Northern bobwhite (Colinus virginianus) COSEWIC status report: chapter 6
Biology
General
As is typical for the family (but not for other gallinaceous birds), males contribute to nest-site selection, nest-building, incubation and care of the young.
Northern Bobwhite are monogamous. Winter coveys require a minimum of 4.9 ha and rarely use more than 20 ha.
Reproduction
The nest is a shallow depression in the ground lined with plant material covered with grasses or vines arched over it for concealment. The mean clutch size is 12 to 16 eggs; incubation takes 23 to 24 days and the downy young can fly at an age of 6 or 7 days. Only one brood is typically raised per season at the northern edge of the range. Nests with eggs have been found from late May through mid-September, but the likelihood of successful hatching or fledging decreases as the season progresses. Mean nesting losses may be 60 to 70 percent.
Survival
About 80 percent of the fall population consists of juvenile birds and the mean annual mortality of the species (including young birds) is about 80 percent. Adult annual survival is about 30 percent.
Movements/dispersal
Northern Bobwhite are nonmigratory and most individuals likely do not move more than a kilometre from their point of hatching. However, some individuals do disperse in the fall, when movements of up to 40 kilometres have been recorded.