Cactus height increases the modularity of a plant-frugivore network in the Caatinga dry forest

Cacti fruits are key resources to many frugivorous animals in Neotropical arid and semiarid regions. However, most studies have focused on a particular animal group or cacti species, but few have explored the overall interactions of such species at the community level. Here we monitored frugivory on five cacti species using camera traps that sampled diurnal and nocturnal interactions. We investigated the structure of interactions with bird, mammal, and reptile frugivores in the Brazilian Caatinga dry forest. We hypothesized that the height of cacti limit interactions with different types of frugivores, which would result in highly structured and modular interaction networks. In 2,929 camera-days, we recorded 23 vertebrate species feeding on cacti fruits, including seven new records, all determined to be primary seed dispersers. As predicted, the cacti-frugivore network was modular and non-nested, with the two shortest cacti species grouped in a module dominated by interactions with rept..., Fruiting phenology
We collected monthly data on fruit availability on the cacti from September 2018 to July 2019 (except in June). To collect phenological data, we established five transects in the study area based on pre-existing trails, covering a total area of 5,250 m². All transects had 5 m width but different extensions (130 m, 120 m, 100 m, 300 m, and 400 m) because the trails’ lengths were different. We then quantified and summarized the number of reproductive individuals (or agglomerations in the case of T. inamoena) per cacti species along transects (Table S2). Every month, we recorded the presence/absence of the fruiting phenophase and quantified the number of individuals with ripe or unripe fruits (d’Eça-Neves and Morellato 2004). We then calculated the monthly percentage of fruiting individuals for every species by dividing the number of fruiting plants (sum of all plots) by the total number of adult plants (sum of the individuals’ number at all plots).
Frugivory records
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