Season 1: Episode 1- King Kong

We dive into King Kong, from 2017’s Kong: Skull Island. Adam has a creative system for Kong’s heat loss, Dave turns one of the most majestic movie monsters of all time into a hairless, toeless freak, and Sam sits around mumbling things hungover.

Film: Kong- Skull Island [2017]
Production Company: Legendary Pictures & Tencent Pictures
Distributed By: Warner Bros. Pictures
Monster: King Kong
Featuring: Sam, Adam, David
Rating: Mature (for some offensive language and adult themes)

Episode 1- King Kong Fact Sheet



physiology- kong 1
Warner Bros. Pictures, 2017


King Kong might be the ruler of skull island, but his biology would apply by the same basic laws that govern all life on our planet. In this section, we will discuss some of the general aspects of how King Kong might work in the real world and if he would be able to breathe, eat, and move around like the rest of us.


In the film we know that King Kong is a juvenile male, but for the sake of our discussion we will treat him like an adult. He also appears to be some form of hybrid between a gorilla and a chimp. In order to have a discussion about his physiology, we should talk about the two species he is based upon.

Common Chimpanzee (Pan troglodytes)

The average common male chimpanzee stands approximately 1.2 metres tall and weighs approximately 91 kilograms. They are native to sub-Saharan Africa and their diet consists primarily (98%) of vegetations including leaves, seeds and fruits. A small portion of their diet (2%) is also made up of insects, eggs and meat (including other primates)

Height= 1.2 metres
Weight= 91 kg

Western Gorilla (Gorilla gorilla)

The average western gorilla male stands approximately 1.6 metres tall and weighs approximately 204 kilograms. They are native to sub-Saharan Africa and their diet consists primarily of fruits, vegetables and insects. They do not consume meat, and rarely drink water as most of their hydration is met by the consumption of succulent vegetation and morning dew.

Height= 1.6 metres
Weight= 204 kg


Knowing some facts about the animals that King Kong is based upon, allows us to roughly calculate what his mass would be by applying the square-cube law to our example species.

The square-cube law (or cube square law) is the idea that if a cube doubles in height, its’ surface area and and volume will not simply double as well. Instead, these values will increase logarithmically as the cube values on all sides are increased by a factor of two. This means that if a cube doubles in height (2x), the surface area will increases by four times (x^2 = 2^2 = 4) and the volume will increase by 8 times (x^3 = 2^3 = 8). In biology, if an individual is twice as tall as a similar animal, its’ cross sectional areas (example leg diameters) will be four times greater (x^2) while its’ weight will be eight times greater (x^3).

The official statement from Warner Brothers stated that King Kong was approximately 100 feet or 30.5 meters tall. Using this information we calculate that:

  • King Kong vs Gorilla Mass Calculation:
      • King Kong is approximately 17 times taller than an average gorilla
      • King Kong’s weight would be ~17^3 or 4913 times greater than a gorilla
      • Weight Estimate= 1,110,338 kg
  • King Kong vs Chimpanzee Mass Calculation:
      • King Kong is approximately 26 times greater than an average chimpanzee
      • King Kong’s weight would be ~26^3 or 17576 times greater than a chimpanzee
      • Weight Estimate= 1,599,416 kg
  • King Kong Estimated Mass
    • If we take an average between the two values
    • King Kong Estimate Weight= 1,360,777 kg or 1500 tons

King Kong’s Mass- Final Thoughts
King Kong would be a very heavy animal. He would have difficulties supporting himself, meeting his metabolic requirements, and simply breathing. We explore some of these ideas below.


King Kong would need a very high metabolism to move his extreme mass around. When discussing the energy requirements of life of life on earth, we discuss their Basal Metabolic Rate (BMR) and their Daily Energy Requirements (DER).

The BMR is a measure of the amount of energy required per day for any creature to function. This is just a measure of the amount of energy needed to run internal processes, without taking into account external activities. To calculate what King Kong’s BMR might be, we will need to use Kleiber’s Law.

As a mammal or endotherm increases in size, it’s metabolism does not scale at the same rate. As a mammal grows, it is better able to hold its’ owner body heat and regulation of many basic internal functions take about the same amount of energy regardless of size. As a result, a mouse has a much higher proportional metabolic rate than an elephant. This relationship is expressed by Kleiber’s Law in the following formula:

BMR (kcal/day)= (a)M^¾
*a= the constant of proportionality (often rounded to 50)
*M= mass

Over the years there have been modifications to Kleiber’s Law to try and better take into account variations in temperature, lifespan, etc. However, for the sake of simplicity we will continue to stick to Kleiber’s original formula.

