A Bird's-Eye View of Pollination: Biotic Interactions as Drivers of Adaptation and Community Change

Literature Cited

1. Abrahamczyk S, Renner SS. 2015. The temporal build-up of hummingbird/plant mutualisms in North America and temperate South America. BMC Evol. Biol. 15:1104
   [Google Scholar]
2. Abrahamczyk S, Souto-Vilarós D, Renner SS 2014. Escape from extreme specialization: passionflowers, bats and the sword-billed hummingbird. Proc. R. Soc. B 281:179520140888
   [Google Scholar]
3. Adler PB, HilleRisLambers J, Levine JM 2007. A niche for neutrality. Ecol. Lett. 10:295–104
   [Google Scholar]
4. Aigner PA. 2004. Floral specialization without trade-offs: optimal corolla flare in contrasting pollination environments. Ecology 85:92560–69
   [Google Scholar]
5. Aizen MA, Feinsinger P. 1994. Forest fragmentation, pollination, and plant reproduction in a Chaco dry forest, Argentina. Ecology 75:2330–51
   [Google Scholar]
6. Aizen MA, Rovere AE. 2010. Reproductive interactions mediated by flowering overlap in a temperate hummingbird-plant assemblage. Oikos 119:4696–706
   [Google Scholar]
7. Aizen MA, Vázquez DP. 2006. Flowering phenologies of hummingbird plants from the temperate forest of southern South America: Is there evidence of competitive displacement?. Ecography 29:3357–66
   [Google Scholar]
8. Anderson B, Cole WW, Barrett SCH 2005. Specialized bird perch aids cross-pollination. Nature 435:703841–42
   [Google Scholar]
9. Anderson SH, Kelly D, Ladley JJ, Molloy S, Terry J 2011. Cascading effects of bird functional extinction reduce pollination and plant density. Science 331:60201068–71
   [Google Scholar]
10. Armstrong DP. 1991. Aggressiveness of breeding territorial honeyeaters corresponds to seasonal changes in nectar availability. Behav. Ecol. Sociobiol. 29:2103–11
    [Google Scholar]
11. Aslan CE, Zavaleta ES, Tershy B, Croll DON, Robichaux RH 2013. Imperfect replacement of native species by non-native species as pollinators of endemic Hawaiian plants. Conserv. Biol. 28:478–88
    [Google Scholar]
12. Barrett SCH. 2013. The evolution of plant reproductive systems: how often are transitions irreversible?. Proc. R. Soc. B 280:176520130913
    [Google Scholar]
13. Benadi G, Pauw A. 2018. Frequency dependence of pollinator visitation rates suggests that pollination niches can allow plant species coexistence. J. Ecol. 106:51892–901
    [Google Scholar]
14. Bergamo PJ, Rech AR, Brito VLG, Sazima M 2016. Flower colour and visitation rates of Costus arabicus support the ‘bee avoidance’ hypothesis for red-reflecting hummingbird-pollinated flowers. Funct. Ecol. 30:5710–20
    [Google Scholar]
15. Bergamo PJ, Wolowski M, Maruyama PK, Vizentin-Bugoni J, Sazima M 2018. Trait patterns across space and time suggest an interplay of facilitation and competition acting on Neotropical hummingbird-pollinated plant communities. Oikos 127:111690–700
    [Google Scholar]
16. Betts MG, Hadley AS, Kress WJ 2015. Pollinator recognition by a keystone tropical plant. PNAS 112:113433–38
    [Google Scholar]
17. Biddick M, Burns KC. 2018. Phenotypic trait matching predicts the topology of an insular plant-bird pollination network. Integr. Zool. 13:3339–47
    [Google Scholar]
18. Blüthgen N, Menzel F, Blüthgen N 2006. Measuring specialization in species interaction networks. BMC Ecol 6:19
    [Google Scholar]
19. Bond WJ. 1994. Do mutualisms matter—assessing the impact of pollinator and disperser disruption on plant extinction. Philos. Trans. R. Soc. B 344:130783–90
    [Google Scholar]
20. Botes C, Johnson SD, Cowling RM 2008. Coexistence of succulent tree aloes: partitioning of bird pollinators by floral traits and flowering phenology. Oikos 117:875–82
    [Google Scholar]
21. Bowie RC, Fjeldsa J, Hackett SJ, Crowe TM 2004. Molecular evolution in space and through time: mtDNA phylogeography of the Olive Sunbird (Nectarinia olivacea/obscura) throughout continental Africa. Mol. Phylogenet. Evol. 33:156–74
    [Google Scholar]
