Data from: Direct and indirect effects of cougar predation on bighorn sheep fitness
Data files
Apr 24, 2024 version files 645.26 KB
Abstract
We sought to evaluate the direct and indirect fitness effects of intense cougar (Puma concolor) predation using 48 years of data on marked bighorn sheep (Ovis canadensis) in Ram Mountain, Alberta, Canada. We compared years of intense cougar predation with years with no or occasional cougar predation. We first quantified the effects of predation on neonatal, weaning, and overwinter lamb survival, three metrics potentially affected by direct and indirect effects. We then investigated the possible indirect effects of intense cougar predation on lamb production, female summer mass gain, and lamb mass at weaning. Indirect effects included a 14.2% decline in lamb production. Female summer mass gain decreased by 15.6 % and lamb mass at weaning declined by 8.0% in years of intense cougar predation. Here are the six datasets, joined with a README.md file for the data description, in addition to the six corresponding R scripts for replicating the results.
README: Data from: Direct and indirect effects of cougar predation on bighorn sheep fitness
Description of the data and file structure
"data_1.csv"
This dataset is to be used in "Script_1.qmd" for the analysis of neonatal survival. It contains data between 1976 and 2022 of the Ram Mountain bighorn sheep population.
Each row is unique and is associated with a female bighorn sheep that carried a lamb. Here is a list of each variable's description:
- Pred_2019N_t_1 : Cougar predation year (1) or not (0) in the year of conception, considering 2019 as a non-predation year (binomial).
- Pred_2019Y_t_1 : Cougar predation year (1) or not (0) in the year of conception, considering 2019 as a predation year (binomial).
- Mom_wt_sept_t_1 : Maternal mass adjusted to September 15 in the year of conception (Kg; numeric).
- Density_t_1 : Population density in the year of conception (numeric).
- Pred_2019N_t : Cougar predation year (1) or not (0) in the year of birth, considering 2019 as a non-predation year (binomial).
- Pred_2019Y_t : Cougar predation year (1) or not (0) in the year of birth, considering 2019 as a predation year (binomial).
- Mom_Age_t : Maternal age in years during the year of birth (numeric).
- Neonate_surv_t : Lamb survival of neonatal stage (0 = no, 1 = yes; binomial).
- Mom_ID : Reproductive female unique identity (numeric).
- Year_t : Year of birth from 1976 onwards (numeric).
The prefix "S_" distinguishes numeric variables that were scaled and used in the analyses. These variables were scaled by subtracting the mean and dividing by 1 standard deviation unit.
"data_2.csv"
This dataset is to be used in "Script_2.qmd" for the analysis of survival to weaning. It contains data between 1975 and 2022 of the Ram Mountain bighorn sheep population.
Each row is unique and is associated with a female bighorn sheep whose lamb survived the neonatal stage. Here is a list of each variable's description:
- Pred_2019N_t : Cougar predation year (1) or not (0) in the year of birth, considering 2019 as a non-predation year (binomial).
- Pred_2019Y_t : Cougar predation year (1) or not (0) in the year of birth, considering 2019 as a predation year (binomial).
- Weaning_t : Lamb survival to weaning (0 = no, 1 = yes; binomial).
- Mom_wt_gain_t : Maternal mass gain between June 5 and September 15 (Kg; numeric).
- Mom_Age_t : Maternal age in years during the year of birth (numeric).
- Density_t : Population density (numeric).
- Mom_ID : Maternal unique identity (numeric).
- Year_t : Year of birth from 1975 onwards (numeric).
The prefix "S_" distinguishes numeric variables that were scaled and used in the analyses. These variables were scaled by subtracting the mean and dividing by 1 standard deviation unit.
"data_3.csv"
This dataset is to be used in "Script_3.qmd" for the analysis of lamb overwinter survival. It contains data between 1975 and 2022 of the Ram Mountain bighorn sheep population.
Each row is unique and corresponds with a bighorn sheep lamb that survived to weaning. Here is a list of each variable's description:
- Lamb_sex : The lamb's sex (0 = female, 1 = male; binomial).
- Pred_2019N_t : Cougar predation year (1) or not (0) in the year of birth, considering 2019 as a non-predation year (binomial).
- Pred_2019Y_t : Cougar predation year (1) or not (0) in the year of birth, considering 2019 as a predation year (binomial).
- OWSurv_t.1 : Lamb overwinter survival 0 = no, 1 = yes; binomial).
