oxford: Pergamon PressFeinsinger, P., Coevolution and pollination (1983) Coevolution, pp. 282-310. , D. Futuyma and M. Slatkin (Eds.), Sunderland: Sinauer AssociatesFeinsinger, P., Busby, W.H., Pollen carryover: experimental comparisons between morphs of Palicourea lasiorrachis (Rubiaceae), a distylous, bird-pollinated, tropical treelet (1987) Oecologia, 73, pp. 231-235Feinsinger, P., Colwell, R.K., Community organization among Neotropical nectar-feeding birds (1978) Am Zoo, 18, pp. 779-795Feinsinger, P., Busby, W.H., Tiebout, H.M., Effects of indiscriminate foraging by tropical hummingbirds on pollination and plant reproductive success: experiments with two tropical treelets (Rubiaceae) (1988) Oecologia, 76, pp. 471-474Fenster, C.B., Armbruster, W.S., Wilson, P., Dudash, M.R., Thomson, J.D., Pollination syndromes and floral specialization (2004) Ann Rev Ecol Evol Syst, 35, pp. 375-403Fowler, J., Cohen, L., Jarvis, P., (1998) Practical Statistics for Field Biology, , 2nd edn., Chichester: WileyGaletto, L., Bernardello, G., Rewards in flowers-nectar (2005) Practical Pollination Biology, pp. 261-313. , A. Dafni, P. G. Kevan, and B. C. Husband (Eds.), Ontario: EnviroquestGentry, A.H., Flowering phenology and diversity in tropical Bignoniaceae (1974) Biotropica, 6, pp. 64-68Gentry, A.H., Dodson, C.H., Diversity and biogeography of Neotropical vascular epiphytes (1987) Ann Missouri Bot Gard, 74, pp. 205-233Grant, K.A., Grant, V., (1968) Hummingbirds and Their Flowers, , New York: Columbia University PressGrantsau, R., (1989) Os Beija-Flores Do Brasil, , Rio de Janeiro: Editora Expressão e CulturaHerrera, C.M., Components of pollinator "quality": comparative analysis of a diverse insect assemblage (1987) Oikos, 50, pp. 79-90Herrera, J., Pollination relationships in southern Spanish Mediterranean shrub lands (1988) J Ecol, 76, pp. 274-287Herrera, C.M., Pollinator abundance, morphology, and flower visitation rate: analysis of the "quantity" component in a plant-pollinator system (1989) Oecologia, 80, pp. 241-248Horvitz, C.C., Schemske, D.W., Spatiotemporal variation in insect mutualists of a Neotropical herb (1990) Ecology, 71, pp. 1085-1097Inouye, D.W., Gill, D.E., Dudash, M.R., Fenster, C.B., A model and lexicon for pollen fate (1994) Am J Bot, 81, pp. 1517-1530Johnson, S.D., Pollinator-driven speciation in plants (2006) Ecology and Evolution of Flowers, pp. 295-310. , L. D. Harder and S. C. H. Barrett (Eds.), Oxford: Oxford University PressKay, K.M., Voelckel, C., Yang, J.Y., Hufford, K.M., Kaska, D.D., Hodges, S.A., Floral characters and species diversification (2006) Ecology and Evolution of Flowers, pp. 311-325. , L. D. Harder and S. C. H. Barrett (Eds.), Oxford: Oxford University PressKöppen, W., (1948) Climatologia: Con Un Estudio De Los Climas De La Tierra, , Mexico: Fondo de Cultura EconómicaKrömer, T., Kessler, M., Herzog, S.K., Distribution and flowering ecology of bromeliads along two climatically contrasting elevational transects in the Bolivian Andes (2006) Biotropica, 38, pp. 183-195Lau, P., Bosque, C., Pollen flow in the distylous Palicourea fendleri (Rubiaceae): an experimental test of the disassortative pollen flow hypothesis (2003) Oecologia, 135, pp. 593-600Levin, D.A., Berube, D.E., Phlox and Colias: the efficiency of a pollination system (1972) Evolution, 26, pp. 242-250Lloyd, D.G., Schoen, D.J., Self- and cross-fertilization in plants I. Functional dimensions (1992) Int J Pl Sci, 153, pp. 358-369Machado, I.C., Lopes, A.V., Floral traits and pollination systems in the Caatinga, a Brazilian tropical dry forest (2004) Ann Bot, 94, pp. 365-376Machado, C.G., Semir, J., Fenologia de floração e biologia floral de bromeliáceas ornitófilas de uma área da Mata Atlântica do Sudeste brasileiro (2006) Rev Bras Bot, 29, pp. 163-174Martin, F.N., Staining and observing pollen tubes in the style by means of fluorescence (1959) Stain Tech, 34, pp. 125-128Mayfield, M.M., Waser, N.M., Price, M.V., Exploring the "most effective pollinator principle" with complex flowers: bumblebees and Ipomopsis aggregata (2001) Ann Bot, 88, pp. 591-596McGill, R., Tukey, J.W., Larssen, W.A., Variations of box plots (1978) Am Stat, 32 (1), pp. 12-16McWilliams, E.L., Evolutionary ecology (1974) Flora neotropica monographs, 14, pp. 40-55. , (pp 58-64), In: Smith LB, Downs RJ (eds) Pitcairnioideae (Bromeliaceae)Morellato, L.P.C., Sazima, M., (1992) Modos De polinização Em Uma Floresta Semi-decídua No Sudeste Do Brasil (Reserva De Santa Genebra, Campinas, SP), p. 13. , Resumos Seminário Mata Santa Genebra-conservação e pesquisa em uma reserva florestal urbana em Campinas, Brazil: CampinasMurcia, C., Effect of floral morphology and temperature on pollen receipt and removal in Ipomea trichocarpa (1990) Ecology, 