Improved estimation of gut passage time considerably affects trait‐based dispersal models

作者：Andrew J. Abraham, Tomos O. Prŷs‐Jones, Annelies De Cuyper, Chase Ridenour, Gareth P. Hempson, Toby Dylan Hocking, Marcus Clauß, Christopher E. Doughty · 发表于：Functional Ecology · 年份：2020 · DOI：10.1111/1365-2435.13726 · 被引用次数：23 · 研究领域：Wildlife Ecology and Conservation、Ecology and Vegetation Dynamics Studies、Species Distribution and Climate Change

Abstract Animals are important vectors for transporting seeds, nutrients and microbes across landscapes. However, models that quantify the magnitude of these ecosystem services across a broad range of taxa often rely on generalised mass‐based scaling parameters for gut passage time. This relationship is weak and fundamentally breaks down when considering individual species, indicating that current models may incorrectly attribute or estimate the magnitude of dispersal. We collated a large dataset of gut passage time for endothermic animals measured using undigested markers ( n = 391 species). For each species, we compiled trait data, including body mass, morphology, gut physiology, diet and phylogeny. We then compared the ability of five statistical models (constant, generalised least squares, phylogenetic generalised least squares, general linear model and random forest) to estimate the time of first marker appearance (transit time; TT) and mean marker retention time (MRT) for particle and solute markers in mammals and birds separately. For mammals, we found that the inclusion of additional traits appreciably reduced the median root‐mean squared error across all markers in a leave‐one‐out cross validation. For birds, however, additional traits did not significantly improve our ability to predict gut passage time across markers. This may have occurred due to the smaller number of bird species included in our analysis or the absence of important explanatory factors such as dif...