A terrestrial bird is a type of bird that stays primarily on the ground, not only foraging on the ground but also generally nesting and roosting on the ground or very low in shrubbery or brush. These birds will freeze, walk, or run when threatened instead of taking flight.
While some terrestrial birds are naturally flightless, others are simply reluctant fliers that may not be able to fly long distances easily. Most terrestrial birds that do fly will stay low above the ground or close to cover when flying, and typically fly only in short, frantic bursts rather than going long distances. Terrestrial birds are also known as land birds or ground birds.
Traits of Terrestrial Birds
In addition to their preference for keeping low, terrestrial birds also share a range of other physical and behavioral characteristics, although not all terrestrial birds will have every trait. These include:
- Round, plump jizz with compact body shapes and round heads that may look smaller than they should be for their body size.
- Blunt, rounded wings that make them less agile and unable to fly for long periods, and flight patterns that include rapid, frantic wing beats and direct paths.
- Heavily camouflaged plumage, particularly for females, though males may have bold coloration and markings that are useful for attracting mates and courtship displays.
- Large broods of chicks that can leave the nest shortly after hatching, though they remain under parents' guidance for several weeks or months.
- Most are social animals and gather in large family groups or flocks for safety, with some birds standing guard or serving as lookouts for the group.
- Generally non-migratory ranges or very limited migration due to their less developed flight abilities and dislike for flying.
- Strong, powerful legs that may be proportionally long for their body size but make them fast runners who can outrun their predators.
- Often, though not exclusively, terrestrial birds are herbivores, eating a diet of grains, seeds, and plants, although young birds will eat insects for protein.
- Terrestrial birds enjoy dust baths and sunning to help maintain their feathers, rather than getting wet and waterlogged that could make flying even more difficult for them.
Types of Terrestrial Birds
The most familiar terrestrial birds are popular game birds, including grouse, quail, pheasants, junglefowl, turkeys, partridges, prairie-chickens, sage-grouse, bobwhites, ptarmigan, and guineafowl. Domestic chicken breeds are also terrestrial. Other types of terrestrial birds are:
- Burrowing owls
While some of these birds are fully flightless, others are easily capable of flight but prefer to stay on the ground.
Flightless Birds That Aren't Terrestrial
While most flightless birds are terrestrial, there are several types of flightless birds that aren't considered terrestrial. Penguins and some flightless duck and grebe species are more aquatic and they spend the majority of their lives in the water. They forage in the water, evade predators, migrate, and may even perform courtship displays in water, making them different than other ground-dwelling birds.
As a classification, the term terrestrial is only applied to birds that are permanently ground-dwelling as mature, healthy adults. Pet birds or agricultural birds that have had their wings clipped as a way to limit escape attempts are not considered terrestrial, even though they have only limited flight abilities and instead stay on the ground or climb about their enclosures. If their trimmed feathers regrow, the birds would regain their full ability to fly. Similarly, injured birds that temporarily or permanently lack flight skills or young birds that have not yet learned to fly are not considered terrestrial.
Threats to Terrestrial Birds
Because terrestrial birds do not fly away from threats or predators, they face hazards that threaten their nests, breeding grounds, feeding ranges, roosting spots, and other territories. Terrestrial birds are vulnerable to habitat loss, as they are less capable of moving to new ranges if their habitat is destroyed. Invasive predators, including feral cats, are another threat to these birds, as their ground nests and life spent on the ground put them in the path of predators more easily. They are also susceptible to lead poisoning from shot pellets that may be left on the ground in their range, particularly since many terrestrial birds are also game birds that are hunted regularly and careless hunting practices can leave debris that will impact remaining birds.