Divergence in floral trait preferences between nonflower-specialized birds and insects on the Galápagos

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisTidsskriftartikelForskningpeer review

DOI

  • Sandra Hervías-Parejo, Institut Mediterrani d'Estudis Avançats (CSIC-UIB)
  • ,
  • Ruben Heleno, Universidade de Coimbra
  • ,
  • Manuel Nogales, Instituto de Productos Naturales y Agrobiología (CSIC-IPNA)
  • ,
  • Jens M. Olesen
  • Anna Traveset, Institut Mediterrani d'Estudis Avançats (CSIC-UIB)

Premise of the Study: The characteristic scarcity of insects on remote oceanic islands has driven nonflower-specialized vertebrates to broaden their trophic niches and explore floral resources. From our previous studies in the Galápagos, we know that native insectivorous and frugivorous birds visit a wide range of entomophilous flowers and can also act as effective pollinators. Here, we tested whether opportunistic Galápagos birds show any preference for specific floral traits, and if so, this preference differs from that of insects. Methods: Sixteen floral morphology and nectar traits of 26 native species were studied, as well as the frequency with which they are visited by birds and insects. Nonmetric multidimensional scaling (NMDS) was used to evaluate the distribution of flower traits values along two main dimensions and measure the similarity between the plants visited mostly by birds versus those by insects. Key Results: NMDS of floral traits resulted in two species groups: (1) bell-shaped, white flowers with wider corollas at nectary level and higher nectar volume, associated with high bird visitation rates; and (2) bowl and tubular-shaped flowers with narrower corollas at nectary level and lower nectar volume, associated with high insect visitation rates. Conclusions: Despite the divergence in floral trait preferences between opportunistic Galápagos birds and insects, bird-visited flowers display mixed traits not fitting the classical ornithophilous syndrome. This finding is compatible with the existence of a transitional or bet-hedging phenotype between insect and bird visitors and underscores the importance of coevolution and floral diversification in nonspecialized plant–visitor interactions.

OriginalsprogEngelsk
TidsskriftAmerican Journal of Botany
Vol/bind106
Nummer4
Sider (fra-til)540-546
Antal sider7
ISSN0002-9122
DOI
StatusUdgivet - apr. 2019

Se relationer på Aarhus Universitet Citationsformater

ID: 152368144