22. Bradshaw HD, Schemske DW. 2003. Allele substitution at a flower colour locus produces a pollinator shift in monkeyflowers. Nature 426:6963176–78
    [Google Scholar]
23. Brice AT, Grau CR. 1991. Protein requirements of Costa's hummingbirds Calypte costae. Physiol. Zool 64:2611–26
    [Google Scholar]
24. Brodie ED 3rd, Ridenhour BJ 2003. Reciprocal selection at the phenotypic interface of coevolution. Integr. Comp. Biol. 43:3408–18
    [Google Scholar]
25. Brown ED, Hopkins MJG. 1996. How New Guinea rainforest flower resources vary in time and space: implications for nectarivorous birds. Aust. J. Ecol. 21:4363–78
    [Google Scholar]
26. Brown M, Downs CT, Johnson SD 2010. Concentration-dependent sugar preferences of the malachite sunbird (Nectarinia famosa). Auk 127:1151–55
    [Google Scholar]
27. Bruna EM, Kress WJ. 2002. Habitat fragmentation and the demographic structure of an Amazonian understory herb (Heliconia acuminata). Conserv. Biol. 16:51256–66
    [Google Scholar]
28. Bruneau A. 1997. Evolution and homology of bird pollination syndromes in Erythrina (Leguminosae). Am. J. Bot. 84:154–71
    [Google Scholar]
29. Burd M. 1995. Pollinator behavioral-responses to reward size in Lobelia deckenii—no escape from pollen limitation of seed set. J. Ecol. 83:5865–72
    [Google Scholar]
30. Burns KJ, Hackett SJ, Klein NK 2003. Phylogenetic relationships of Neotropical honeycreepers and the evolution of feeding morphology. J. Avian Biol. 34:4360–70
    [Google Scholar]
31. Byrne M, Elliott CP, Yates C, Coates DJ 2007. Extensive pollen dispersal in a bird-pollinated shrub, Calothamnus quadrifidus, in a fragmented landscape. Mol. Ecol. 16:61303–14
    [Google Scholar]
32. Calf KM, Downs CT, Cherry MI 2001. Territoriality and breeding success in Gurney's sugarbird. Promerops gurneyi. Afr. Zool. 36:2189–95
    [Google Scholar]
33. Calf KM, Downs CT, Cherry MI 2003. Territoriality and breeding success in the Cape Sugarbird (Promerops cafer). Emu Austral Ornithol 103:129–35
    [Google Scholar]
34. Campbell DR. 1996. Evolution of floral traits in a hermaphroditic plant: field measurements of heritabilities and genetic correlations. Evolution 50:41442–53
    [Google Scholar]
35. Carlson JE, Holsinger KE. 2010. Natural selection on inflorescence color polymorphisms in wild Protea populations: the role of pollinators, seed predators, and intertrait correlations. Am. J. Bot. 97:6934–44
    [Google Scholar]
36. Carstensen DW, Olesen JM. 2009. Wallacea and its nectarivorous birds: nestedness and modules. J. Biogeogr. 36:81540–50
    [Google Scholar]
37. Castellanos MC, Wilson P, Thomson JD 2004. ‘Anti-bee’ and ‘pro-bird’ changes during the evolution of hummingbird pollination in Penstemon flowers. J. Evol. Biol. 17:4876–85
    [Google Scholar]
38. Castro I, Robertson AW. 1997. Honeyeaters and the New Zealand forest flora: the utilisation and profitability of small flowers. N. Z. J. Ecol. 21:2169–79
    [Google Scholar]
39. Chaves JA, Pollinger JP, Smith TB, LeBuhn G 2007. The role of geography and ecology in shaping the phylogeography of the speckled hummingbird (Adelomyia melanogenys) in Ecuador. Mol. Phylogenet. Evol. 43:3795–807
    [Google Scholar]
40. Chesson P. 2000. Mechanisms of maintenance of species diversity. Annu. Rev. Ecol. Syst. 31:1343–66
    [Google Scholar]
41. Churchill DM, Christensen P. 1970. Observations on pollen harvesting by brush-tongued lorikeets. Aust. J. Zool. 18:4427–37
    [Google Scholar]
42. Coetzee A, Barnard P, Pauw A 2018. Urban nectarivorous bird communities in Cape Town, South Africa, are structured by ecological generalisation and resource distribution. J. Avian Biol. 49:6 jav-01526
    [Google Scholar]
43. Colwell RK. 1973. Competition and coexistence in a simple tropical community. Am. Nat. 107:958737–60
    [Google Scholar]
44. Colwell RK, Betts BJ, Bunnell P, Carpenter FL, Feinsinger P 1974. Competition for the nectar of Centropogon valerii by the hummingbird Colibri thalassinus and the flower-piercer Diglossa plumbea, and its evolutionary implications. Condor 76:4447–52
