DOI: 10.5061/dryad.9cnp5hqz0
title: Disentangling the interrelations of body mass, egg deposition site, climate and microhabitat use in frogs and salamanders

description: Amphibians exhibit a large diversity in reproductive and developmental
 strategies, which in turn are linked to their body size, life history and
 habitat. Here, we explore why terrestrial egg-laying frogs are on average
 smaller than aquatic egg-laying ones and whether this pattern exists in
 salamanders, too. We hypothesized that egg deposition site and body mass
 are not linked directly across species, but that terrestrial egg layers
 occur in climates and use microhabitats that favor small masses. To test
 this, we compiled a dataset on egg deposition site (terrestrial or
 aquatic), development mode (biphasic with larvae or direct development
 without larvae), body mass, microhabitat use (water-dependent,
 ground-dwelling or arboreal) and climate within their distribution area
 (temperature, precipitation and seasonality in both) of 3091 frog and 244
 salamander species. We analyzed the interrelations between these traits
 and environmental factors by using a cross-species approach and
 phylogenetic generalized least squares analysis. Body masses increased
 along a gradient from warm, humid and unseasonal climates to cold, dry and
 seasonal climates in frogs and salamanders. Terrestrial egg deposition was
 constrained to warm, humid and unseasonal climates only in frogs.
 Terrestrial eggs and an arboreal microhabitat use were linked in frogs and
 salamanders, and arboreal frogs were smaller than non-arboreal ones. We
 confirmed that frogs with terrestrial eggs had smaller average body masses
 than those with aquatic eggs, irrespective of their development mode, but
 this difference disappeared when we corrected body masses for the effects
 of climate and microhabitat use. In salamanders, however, egg deposition
 site and development mode were neither directly related to body mass, nor
 indirectly via the effects of climate and microhabitat use. Our results
 suggest that thermal and hydric environmental conditions determine the
 geographical distribution of body mass and reproductive strategies in
 amphibians and set the framework for their evolution.
description: # Disentangling the interrelations of body mass, egg deposition site,
 climate and microhabitat use in frogs and salamanders Dataset DOI:
 [10.5061/dryad.9cnp5hqz0](10.5061/dryad.9cnp5hqz0) ## Description of the
 data and file structure The data in
 "Dataset_Cejp_Griebeler.xlsx" and
 "Dataset_Cejp_Griebeler.csv" were collected from the literature
 sources listed in "Data_sources_Cejp_Griebeler.txt". The data
 were used in the analyses for which the code is provided
 in RCode_Cejp_Griebeler.txt. In the study, we compared body mass
 differences between frog and salamander species of different reproductive
 modes. We explored whether these differences could be a consequence of 1)
 thermal and hydric needs of adult individuals constraining body mass
 differently in different climates and microhabitats, and of 2) thermal and
 hydric needs of eggs constraining terrestrially egg laying species to
 those climates and microhabitats in which species are constrained to small
 adult body masses. For more detail, refer to the published article. ###
 Files and variables #### File: Dataset_Cejp_Griebeler.xlsx
 **Description:** Dataset_Cejp_Griebeler.xlsx contains the data used in the
 study. There are 3091 frog species and 244 salamander species in the
 dataset. For each of them, the dataset contains information on the
 variables listed below. For more details and a description of the
 analyses, refer to the methods section in the published article. #####
 Variables * Order (Anura or Caudata) * Family (following Frost 2024) *
 Species_Tree (Species names using the nomenclature of the phylogenetic
 tree of Jetz & Pyron 2018), * mean body mass (grams) * microhabitat
 use (water-dependent, ground-dwelling, or arboreal) * reproductive mode
 (Aq-L: aquatic eggs and biphasic, larval development; Ter-L: terrestrial
 eggs and biphasic, larval development; Ter-D: terrestrial eggs and direct
 development without a larval stage) * PC1 and PC2 values calculated from
 the mean values across the species distribution area of: * BIO1 (mean
 annual temperature, °C) * BIO7 (annual temperature range, °C) * BIO 12
 (total annual precipitation, mm) * BIO15 (precipitation seasonality,
 coefficient of variation) #### File: Dataset_Cejp_Griebeler.csv
 **Description:** Dataset_Cejp_Griebeler.csv contains the same data table
 as Dataset_Cejp_Griebeler.xlsx but is in a tab-delimited csv format. ####
 File: Data_sources_Cejp_Griebeler.txt
 **Description:** Data_sources_Cejp_Griebeler.txt contains a list of the
 literature surveyed to gather the data. #### File:
 RCode_Cejp_Griebeler.txt
 **Description:** RCode_Cejp_Griebeler.txt contains the R-code to conduct
 the analyses. #### ## Code/software All analyses were done in R version
 4.4.0. All required packages are listed in the methods section of the
 published article and in the RCode_Cejp_Griebeler.txt. ## Access
 information Data was derived from the following sources: *
 see Data_sources_Cejp_Griebeler.txt