Slate gray head and back; rufous (reddish brown) breast; pale rufous belly; slate gray central tail ; white outer tail feathers; red eye. Approx. 20 cm (8 in) wingspan. Wedge-shaped tail, pointed at the center.
The breeding season for this bird was probably from April extending until July. The breeding habitat was forested areas. The Passenger Pigeon was mostly a colonial nesting species, with up to 100 nests in an individual nest tree grouped into a colony spanning up to hundreds of square miles. The nest was a platform nest made from twigs. Usually, the female laid one egg that was incubated by both adults for about 13 days. Apparently the male did most of the incubating during midday (from about 10 a.m. to 3 p.m.). The adults would care for the altricial young for about two weeks, after which the chick was left to fend for itself.
These birds were highly social, collecting into large flocks for migration. Some flocks were recorded to have been a mile wide and around 300 miles long, darkening the sky for days as they passed through an area. A single flock has been estimated to have had up to 2 billion birds. During migration, groups of Passenger Pigeons gathered in an area to roost for the evening.
The range of the Passenger Pigeon was apparently throughout North America east of the Rocky Mountains. The winter range was in the southern United States.
The Passenger Pigeon was once the most abundant bird in North America, with numbers estimated as high as 5 billion birds, but it is now extinct. Its large numbers and its colonial nesting and roosting behavior made killing many birds fairly easy. Some records list a processing plant that handled over 18,000 birds each day in 1855. Passenger Pigeons were hunted for their market value as a food source, and new weapons helped increase the number taken. The decline of this species reportedly began as early as the mid-1800s. The last known Passenger Pigeon died in the Cincinnati Zoo in 1914.
The most similar species is probably the Mourning Dove. The Mourning Dove is smaller, lacks the reddish breast, and has a dark spot on each side of the neck.