Despite a growing number of studies, the role of pollinators as a selection agent for nectar traits remains unclear. Moreover, the lack of data from some biogeographic regions prohibits us from determining their general importance and global patterns. We analyzed nectar carbohydrate traits and determined the main pollinators of 66 plant species in the tropical forests of Mount Cameroon (tropical West Africa). The measured nectar traits included total sugar amounts and proportions of sucrose and hexoses (i.e., glucose and fructose). We report the nectar properties for plants visited by five pollinator groups (bees, butterflies, moths, hoverflies, and specialized birds). Our results indicate that, rather than specific evolution in each of the five plant groups, there was a unique nectar-trait evolution in plants pollinated by specialized birds. The ornithophilous plants had a higher proportion of sucrose and produced larger sugar amounts than the plants pollinated by insects. We also demonstrated a significant phylogenetic signal in the nectar properties in some lineages of the studied plants.

Biology Centre Czech Academy of Sciences Branišovská 31 CZ 370 05 České Budějovice Czech Republic

Bokwango Buea Southwest Region Cameroon

Department of Ecology Faculty of Science Charles University Viničná 7 CZ 128 44 Prague 2 Czech Republic

Department of Nursing Faculty of Health Science Herzing University 1865 SR 436 Winter Park Orlando FL 32792 USA

Department of Zoology and Animal Physiology Faculty of Science University of Buea Buea 63 Cameroon

Department of Zoology Faculty of Sciences University of South Bohemia Branišovská 1760 CZ 370 05 České Budějovice Czech Republic

Naturalis Biodiversity Center Darwinweg 2 2233 CR Leiden The Netherlands

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