Penguins are marine flightless birds that usually have the same diet of many other seabirds. Penguins’ diet includes small fish, squid, and crustaceans. It is not a hard task for the penguins to eat their prey. They have a hook-shaped bill which can catch hold of the prey without letting them slip down.
There is also spiky bristle that faces back towards the throat which can effortlessly help in clutching the dinner to swallow. Penguins eat their food when they are in the ocean underwater.
Penguins do not live in fresh water when they swallow the food the glands in the body filter the salt from the water and send them out through the bill. The filtration is done by the system when the penguin drinks the salt water; it doesn’t affect their body.
The backward faced stiff spine which is continued till the throat help the live prey from slipping and also takes care of rough handling of the food for sending to digestion.
The food diet of the penguins depends on each species. Penguins have strong jaws to catch the prey, and they also swallow them as a whole and never try to eat by poking the prey.
Penguins can dive up to 60 feet below the surface of the water. They can effectively dive and swim where they cannot miss swallowing the prey when they are hungry. The food preferences of penguins depend on the genus to which they belong and also the climatic conditions and habitat where they are endemic.
Chicks and their food:
Until chicks grow with the plumages grown completely with the oil coating to become waterproof, they don’t go for hunting. The newborn will be under the father or mother’s body until they complete two weeks.
Even though the chicks waddle along with other chicks in the crèche, the parents feed them. The parents, who go for hunting, get half-digested food and drop it into the chick’s mouth.
Adult penguins feed their chicks in three distinct ways. They throw up the food once they are from hunting. This method of regurgitating the food carried when the food gets digested in the parent’s stomach.
Once the adult penguin reaches the chick, it regurgitates the food forcefully to transfer it to the young. The digestion before regurgitating takes few hours.
Sometimes it is noted by the scientists that few species of penguins digest the food completely and only through up the milk obtained from the fish. The completely digested food in the parent’s stomach takes a lot of days to result with the milk. The oil got out of the thoroughly digested fish, krill and crab are the milk achieved.
Researchers also have found that penguins store the whole prey in the stomach for some days to feed the chicks when they are backing home after hunting. The enzymes in the penguins’ stomach prevent the food from getting spoilt. Even though, when the swallowed prey is in body temperature, it is preserved by the enzymes secreted.
The method of feeding the chicks is similar in penguins, and also the method is common in other bird species. The traditional way of feeding food is always preferred by the penguins to transfer the half-digested food to the chick’s mouth.
Since the chick’s mouth will be quite small to take the food; the adult penguin arranges the food to accommodate in the little ones’ mouth with the help of their beak which acts as a spoon to keep the food in place.
Penguins’ digestive system:
Penguins’ digestive system is similar to that of the human’s digestive system. Not only the digestive system is similar; even the physiology is similar to that of human’s.
The digestive system of penguin consists of mouth, esophagus, gizzard, intestine, liver, pancreas, cloaca, gullet, proventriculus and glands that filter the salt water. During winter, molting and incubating season, penguins do not eat food and they even fast for long days.
At the time of fasting, penguin’s digestive system does not get harmed in any way. Like few birds, penguins do not have a crop for the chicks to feed. The two-chambered stomach helps the penguins to store the food to carry to the chicks.
The food to feed the chicks is in the first chamber, the proventriculus. Common of the digestion takes place in the gizzard, and the grit helps in crushing the stronger food.
Food and the stone:
Apart from swallowing the prey, penguins also swallow the stones to reduce the buoyancy when they dive for hunting. They swallow the stones one by one to up to certain numbers by picking up by their bill.
Penguins swallow stones by shaking their neck to and fro to get the stones to roll down the throat. It scientists believe that this behavior is carried to ease out the digestion process by breaking the food.
Maybe the necessity to swallow the stones might be because of the diet which consists of vertebrates like fish, crustaceans and rock crabs. Not every penguin swallow stones, rockhopper penguins and chinstrap penguins had swallowed the highest number of stones.
Conclusion:
Penguins also eat snow which is fresh water. The salt water is taken care of the glands in the eyes. So penguins will not face any ill effects by the salt water while swallowing the food.
The keen eyesight of the penguins helps them spot the prey easily and reach them more swiftly before they move from the targeted position.
Penguins are opportunistic feeders; they eat which is available in their habitat. To build up fat for energy conservation, they have to feed mainly on fish and krill. A small variety of fish makes the major part of the penguins’ diet.
The amount of intake of food depends on the season to season. Like, in summer they consume a lot of food since they work very hard and in winter they consume one-third of the usual quantity.
Penguins do not have teeth, but the tongue which has the sharp spines does the required job with the food. The sharp bill aids penguins to get the krill that are under the ice and in between of the ice or small rocks.
In many of the penguins’ habitat, krill is the abundantly found food, and they consume krill since it is easy to catch by all sized penguins. The spines on the throat also help to keep the prey in place and collect the krill and trap it as a net.
References:
https://sciencing.com/penguins-feed-their-chicks-4567587.html
https://www.kidzone.ws/animals/penguins/facts4.htm
https://sciencing.com/penguins-hunt-food-4567269.html
https://www.animalwised.com/a-penguin-s-diet-what-do-penguins-eat-372.html
https://www.thespruce.com/what-do-penguins-eat-386597