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 also prefer to freeze, walk, or run when threatened rather than taking flight. While some terrestrial birds are naturally flightless, others are simply reluctant fliers that may have cumbersome flight styles less suited to lengthy flights. Most terrestrial birds that do fly generally stay low above the ground or close to cover when flying, and typically fly only in short, frantic bursts rather than making lengthy flights.
(rhymes with "her-rest-tee-hull herd" and "curr-best-fee-dull curd")
In addition to their preference for keeping low, terrestrial birds also share a range of other physical and behavioral characteristics, including:
- Round, plump jizz with compact body shapes and often round heads that seem proportionally small for the bird's overall size
- Blunt, rounded wings that are less capable of aerial acrobatics, longer flights, or maneuverability, 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 precocial chicks that can leave the nest shortly after hatching, though they remain under parents' guidance for several weeks or months
- Often gregarious behavior and gather in large family groups or flocks for the protection available in numbers, 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 reluctance to fly
- Strong, powerful legs that may be proportionally long for the overall body size and are essential for fast running and outdistancing predators
- Often, though not exclusively, herbivorous diets of grains, seeds, and plant material, though insects are important as protein for young, growing birds
- Preference for dust baths and sunning to help maintain their plumage, rather than getting wet and waterlogged that could further compromise their limited flight abilities
Not all terrestrial birds may exhibit every trait, but all these birds do share at least several of these characteristics in their ground-dwelling lifestyles.
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 that are less well known but no less ground-loving are:
- Burrowing owls
While some of these birds are fully flightless, others are easily capable of flight but generally prefer to stay on the ground.
Flightless Birds That Aren't Terrestrial
It is easy to assume that all flightless birds must be terrestrial. While this is largely true, there are several types of flightless birds that aren't properly considered terrestrial. Penguins and several flightless duck and grebe species are far more aquatic than they are terrestrial, 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 aquatically, making them far less terrestrial than other ground-dwelling birds.
It should be noted that 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. When their trimmed feathers regrow, the birds would regain their full flight capabilities. Similarly, injured birds that temporarily or permanently lack flight skills or young birds that have not yet learned to fly are not considered terrestrial. As a classification, the term terrestrial is only applied to birds that are permanently ground-dwelling as mature, healthy adults.
Because terrestrial birds do not readily fly away from threats, they face grave hazards that threaten their nests, breeding grounds, feeding ranges, roosting spots, and other territories. Terrestrial birds are acutely vulnerable to habitat loss, as they are less capable of relocating to new ranges if suitable habitat is destroyed. Invasive predators, including feral cats, are another critical threat to these birds, as their ground nests and terrestrial habits 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.
Terrestrial birds are also known as land birds or ground birds.