Maria AlejandraMaglianesiBiodiversity and Climate Research Centre (BiK-F) & Senckenberg Gesellschaft fuer Naturforschung

Senckenberganlage 25FrankfurtD-60325Germany

KatrinBoehning-GaeseBiodiversity and Climate Research Centre (BiK-F) & Senckenberg Gesellschaft fuer Naturforschung

Senckenberganlage 25FrankfurtD-60325Germany

MatthiasSchleuningBiodiversity and Climate Research Centre (BiK-F) & Senckenberg Gesellschaft fuer Naturforschung

Senckenberganlage 25FrankfurtD-60325Germany

2014-11-061. In plant-pollinator networks, the floral morphology of food plants is an important determinant of the interaction niche of pollinators. Studies on foraging preferences of pollinators combining experimental and observational approaches may help to understand the mechanisms behind patterns of interactions and niche partitioning within pollinator communities. 2. In this study, we tested whether morphological floral traits were associated with foraging preferences of hummingbirds for artificial and natural flower types in Costa Rica. We performed field experiments with artificial feeders, differing in length and curvature of flower types, to quantify the hummingbirds' interaction niche under unlimited nectar resources. To quantify the interaction niche under real-world conditions of limited nectar resources, we measured foraging preferences of hummingbirds for a total of 34 plant species. 3. Artificial feeders were visited by Eupherusa nigriventris and Phaethornis guy in the pre-montane forest, and Lampornis calolaemus in the lower montane forest. Under experimental conditions, all three hummingbird species overlapped their interaction niches and showed a preference for the short artificial flower type over the long-straight and the long-curved flower types. Under natural conditions, the two co-occurring hummingbird species preferred to feed on plant species with floral traits corresponding to their bill morphology. The short-billed hummingbird E. nigriventris preferred to feed on short and straight flowers, whereas the long- and curved-billed P. guy preferred long and curved natural flowers. The medium-size billed species L. calolaemus preferred to feed on flowers of medium length and did not show preferences for plant species with specific corolla curvature. 4. Our results show that floral morphological traits constrain access by short-billed hummingbird species to nectar resources. Morphological constraints, therefore, represent one important mechanism structuring trophic networks. In addition, other factors, such as competition and differences in resource quantity or quality, define the interaction niches of consumer species in real-world communities, enforcing patterns of niche segregation between co-occurring consumer species. This suggests that experimental studies are needed to disentangle effects of morphological constraints from those of competition for resources in plant-pollinator interactions and other types of trophic interactions.artificial feedersbiotic interactionscosta ricafield experimentsfloral morphologyfloral traitsforaging preferenceshummingbirdsinteraction nichemorphological constraintsresource partitioningtropical forestObtain permission from data set owner(s)Braulio Carrillo National Park-84.0833-84.116710.266710.18332011-05-012012-04-30We included three species of hummingbirds in total and the plant species they visitedTrochilidae (family)Lampornis calolaemusTrochilidae (family)Eupherusa nigriventrisTrochilidae (family)Phaethornis guyMatthiasSchleuningBiodiversity and Climate Research Centre (BiK-F) & Senckenberg Gesellschaft fuer Naturforschung

Senckenberganlage 25FrankfurtD-60325Germany

matthias.schleuning@senckenberg.deMaria AlejandraMaglianesiBiodiversity and Climate Research Centre (BiK-F) & Senckenberg Gesellschaft fuer Naturforschung

Senckenberganlage 25FrankfurtD-60325Germany

KatrinBoehning-GaeseBiodiversity and Climate Research Centre (BiK-F) & Senckenberg Gesellschaft fuer Naturforschung

Senckenberganlage 25FrankfurtD-60325Germany

The study was conducted in two sites in the Braulio Carrillo National Park, Costa Rica. During the year of sampling, we collected data on hummingbird abundances and bill traits, morphological floral traits and plant-hummingbird interactions across seven sampling periods per site, each lasting for about 10 days. We conducted field experiments with artificial feeders for a subset of two sampling periods per forest type, covering both seasons. Experiments were carried out during five days in August (wet season) and four days in February-March (dry season).

