Thermal imaging, also known as thermography, captures infrared radiation and turns it into an image similar to standard photography, which does the same thing with light in the visible spectrum. Thermal imaging is an important tool for science because warmer objects emit more radiation, which translates on thermal images as brighter colors (the brightest possible value for a thermal image is pure white).

Thermal cameras are used in a wide variety of industrial and commercial settings in everything from parts manufacturing (to make sure things stay the proper temperature throughout the production run) to utility line repairs (faulty lines and switches show up hotter than they should). In the world of green, they are used by energy efficiency professionals to detect leaks in building envelopes.

One of my favorite applications of the technology is thermal images created of animals. I’m an armchair biologist and am fascinated by the mind-blowing morphological diversity created by evolution and natural selection. I am also a huge fan of biomimicry and know that there is an enormous amount that we can learn from the natural world to better inform how we design our own. At the very least, they’re really cool to look at.




Ostriches are the largest bird in the world. They can weigh hundreds of pounds, stand more than nine feet tall, and run 40 miles per hour for over thirty minutes. In short, they’re totally badass. Ostriches are native to Africa and can be found throughout much of the continent. They need to be able to both vent heat during the hot days as well as conserving it during the cool nights. As the thermal images show, the giant bird throws a lot of heat off its legs and long neck. At night, when they settle down for sleep, they tuck their legs up underneath them, helping to preserve warmth. During the day their feathers reflect away heat while running around helps circulate cooler air over their skin.


Lions are enormous predators found in Africa and Asia that sit firmly atop their local food web (if you factor out humans). They are considered a vulnerable species and have seen their numbers plummet over the years to hunting and habitat loss. The estimated number of lions in Africa has fallen as much as 90% since the 1950s and has showed no signs of slowing over the last few decades. Conservation efforts have helped to carve out protected habitat for the King of the Beasts, but they are still an embattled species. You can learn more about the effort at the <a href=”">Lion Conservation Fund</a>.

In its natural range, the lion has to deal with the hot days and cold nights of the savanna and its thermal image shows how the thick mane of a male helps it retain warmth during the night while it pants off heat during the day.


Vultures describes any of the number of actual species of large scavenger birds and are found throughout the world. They don’t have a particularly sterling reputation but are actually a hugely important player in natural systems. India is currently suffering from a precipitous drop in their vulture population caused by the widespread use by farmers of a painkiller that soothes their cows but kills the scavenging birds. Without vultures  to eat and breakdown dead animals, the bodies are left to slowly rot away where they fell or are piled up in huge mountains of stink that attract and support roving bands of vicious dogs.


OK, this one is just adorable. Dogs (the non-corpse-eating ones) are awesome. That’s a good boy!! Who’s a good thermal boy!?


Snakes are known as cold-blooded for a reason—they barely show up in thermal imaging! While there are thousands of different kinds of snakes, they all share the trait of using external heat sources to regulate internal temperatures. Most exist in a spectrum between being cool and slow moving and warm and active and have evolved to efficiently retain any heat they pick up from the environment.

This image shows the striking contrast between the warmth thrown off by a small mouse and that of the heat-stingy snake.


These lizards look like they’re having a great time lounging out on some very warm rocks.


Deer are found throughout the world and are made up of a huge number of individual species. I suspect that the kind of deer seen in this thermal image lives in a temperate environment where it’s valuable to be able to retain internal body warmth. Though it’s positively glowing around its mouth and eyes, the dark colors found on its body shows how well its fur retains heat.


Tarantulas have a unique circulatory system that uses a blood-like liquid called hemolymph to transport oxygen throughout its body. This tarantula’s morphology vents it heat almost entirely on the top of its abdomen.


Meow. This is the internet, had to have a cat in here somewhere. This image was taken through the sniper scope of a doberman assassin name Francois.

Polar Bear

Polar bears are masters of retaining body heat, as you can see in this thermal image. Millions of years of evolving in an arctic environment have perfect honed their ability to hold on to as much of their internally generated heat as possible. An interesting note about the polar bear is that their skin is actually black—their clear hollow hairs channel the suns rays onto their dark skin and reflect light away to give them their snowy white coloring.


The wings of this bat look like they’re doing a damn good job keeping it warm.


What, are you taking to me?

Ring tailed lemur

Ring tailed lemurs are endemic to Madagascar and their range have been pushed to forests on the southern end of the island. It can get warm in Madagascar and as this thermal image shows, lemurs have evolved the ability to throw a lot of unwanted heat off their large tails.


Photo credits: Glowing cat face, Ostrich, Lion, Vulture, Dog, Snake around arm, Snake eating mouse, Lizards, Deer, Tarantula, Cat, Polar Berar, Bats, Eagle, & Ring tailed lemur.