    [Google Scholar]
45. Cortés-Rodríguez N, Hernández-Baños BE, Navarro-Sigüenza AG, Townsend Peterson A, García-Moreno J 2008. Phylogeography and population genetics of the Amethyst-throated Hummingbird (Lampornis amethystinus). Mol. Phylogenet. Evol. 48:11–11
    [Google Scholar]
46. Cox PA. 1983. Extinction of the Hawaiian avifauna resulted in a change of pollinators for the Ieie, Freycinetia arborea. Oikos 41:195–99
    [Google Scholar]
47. Cresswell JE. 1998. Stabilizing selection and the structural variability of flowers within species. Ann. Bot. 81:4463–73
    [Google Scholar]
48. Cronk Q, Ojeda I. 2008. Bird-pollinated flowers in an evolutionary and molecular context. J. Exp. Bot. 59:4715–27
    [Google Scholar]
49. Cunningham SA. 2000. Depressed pollination in habitat fragments causes low fruit set. Proc. R. Soc. B 267:14481149–52
    [Google Scholar]
50. da Silva LP, Ramos JA, Olesen JM, Traveset A, Heleno RH 2014. Flower visitation by birds in Europe. Oikos 123:111377–83
    [Google Scholar]
51. Dalsgaard B, Magård E, Fjeldså J, Martin González AM, Rahbek C et al. 2011. Specialization in plant-hummingbird networks is associated with species richness, contemporary precipitation and Quaternary climate-change velocity. PLOS ONE 6:10e25891
    [Google Scholar]
52. del Hoyo J, Elliott A, Christie DA 2008. Handbook of the Birds of the World, Vol. 13: Penduline-Tits to Shrikes Barcelona, Spain: Lynx Ed.
53. Diamond J, Pimm SL, Gilpin ME, LeCroy M 1989. Rapid evolution of character displacement in myzomelid honeyeaters. Am. Nat. 134:5675–708
    [Google Scholar]
54. Diamond JM. 1972. Biogeographic kinetics: Estimation of relaxation times for avifaunas of Southwest Pacific Islands. PNAS 69:113199–203
    [Google Scholar]
55. Diamond JM. 1975. Assembly of species communities. Ecology and Evolution of Communities ML Cody, JM Diamond 342–444 Cambridge, MA: Harvard Univ. Press
    [Google Scholar]
56. Ducroquet JPHJ, Hickel ER. 1997. Birds as pollinators of Feijoa (Acca sellowiana Bera). Acta Hortic 452:37–40
    [Google Scholar]
57. Dudash MR, Hassler C, Stevens PM, Fenster CB 2011. Experimental floral and inflorescence trait manipulations affect pollinator preference and function in a hummingbird-pollinated plant. Am. J. Bot. 98:2275–82
    [Google Scholar]
58. Faegri K, van der Pijl L 1979. The Principles of Pollination Ecology Oxford, UK: Pergamon. , 2nd ed..
59. Feinsinger P, Swarm LA, Wolfe JA 1985. Nectar-feeding birds on Trinidad-and-Tobago—comparison of diverse and depauperate guilds. Ecol. Monogr. 55:11–28
    [Google Scholar]
60. Feinsinger P, Tiebout HM. 1991. Competition among plants sharing hummingbird pollinators—laboratory experiments on a mechanism. Ecology 72:61946–52
    [Google Scholar]
61. Feldman RE, McGill BJ. 2014. How important is nectar in shaping spatial variation in the abundance of temperate breeding hummingbirds?. J. Biogeogr. 41:3489–500
    [Google Scholar]
62. Felsenstein J. 1985. Phylogenies and the comparative method. Am. Nat. 125:11–15
    [Google Scholar]
63. Fenster CB. 1991. Selection on floral morphology by hummingbirds. Biotropica 23:198–101
    [Google Scholar]
64. Fleischer RC, James HF, Olson SL 2008. Convergent evolution of Hawaiian and Australo-Pacific honeyeaters from distant songbird ancestors. Curr. Biol. 18:241927–31
    [Google Scholar]
65. Fleming TH, Muchhala N. 2008. Nectar-feeding bird and bat niches in two worlds: pantropical comparisons of vertebrate pollination systems. J. Biogeogr. 35:5764–80
    [Google Scholar]
66. Fleming TH, Sahley CT, Holland JN, Nason JD, Hamrick JL 2001. Sonoran Desert columnar cacti and the evolution of generalized pollination systems. Ecol. Monogr. 71:4511–30
    [Google Scholar]
67. Ford HA, Paton DC. 1982. Partitioning of nectar sources in an Australian honeyeater community. Austral. J. Ecol. 7:2149–59
    [Google Scholar]
68. Forrest NC, Ottewell KM, Whelan RJ, Ayre DJ 2011. Tests for inbreeding and outbreeding depression and estimation of population differentiation in the bird-pollinated shrub Grevillea mucronulata. Ann. Bot 108:1185–95
