Adaptations: How has the Mallard thrived?

Photo coutesy of Terry Sohl
Camouflage

These birds have developed feathers that enable them to blend in to their habitat quite well. The females have brownish feathers that mimic that of the marshes, potholes, and smaller reed-covered waterways that make them almost undetectable. The young have similar colored down before they mature and grow their more distinctive feathers.

The males have their very distinctive green head, white ring collar, and dark brown chest. The males, however, will lose much of their coloration after breeding in the spring. This time period is called the 'eclipse molt', where the males will also lose their flight feathers until around August. Females will also lose their flight feathers once the ducklings can fend for themselves. Until they grow their flight feathers back, they are unable to fly, and therefore must be able to blend in better than normal, which is why they end up looking somewhat plain and can avoid predation better.

Defending the Young

The males will leave the females to raise the young ducklings on her own and will usually congregate with other males. The females must be able to deter predators using some interesting strategies. If a threat approaches, the mother will sound the alarm by quacking loudly. If the threat gets closer, she will usually fly away, leaving her ducklings behind, trying to draw the predator away from the nest. The ducklings have been taught to remain still and quiet. The mother will sometimes (if they are in or near water) swim out into the open water and flop around, as if she was injured. This is another way to try and draw the threat away from the little ones. Females are not afraid to attack or threaten other ducks if they wander too close to their own ducklings. Despite all of her tricks, she will be fortunate to keep four or five ducklings through the summer.
Photo courtesy of Terry Sohl
Flight

The Mallard, unlike many other large birds, has the ability to take off or 'explode' out of the water almost vertically. Many other diving birds, such as the loon, need a large area to take off. The Mallard almost jumps right out of the water and can ascend rapidly before leveling off. This is due to the enormous force generated by the wings, in conjunction with the rapid paddling of its webbed feet. This ability enables them to escape danger very quickly.

The Amniotic Egg

The ability for reptiles, birds, and some mammals to reproduce utilizing the amniotic egg. This egg is an important feature of these terrestrial animals. The embryo can develop without drying out, and it can survive in a variety of habitats outside of water. The different sections of the egg provide the embryo with water, food, and other nutrients, and also removes and contains wastes. Oxygen and carbon dioxide can easily diffuse through the shell also.

Other Physiological Adaptations

Webbed feet allow the Mallard to paddle quickly and efficiently on the water and underwater if necessary. Most birds that have webbed feet can move efficiently through the water, but usually walk awkwardly on land. The caudal arrangement (further towards the tail end compared to other related birds) of the feet help the feet aid the Mallard in walking less awkwardly.

The bill has been flattened out and uses well defined lamellae for use in filter-feeding on items underwater in debris-filled water.

Since the bill is optimized for filter-feeding and not biting and tearing food, and does not have talons to tear apart food, the Mallard needs an efficient way to digest the food it consumes. Many birds have a gizzard to do this, in addition to a true stomach. The gizzard is used to grind and squish the food that is ingested. The Mallard will often swallow small rocks or similar objects which travel down to the gizzard and aid in breaking down the food. This food is then passed on to the true stomach where most of the digestion will take place.

The feathers and buoyancy of the Mallard are also very important given what type of habitat the Mallard resides in. The Mallard is an exceptional swimmer in the water, but it also must be able to repel water. The feathers utilize oils that make it incredibly water resistant.     



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