DOI: 10.5061/dryad.wm37pvmpr
title: Factors influencing survival of female eastern wild turkeys in northeastern South Dakota

description: Population growth can be sensitive to changes in survival rates for many
 avian species. Understanding sources of mortality, and how to mitigate
 negative effects on survival, can give managers insight into factors
 contributing to population change. Harvest trends of eastern wild turkeys
 (Meleagris gallopavo silvestris) in northeastern South Dakota suggest a
 decline in abundance. We investigated factors influencing survival of wild
 turkeys to identify potential factors contributing to the decline. We
 monitored 122 female wild turkeys using VHF radio transmitters from
 February 2017 to April 2019. Annual survival was 0.52 (95% CI = 0.33–0.64)
 for juvenile and 0.49 (95% CI = 0.23–0.63) for adult females,
 respectively. Daily survival probability was significantly lower during
 the spring (log‐odds ratio [LOR] = −0.9; 95% CI = −1.5–−0.2) and while a
 juvenile female was incubating (LOR = −0.67; 95% CI = −1.23–−0.09) but not
 while an adult female was incubating (LOR = −0.35; 95% CI = −0.92–0.24).
 Mammalian predation was the leading cause of mortality, and female wild
 turkeys were most vulnerable to predation during the spring while engaging
 in nesting and rearing of young broods. Wild turkeys were at risk for
 additional sources of mortality while incubating nests that were not
 contributors to mortality during other periods of the year, as deaths
 caused by haying equipment—the second greatest cause of mortality—only
 occurred while a female was incubating. Reducing female mortality due to
 haying, by delaying cutting, installing flushing bars on haying equipment,
 or increasing availability of suitable nesting cover types to reduce the
 probability of nesting in hayfields, could improve female survival. Annual
 survival during our study was about 16–29% lower than survival estimates
 from northeastern South Dakota during the 1990s, suggesting that reduced
 female survival could be contributing to the apparent decline in wild
 turkey abundance.
description: # Factors Influencing Survival of Female Eastern Wild Turkeys in
 Northeastern South Dakota: Open Source Data ## **Metadata for The Hen
 (Female) Survival Analysis Prior Distribution Calculation** Files needed
 to calculate Hen Survival Analysis Prior Distributions: * beta.txt – JAGS
 model code for survival probability estimation * gaussian.txt – JAGS model
 code for age-class specific survival probability estimation *
 Prior_Distribution.RMD – R Markdown file used to run prior distribution
 calculation  * Prior_Estimates.xlsx – Excel Workbook (2 sheets) containing
 published estimates of hen annual survival from studies of turkeys in the
 Midwest used to calculate prior distributions for the hen survival
 analysis Description of variables within “Prior_Estimates.xlsx” * Sheet =
 Combined * Estimate – published annual hen survival estimates where hen
 age was pooled * Source – the published study each estimate originated
 from * Sheet = Age * Adult – published annual survival estimates for adult
 hens * Juv – published annual survival estimates for juvenile/yearling
 hens * Source – the published study each estimate originated from ##
 **Metadata for Hen (Female) Survival Analysis** Files needed to run the
 Hen Survival Analysis: * HenObservations.csv – observation history for
 each hen monitored over the course of the study *
 HenSurvival_InputData.RData – R object containing all hen survival model
 input data * HenSurvivalAnalysis_DataSetUp.R – R code used to develop hen
 survival model input data * HenSurvivalModel.R – R code used to run hen
 survival analysis * hensurvmodel.txt – JAGS model code for hen survival
 analysis * IncubationData.csv – incubation history for each nest attempt *
 MilbankDailySumm2016to2019.csv – raw temperature and precipitation from
 NOAA NCEI CDO (Menne, M. J., I. Durre, B. Korzeniewski, S. McNeal, K.
 Thomas, X. Yin, S. Anthony, R. Ray, R. S. Vose, B. E. Gleason, and T. G.
 Houston. 2012. Global Historical Climatology Network - Daily (GHCN-Daily),
 Version 3.26. NOAA National Climatic Data Center.
 [http://doi.org/10.7289/V5D21VHZ](http://doi.org/10.7289/V5D21VHZ).