    [Google Scholar]
69. Fraser MW. 1989. Short-term responses of birds to fire in old mountain fynbos. Ostrich 60:172–82
    [Google Scholar]
70. Gardner LL. 1925. The adaptive modifications and the taxonomic value of the tongue in birds. Proc. U. S. Natl. Mus. 67:1–49
    [Google Scholar]
71. Gause GF, Witt AA. 1935. Behavior of mixed populations and the problem of natural selection. Am. Nat. 69:725596–609
    [Google Scholar]
72. Geerts S. 2016. Can short-billed nectar thieving sunbirds replace long-billed sunbird pollinators in transformed landscapes?. Plant Biol 18:61048–52
    [Google Scholar]
73. Geerts S, Malherbe S, Pauw A 2012. Reduced flower visitation by nectar-feeding birds in response to fire in Cape fynbos vegetation, South Africa. J. Ornithol. 153:2297–301
    [Google Scholar]
74. Geerts S, Pauw A. 2009. African sunbirds hover to pollinate an invasive hummingbird-pollinated plant. Oikos 118:4573–79
    [Google Scholar]
75. Geerts S, Pauw A. 2011. Easy technique for assessing pollination rates in the genus Erica reveals road impact on bird pollination in the Cape fynbos, South Africa. Austral Ecol 36:6656–62
    [Google Scholar]
76. Geerts S, Pauw A. 2012. The cost of being specialized: Pollinator limitation in the endangered geophyte Brunsvigia litoralis (Amaryllidaceae) in the Cape Floristic Region of South Africa. South Afr. J. Bot. 78:159–64
    [Google Scholar]
77. Gill FB, Wolf LL. 1975. Economics of feeding territoriality in the Golden-Winged Sunbird. Ecology 56:2333–45
    [Google Scholar]
78. González C, Ornelas JF, Gutiérrez-Rodríguez C 2011. Selection and geographic isolation influence hummingbird speciation: genetic, acoustic and morphological divergence in the wedge-tailed sabrewing (Campylopterus curvipennis). BMC Evol. Biol. 11:138
    [Google Scholar]
79. Gould SJ, Vrba ES. 1982. Exaptation—a missing term in the science of form. Paleobiology 8:14–15
    [Google Scholar]
80. Grant V, Grant KA. 1965. Flower Pollination in the Phlox Family New York: Columbia Univ. Press
81. Greig EI, Wood EM, Bonter DN 2017. Winter range expansion of a hummingbird is associated with urbanization and supplementary feeding. Proc. R. Soc. B 284:185220170256
    [Google Scholar]
82. Hadley AS, Betts MG. 2009. Tropical deforestation alters hummingbird movement patterns. Biol. Lett. 5:2207–10
    [Google Scholar]
83. Hadley AS, Frey SJK, Robinson WD, Betts MG 2018. Forest fragmentation and loss reduce richness, availability, and specialization in tropical hummingbird communities. Biotropica 50:174–83
    [Google Scholar]
84. Hartl DL, Clark AG. 2007. Principles of Population Genetics Sunderland, MA: Sinauer
85. Heystek A, Geerts S, Barnard P, Pauw A 2014. Pink flower preference in sunbirds does not translate into plant fitness differences in a polymorphic Erica species. Evol. Ecol. 28:3457–70
    [Google Scholar]
86. Heystek A, Pauw A. 2014. Does competition for pollinators contribute to structuring Erica communities?. J. Veg. Sci. 25:3648–56
    [Google Scholar]
87. Hingston AB, Gartrell BD, Pinchbeck G 2004. How specialized is the plant-pollinator association between Eucalyptus globulus ssp. globulus and the swift parrot Lathamus discolor?. Austral Ecol 29:6624–30
    [Google Scholar]
88. Hubbell SP. 2001. The Unified Neutral Theory of Biodiversity and Biogeography Princeton, NJ: Princeton Univ. Press
89. Hughes M, Möller M, Edwards TJ, Bellstedt DU, de Villiers M 2007. The impact of pollination syndrome and habitat on gene flow: a comparative study of two Streptocarpus (Gesneriaceae) species. Am. J. Bot. 94:101688–95
    [Google Scholar]
90. Jackson S, Nicolson SW, Lotz CN 1998. Sugar preferences and “side bias” in Cape Sugarbirds and Lesser Double-collared Sunbirds. Auk 115:1156–65
    [Google Scholar]
91. Johnson SD, Hargreaves AL, Brown M 2006. Dark, bitter-tasting nectar functions as a filter of flower visitors in a bird-pollinated plant. Ecology 87:112709–16
    [Google Scholar]