  • Simple Kleiber’s Law BMR Estimate
    • Just using Kleiber Law on its own will give us a basic idea of what Kong’s metabolism would look like. For simplicity we can use the constant of proportionality most often use with humans (a= 50):

      *a= 50
      *M= 1,360,777 kg
      BMR= 1,992,096 kca/day
  • Kleiber’s Law BMR Estimate- Gorilla Comparison
    • In order to better explore what the metabolic requirements might look, we can also calculate a constant of proportionality based on a gorilla.An average gorilla weighing 123.7 kg has a BMR of ~3160 kcal/day
      BMR = (a)M^¾
      3160= (a)123.7^¾
      a= 37
      Gorilla to Kong BMR= (37)(1,360,777^¾)= 1,474,151 kcal/day
  • King Kong BMR Estimate
    • Kong’s BMR will be between 1,992,096 kca/day and 1,474,151 kcal/day.
    • Kong will have an average BMR of 1.7 million kcal/day

The DER is a the amount energy required for an animal daily activities. This includes the energy required to run internal processes plus what is used in running, hunting, foraging, etc. To calculate it, we take the BMR and multiply it by a set value base on how active our animal is. Kong would be a very active animal running across the island, fighting with skull crawlers, and trying to take down helicopters. In veterinary medicine, an active animal’s DER is typically placed between 2 and 5 times their BMR.

  • KONG DER= (2-5)(BMR)
    DER= (2-5) (1,777,534 kcal/day)
    DER= 3,555,068 to 8,887,672 kcal/day
    Mean DER= ~6 kcal/day

Meeting Metabolic Requirements
King Kong would need to meet his incredibly high energy requirements, the same way that other primates do, by consuming food. There is only one clear time during the film during which Kong can be seen eating. The primary example being the consumption of the mire squid. We can roughly calculate how many kcal might be obtained by their consumption by taking a normal squid and scaling it up:

  • Average Kcal Per Mire Squid
    Average Squid Weight= 10 metres and 199.6 kg
    Average Squid kcal= 92 cal/100 grams
    Estimated Mire Squid Height= 37 metres (~3.6 times greater than average squid)
    Estimated Mire Squid Weight= 47 times weight increase= 9381 kg
    Estimated Total Kong Giant Squid kcal= 863,052 kcal
    1 Squid= Approximately 1/8th of Kong’s Estimated DER

King Kong’s Metabolic Rate- Final Thoughts
King Kong’s metabolic requirements would be very high based on what was seen, and I am not sure he could make them. It is more likely that he would take on survival strategies like decreasing his general activity and sleeping for long periods in order to ensure that he wouldn’t starve and perish.


All animals must consume a certain amount of fluid per day in order to maintain a fluid balance. Fluids are crucial for removing metabolic waste products, hydrating our cardiovascular system, and just generally keeping us alive. The average human male consumes around 3.7 liters of fluid per day.

King Kong Fluid Rate Calculations
Gorillas in the wild get very little hydration from their environment directly, and get most of their fluid from their fruit. However, as there appears to be no megafauna on Skull Island, Kong will not be able to do this. Instead he will need to consume water directly. To calculate this, we need to understand that an average animal requires 50-70 mL of fluid per kg of weight per day to survive [Boardman 2009], meaning that Kong will require:

Fluid Maintenance Rate= 50-70 mL/kg/24hrs
Kong Mass= 1,360,777 kg
Kong Maintenance Rate= 68,038,850 mL-95,254,390 mL (~ 68,038 to 95,254 L per day)
Kong Estimated Daily Fluid Requirements= 81 thousand L/day

King Kong Fluid Requirements- Final Thoughts
Unlike gorillas or some other primates, Kong would need to focus on making his fluid requirements through direct consumption of fluid from local water sources. Luckily, based on the fact that he lives on an island with lots of lakes in a tropical environment he will probably be able to meet these demands through frequent trips to the lake to drink.


