Supplement 1. Competition experiment data set and R code for model 1 (individual level), model 2 (basin level), and model 3 (basin level accounting for heteroscedasticity).

File List Competition_Model_Code.txt (MD5: 70506b9d3752928cbc45b020488d6c33) Tadpole_Competition_Data.txt (MD5: 1dfe519a33a7f7bfd54ba2ae682e4a66) Description Tadpole_Competition_Data.txt: This is tab-delimited data from tadpole competition experiments. Column descriptions below: Block = categorical A, B, C, or D corresponding to temporal block (date) Start = Start date of experiment End = End date of experiment Species = categorical F, M, or P corresponding to one of the three species of the focal individual Basin = categorical basin code corresponding to one of the 36 basins used in experiment Trt = categorical F, M, P, or C corresponding to competition treatment (C = low density / 60 individuals of focal species) Examples: Species = F, Trt = F → high density F treatment Species = F, Trt = P → F individual in P treatment Stage = response variable Gosner developmental stage (ranging from 25 to 46 or NA if the individual did not survive) Mass = response variable final weight (g) (NA if individual did not survive) Length = Body length (mm) (NA if individual did not survive) Survival = 1 if individual survived; 0 if individual did not survive until the end of the experiment. Competition_Model_Code.txt: This file contains R code to perform the following: Analyze the tadpole competition data with the three models described in the main text of the manuscript

文件清单：Competition_Model_Code.txt（MD5: 70506b9d3752928cbc45b020488d6c33）、Tadpole_Competition_Data.txt（MD5: 1dfe519a33a7f7bfd54ba2ae682e4a66）

### Tadpole_Competition_Data.txt 说明
该文件为制表符分隔的蝌蚪竞争实验数据集，各列含义如下：
- Block：分类变量，取值为A、B、C或D，对应实验的时间批次（即实验开展日期）
- Start：实验开始日期
- End：实验结束日期
- Species：分类变量，取值为F、M或P，对应3种目标实验物种之一
- Basin：分类变量，取值为本次实验所用36个流域之一的流域编码
- Trt：分类变量，取值为F、M、P或C，对应竞争处理方式（其中C代表低密度处理，即投放60个目标物种个体）
示例：
1. 当Species=F且Trt=F时，为高密度F物种处理组
2. 当Species=F且Trt=P时，为F物种个体置于P处理组中
- Stage：响应变量，为戈斯内尔发育阶段（Gosner developmental stage），取值范围25至46，若个体未存活则取值为NA
- Mass：响应变量，为最终体重（单位：克；若个体未存活则取值为NA）
- Length：体长（单位：毫米；若个体未存活则取值为NA）
- Survival：生存状态变量，1代表个体存活至实验结束，0代表个体未存活至实验结束

### Competition_Model_Code.txt 说明
该文件包含用于执行以下操作的R语言代码：使用论文正文所述的三种模型对蝌蚪竞争实验数据进行分析。