92. Johnson SD, Nicolson SW. 2008. Evolutionary associations between nectar properties and specificity in bird pollination systems. Biol. Lett. 4:149–52
    [Google Scholar]
93. Kay KM. 2006. Reproductive isolation between two closely related hummingbird-pollinated neotropical gingers. Evolution 60:3538–52
    [Google Scholar]
94. Kay KM, Reeves PA, Olmstead RG, Schemske DW 2005. Rapid speciation and the evolution of hummingbird pollination in neotropical Costus subgenus Costus (Costaceae): evidence from nrDNA ITS and ETS sequences. Am. J. Bot. 92:111899–910
    [Google Scholar]
95. Keast A. 1968. Seasonal movements in the Australian honeyeaters (Meliphagidae) and their ecological significance. Emu Austral Ornithol 67:3159–209
    [Google Scholar]
96. Kelly D, Ladley JJ, Robertson AW 2007. Is the pollen-limited mistletoe Peraxilla tetrapetala (Loranthaceae) also seed limited?. Austral Ecol 32:8850–57
    [Google Scholar]
97. Kelly D, Ladley JJ, Robertson AW, Norton DA 2000. Limited forest fragmentation improves reproduction in the declining New Zealand mistletoe Peraxilla tetrapetala (Loranthaceae). Genetics, Demography and Viability of Fragmented Populations AG Young, GM Clarke 241–51 Cambridge, UK: Cambridge Univ. Press
    [Google Scholar]
98. Kimura M. 1983. The Neutral Theory of Molecular Evolution Cambridge, UK: Cambridge Univ. Press
99. Kramer AT, Fant JB, Ashley MV 2011. Influences of landscape and pollinators on population genetic structure: Examples from three Penstemon (Plantaginaceae) species in the Great Basin. Am. J. Bot. 98:1109–21
    [Google Scholar]
100. Krauss SL, He T, Barrett LG, Lamont BB, Enright NJ et al. 2009. Contrasting impacts of pollen and seed dispersal on spatial genetic structure in the bird-pollinated Banksia hookeriana. Heredity 102:3274–85
     [Google Scholar]
101. Krauss SL, Phillips RD, Karron JD, Johnson SD, Roberts DG, Hopper SD 2017. Novel consequences of bird pollination for plant mating. Trends Plant Sci 22:5395–410
     [Google Scholar]
102. Lagomarsino LP, Condamine FL, Antonelli A, Mulch A, Davis CC 2016. The abiotic and biotic drivers of rapid diversification in Andean bellflowers (Campanulaceae). New Phytol 210:41430–42
     [Google Scholar]
103. Lagomarsino LP, Forrestel EJ, Muchhala N, Davis CC 2017. Repeated evolution of vertebrate pollination syndromes in a recently diverged Andean plant clade. Evolution 71:81970–85
     [Google Scholar]
104. Lande R, Arnold SJ. 1983. The measurement of selection on correlated characters. Evolution 37:61210–26
     [Google Scholar]
105. Lara C, Ornelas JF. 2001. Preferential nectar robbing of flowers with long corollas: experimental studies of two hummingbird species visiting three plant species. Oecologia 128:2263–73
     [Google Scholar]
106. Latimer AM, Silander JA, Rebelo AG, Midgley GF 2009. Experimental biogeography: the role of environmental gradients in high geographic diversity in Cape Proteaceae. Oecologia 160:1151–62
     [Google Scholar]
107. Lindberg AB, Olesen JM. 2001. The fragility of extreme specialization: Passiflora mixta and its pollinating hummingbird Ensifera ensifera. J. Trop. Ecol 17:323–29
     [Google Scholar]
108. Lucas FA. 1895. The tongues of birds. Rep. U. S. Natl. Mus. 1895:1003–20
     [Google Scholar]
109. MacArthur RH, Wilson EO. 1967. The Theory of Island Biogeography Princeton, NJ: Princeton Univ. Press
110. Mac Nally R, McGoldrick JM 1997. Landscape dynamics of bird communities in relation to mass flowering in some eucalypt forests of central Victoria, Australia. J. Avian Biol. 28:2171–83
     [Google Scholar]
111. Mac Nally R, Timewell CAR 2005. Resource availability controls bird-assemblage composition through interspecific aggression. Auk 122:41097–111
     [Google Scholar]
112. Maglianesi MA, Blüthgen N, Böhning-Gaese K, Schleuning M 2014. Morphological traits determine specialization and resource use in plant-hummingbird networks in the neotropics. Ecology 95:123325–34
     [Google Scholar]
