Life-history theory suggests species that typically have a large number of offspring and high adult mortality may make decisions that benefit offspring survival in exchange for increased adult risks. Such behavioral adaptations are essential to understanding how demographic performance is linked to habitat selection during this important life-history stage. Though studies have illustrated negative fitness consequences to attendant adults or potential fitness benefits to associated offspring because of adaptive habitat selection during brood rearing, equivocal relationships could arise if both aspects of this reproductive trade-off are not assessed simultaneously. To better understand how adaptive habitat selection during brood-rearing influences demographics, we studied the brood survival, attendant parental survival, and space use of two sympatric ground-nesting bird species, the northern bobwhite (hereafter: “bobwhite”; Colinus virgininanus) and scaled quail (Callipepla squamata). During the 2013-2014 breeding seasons, we estimated habitat suitability across two grains (2 m and 30 m) for both species and determined how adult space-use of these areas influenced individual chick survival and parental risk. We found the proportion of a brood’s home range containing highly suitable areas significantly increased bobwhite chick survival (β = 0.02, SE = 0.006). Additionally, adult weekly survival for bobwhite was greater for individuals not actively brooding offspring (0.9716, SE = 0.0054) as compared to brooding adults (0.8928, SE = 0.0006). Conversely, brood habitat suitability did not influence scaled quail chick survival during our study, nor did we detect a survival cost for adults that were actively brooding offspring. Our research illustrates the importance of understanding life-history strategies and how they might influence relationships between adaptive habitat selection and demographic parameters.
Northern bobwhite chick encounter history file for Program MARK
INP file associated with encounter histories for northern bobwhite (Colinus virginianus) chick survival. INP file is the standard encounter history file format associated with Program MARK software.
NOBOChick.inp
Scaled quail chick encounter history file for Program MARK
INP file associated with encounter histories for scaled quail (Callipepla squamata) chick survival. INP file is the standard encounter history file format associated with Program MARK software.
SCQUChick.inp
Principal components analysis values for weather
Principal components analysis values for weather data obtained from local weather stations on Beaver River Wildlife Management Area.
PCAValues.xlsx
Adult northern bobwhite encounter history file for Program MARK
Adult northern bobwhite (Colinus virginianus) encounter history file associated with both brooding and non-brooding individual survival. INP file is the standard encounter history file format associated with Program MARK software.
NOBOnonbroodanalysis.inp
Adult scaled quail encounter history file for Program MARK
Adult scaled quail (Callipepla squamata) encounter history file associated with both brooding and non-brooding individual survival. INP file is the standard encounter history file format associated with Program MARK software.
SCQUnonbroodanalysis.inp
2 meter resolution environmental layers
Contains ASCII files associated with the spatial environmental layers used in Maxent analyses
for northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) broods and non-brooding adults
to estimate habitat suitability indices. ASCII files are represented at a 2 meter resolution. All ASCII files are
representative of the environmental layers retained after second order Maxent analyses though have not yet been
vetted through correlation analyses or by removing poorly contributing (i.e., 5% or less contribution to model
accuracy gain of the Maxent model) variables.
EnvLayers2m.zip
30 meter resolution environmental layers
This zipped file contains ASCII files associated with the spatial environmental layers used in Maxent analyses
for northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) broods and non-brooding adults
to estimate habitat suitability indices. ASCII files are represented at a 30 meter resolution. All ASCII files are
representative of the environmental layers retained after second order Maxent analyses though have not yet been
vetted through correlation analyses or by removing poorly contributing (i.e., 5% or less contribution to model
accuracy gain of the Maxent model) variables. NOTE: Zip file was created using 7-Zip version 18.05.
EnvLayers30m.zip
Northern bobwhite non-brooding adult locations
CSV file containing coordinates for non-brooding northern bobwhite (Colinus virginianus) adults located during the brooding seasons of 2013-2014. These locations were used as occurrences for building non-brooding northern bobwhite Maxent models. Geographic Coordinate System: GCS_WGS_1984; Datum: D_WGS_1984; Prime Meridian: Greenwich; Angular Unit: Degree.
201314NOBONonBroodEqualSample.csv
Scaled quail non-brooding adult locations
CSV file containing coordinates for non-brooding scaled quail (Callipepla squamata) adults located during the brooding seasons of 2013-2014. These locations were used as occurrences for building non-brooding scaled quail Maxent models. Geographic Coordinate System: GCS_WGS_1984; Datum: D_WGS_1984; Prime Meridian: Greenwich; Angular Unit: Degree.
201314SCQUNonBroodEqualSample.csv
Northern bobwhite brood home ranges
Northern bobwhite (Colinus virginianus) brood home ranges representing brood space use during the 2013-2014 brooding seasons. Brood home ranges were calculated using a 95% fixed-kernel method with least squares cross-validation within the Geospatial Modeling Environment 0.7.2.1. Projected Coordinate System: WGS_1984_UTM_zone_14N; Projection: Transverse_Mercator.
HomeRangesNOBO.zip
Scaled quail brood home ranges
Scaled quail (Callipepla squamata) brood home ranges representing brood space use during the 2013-2014 brooding seasons. Brood home ranges were calculated using a 95% fixed-kernel method with least squares cross-validation within the Geospatial Modeling Environment 0.7.2.1. Projected Coordinate System: WGS_1984_UTM_zone_14N; Projection: Transverse_Mercator.
HomeRangesSCQU.zip
Northern bobwhite brooding adult locations
CSV file containing coordinates for brooding northern bobwhite (Colinus virginianus) adults located during the brooding seasons of 2013-2014. These locations were used as occurrences for building first order brooding northern bobwhite Maxent models. Geographic Coordinate System: GCS_WGS_1984; Datum: D_WGS_1984; Prime Meridian: Greenwich; Angular Unit: Degree.
201314NOBOChick.csv
Scaled quail brooding adult locations
CSV file containing coordinates for brooding scaled quail (Callipepla squamata) adults located during the brooding seasons of 2013-2014. These locations were used as occurrences for building first order brooding scaled quail Maxent models. Geographic Coordinate System: GCS_WGS_1984; Datum: D_WGS_1984; Prime Meridian: Greenwich; Angular Unit: Degree.
201314SCQUChick.csv
Chick associations with broods
An Excel file containing the chick ID number and the associated brood ID number for northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) from 2013-2014. Chick ID numbers are associated with the Program MARK encounter history files while brood ID numbers are associated with home range files.
ChicktoBroodAssociations.xlsx
Results from niche identiy tests
Number of psuedo-replications estimating relative rank metrics for niche similarity for habitat suitability indices of brooding and non-brood northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) for 2 meter and 30 meter resolutions. Numbers reflect the number of psuedo-replications out of 100 runs that correspond to a specific relative rank value.
NicheIdenityResults.xlsx
Study site weather data
Site specific weather data used in the principal components analysis. Variables: TAvgVar (average daily variance in ambient temperature [°C]), TempMax (maximum daily ambient temperature [°C]), TempAvg (average daily ambient temperature [°C]), TempMin (minimum daily ambient temperature [°C]), MaxSolar (maximum daily solar radiation [W/m2]), AvgWind (average daily wind speed [km/h]), Precip (daily precipitation [mm]), and AvgRH (average daily relative humidity [%]).
PCAWeather.csv