As we discussed previously, the Square-Cube Law applies to all aspects of an enlarged organism’s physical makeup, including bones. As discussed, an animal that is twice as tall as another, will have cross sectional areas of the bones four times as great, and a weight eight times as great. Larger terrestrial mammals carry much larger relative masses on their bones, and are often at a much higher risk of breaking bones or developing joint issues, than are smaller animals. To discuss how the issues that King Kong would face walking on only his two hind limbs, we need to know how big his bones would be

Chimpanzee to Kong- Bone Calculations
The simplest method of discussing how big Kong’s bones would be is by discussing how thick his femur would be. The femur is one of the strongest bones in your body and is found within the thigh, connecting your lower leg to your pelvis. Since King Kong spent most of the film walking like a Chimpanzee, his comparison to their skeletal structure and measurements would make the most sense:

  • Chimpanzee Femur Values
    Average Total Height= 1.2 metres
    Average Femoral Head Diameter=  33.9 mm [Kuo 1998] (or 0.2914 metres)
    Average Femur Length=  291.4 mm [Kuo 1998] (or 0.0339 metres)
    Average Skeleton Weight= 15% of total mass
    Average Single Femur Weight= 3% of skeleton mass
  • Kong Femur Calculations
    Kong Height= ~25 times greater than an average chimpanzee
    Estimated Kong Femur Length= 0.2914 x 25.4= 7.4 metres
    Estimated Kong Femur Diameter= 0.035 x 25.4= 0.86 metres (radius= 0.43)
  • Kong Femur Volume Calculations
    *To get the volume of the femur we will estimate the femur to be a cylinder (V=π(r^2)h)
    Estimated Kong Femur Length= 7.4 metres => 291.3 inches
    Estimated Kong Femur Radius= radius= 0.43 metres => 16.9 inches
    V= 2.61×10^5 or 261000 cubic inches
  • Kong Femur Weight Calculations
    Kong Weight= 1,360,777 kg
    Estimated Kong Total Skeleton Weight (15% of mass)=  204,117 kg
    Estimated Kong Single Femur Weight (3% of skeleton) = 6,124 kg

Kong Femur Weight Bearing Abilities
It is reported that a cubic inch of bone can in principle bear a load of 19,000 lbs (8,626 kg) before it breaks (compression force). Therefore, if we assume that approximately 40% of the femur is composed of marrow:

  • Weight Support Based On Cubic Inches Of Bone
    Volume of Kong’s Bone Filled Femur= 261,000 x 0.4=> 104400 cubic inches
    Load Bearing Capabilities of One Kong Femur = 900,554,400 kg

Kong Femur Strength- Final Thoughts
In theory, King Kong’s femurs would be able to individually bear his incredible weight. However, we only calculated for the compression forces (weight pushing down on the bone). It is still likely that stress applied along the length of the bone would be able to fracture it, and it is unlikely that King Kong’s joints would be able to bear his weight as well as his bones. In order to work, it is likely that King Kong would adapt many of the features seen in large terrestrial animals. He would not be able to jump or risk destroying the joints in his knees, he would need to reduce the total length of his bones to decrease the risk of fractures from bending forces, and he would need to remove his toes (like an elephant) or risk tearing them off with each step.


Another effect of the Square-Cube Law is that larger animals have less relative muscle strength than small animals. Both the muscle strength and bone strength are functions of the cross sectional area, while the weight of the animal is a function of volume. It is because of this that an ant can lift 50 times its own weight, a human can lift approximately its own weight, and an elephant can lift only 25% of its own weight. The greater muscle to weight ratio of smaller animals allows them to jump several times their own height, while an elephant cannot jump at all.

King Kong Musculoskeletal- Final Thoughts
In order for King Kong to move around, he would need to bound by the same limitations. He would not be super strong and would be able to realistically lift far less than even 25% of his owner body weight. He would be very slow moving and rely primarily on slow twitch/endurance muscle fibers to slowly life his large limbs and place them carefully back down, taking on a sort of shuffling gait.


Most terrestrial mammals mammals need to breathe, and King Kong would be no exception. The mechanism by which your lungs oxygenate your blood, and indirectly your tissues, is through simple diffusion. As the muscle in your chest contract and cause your lungs to expand they are filled with room air (approximately 21% oxygen). Once the lungs and the small sacs attached to it called the alveoli are filled, oxygen can diffuse through the lung tissue into the vasculature. Carbon dioxide (a byproduct of cellular metabolism) can also leave the vasculature and pass into the air stored within the lungs. Expiration occurs, and then the cycle of inspiration and transfer starts again.

