Colinus virginianus
northern bobwhite

Northern bobwhites can be found from southeastern Ontario to Central America. Highest population densities are reached in the eastern United States and Mexico. Bobwhites can also be found throughout Cuba. Disjunct populations exist in Washington, Oregon, Idaho and northwestern Mexico. (Dimmick, 1992)

In forest habitats, northern bobwhites show a clear preference for early successional vegetation created by disturbances from fire, agriculture, and timber-harvesting. In rangeland habitats, bobwhites are found in both early and later successional vegetation. Bobwhite habitats must contain a diversity of invertebrates, seeds, and herbaceous plants. Cover that provides protection from predators, weather, and provides nesting material is also essential. Water is not normally an important factor in habitat determination of the bobwhite because ample water can be obtained from dew. (Brennan, 1999; Dimmick, 1992)

Bobwhites are small (140 to 170 grams) galliform birds with rounded wings and a square tail. They range in length from 20.3 to 24.7 cm with a wingspan from 9 to 12 cm. Bobwhites are sexually dimorphic with regard to facial and throat coloration, wing coverts, and beak color. Adult males are distinguished by white facial stripes and throat in contrast to the buff coloration of females and juveniles. The wing coverts of males have sharply contrasting black markings on the feathers while the wing coverts of females lack color distinctions. The base of the mandible is black in males and yellow in females. White edges, dark bars, and vermiculations on the reddish brown back and white breast create a mottled appearance. (Dimmick, 1992)

Northern bobwhites have a short life span and high mortality rates. Few individuals live longer than five years, and about 80% live less than one year. Exposure is an important source of mortality during the winter. Deep snows and prolonged periods of cold may cause extensive losses. Also, feeding in agricultural environments can lead to exposure to contaminants which often have lethal effects. (Brennan, 1999)

Beginning in late summer bobwhites form coveys of parents, offspring, and unsuccessful breeding pairs. Coveys are fluid and by autumn family groups have become dispersed due to apparently random joining and leaving of individuals (Dimmick 1992).

Bobwhites have many calls initiating and directing group movement; 1 call for food location, 11 to aid in the avoidance of enemies, 6 sexual and agonistic and 2 parental calls. Bobwhites have a male social hierarchy system (Stokes 1967).

Bobwhites are typically diurnal. Feeding is most active during the early morning and late afternoon. They can fly relatively short distances, with the average flight lasting 5.1 seconds, but spend most of their time on the ground. (Brennan, 1999; Dimmick, 1992; Stokes, 1967)

Populations are typically sedentary, year-round residents, particularly in areas of moderate to high quality habitat. Population density depends upon many factors, such as frequency and intensity of disturbance. Densities of 2.2 to 4.4 birds/hectare are typical in high quality habitat, and densities can reach up to 6.6 birds/hectare.

Home Range

Home range sizes are highly variable depending on habitat conditions and reproductive status of individuals. Unmated males roam over larger areas than mated males. (Brennan, 1999)

The well known "bob-white" call is a minor part of northern bowhites' overall vocal repetoire. Their entire vocal array is known and has been classified into calls based on group movement, food-finding, avoidance of enemies, and reproduction (sexual and parental). Nonvocal interactions are diverse and characteristic of many small quails. For example, head-shaking, head-scratching and preening are characteristic of dominant birds. (Brennan, 1999)

The diet consists primarily of seeds but also includes green leafy material, fruits, and invertebrates. Approximately 85% of the diet is vegetation and 15% animal matter. However, the relative quantity of each is seasonal (Ehrlich, et al 1988).

In early spring, leafy material is an important source of vitamins. Insects are important from spring until autumn; during these months they may constitue a quarter of the diet. Females consume more insects than males in response to elevated need for protein during egg laying. Fruits are also an important summer source of carbohydrates. Seeds and legumes constitute the majority of the bobwhite diet in fall and winter. Hatchlings are completely dependent on insects as a food source (Landers and Mueller 1986).

Predation is an important source of mortality for northern bobwhites. Known predators include Cooper's hawks, raccoons, opossums, skunks and foxes. When adults with chicks encounter predators, they perform distraction displays such as fluttering and wing-dragging. This anti-predator behavior seems to be learned and is rarely seen in captive-reared birds. Their coloration helps to make them hard to see in the dense undergrowth that is their preferred habitat. (Brennan, 1999)

Northern bobwhites are host to parastic worms. These worms do not often kill their host, but their presence is associated with low body weight in northern bobwhites and this may negatively influence survival and reproduction. Northern bobwhites also host a wide variety of external parasites such as lice, ticks, mites, and fleas. (Brennan, 1999)

Northern bobwhites are important prey for birds of prey and small, terrestrial predators. They are also important seed and foliage predators and may influence the plant communities in which they live.

There are no known adverse affects of northern bobwhites on humans.

Economically, northern bobwhites are one of North America's most important game birds, especially in the southern and midwestern United States. Annual harvest in 1970 was estimated to be 35 million birds in 37 states and 2 Canadian provinces, the largest harvest of non-migratory upland game birds (Dimmick 1992). Northern bobwhites are one of the most extensively studied species of birds in the world. They have played a major role in captive laboratory studies to test the physiological and behavioral effects of pesticides on wildlife. They also were the subject of the first modern systematic study of a wild animal's life history in relation to environmental and habitat factors that influence its abundance. (Brennan, 1999; Dimmick, 1992)

Populations of northern bobwhite are declining. Habitat loss, particularly due to the increase in large-scale farming and the reduction of fence rows and suitable habitat plots are thought to be the major factor in the decline. One subspecies, the masked bobwhite (Colinus virginianus ridgwayi), is considered endangered. Northern bobwhite are listed as near threatened by the IUCN. (Brennan, 1991)