71, pp. 1098-1109Murcia, C., Feinsinger, P., Interspecific pollen loss by hummingbirds visiting flower mixtures: effects of corolla architecture (1996) Ecology, 77, pp. 550-560Newstrom, L.E., Frankie, G.W., Baker, H.G., A new classification for plant phenology based on flowering patterns in lowland tropical rain forest trees at La Selva, Costa Rica (1994) Biotropica, 26, pp. 141-159Nieder, J., Prosperi, J., Michaloud, G., Epiphytes and their contribution to canopy diversity (2001) Plant Ecol, 153, pp. 51-63Nimer, E., Climatologia da região sudeste do Brasil (1977) Rev Bras Geog, 34, pp. 3-48Ollerton, J., Reconciling ecological processes with phylogenetic patterns: the apparent paradox of plant-pollinator systems (1996) J Ecol, 84, pp. 767-769Olsen, K.M., Pollination effectiveness and pollinator importance in a population of Heterothecasubaxillaris (Asteraceae) (1997) Oecologia, 109, pp. 114-121Opler, P.A., Baker, H.G., Frankie, G.W., Plant reproductive characteristics during secondary succession in Neotropical lowland forest ecosystems (1980) Biotropica, 12, pp. 40-46Pellmyr, O., Thompson, J.N., Brown, J.M., Harrison, R.G., Evolution of pollination and mutualism in the yucca moth lineage (1996) Am Nat, 148, pp. 827-847Rademaker, M.C.J., de Jong, T.J., Klinkhamer, P.G.L., Pollen dynamics of bumble-bee visitation on Echium vulgare (1997) Funct Ecol, 11, pp. 554-563Radford, A.E., Dickinson, W.C., Massey, J.R., Bell, C.R., (1974) Vascular Plant Systematics, , New York: Harper and RowReitz, R., (1983) Bromeliáceas E a malária-bromélia endêmica, , Itajaí: Flora Ilustrada CatarinenseRichards, A.J., (1986) Plant Breeding Systems, , London: George Allen and Unwin Publishers LtdRocca, M.A., Sazima, M., Beyond hummingbird-flowers: the other side of ornithophily in the Neotropics (2010) Oecol Aust, 14, pp. 67-99Rocca-de-Andrade, M.A., (2006) Recurso floral para aves em uma comunidade de Mata Atlântica de encosta: Sazonalidade e distribuição vertical, , Dissertation, Universidade Estadual de CampinasSazima, I., Buzato, S., Sazima, M., The saw-billed hermit Ramphodon naevius and its flowers in southeastern Brazil (1995) J Ornithol, 136, pp. 195-206Sazima, I., Buzato, S., Sazima, M., An assemblage of hummingbird-pollinated flowers in a montane forest in Southeastern Brazil (1996) Bot Acta, 109, pp. 149-160Sazima, M., Buzato, S., Sazima, I., Polinização por beija-flores em Nidularium e gêneros relacionados (2000) Bromélias Da Mata Atlântica-Nidularium, pp. 188-195. , E. C. Leme (Ed.), Rio de Janeiro: Hamburg Donnelley Gráfica Editora LtdaSchemske, D.W., Horvitz, C.C., Variation among floral visitors in pollination ability: a precondition for mutualism specialization (1984) Science, 225, pp. 519-521Sick, H., (1997) Ornitologia Brasileira, , Rio de Janeiro: Editora Nova FronteiraStebbins, G.L., Adaptive radiation of reproductive characteristics in angiosperms I: pollination mechanisms (1970) Ann Rev Ecol Syst, 1, pp. 307-326Stiles, F.G., Ecology, flowering phenology, and hummingbird pollination of some Costa Rican Heliconia species (1975) Ecology, 56, pp. 285-301Stiles, F.G., Temporal organization of flowering among the hummingbird food plants of a tropical wet forests (1978) Biotropica, 10, pp. 194-210Stiles, F.G., Geographical aspects of bird-flower coevolution, with particular reference to Central America (1981) Ann Missouri Bot Gard, 68, pp. 323-351Tremblay, R.L., Distribution and dispersion patterns of individuals in nine species of Lepanthes (Orchidaceae) (1997) Biotropica, 29, pp. 38-45van Dunné, H.J.F., Effects of the spatial distribution of trees, conspecific epiphytes and geomorphology on the distribution of epiphytic bromeliads in secondary montane forest (Cordillera Central, Colombia) (2002) J Trop Ecol, 18, pp. 198-213Waser, N.M., Price, M.V., Optimal and actual outcrossing in plants, and the nature of plant-pollinator interaction (1983) Handbook of Experimental Pollination Biology, pp. 341-359. , C. E. Jones and R. J. Little (Eds.), New York: Van Nostrand ReinholdWendt, T., Canela, M.B.F., Faria, A.P.G., Rios, R.I., Reproductive biology and natural hybridization between two endemic species of Pitcairnia (Bromeliaceae) (2001) Am J Bot, 88, pp. 1760-1767Wendt, T., Canela, M.B.F., Klein, D.E., Rios, R.I., Selfing facilitates reproductive isolation among three sympatric species of Pitcairnia (Bromeliaceae) (2002) Plant Syst Evol, 232, pp. 201-212Wester, P., Claßen-Bockhoff, R., Bird pollination in South African Salvia species (2006) Flora, 201, pp. 396-406Wolf, L.L., Stiles, F.G., Hainsworth, F.R., Ecological organization of a tropical, highland hummingbird community (1976) J Anim Ecol, 45, pp. 49-379Zar, J.H., (1984) Biostatistical Analysis, , New Jersey: Prentice Hall International