113. Marki PZ, Kennedy JD, Cooney CR, Rahbek C, Fjeldså J 2019. Adaptive radiation and the evolution of nectarivory in a large songbird clade. Evolution 73:61226–40
     [Google Scholar]
114. Martén-Rodríguez S, Fenster CB, Agnarsson I, Skog LE, Zimmer EA 2010. Evolutionary breakdown of pollination specialization in a Caribbean plant radiation. New Phytol 188:2403–17
     [Google Scholar]
115. Maruyama PK, Sonne J, Vizentin-Bugoni J, Martín González AM, Zanata TB et al. 2018. Functional diversity mediates macroecological variation in plant-hummingbird interaction networks. Glob. Ecol. Biogeogr. 27:101186–99
     [Google Scholar]
116. Mauck WM, Burns KJ. 2009. Phylogeny, biogeography, and recurrent evolution of divergent bill types in the nectar-stealing flowerpiercers (Thraupini: Diglossa and Diglossopis). Biol. J. Linn. Soc. 98:114–28
     [Google Scholar]
117. Mayr E, Diamond JM. 2001. The Birds of Northern Melanesia: Speciation, Ecology and Biogeography Oxford, UK: Oxford Univ. Press
118. Mayr G. 2004. Old World fossil record of modern-type hummingbirds. Science 304:5672861–64
     [Google Scholar]
119. McGuire JA, Witt CC, Remsen JV, Corl A, Rabosky DL et al. 2014. Molecular phylogenetics and the diversification of hummingbirds. Curr. Biol. 24:8910–16
     [Google Scholar]
120. Meléndez-Ackerman E, Campbell DR, Waser NM 1997. Hummingbird behavior and mechanisms of selection on flower color in Ipomopsis. Ecology 78:82532–41
     [Google Scholar]
121. Mnisi EB. 2017. The Iingcungcu Project: Restoring nectar feeding birds, building biodiversity leadership Masters Thesis, Stellenbosch University, Stellenbosch S. Africa:
122. Montgomerie RD, Gass CL. 1981. Energy limitation of hummingbird populations in tropical and temperate communities. Oecologia 50:2162–65
     [Google Scholar]
123. Mortensen HS, Dupont YL, Olesen JM 2008. A snake in paradise: disturbance of plant reproduction following extirpation of bird flower-visitors on Guam. Biol. Conserv. 141:82146–54
     [Google Scholar]
124. Muchhala N, Johnsen S, Smith SD 2014. Competition for hummingbird pollination shapes flower color variation in Andean Solanaceae. Evolution 68:82275–86
     [Google Scholar]
125. Murcia C, Feinsinger P. 1996. Interspecific pollen loss by hummingbirds visiting flower mixtures: effects of floral architecture. Ecology 77:2550–60
     [Google Scholar]
126. Nattero J, Cocucci AA. 2007. Geographical variation in floral traits of the tree tobacco in relation to its hummingbird pollinator fauna. Biol. J. Linn. Soc. 90:4657–67
     [Google Scholar]
127. Nicolson SW, Fleming PA. 2003. Nectar as food for birds: the physiological consequences of drinking dilute sugar solutions. Plant Syst. Evol. 238:1–4139–53
     [Google Scholar]
128. Nistelberger HM, Byrne M, Coates D, Roberts JD 2015. Genetic drift drives evolution in the bird-pollinated, terrestrial island endemic Grevillea georgeana (Proteaceae). Bot. J. Linn. Soc. 178:1155–68
     [Google Scholar]
129. Paton DC. 1982. The diet of the New Holland honeyeater, Phylidonyris novaehollandiae. Aust. J. Ecol. 7:3279–98
     [Google Scholar]
130. Paton DC. 2000. Disruption of bird-plant pollination systems in southern Australia. Conserv. Biol. 14:51232–34
     [Google Scholar]
131. Paton DC, Collins BG. 1989. Bills and tongues of nectar-feeding birds: a review of morphology, function and performance, with intercontinental comparisons. Aust. J. Ecol. 14:473–506
     [Google Scholar]
132. Pauw A. 1998. Pollen transfer on birds’ tongues. Nature 394:6695731–32
     [Google Scholar]
133. Pauw A, Johnson CM. 2018. Mutualism between co-occurring plant species in South Africa's Mediterranean climate heathland is mediated by birds. Plant Biol 20:224–30
     [Google Scholar]
134. Pauw A, Louw K. 2012. Urbanization drives a reduction in functional diversity in a guild of nectar-feeding birds. Ecol. Soc. 17:227
     [Google Scholar]
135. Pauw A, Stanway R. 2015. Unrivalled specialization in a pollination network from South Africa reveals that specialization increases with latitude only in the Southern Hemisphere. J. Biogeogr. 42:4652–61
