Data from: Northern bobwhite chick survival, growth, and movement in relation to broadcast supplemental feed and drought
Data files
Aug 05, 2025 version files 36.79 KB
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ChickGrowthSurvival.R
10.22 KB
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growthcombined.csv
3.27 KB
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post_multi.csv
1.93 KB
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prefledge_clean.csv
2.71 KB
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quaillocations.csv
11.78 KB
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README.md
6.87 KB
Abstract
The northern bobwhite is an economically important species across its geographic range that has experienced declining population numbers. There is ample research dedicated to evaluating management practices for the adult life stage. However, the effects of management on bobwhite chicks remain understudied, despite this being the most vulnerable age class. We evaluated the effects of broadcast supplemental feed on bobwhite chick survival, mass, and location both during a breeding season with normal precipitation and one with historically low precipitation. We followed broods via radio transmitters on hens until chicks were large enough to carry their transmitters at around 12 days of age, then followed chicks until independence. From 0-12 days old, broods had higher survival in control units than supplementally fed units, but there was no effect of supplemental feed on 12-35-day-old survival. Likely due to severe drought conditions in 2011, chicks weighed more in 2012 than in 2011. Feed treatment was not predictive of chick mass except for 4-day-old chicks in 2012, for which chicks in supplemental feed units were heavier. This could suggest that, under normal weather conditions, supplemental feed helps hens produce heavier chicks, but that this advantage disappears with age. Additionally, we found that broods in fed units were closer to roads, along which feed was broadcast, than in control units, where roads had no added management impacts. Overall, supplemental feed had little or no clear influence on chick survival and body condition. Despite this, supplemental feed remains a useful management practice for adult bobwhites.
Description of the data and file structure
Datasets and associated analysis code for a comparison of chick survival, growth, and locations in supplementally fed areas versus control unfed areas.
Datasets and variables
growthcombined.csv: Dataset for analyzing chick size across treatment, year, and age
| Column name | Description | Units | Data format | Missing data code |
|---|---|---|---|---|
| weight | Chick weight | grams | Number | - |
| Year | Year of study | - | Factor | - |
| Treatment | Feed (Exp) or unfed control (Ctl) | - | Factor | - |
| age | Chick age in days post-hatch | - | Factor | - |
| Attempt | Number of nest attempts of the hen | Brood count | Number | - |
| ID | ID of the chick | - | Factor | - |
post_multi.csv: Dataset for analyzing the survival of radio-tagged chicks ages 12-35. Chicks are the sampling units.
| Column name | Description | Units | Data format | Missing data code |
|---|---|---|---|---|
| ID | ID of the chick | - | Factor | - |
| Treatment | Feed (Exp) or unfed control (Ctl) | - | Factor | - |
| Weight | Chick weight at tagging | grams | Number | - |
| Brood | ID of the brood | - | Factor | - |
| ch | Individual capture history for the multi-state model | - | Factor | - |
| Fate | Fate of the chick. Censor refers to dropped tags or radio malfunctions | - | Factor | - |
prefledge_clean.csv: Dataset for analyzing survival of unmarked chicks ages 0-12 with the Nest Survival model. Brood is the sampling unit.
| Column name | Description | Units | Data format | Missing data code |
|---|---|---|---|---|
| Brood | ID of the brood | - | Factor | - |
| Treatment | Feed (Exp) or unfed control (Ctl) | - | Factor | - |
| ClutchSize | Number of chicks hatched per brood | Chick count | Number | - |
| Attempt | Numberof nest attempts of the hen | - | Number | - |
| Year | Year of study | - | Factor | - |
| Day1 | Earliest nest date for that year, first day ofthe study period | Julian date | Number | - |
| AgeDay1 | Age of the nest on Day 1 (negative for all nests found later thanDay 11) | Day count | Number | - |
| FirstFoundDate | The date the nest was found | Julian date | Number | - |
| LastPresentDate | Date the nest was last observed active | Julian date | Number | - |
| FateDate | Date the nest was found hatched or failed | Julian date | Number | - |
| Fate | Hatched = 0, Failed = 1 | - | Factor | - |
| FirstFound | Day of the study period when the nest was found | Day count | Number | - |
| LastPresent | Day of the study period when the nest was last observed active | Day count | Number | - |
| LastChecked | Day of the study period when the nest was found hatched or failed | Day count | Number | - |
quaillocations.csv: Dataset with brood locations for analyzing proximity to feedlines
| Column name | Description | Units | Data format | Missing data code |
|---|---|---|---|---|
| Date | Date of observation | date | Number | - |
| Brood | ID of the brood | - | Factor | - |
| Treatment | Feed (Exp) or unfed control (Ctl) | - | Factor | - |
| AgeDays | Age of the brood at observation | Day count | Number | - |
| Easting | X coordinate | NAD 1983 UTM Zone 14N | Number | - |
| Northing | Y coordinate | NAD 1983 UTM Zone 14N | Number | - |
| Year | Year of study | - | Factor | - |
| Unit | Treatment unit ID | - | Factor | - |
| NEAR_DIST | Distance of brood to nearest feeding | meters | Number | - |
Code/software
All analyses were completed in R version 4.5.0. Required packages are indicated in the script below.
ChickGrowthSurvival.R: Code used for analyses of chick weight, survival, and proximity to feedlines
