Does a lack of juveniles indicate a threat? Understanding body size distributions in a group of long-lived vertebrates

This data set contains size and/or sex data from 41,021 freshwater turtles
from 38 species and 428 populations located in parts of Australia both
with and without introduced foxes, as well as populations in the United
States of America, which naturally have raccoons (Procyon lotor), foxes,
and other nest predators. The goal was to examine population-level body
size distributions to establish a baseline for “typical” turtle
populations and test whether populations that are exposed to introduced
foxes have proportionately fewer juveniles compared to both AU populations
that lack introduced foxes and USA populations that are naturally exposed
to nest predators. We additionally conducted analyses on the biases of
trapping methods, effects of sample size, and effects of water body type.
This data set was assembled by pooling the data from numerous researchers.

本数据集涵盖了来自38个物种、428个种群的41021只淡水龟的体型及/或性别数据。这些种群分布于澳大利亚部分区域（涵盖存在入侵狐狸与未出现入侵狐狸的区域），以及美国的相关种群；其中美国种群自然栖息有浣熊（Procyon lotor）、狐狸及其他巢捕食者。本研究的核心目标为：探究种群水平的体型分布规律，为“典型”淡水龟种群建立基准基线；同时对比三类种群，验证暴露于入侵狐狸的种群，其幼体占比是否较未受入侵狐狸影响的澳大利亚种群，以及自然存在巢捕食者的美国种群更低。此外，本研究还针对诱捕方法的偏差、样本量效应以及水体类型效应开展了相关分析。本数据集通过整合多位研究者的相关数据汇编而成。