Quantitative variables related to color, territory, behavior, and morphology for male lesser prairie-chickens used in discrete choice models in mate choice study
Data files
Apr 13, 2021 version files 92.46 KB
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Gould_&_Augustine_BEAS.csv
Abstract
Sexual selection theory maintains that traits under selection honestly advertise qualities of signaling individuals and that only individuals in the best condition can survive while displaying maximally elaborated secondary sexual ornaments. Recent trends in mate choice studies have favored the consideration of the effects of multiple traits on mating success, including suites of traits transmitted in different sensory modalities. Sexual selection is expected to be especially strong in lek-mating species. The lesser prairie-chicken (Tympanuchus pallidicinctus) is a grouse species which breeds on leks. Males of this species perform audio and locomotor displays and exhibit two pairs of brightly colored ornaments. We performed an observational study of mate choice in spring 2016-2018 and noted 40 copulations on seven leks. We quantified behavioral, territorial, and morphological characteristics of males along with ornament color properties. We found that variables from all categories considered predicted female choice. Age had the strongest effect, with adult males experiencing higher female choice relative to yearlings. Allocation of aggressive behavior and comb color properties were also strongly correlated with female choice. Our results show that modulating behavior depending on whether females are present contributes to male mating success and highlight the importance of the size and color properties of secondary ornaments. Further research is required to determine how the variables most strongly associated with mate choice relate to one another and which aspects of individual quality, if any, are signaled by color ornaments. Future studies could also incorporate variables related to females to determine if selection on females occurs.
Methods
The data was collected in the field and is based on readings and measurements taken from wild Lesser Prairie-Chickens. The variables beginning with "pc" resulted from a principal components analysis of several behavioral variables. The raw values of the other variables were standardized (mean = 0, SD=1).
The columns beginning with "as" and "cmb" represent color readings from air sacs and combs respectively. The raw spectra obtained with spectrometry were processed using color space models in the R package pavo.
Dist and mcp are spatial variables which were determined through the use of GIS software.
Usage notes
There are no missing values.
The columns and abbreviations are as follows:
individual - cases with a common number represent males which were available to be chosen by one copulating female
male - the ID numbers of the males in question
choice - which male with a common "individual" number was chosen by the female. Only one "yes" is possible for each set of individuals with a common individual number
age - categorical. After second year (adult, ASY) or second year (yearling, SY)
mass - originally measured in grams
tarsus - tarsus length originally measured in mm
tail - tail length originally measured in mm
wing - wing length originally measured in mm
comb - comb area - the product of comb height and comb width, originally measured in mm2
dist - distance to lek center. defined as the distance between the centroid of a male's territory and the centroid of the lek
mcp - 95% minimum convex polygon outlining a male's territory
asht - air sac theta (non-UV hue)
ashp - air sac phi (UV hue)
asrach - air sac r-achieved (saturation)
aslum - air sac luminance (brightness)
the next four columns represent the same variables measured for combs
pconea - first principal component (display behavior) with females absent
pctwoa - second principal component (aggressive behavior) with females absent
the next two columns represent PC's 1 & 2 for females present