     [Google Scholar]
136. Pellissier L, Albouy C, Bascompte J, Farwig N, Graham C et al. 2018. Comparing species interaction networks along environmental gradients. Biol. Rev. 93:2785–800
     [Google Scholar]
137. Price MV, Campbell DR, Waser NM, Brody AK 2008. Bridging the generation gap in plants: pollination, parental fecundity, and offspring demography. Ecology 89:61596–604
     [Google Scholar]
138. Ramsey J, Bradshaw HD, Schemske DW 2003. Components of reproductive isolation between the monkeyflowers Mimulus lewisii and M. cardinalis (Phrymaceae). Evolution 57:71520–34
     [Google Scholar]
139. Rand AL. 1961. The tongue and nest of certain flowerpeckers, Aves: Dicaeidae. Fieldiana Zool 39:53581–87
     [Google Scholar]
140. Ricklefs RE, Lovette IJ. 1999. The roles of island area per se and habitat diversity in the species-area relationships of four Lesser Antillean faunal groups. J. Anim. Ecol. 68:61142–60
     [Google Scholar]
141. Robertson AW, Ladley JJ, Kelly D 2005. Effectiveness of short-tongued bees as pollinators of apparently ornithophilous New Zealand mistletoes. Austral Ecol 30:3298–309
     [Google Scholar]
142. Sanderson JG, Diamond JM, Pimm SL 2009. Pairwise co-existence of Bismarck and Solomon landbird species. Evol. Ecol. Res. 11:5771–86
     [Google Scholar]
143. Sazima M, Vogel S, do Prado AL, de Oliveira DM, Franz G, Sazima I 2001. The sweet jelly of Combretum lanceolatum flowers (Combretaceae): a cornucopia resource for bird pollinators in the Pantanal, western Brazil. Plant Syst. Evol. 227:3–4195–208
     [Google Scholar]
144. Schemske DW, Bradshaw HD. 1999. Pollinator preference and the evolution of floral traits in monkeyflowers (Mimulus). PNAS 96:2111910–15
     [Google Scholar]
145. Schmid B, Nottebrock H, Esler KJ, Pagel J, Böhning-Gaese K et al. 2016a. A bird pollinator shows positive frequency dependence and constancy of species choice in natural plant communities. Ecology 97:113110–18
     [Google Scholar]
146. Schmid B, Nottebrock H, Esler KJ, Pagel J, Pauw A et al. 2015. Reward quality predicts effects of bird-pollinators on the reproduction of African Protea shrubs. Perspect. Plant Ecol. Evol. Syst. 17:3209–17
     [Google Scholar]
147. Schmid B, Nottebrock H, Esler KJ, Pagel J, Pauw A et al. 2016b. Responses of nectar-feeding birds to floral resources at multiple spatial scales. Ecography 39:619–29
     [Google Scholar]
148. Schmidt-Lebuhn AN, Kessler M, Hensen I 2007. Hummingbirds as drivers of plant speciation?. Trends Plant Sci 12:8329–31
     [Google Scholar]
149. Schulke B, Waser NM. 2001. Long-distance pollinator flights and pollen dispersal between populations of Delphinium nuttallianum. Oecologia 127:2239–45
     [Google Scholar]
150. Schweizer M, Güntert M, Seehausen O, Leuenberger C, Hertwig ST 2014. Parallel adaptations to nectarivory in parrots, key innovations and the diversification of the Loriinae. Ecol. Evol. 4:142867–83
     [Google Scholar]
151. Serrano-Serrano ML, Rolland J, Clark JL, Salamin N, Perret M 2017. Hummingbird pollination and the diversification of angiosperms: an old and successful association in Gesneriaceae. Proc. R. Soc. B 284:185220162816
     [Google Scholar]
152. Sersic AN, Cocucci AA. 1996. A remarkable case of ornithophily in Calceolaria: food bodies as rewards for a non-nectarivorous bird. Bot. Acta 109:2172–76
     [Google Scholar]
153. Sibley CG, Ahlquist JE. 1974. The relationships of the African sugarbirds (Promerops). Ostrich 45:122–30
     [Google Scholar]
154. Siegfried WR, Rebelo AG, Prys-Jones RP 1985. Stem thickness of Erica plants in relation to avian pollination. Oikos 45:1153–55
     [Google Scholar]
155. Smith J, Lill A. 2008. Importance of eucalypts in exploitation of urban parks by Rainbow and Musk Lorikeets. Emu Austral Ornithol 108:2187–95
     [Google Scholar]
156. Smith SD, Ané C, Baum DA 2008. The role of pollinator shifts in the floral diversification of Iochroma (Solanaceae). Evolution 62:4793–806