- Lamb_wt_w_t : Lamb mass at weaning (adjusted to September 15; Kg; numeric).
- Density_t : Population density (numeric).
- Mom_ID : Maternal unique identity (numeric).
- Lamb_ID : Lamb unique identity (numeric).
- Year_t : Year of birth from 1975 onwards (numeric).
The prefix "S_" distinguishes numeric variables that were scaled and used in the analyses. These variables were scaled by subtracting the mean and dividing by 1 standard deviation unit.
"data_4.csv"
This dataset is to be used in "Script_4.qmd" for the analysis of female lamb production. It contains data between 1975 and 2022 of the Ram Mountain bighorn sheep population.
Each row is unique and corresponds with a prime-age female bighorn sheep. Here is a list of each variable's description:
- Weaning_t_1 : Previous reproductive status. Did the female wean a lamb the previous year or not (0 = no, 1 = yes; binomial).
- Mom_wt_sept_t_1 : Female mass adjusted to September 15 in the year of conception (Kg, numeric).
- Density_t_1 : Population density in the year of conception (numeric).
- Pred_2019N_t_1 : Cougar predation year (1) or not (0) in the year of conception, considering 2019 as a non-predation year (binomial).
- Pred_2019Y_t_1 : Cougar predation year (1) or not (0) in the year of conception, considering 2019 as a predation year (binomial).
- Pregnancy_t : Lamb production (0 = no, 1 = yes; binomial).
- Mom_Age_t : Female age in years during the year of birth (numeric).
- Mom_ID : Maternal unique identity (numeric).
- Year_t : Year of birth from 1975 onwards (numeric).
The prefix "S_" distinguishes numeric variables that were scaled and used in the analyses. These variables were scaled by subtracting the mean and dividing by 1 standard deviation unit.
"data_5.csv"
This dataset is to be used in "Script_5.qmd" for the analysis of female summer mass gain. It contains data between 1975 and 2022 of the Ram Mountain bighorn sheep population.
Each row is unique and corresponds with a prime-age female bighorn sheep. Here is a list of each variable's description:
- Weaning_t : Reproductive status. Did the female wean a lamb or not (0 = no, 1 = yes; binomial).
- Fem_wt_june_t : Female mass adjusted to June 5 (Kg; numeric).
- Fem_wt_gain_t : Female mass gain between June 5 and September 15 (Kg; numeric).
- Fem_Age_t : Female age in years (numeric).
- Density_t : Population density (numeric).
- Pred_2019N_t : Cougar predation year (1) or not (0), considering 2019 as a non-predation year (binomial).
- Pred_2019Y_t : Cougar predation year (1) or not (0), considering 2019 as a predation year (binomial).
- Fem_ID : Female unique identity (numeric).
- Year_t : Year from 1975 onwards (numeric).
The prefix "S_" distinguishes numeric variables that were scaled and used in the analyses. These variables were scaled by subtracting the mean and dividing by 1 standard deviation unit.
"data_6.csv"
This dataset is to be used in "Script_6.qmd" for the analysis of lamb overwinter survival. It contains data between 1975 and 2022 of the Ram Mountain bighorn sheep population.
Each row is unique and corresponds with a bighorn sheep lamb that survived to weaning. Here is a list of each variable's description:
- Lamb_wt_w_t : Lamb mass at weaning (adjusted to September 15; Kg; numeric).
- Lamb_sex : The lamb's sex (0 = female, 1 = male; binomial).
- Mom_wt_gain_t : Maternal mass gain between June 5 and September 15 (Kg; numeric).
- Mom_Age_t : Maternal age in years (numeric).
- Density_t : Population density (numeric).
- Pred_2019N_t : Cougar predation year (1) or not (0) in the year of birth, considering 2019 as a non-predation year (binomial).
- Pred_2019Y_t : Cougar predation year (1) or not (0) in the year of birth, considering 2019 as a predation year (binomial).
- Mom_ID : Maternal unique identity (numeric).
- Lamb_ID : Lamb unique identity (numeric).
- Year_t : Year of birth from 1975 onwards (numeric).
The prefix "S_" distinguishes numeric variables that were scaled and used in the analyses. These variables were scaled by subtracting the mean and dividing by 1 standard deviation unit.
Methods
Data was collected by trapping bighorn sheep individuals multiple times per field season and other variables were assessed from long-term monitoring.