VariableDescription.csvVariableDescription.csv19061#x0Acolumn,ecogrid://knb/bikf.335.1uid=mmaglianesi,o=bikf,dc=ipg,dc=uni-frankfurt,dc=dealluid=mschleuning,o=bikf,dc=ipg,dc=uni-frankfurt,dc=dealluid=kboehninggaese,o=bikf,dc=ipg,dc=uni-frankfurt,dc=deallFile NameFile NameText valuesVariableVariableText valuesDescriptionDescriptionText values16Traits_Plant.csvTraits_Plant.csv190471#x0Acolumn,ecogrid://knb/bikf.336.1uid=mmaglianesi,o=bikf,dc=ipg,dc=uni-frankfurt,dc=dealluid=mschleuning,o=bikf,dc=ipg,dc=uni-frankfurt,dc=dealluid=kboehninggaese,o=bikf,dc=ipg,dc=uni-frankfurt,dc=deallElevationElevationText valuesSpeciesSpeciesText valuesGenusGenus of the plants visited by the hummingbirds.Text valuesFamilyFamily of the plants visited by the hummingbirds.Text valuesIndividualID for the plant individual of a particular species.numbernaturalLengthLength of the corolla in mm. Corolla length was measured from the base to the tip.millimeterrealDeflectDeflection of the tip of the corolla in mm. The deflection was measured from the tip through the base of the corolla to the nearest 0.10 mm.millimeterrealCurvatureTo determine the curvature (angle of deflection), we divided the deflection by the corolla length and calculated the angle of deflection by using the sine rule.gradreal326Preference_Index_Feeders.csvPreference_Index_Feeders.csv30501#x0Acolumn,ecogrid://knb/bikf.337.1uid=mmaglianesi,o=bikf,dc=ipg,dc=uni-frankfurt,dc=dealluid=mschleuning,o=bikf,dc=ipg,dc=uni-frankfurt,dc=dealluid=kboehninggaese,o=bikf,dc=ipg,dc=uni-frankfurt,dc=deallElevationStudy sites at low, mid and high elevation.Text valuesSeasonSeasons: dry and rainy.Text valuesHummingbSpeciesHummingbird species names: Eupherusa nigriventris; Phaethornis guy and Lampornis calolaemus.Text valuesLocationReplication of the experiments at each study site: location are A, B, C and D.Text valuesTubeTubes (artificial flowers) from the feeders: long_curved; long_straight and short.Text valuesTotalVisitTotal number of visits of hummingbirds to artificial feeders or natural flowers.numbernaturalPIPreference index of hummingbird species which ranges from 0 to 1.numberreal60Preference_Index_Plants.csvPreference_Index_Plants.csv71831#x0Acolumn,ecogrid://knb/bikf.338.1uid=mmaglianesi,o=bikf,dc=ipg,dc=uni-frankfurt,dc=dealluid=mschleuning,o=bikf,dc=ipg,dc=uni-frankfurt,dc=dealluid=kboehninggaese,o=bikf,dc=ipg,dc=uni-frankfurt,dc=deallElevationElevationText valuesSeasonSeasonText valuesHummingbSpeciesHummingbSpeciesText valuesPlantSpeciesPlant species namesText valuesTotalVisitTotal number of visits of hummingbirds to artificial feeders or natural flowers.dimensionlessnaturalProportionNumber of visits of each hummingbird species to a given plant species relative to the total number of visits of the hummingbird species to all plant species.dimensionlessrealPIPreference index of hummingbird species which ranges from 0 to 1.numberreal114attached_fileNot authorized to access resourceOtherattached_fileNot authorized to access resourceOtherattached_fileNot authorized to access resourceOtherattached_fileNot authorized to access resourceOtherattached_fileNot authorized to access resourceOtherattached_fileNot authorized to access resourceOtherattached_fileNot authorized to access resourceOther timeslices monthly