     [Google Scholar]
157. Smith TB, Freed LA, Lepson JK, Carothers JH 1995. Evolutionary consequences of extinctions in populations of a Hawaiian honeycreeper. Conserv. Biol. 9:1107–13
     [Google Scholar]
158. Smith TB, Thomassen HA, Freedman AH, Sehgal RNM, Buermann W et al. 2011. Patterns of divergence in the olive sunbird Cyanomitra olivacea (Aves: Nectariniidae) across the African rainforest-savanna ecotone. Biol. J. Linn. Soc. 103:4821–35
     [Google Scholar]
159. Stebbins GL. 1970. Adaptive radiation of reproductive characteristics in angiosperms, 1: pollination mechanisms. Annu. Rev. Ecol. Syst. 1:307–26
     [Google Scholar]
160. Stiles FG. 1978. Ecological and evolutionary implications of bird pollination. Am. Zool. 18:715–27
     [Google Scholar]
161. Stouffer PC, Bierregaard RO. 1995. Effects of forest fragmentation on understory hummingbirds in Amazonian Brazil. Conserv. Biol. 9:51085–94
     [Google Scholar]
162. Streisfeld MA, Kohn JR. 2006. Environment and pollinator-mediated selection on parapatric floral races of Mimulus aurantiacus. J. Evol. Biol 20:122–32
     [Google Scholar]
163. Taylor J, White SA. 2007. Observations of hummingbird feeding behavior at flowers of Heliconia beckneri and H. tortuosa in southern Costa Rica. Ornitol. Neotropical 18:133–38
     [Google Scholar]
164. Temeles EJ. 1996. A new dimension to hummingbird-flower relationships. Oecologia 105:4517–23
     [Google Scholar]
165. Temeles EJ, Pan IL, Brennan JL, Horwitt JN 2000. Evidence for ecological causation of sexual dimorphism in a hummingbird. Science 289:5478441–43
     [Google Scholar]
166. Thomson JD, Wilson P. 2008. Explaining evolutionary shifts between bee and hummingbird pollination: convergence, divergence, and directionality. Int. J. Plant Sci. 169:123–38
     [Google Scholar]
167. Tokita M, Yano W, James HF, Abzhanov A 2017. Cranial shape evolution in adaptive radiations of birds: comparative morphometrics of Darwin's finches and Hawaiian honeycreepers. Philos. Trans. R. Soc. B 372:171320150481
     [Google Scholar]
168. Toon A, Cook LG, Crisp MD 2014. Evolutionary consequences of shifts to bird-pollination in the Australian pea-flowered legumes (Mirbelieae and Bossiaeeae). BMC Evol. Biol. 14:143
     [Google Scholar]
169. Traveset A, Olesen JM, Nogales M, Vargas P, Jaramillo P et al. 2015. Bird-flower visitation networks in the Galápagos unveil a widespread interaction release. Nat. Commun. 6:6376
     [Google Scholar]
170. Van der Niet T, Pirie MD, Shuttleworth A, Johnson SD, Midgley JJ 2014. Do pollinator distributions underlie the evolution of pollination ecotypes in the Cape shrub Erica plukenetii?. Ann. Bot. 113:2301–16
     [Google Scholar]
171. Van Tets IG, Nicolson SW 2000. Pollen and the nitrogen requirements of the Lesser Double-collared Sunbird. Auk 117:3826–31
     [Google Scholar]
172. Vellend M. 2016. The Theory of Ecological Communities Princeton, NJ: Princeton Univ. Press
173. Volpe NL, Robinson WD, Frey SJK, Hadley AS, Betts MG 2016. Tropical forest fragmentation limits movements, but not occurrence of a generalist pollinator species. PLOS ONE 11:12e0167513
     [Google Scholar]
174. Waser NM, Real LA. 1979. Effective mutualism between sequentially flowering plant species. Nature 281:670–72
     [Google Scholar]
175. Whittall JB, Hodges SA. 2007. Pollinator shifts drive increasingly long nectar spurs in columbine flowers. Nature 447:706–10
     [Google Scholar]
176. Wilson P, Wolfe AD, Armbruster WS, Thomson JD 2007. Constrained lability in floral evolution: counting convergent origins of hummingbird pollination in Penstemon and Keckiella. New Phytol 176:4883–90
     [Google Scholar]
177. Wolf LL, Stiles FG, Hainsworth FR 1976. Ecological organization of a tropical, highland hummingbird community. J. Anim. Ecol. 45:2349–79
     [Google Scholar]
178. Zanata TB, Dalsgaard B, Passos FC, Cotton PA, Roper JJ et al. 2017. Global patterns of interaction specialization in bird-flower networks. J. Biogeogr. 44:81891–910
     [Google Scholar]