Parameter estimates utilizing restricted maximum likelihood estimation for a linear mixed-effects model assessing the influence of biological (litter type, maternal age, and study program) and environmental factors on parturition date (Julian date) of singleton and twin white-tailed deer at Kerr Wildlife Management Area, Kerr County, TX from 1977–2012.

Litter types (LitType) were comprised of singleton female and male (F, M), twin females and males (FF, MM), and Mix (twin mixed sex). MaternalAge and its quadratic term was the known age of the mother. StudyProgram consisted of grouped study programs (StudyProgram1 = 16% protein diet throughout life, StudyProgram2 = sires possessed spike antler characteristics when they were 1.5 years of age, and StudyProgram3 = sires consumed 8% protein diet from 0.5–1.5 years of age and then placed on 16% protein diet for the rest of life). Precipitation (mm) was calculated for each month or range of months by summing total precipitation over the defined time span. Temperature (°C) was calculated as the average maximum temperature for the defined month. Random effects consisted of dam identification (SD = 11.26), year of birth (SD = 4.85), and residual variance (SD = 15.22).
Parameter estimates utilizing restricted maximum likelihood estimation for a linear mixed-effects model assessing the influence of biological (litter type, maternal age, and study program) and environmental factors on parturition date (Julian date) of singleton and twin white-tailed deer at Kerr Wildlife Management Area, Kerr County, TX from 1977–2012.