Eating the fruit of passion: bird functional traits and geography explains fruit removal by frugivorous birds in Blue Passionflower (Passiflora caerulea)

FACUNDO XAVIER PALACIO; FRANCISCO CATAUDELA; DIEGO MONTALTI; MARIANO ORDANO

Cape May, New Jersey

Encuentro; 2019 Joint Meeting WOS - AFO; 2019

Wilson Ornithological Society; Association of Field Ornithologists

Geographicvariation in bird-fruit interactions represents a complex ecologicalscenario which determines a mosaic of selection pressures betweeninteractors. This mosaic may partly the result from geographicvariation in bird assemblages, in which birds are expected to fulfildifferent ecological functions with strong consequences for seeddispersal patterns. However, the drivers of fruit removal by birds ata geographical scale are not fully understood. We describedgeographic variation in fruit removal and functional diversity (FD)of frugivorous bird assemblages among Blue Passionflower (Passifloracaerulea)populations, a bird-dispersed vine. We observed bird fruitconsumption and frugivorous bird abundance in nine plant populationsfrom northern and central Argentina (spanning 10° of latitude,0-1250 masl, three biogeographical provinces). We quantified FD offrugivorous bird assemblages on the basis of body mass,fruit-handling behavior (gulper, pulp consumer or seed predator), anddegree of frugivory. We recorded 14 bird species consumingpassionflower fruits and detected a non-linear trend of higherfrugivorous bird FD towards lower latitudes. Also, the number ofbirds consuming fruits (visits) per plant was negatively related tolatitude, the proportion of gulper species, the degree of frugivory,and mean body mass. The Blue Passionflower shows functionally diversefrugivorous bird assemblages throughout its distribution range, whichseems mainly driven by biogeographical factors at the geographicalscale. At the population level, seed dispersal is presumably enhancedby small-sized generalist pulp consumers, whereas large birds maycompensate lower visitation rates by increased fruit consumption.p { margin-bottom: 0.25cm; direction: ltr; line-height: 115%; text-align: left; orphans: 2; widows: 2 }