Metabolism differences between Crocodiles and Raptor birds

Abhidyu Ajila
4 min readDec 22, 2021

The very existence of avians and reptiles are crucial to maintain balance in nature, while one soars the sky, the other lives on land dominating as the apex predator in certain regions. We have a plethora of examples and infographic shows tell alot about their characteristic and day to day life. But I’ll be talking about an essential component which produces energy for daily activities by uses stored food reserves which is also referred to as metabolism. In this article, I will be explaining what is metabolism and compare the rates of metabolism in raptors and crocodiles.

What is Metabolism?

Well, defining it most simply, metabolism is the conversion of the everyday food we eat into energy. This process helps us in accomplishing everyday tasks and performing at our very best daily. Several components come into play while talking about metabolism i.e food habit, habitat, and body mass.

Metabolism in Birds Of Prey (Raptors)

Birds like falcons, shikra, eagles and owls come under the category raptors or also known as birds of prey. They hunt for food and have a high protein diet. Since they’re always on the move to hunt for prey, they tend to use a lot of energy and have a high rate of metabolism. Since the rate of metabolism varies between particular species, we do know that the larger the bird in size the more metabolic activity will take place. Birds of prey are categorised in 2 types: Generalist and Specialist. Examples (Specialist: hummingbirds) (Generalist: Common Buzzard)

Metabolism rates in Common Buzzard(Buteo buteo)

Picture credits : ebird.org

Description: Medium to the large-sized bird of prey, they occur in Europe with their subspecies found in Africa and Eastern Asia. They are generalist types of predators which feed on all types of prey from mammals to invertebrates. They usually stay on a perch and when they’ve located their prey, they fly directly towards it. Furthermore, they also walk on the ground in search of invertebrates. If any of the following conditions are not favourable or they can’t find any prey, they’ll feed on carrion.

Picture Credit: fernbank.org

Being a generalist type of raptor, buzzards tend to have a larger small intestine which allows them to have better digestion and also have a good metabolism and metabolic rate with recent studies showing that common buzzards have a glucose range between 15.0 to 28.0. These types of high metabolism are necessary for such raptors which use a lot of energy while hunting and flying distances.

Picture Credit: theguardian.com

Metabolism rates in Saltwater Crocodile (Crocodylus porous)

Picture Credit: quora.com

The saltwater crocodile is an opportunistic hyper carnivorous( diet consisting of 75 per cent or over it meat either by hunting or scavenging) apex predator and tends to ambush its predators then drowns them or eat them whole. They are found from the Eastern coasts of India to Northern Australia. They tend to eat all sorts of prey from water buffaloes to turtles, no one can survive the 3700 psi or 16,460 Newton’s of bite force. But unlike the common buzzard, the saltwater crocodile is a cold-blooded reptile so it releases fewer amounts of energy when not hunting, generally lethargic they bask in the sun and stay stationary during daytime and hunt at night. This trait specifically allows them to survive for months without food and keep a slow metabolism as they get their energy while loitering under the sun. Since they absorb and use sunlight as an energy source. Despite all this, they are very agile predators. They tend to have a lower glucose range around 4.5–12.1.

Picture Credit: Wikipedia.org

The study of metabolic rate and glucose rates of Common Buzzard and Saltwater Crocodile shows us the difference between the two different classes of animals also being closest relatives having unique sets of hunting behaviour and energy conversion from the food they consume while having absence of carbohydrates in their diets. While we humans and herbivorous mammals have carbohydrates in our diets, carnivores don’t so inorder to get energy they go through glyconeogenesis while we humans go through glycogenesis. Futhermore, habitats and food habits also contribute towards higher or lower metabolic rates in them along with their behaviour, with Saltwater Crocodiles being lethargic and Buzzards being inactive for most of the time except while hunting when they show real prowess and high levels of agility.

If you love nature and the amazing world of animals then this blog is for you. If you like what I write, then please like and share it with fellow nature and animal enthusiast. As always, in this unprecedented times take it easy. Have a nice day ☺️

References
1. https://www.researchgate.net/publication/263093117_Comparison_of_metabolic_substrates_in_alligators_and_several_birds_of_prey
2. https://journals.physiology.org/doi/abs/10.1152/ajplegacy.1973.225.6.1389

3. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/glyconeogenesis

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Abhidyu Ajila

A zoology student who talks animals, conservation, evolution and geography