Data from: Hovering behaviour of sunbird is determined by both forager and resource plant

The long-standing paradigm that pollination systems adapted to hovering birds evolved only in the New World was recently put into question when hovering pollination by Old World specialized passerine pollinators was proven. In consequence, questions arose whether this Cyanomitra oritis at flowers of the native Old World plant Impatiens sakeriana. We focussed on the length of pedicels and peduncles (PedPed length), which can put the flowers into a position within difficult reach while perching on the stem. Here we ask if PedPed length determines whether sunbirds hover or perch at a flower. Detailed analyses of video records of 334 visits to 57 I. sakeriana flowers (185 hovering/149 perching) have shown that the sunbird C. oritis is forced to hover at flowers growing with long PedPed, whereas it employs both foraging modes when an adequate perch is available. A hovering sunbird was able to deplete nectar in a shorter time than a perching one. The frequency of visits did not increase either at the flowers with longer PedPed or with more numbers of open I. sakeriana flowers in the vicinity. Our study provides evidence that sunbird behaviour does not follow simple energetic models, and that some Old World sunbird pollination systems resemble New World highly specialized hummingbird systems much more than was expected, for example in overall system adaptation to bird-hovering.