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In utero accumulated steroids predict neonate anti-predator response in a wild mammal

Citation

Amin, Bawan et al. (2021), In utero accumulated steroids predict neonate anti-predator response in a wild mammal, Dryad, Dataset, https://doi.org/10.5061/dryad.51c59zw81

Abstract

This file contains the raw data and R-scripts used for the analysis published in the research article: "In utero accumulated steroids predict neonate anti‐predator response in a wild mammal" (https://doi.org/10.1111/1365-2435.13790). A full and detailed description of the methods can be found in the manuscript, or at request from the author (BA).

 

The R-scripts can be used to follow all the steps taken in the analysis and fully reproduce the effects reported. 

The file contains data taken from 185 newborn fallow deer fawns (Dama dama), in two different cohorts. Data were taken at capture and recapture of these fawns, during their first weeks of life. During this period, fallow deer fawns adopt a hiding-strategy where they hide in the vegatation from potential predators.  

We quantified the responses of the fawns, namely their behaviour prior to capture; docility; heartrate at start of capture (HRstart); Heartrate at end of capture (HRend); latency to leave once released. In addition, we collected data on abiotic and biotic factors, such as time of the day, air temperature and bed site visibility among others. 

We also collected hair samples, which were used to quantify chronic levels of cortisol and testosterone. Since these are newborn fawns, these values have been accumulated while in the womb of the mother. 

Specifically, we aimed at testing whether i) newborn fawns display repeatable differences in their response to capture, ii) whether physiological response covaries with behavioural response, given that both are repeatable, and whether iii) these were explained by in utero accumulated steroids. Therefore, the names of the datasets correspond to the responses at the capture (prior behaviour, docility HRstart, HRend, Latency), the covariation between physiology and behavioural responses and the analysis regarding the steroids extracted from the hair samples. 

Methods

All data have been recorded during capture and recapture of newborn fawns. The fawns are part of a free-living population of fallow deer (Dama dama), living in the largest urban park in Europe, namely Phoenix Park in Dublin, Ireland. 

Steroid hormone levels were quantified afterwards, from hair samples taken at the captures. Immunoreactive androgens and glucocorticoids (hereafter referred to as testosterone and cortisol) were quantitated in hair extracts using commercial testosterone and cortisol ELISA kits according to the manufacturer's recommendations (Salimetrics; Ann Arbor, MI, USA, item no. 1-3002, for cortisol, and item no. 1-2402 for testosterone).

The data were analysed by combinations  of generalized linear models and linear mixed-effect models, in R. 

Usage Notes

All analysis can be reproduced using the R-scripts. For instructions, please open the "README.docx" file attached. In addition, there is a "ReadMe_Description of variables.xlsx", where every variable in the dataset is descriped. Here the variable structure and the units are presented clearly.