Yes, gallinules are excellent swimmers. Gallinules are medium-sized marsh-dwelling birds that belong to the rail family Rallidae. There are two main species of gallinule – the Common Gallinule and the Purple Gallinule. Both species have long toes and a frontal shield on their forehead that allows them to swim by spreading their toes. Their light body weight also allows them to walk on floating vegetation. Gallinules are found across North America, South America, Europe, Africa, Asia and Australia. They inhabit marshes, ponds, lakes, rivers and wetlands. With their superb swimming abilities, gallinules are well adapted to their aquatic lifestyle.
Anatomy of Gallinules for Swimming
Gallinules have several key anatomical features that enable them to be agile swimmers:
Long Toes
Gallinules have exceptionally long toes on both their feet that they can spread widely to allow them to propel themselves in water and walk on floating vegetation. Their long toes give them more surface area to provide propulsion in water.
Partial Webbing
The toes of gallinules are partially webbed. Webbing between their toes again improves the surface area of their feet and enables them to push more water backwards as they kick.
Frontal Shield
Gallinules have bare fleshy frontal shields on their forehead which extends partially down their bill. This shield allows them to cut through the water and protects their eyes when swimming.
Lightweight
Gallinules have an average weight of around one pound. Their lightweight frame means less force is required for them to propel themselves through water. Heavier birds would struggle to swim.
Waterproof Feathers
Gallinules have waterproof plumage that prevents waterlogging while swimming. Their feathers contain oils that repel water. Staying dry improves their buoyancy.
How Do Gallinules Swim?
When swimming, gallinules use their long toes and partially webbed feet in a paddling motion to propel themselves through water. They move both feet in unison providing continuous propulsion. Their lightweight allows them to float high in the water. The frontal shield parts the water as they swim. Gallinules can swim several hundred meters at a time without needing to stop for a rest. They change direction with ease by steering with their feet. Generally they swim at a relaxed pace but are capable of bursts of speed when evading danger.
Swimming Behavior
Gallinules most commonly swim when foraging for aquatic vegetation or fleeing predators. Some key observations of their swimming behavior include:
- They swim to edges of ponds/lakes to feed on vegetation.
- The paddle amongst emergent vegetation.
- They escape predators by diving and swimming away using their swift swimming abilities.
- Chicks swim soon after hatching to follow their parents.
- They swim to roost sites at night or if disturbed.
- During the breeding season, males swim to establish and defend territories.
Diving Capabilities
As well as swimming on the water surface, gallinules can dive and swim underwater. They submerge their head first when diving. Their lightweight allows them to float back up easily. Gallinules may dive to escape predators or occasionally to forage beneath the surface. However, most foraging is done in shallow water that does not require full diving.
Comparison to Other Water Birds
When compared to other water bird species, gallinules rank as excellent swimmers due to their combination of adaptations. Their swimming capabilities compare as:
Vs Ducks
Ducks are heavier than gallinules and float lower in the water. Their webbed feet provide significant propulsion but are not as adept at walking on vegetation as the long toes of gallinules. Overall, ducks and gallinules both rank as very strong swimmers.
Vs Grebes
Grebes are specialist water birds that propel themselves with their feet as gallinules do. However, grebes have lobed toes rather than the long toes of gallinules. Overall grebes are faster swimmers optimized for diving, while gallinules are better adapted for shallow water.
Vs Coots
Coots are the closest relatives of gallinules and occupy similar ecological niches. However, coots have rounder wings and shorter toes that make them less efficient swimmers compared to gallinules.
Species | Swimming Ability |
---|---|
Gallinule | Excellent |
Duck | Excellent |
Grebe | Excellent |
Coot | Good |
Conclusion
In summary, gallinules are extremely well adapted for swimming and diving. Their long toes, partial webbing, frontal shield, lightweight and waterproof plumage enable them to swim at speed and maneuver with ease. They use their feet in a paddling motion to propel themselves. Gallinules swim when foraging, defending territories, escaping predators and travelling. Their swimming abilities compare very favorably to other water birds, establishing gallinules as one of the most adept swimming species of all marsh birds. So in answer to the original question – yes gallinules are excellent swimmers!