Birds that spend a lot of time on their knees are usually those that feed or nest on the ground. Some examples of birds that are often seen resting or feeding in a kneeling position include:
Shorebirds
Many types of shorebirds and wading birds spend time on their knees while feeding along shorelines and wetlands. This kneeling position allows them to easily probe into mud or wet sand to catch prey like worms, crustaceans, and mollusks. Examples include:
- Sandpipers
- Plovers
- Stilts
- Avocets
- Snipes
- Oystercatchers
- Curlews
- Godwits
These shorebirds have long legs and bills adapted for probing into the substrate while walking along the shore. Getting into a kneeling position allows them to stabilize themselves and reach even deeper into the mud or water to find food.
Waterfowl
Many species of ducks, geese, and swans also spend time resting and feeding in a kneeling position at the edge of water bodies. This includes birds like:
- Mallards
- Pintails
- Teal
- Wigeons
- Shovelers
- Geese
- Swans
When these waterfowl tip their bodies forward to put their belly and legs into the water while keeping their rear end elevated, it allows them to feed on aquatic plants and small organisms underwater. The kneeling position helps them remain stable and balanced while reaching into the water.
Gamebirds
Various gamebirds that nest and feed on the ground are also known to spend time resting on their knees or legs. These include types of grouse, quail, pheasants, and partridges. Examples include:
- Ruffed grouse
- Spruce grouse
- Greater prairie-chickens
- Ptarmigan
- Sage grouse
- California quail
- Gambel’s quail
- Ring-necked pheasant
- Chukar partridge
- Grey partridge
When resting, these gamebirds will often squat or crouch down into a kneeling position. Their feathers and cryptic coloration allow them to blend into the vegetation and avoid predation. The kneeling posture helps stabilize them while remaining alert.
Songbirds
Some songbirds that forage on the ground may also periodically rest on their knees while pausing between bouts of searching for seeds or insects. Examples include:
- Sparrows
- Juncos
- Towhees
- Larks
- Meadowlarks
- Blackbirds
- Grackles
Kneeling allows these species to take quick breaks while remaining close to the ground where their food sources are located. Their drab brown, grey, or black plumage helps conceal them from potential predators while they are in this resting posture.
Seabirds
A few seabird species will also kneel or squat down into the substrate while nesting. Examples include:
- Black skimmers
- Terns
- Noddies
- Murres
- Murrelets
- Guillemots
- Auklets
- Puffins
Many of these seabirds nest on precarious cliffsides or rocky islands. Kneeling down into their pebbly nests helps stabilize their eggs and chicks and prevent them from rolling away. It also allows adult birds to lower their profile and avoid attracting predators or harsh weather.
Penguins
Penguins spend a lot of time resting and nesting in a kneeling or squatting position. All 17-18 species kneel frequently, including:
- Emperor penguins
- King penguins
- Adelie penguins
- Chinstrap penguins
- Gentoo penguins
- Macaroni penguins
- Rockhopper penguins
- Little penguins
Penguins often nest on hard, rocky terrain. Kneeling helps cushion their bellies and feet. Their upright posture allows them to stay alert for predators trying to steal their eggs and chicks. Their dark back feathers blend in when kneeling, while their white fronts help camouflage them against snow and ice.
Ostriches
Ostriches are very large, flightless birds that also spend a lot of time resting and nesting with their legs folded underneath them in a kneeling position. When sitting on their folded legs, they press their body low against the ground.
Their camouflage-patterned feathers allow kneeling ostriches to blend into the grasslands and savannas where they live. Their kneeling posture helps stabilize their huge bodies while incubating eggs in simple ground nests. It also allows them to quickly stand up to escape predators if needed.
Cranes
Some cranes species like the Sandhill crane and Siberian crane occasionally rest or nest in a kneeling position. However, most cranes usually stand while resting and nesting rather than kneel down.
Ravens
Common ravens sometimes rest on their bellies with their legs folded underneath them in a kneeling posture, especially during cold weather. Kneeling helps conserve body heat and minimize their exposure during icy conditions.
Pigeons
Rock pigeons and other columbid species sometimes kneel while feeding on the ground, resting on perches, or making nests. The kneeling posture allows them to reach forward and access their food or nesting material. Their small size helps stabilize them while kneeling.
Conclusion
In summary, a wide variety of birds spend a lot of time resting, feeding, or nesting on their knees or hocks. Shorebirds, waterfowl, gamebirds, and seabirds rely on the kneeling posture to stabilize themselves in wet, muddy, or uneven terrain. Penguins and ostriches use kneeling to conserve heat and camouflage themselves. Songbirds, corvids, pigeons kneel periodically to reach food or nesting material. However, kneeling behavior is especially prominent and near-constant in shorebirds, penguins, and ostriches.
Kneeling allows these birds to stabilize themselves, access food resources close to the ground, incubate eggs safely, and lower their profile to avoid predators. Their feathers and coloring also help camouflage them in their respective environments while in a kneeling posture. For birds that occupy open areas on land or along the shoreline, resting on their knees provides an effective form of rest while remaining alert and ready to quickly react to danger.
| Bird Group | Example Species | Primary Function of Kneeling Posture |
|---|---|---|
| Shorebirds | Sandpipers, plovers, oystercatchers | Stabilize while feeding in water/mud |
| Waterfowl | Ducks, geese, swans | Reach underwater food sources |
| Gamebirds | Grouse, pheasant, quail | Resting while camouflaged |
| Seabirds | Auks, murres, guillemots | Incubate eggs on cliffs |
| Penguins | All species | Conserve heat; protect eggs |
| Ostriches | Common ostrich | Stabilize large body; incubate |
Other Details on Kneeling Birds
Anatomy
Most birds have an anatomical joint between their tibiotarsus leg bone and tarsometatarsus foot bone that functions similar to the human knee. However, in birds this joint is referred to as the “hock” rather than the knee. When birds lift their tibiotarsus vertical and fold their tarsometatarsus horizontally underneath, they are essentially “kneeling” on their hocks even though the joint is not anatomically a true knee.
Nesting
Birds that nest on the ground, such as ostriches and penguins, rely heavily on their kneeling posture to stabilize their eggs against the substrate. The parent bird’s feathers and body heat help incubate the eggs when pressed close to the ground. Kneeling allows convenient access for rotating the eggs as needed during incubation.
Temperature Regulation
Penguins and other cold climate birds often kneel to conserve body heat. Pressing their bodies against the ground allows chilled air to pass over their backs while their belly remains insulated against the substrate. Their feet are also protected beneath their body in the kneeling posture.
Anti-Predator Adaptation
For many ground-nesting shorebirds and seabirds, kneeling behaviors evolved in part to avoid attracting predators. By flattening themselves close to the substrate, kneeling birds minimize their visible profile and avoid standing out. Their camouflaged feathers allow them to blend into the surrounding environment when resting on their knees.
Physical Adaptations
Birds that kneel frequently have evolved some physical adaptations that facilitate the posture. Long flexible legs, shortened or reduced back toes, and feathers or skin resistant to abrasion are some examples. These adaptations prevent injury and allow extended periods of kneeling comfortably.
Conclusion
Birds across many families demonstrate kneeling behaviors, but shorebirds, penguins, ostriches rely most heavily on this posture. Kneeling provides major benefits like stability while feeding and nesting, temperature regulation, predator avoidance, and access to ground-based food sources. Unique anatomical adaptations allow birds to safely spend prolonged periods resting on their knees (or hocks) as needed. While not all birds kneel, it is an incredibly important position for those ground-dwelling species that have evolved to utilize it regularly.
