Plant-Pollinator interactions along an elevational gradient of the oceanic high-mountain volcano (El Teide, Canary Islands )

Flower-visiting animals
were observed on the plant species from 15th May to 15th August, for two
consecutive years (2014 and 2015), coinciding with the flowering of all plant
species in the different elevational communities. The censuses were carried out
between 9:00 and 19:00 h, avoiding
the beginning and the end of the day, with usually low temperatures and little
insect activity in this high mountain environment, and also avoiding windy days.
All plant species were censused 7-8 hours per locality and year,
throughout the flowering phenology of each plant species, to maximize the
possibility of detecting different floral visitors. Each census lasted 15
minutes, during which the observer remained facing the plant, registering all
insects contacting the flowers as well as, whenever possible, the number of
flowers contacted per individual. We recorded a plant-pollinator interaction when an
insect maintained contact with the reproductive organs of a flower for more
than 1 second. Thus, all flower-visiting insects that feed on flowers were
recorded, regardless of the efficacy of their visit. Insects were either
identified in the field or collected for later identification in the laboratory. During the entire study period, a total of 868 observation hours were
spent during 57 observation days.