 Accessed March 5, 2020.) To run the hen survival analysis, start by
 opening the “HenSurvivalModel.R” file.  Ensure the “Hen Survival” folder
 is set as the working directory. Ensure all required packages (i.e.,
 jagsUI & ggplot2) are installed and loaded. Execute code. Description
 of variables within “HenObservations.csv” * Band_ID – the identification
 number on leg bands of individually marked eastern wild turkey hens. A
 factor with 122 levels where each level is a unique identification number
 (and unique individual hen). * Age – the age of the hen at the time of
 capture. A factor with 2 levels: adult or juvenile (i.e., yearling). *
 Date_Captured – the date each hen was captured.    * Last_Obs_Date – the
 last date the hen was observed alive. If the hen was still alive at the
 end of the study period, then no date is entered into this column for that
 hen. * Date_Mortality – the date the hen was found to have died (i.e.,
 mortality signal was detected) (if applicable). Description of variables
 within “IncubationData.csv” * Band_ID – the identification number on leg
 bands of individually marked eastern wild turkey hens that reached
 incubation of at least one nest during at least one year of the study. A
 factor with 89 levels where each level is a unique identification number
 (and unique individual hen). * Incubation_Date – the start date of the
 incubation period (i.e., first day the hen was known to be incubating a
 nest). * Fate_Date – the day after the end of the incubation period (i.e.,
 first day the hen was known to be no longer incubating a nest).
 Description of variables within “MilbankDailySumm2016to2019.csv” * STATION
 – the station identification code. Please see
 [http://www1.ncdc.noaa.gov/pub/data/ghcn/daily/ghcnd-stations.txt](http://www1.ncdc.noaa.gov/pub/data/ghcn/daily/ghcnd-stations.txt) for a complete list of stations and their metadata. * NAME – the name of the station (usually city/airport name). Optional output field. * LATITUDE – decimated degrees w/ northern hemisphere values &gt; 0 * LONGITUDE – decimated degrees w/ western hemisphere values &lt; 0 * ELEVATION – elevation above mean sea level (tenths of meters) * DATE – the date of the record * PRCP – precipitation in mm * SNOW – snowfall in mm * SNWD – snow depth in mm * TMAX – maximum temperature in Celsius * TMIN – minimum temperature in Celsius * TOBS – temperature at time of observation in Celsius ## **Metadata for Winter Weather Comparison Figure creation** Files needed to create the Winter Weather Comparison figure: * MilbankDailySummary1990to2019.csv – raw temperature and precipitation from NOAA NCEI CDO (Menne, M. J., I. Durre, B. Korzeniewski, S. McNeal, K. Thomas, X. Yin, S. Anthony, R. Ray, R. S. Vose, B. E. Gleason, and T. G. Houston. 2012. Global Historical Climatology Network - Daily (GHCN-Daily), Version 3.26. NOAA National Climatic Data Center. [http://doi.org/10.7289/V5D21VHZ](http://doi.org/10.7289/V5D21VHZ). Accessed March 5, 2020.) * WinterWeatherCompare.png - image illustrating the total snow accumulation (cm) during the winter months (1-January to 31-March) and mean January air temperature (Celsius) recorded in Milbank, South Dakota, USA during the study years compared to 30-year normals. Included as a figure in the manuscript. * WinterWeatherComparison.R – R code used to create “WinterWeatherCompare.png” Description of variables within “MilbankDailySumm2016to2019.csv” * STATION – the station identification code. Please see [http://www1.ncdc.noaa.gov/pub/data/ghcn/daily/ghcnd-stations.txt](http://www1.ncdc.noaa.gov/pub/data/ghcn/daily/ghcnd-stations.txt) for a complete list of stations and their metadata. * NAME – the name of the station (usually city/airport name). Optional output field. * LATITUDE – decimated degrees w/ northern hemisphere values &gt; 0 * LONGITUDE – decimated degrees w/ western hemisphere values &lt; 0 * ELEVATION – elevation above mean sea level (tenths of meters) * DATE – the date of the record * PRCP – precipitation in mm * SNOW – snowfall in mm * SNWD – snow depth in mm * TMAX – maximum temperature in Celsius * TMIN – minimum temperature in Celsius * TOBS – temperature at time of observation in Celsius