King Kong- Respiratory Calculations
Like all other tissues, King Kong’s respiratory tissues would be bound by a version of the square-cube law. However, calculation can be incredibly difficult when starting from scratch. A recent publication on how respiratory and cardiovascular values change with alterations in size can be useful for figuring out information like respiratory rate or total lung capacities [Pypendop 2015]. The calculations they used are listed below:

  • Respiratory Rate [breaths/min]: RR= (53.5)(Mass^-0.26)
    King Kong RR [breaths/min]=  (53.5)(1,360,777^-0.26)= 1.36
    *One breath every 44 seconds
  • Total Lung Capacity (mL): TLC= (53.5)(Mass^1.06)
    King Kong TLC [mL]= (53.5)(1,360,777^1.06)= 169,890,056 mL
    ~170,000 L
  • Oxygen Consumption [ml/min]: OC= (11.6)(Mass^0.76)
    King Kong OC [mL/minute]=(11.6)(1,360,777^0.76)= 532,275 mL/min
    ~500 L O2/min
  • Minute Volume/Volume Respirated [mL/min]: MV= (379)(Mass^0.8)
    King Kong MV [mL/min]= (379)(1,360,777^0.80)= 30,596,291 mL/min
    *This will be approximately the volume moved per breath
    ~30,000 L/breath
  • Total Lung Mass [g]: TLM= (11.3)(Mass^0.99)
    Kong TLM [g]= (11.3)(1,360,777^0.99)= 13,351,422 g
    ~13,000 kg

King Kong- Final Thoughts
In theory King Kong would be able to meet his oxygen demands through typical mammalian respiratory mechanisms. The air, although tropical and containing less oxygen, should still be able to meet his needs on an island rich with vegetation. However, he would struggle with meeting his respiratory demands within the course of his other daily activities. In order to fill his lungs with approximately 30,000 L/breath it would take him nearly a minute to inhale and exhale. He would need to try and eat between breaths and he would not be able to push himself. In line with the discussion we had earlier, he would need to restrict his movement and try not to over exert himself during daily task. It is possible he might take on adaptations ranging from increasing his total number of red blood cells, increasing the amount of iron bound to his red blood cells, or decreasing the vascular surface areas for perfusion (ex: no fingers) [Lu, 2018]. However, it is more likely he would just be forced to live with his limitations.


King Kong would need to have a cardiovascular system equivalent to a blue whale, but without the buoyant properties of water to support him. In order to calculate his cardiovascular values, I used the same paper referenced in the respiratory section:

  • Total Blood Volume [mL]: TBV= (65.6)(Mass^0.995)
    King Kong TBV [mL]=(65.6)(1,360,777^0.995)= 83,180,565 mL
    ~80,000 L
  • Heart Rate [beats/minute]: HR= (241)(Mass^-0.25)
    King Kong HR [beats/min]= (241)(1,360,777^-0.25)= 7 beats/min
  • Hemoglobin Concentration [g/dL]: HC= (12.9)(Mass)
    King Kong HC [g/dL]= 17,554,023 g/dL
    ~175,540,233 g/L
  • Cardiac output (mL/min)= (187)(Mass^0.81)
    King Kong CO [mL/min]= (187)(1,360,777^0.81)= 17,386,375 mL/min
    ~17,000 L/min

King Kong- Final Thoughts
King Kong would have a cardiovascular system under extreme stress, trying to move around 80,000 L of blood throughout his body with a heart that because of filling time limitations, can only beat 7 times per minute. In order to resist the effects of gravity on his blood supply he would most likely need to take on adaptations seen in other large animal species. This could include features like increased elasticity of blood vessel walls and arterial valves like those found in giraffes.


Life expectancy, contrary to popular belief, does not tend to drastically increase with size. This is the reason why your average household cat living in captivity has an average lifespan of 13-17 years  [ASPCA, 2017] similar to the average lifespan of a lion in captivity (14-16 years) [Maryland Zoo, 2017]. A blue whale can live to be almost 100 years old but so can a small tortoise, size doesn’t matter. Therefore, we would assume that King Kong would have a lifespan comparable to an average Gorilla or Chimpanzee.

