This data correspond to Blendinguer et al 2022. "Nutrient balance and energy-acquisition effectiveness: do birds adjust their fruit diet to achieve intake targets?" Accepted for publication in Functional Ecology. Recommended citation for this dataset: Data from: Blendinguer et al 2022. "Nutrient balance and energy-acquisition effectiveness: do birds adjust their fruit diet to achieve intake targets?", Dryad, Dataset. Main location: Mountain cloud forest from North-western Argentina (Yungas forest). The data comprises information gathered from multiple sources. See main text and supplementary material for details on the sources and methodologies used to measure, sample and merging. Contains 7 files that will allow the user to run the R script contained in the Appendix S7 used to analyse the data and answer the question presented in the published main text. Parentheses indicate header and brackets indicate measure unit: 1- bird_sampling2020-08-08.csv : - Number of variables: 10 - Description: consumption rates (fruitstime) [g/min] of fruits (Plant.species) by birds (Bird.species), including fruit mass (fruitmass) [g] and bird mass (birdmass) [g] and source (Source). Data obtained from literature, see appendix 1 for details on search methodology. Bird species were assigned to two categories regarding their foraging behaviour (Foraging.behaviour). Continuos variables were log transformed to model the actual error distribution of the dependent variables (log10birdmass; log10fruitmass; log10fruitstime) 2- bird_mass2020-08-08.csv : - Number of variables: 2 - Description: Average bird mass (birdmass) [g] sampled by us from wild individuals from species (birdspecies) included in this study. Birds were weighted after capture using a pesola (0.1 g accuracy). 3- bird_visits2020-08-08.csv : - Number of variables: 4 - Description: Birds (Bird.species) visits (visits) [countss] to plants (Plant.species) in 7 study sites (Site). This data is dervided from Blendinger et al 2012 and Ruggera et al 2016 (see main text for details). 4- fruit_fraits2020-08-08.csv : - Number of variables: 6 - Description: Nutritional traits of the fruits (Plant.species) included in this study. The data contain fruit mass (fruitmass) [g] and energy contained in form of lipids (Lipids.kJ.fruit) [kJ/g dry pulp], non-structural carbohydrates (Carbohydrates.kJ.fruit) [kJ/g dry pulp], proteins (Proteins.kJ.fruit) [kJ/g dry pulp] and total energy concentration in fruits (Total.energy.kJ.fruit) [kJ/g dry pulp]. See main text and supplementary material for further details. This is a subset of the data used in Rojas et al 2021 and Rojas et al 2022. 5- treebird : - description: phylogenetic tree of the birds included in this study. Is a pruned tree from birdtree.org 6- disp_promedio.txt : - Description: Abundance matrix of fruits (rows) in each site (columns) measured as grams per hectare. 7- known_interactions.xlsx : - Description: Qualitative matrix (binary) informing recorded interactions of birds with fruits included in the study. The data was recorded along more than 15 years of research and observations.