  • Gorilla Average Life Expectancy (wild)= 35- 40 years
  • Chimp Average Life Expectancy (wild)= 30-50 years


ecology- kong 1
Warner Bros. Pictures, 2017


We know that the life on Skull Island is much different than what we are used to seeing in our day to day lives. There are many examples of insane versions of animals (Kong, the giant water buffalo, the enormous squid), but we don’t see any examples of bigger, crazier versions of plants on the island. This can be a problem, as the larger herbivores and omnivores of the island are going to need large plants, or they run the risk of eating the entire island bare.

To get around this, we think that King Kong can supplement his diet with the various animal-plant hybrids on the island. The bamboo spiders, for example, have legs which are partially composed of plant structures, in this case bamboo. The comic holds more examples of these hybrids, but the take home message is that life on this island found a way to use and exploit niches in interesting ways.


The cool thing about evolution on an island is that the animals that evolve there tend to be larger than their mainland counterparts. The only problem there is that this rule only applies to small animals, whereas larger animals tend to actually get smaller on islands. We are going to say that Kong and his ancestors are the exception that proves the rule, with their massive size coming as a by-product of their lack of competition on the island.

Skull Island is probably an oceanic island, which was formed by oceanic crust rising to the surface, so all of the species on the island need to have arrived by immigration, which implies that the storms surrounding the island weren’t always there. Distance to nearest mainland may not be that high, but the storm system would seem to preclude any sort of immigration since well before the last ice age. Islands in this area are characterized by high rainfall, high temperature, low monthly variation in temperature, high variation in monthly precipitation, and high precipitation. Island biogeography also theorizes that species richness increases with area but decreases with isolation, meaning that Skull Island has theoretically been isolated for millions of years, as the time needed for those new species to evolve must have been a quite substantial period.

We’ll use whale evolution as an example. Whales took 20 million years to evolve from artiodactyls, and that’s considered a very small timescale for this amount of evolution to happen. Buffaloes evolved about 10 million years ago, so let’s be VERY generous and say that Skull Island has only been isolated for 5 millions years.

So we are going to say that Skull Island has been isolated for maybe 10 million years, and species dispersed onto it before then. This gives time for the skull crawlers to arrive on the island and barely enough time for these arrivals to evolve to their current states. That also theoretically gives Kong’s ancestors time to grow to that size, UNLESS they were somehow able to migrate there at their current size. This is more likely if the skull crawlers retreated underground when the ice age started, leaving the Kong species free of competition, and allowing for the skull crawlers to grow MUCH bigger under there. Another possibility is that the skull crawlers evolved on a nearby island chain and migrated to Skull Island. Another intriguing possibility is that the water levels have risen since the last ice age, isolating Skull Island and the storm system from a larger chain of islands. A larger island means that less time to evolve in isolation would be needed.


One big problem with having both Kong and the skull crawlers on the island is the issue of competition. In nature when you have one large predator or consumer like Kong, you can really only have another large predator/consumer (like the skull crawlers) if the two organisms differ in their habitat or the way they acquire resources. Kong, like other primates, is going to be an omnivore. So while he can and does eat meat, most of his diet will be plant-based. The skull crawlers, however, are strictly carnivorous. Because the smaller ones hunt in packs, and they tend to spend most of their time underground, there is enough separation between the two species for the two large consumers to live in relative harmony.


The movie tells us that Kong is the last of his kind, and we know that his species requires an enormous amount of food and space, so unless the island used to be a lot lot larger than it currently is there is no way that there would have ever been a sizeable population. So, what we have is a small population of animals living in isolation for a very long time. This means a LOT of inbreeding.

Kong’s ancestors were likely very closely related to one another, well past the “kissing cousin” level of inbreeding. Because the animals are very closely related, their offspring are going to acquire more and more genetic defects and abnormalities. This isn’t good, but it doesn’t mean that the species couldn’t survive. For that to happen, we need two things: a species that is more or less immune to the effects of inbreeding, and purging. Being immune to inbreeding speaks for itself, but purging is a seriously cool phenomenon. What happens is that there is such strong selection against bad alleles or bad traits that all of the individuals with these traits or alleles die off, leaving a population that only has “good” alleles.

While highly unlikely, Kong and his ancestors could have lasted as long as they did due to some kind of immunity to inbreeding and the purging of bad alleles from the population.


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