Tag Archive: venomous


Komodo Dragon

Komodo dragon, resting on a rock. Image taken at Woodland Park Zoo, Seattle.

Komodo dragons are crazy cool lizards, with no natural enemies. They’re only found on a few small islands in Indonesia and most of what we know about them we’ve only learned in the last 30 years. They are the largest living lizards in the world, averaging 150 lbs (68kg) and 8 ft. (2.4m) in length, though they’ve been known to grow as much as 300 lbs and 10 ft. in length. And actually, since they can eat 80% of their body weight in one sitting (!!), a male that just finished a large meal can be weighed at more than 550 pounds. This big lizard had big ancestors. Their largest ancestor was the Megalania prisca, which grew to over 23 ft and 1,400 pounds and was the largest venomous animal to have ever lived (as far as we know).

Sleeping Dragon

A resting Komodo dragon. Image taken at the Woodland Park Zoo, Seattle.

Predominantly ambush predators, these lizards can hunt animals 5 times larger than themselves and 15 times their weight, including deer and water buffalo.  Although they appear toothless, because their gums cover their teeth until they’re ready to bite, they have 60 inch-long teeth and deliver deeper and more damaging wounds than a crocodile. When they eat, their gums tear and bleed. The blood mixes with the saliva and makes a slime that allows them to swallow their food whole. Every part of the prey is eaten, even hooves, and it all gets dissolved in their strong stomach acids. The lizard may have to sleep for up to an entire week while its food digests after eating a big meal.

Sleepy Komodo Dragon

Resting Komodo dragon at the Woodland Park Zoo, Seattle.

Oh and they’re venomous. What’s that you say? No they’re not? You learned a long time ago that the Komodo dragon has bacteria in its mouth and it’s a bacterial infection that causes the slow, agonizing death of the prey? Yeah, so did I. It wasn’t until 2009 that scientists discovered that they are venomous. They have venom glands in their mouth and venom causes their prey to continuously bleed. They die from blood loss and infection.

Cutey Pie

Komodo dragon. Image taken at the Woodland Park Zoo, Seattle.

Nothing is safe from a Komodo dragon-not even Komodo dragons. They are cannibalistic, with healthy dragons eating the young, old or injured dragons. Young Komodo dragons make up about 10% of an adult dragon’s diet. For this reason, when young dragons hatch, they dash up into the trees to avoid being eaten. But many won’t make it. Birds, snakes and other Komodo dragons-sometimes even their mothers- will catch them before they can reach the safety of the tree. They have to be cautious and quick when they come down for water and sometimes they may roll around in feces to mask their odor from adults.

I see you

A Komodo dragon. Image taken at Los Angeles Zoo.

One reason why they eat their own young may be that they need to in order to reach their huge size. The young eat insects, and small lizards and mammals, but there are very few medium sized animals on the islands. Those that are there were introduced and so weren’t always around. Perhaps eating their own young gets them to the next size level where they can go after bigger animals.

adorable lizard

Komodo dragon resting on a big rock. Image taken at the Woodland Park Zoo, Seattle.

These predators have excellent senses. They have a forked 16-inch tongue that works like a snake’s tongue-flicking it out into the world, they can taste/smell with their tongue. They can find carrion more than 5 miles away. They are covered in hard scales, each one with a sensory plaque for increased sensitivity. On their face and feet, each scale has 3 or more sensory plaques, further heightening their sensitivity. They can see in color. We used to think they were deaf, but that was disproved by a zookeeper that trained one to come when it heard her voice. Now we know that they only hear sounds in the low range of pitches. They can even distinguish between different human voices.

I see you

A Komodo dragon checking us out. Image taken at the Los Angeles Zoo.

Male Komodo dragons are territorial. Females and young can inhabit their territory, but males are only allowed to pass through when the visitor is tracking prey. They will fight other males to breed, standing on their hind legs and balancing on their tales. After the loser falls, he will lie still while the winner scrapes his claws along the loser’s back and tail as a sign of dominance.

Females use their claws to dig egg chambers. Since Komodo dragons will raid each others’ nests, the mother dragon will dig mazes of false tunnels to confuse any would-be egg raiders.

dragon claws

Komodo dragon claws, front foot. Females use their claws to dig egg chambers. Males will scrape them across defeated Komodos. Image taken at Los Angels Zoo.

dragon claws

Front feet of the Komodo dragon.  Image taken at the Los Angeles Zoo.

back claws

Komodo dragon claws, hind leg. Image taken at the Los Angeles Zoo.

Females will also guard their nests for up to 3 months. She’ll leave once the rainy season hits, since the chances of her eggs being disturbed are substantially less.

In 2006, we discovered another surprising fact about Komodo dragon reproduction. The females can be parthenogenetic! In London’s Chester Zoo, a female produced 8 offspring without ever having met a male, giving us our first glimpse at this cool adaptation.

Komodo dragons can live 50 years in the wild and up to 9 months without water. They are strong swimmers, able to travel between islands and dive to depths of 15 feet.

Swim time

Time to cool off. A Komodo dragon about to take a swim. Image taken at the Los Angeles Zoo.

Komodo Swimming

Komodo dragon going for a swim. Image taken at the Los Angeles Zoo.

People in Komodo and Rinca take precautions to avoid attacks from Komodo dragons. They don’t wander into the forests or grasslands alone and they never antagonize or approach the dragons. They’ve also had a long-held belief that if they feed the old dragons that could no longer hunt, throwing them old deer heads and hides and fish heads and guts, it was sort of a peace offering and it kept them and their children safe from getting attacked. Younger dragons sometimes ate the food as well. There was only 1 human death recorded in 30 years (since records started) from 1965-1995.

However, in 1995 Komodo park authorities banned the feeding of Komodo dragons, which environmentalists thought would make them grow lazy and forget how to hunt themselves. They also outlawed the dogs, which are considered an invasive species, which have been used to keep the dragons out of the villages. Since these things have been put in place, several people have been killed by Komodo dragons since 2000 and some dragons have recently begun to enter school buildings and homes. That’s right. Imagine a giant 8-foot venomous lizard walking down your school hallway.

K. dragon

Komodo dragon. Image taken at the Los Angeles Zoo.

It may surprise you to know that King Kong was actually based on an expedition to collect Komodo dragons. The best trappers had extreme difficulty and the dragons were escaping. The movie producer Merian C. Cooper took the story and changed the giant lizard to an ape.

Komodo dragons appear in a few other movies as well. In The Freshman they used an Asian water monitor to be a “Komodo dragon.” In Komodo Dragon, the dragons are computer generated. It turns out that real Komodos don’t do well with handling.

You can also find cool Komodo dragon art, like this awesome statue that lives at the Woodland Park Zoo in Seattle, that kids are allowed to climb on.

Dragon statue

A Komodo dragon statue in Woodland Park Zoo, Seattle. There are brightly colored tiles along its back. Children are allowed to play on it.

Alright, one last cool tidbit on this really long post. At a Singapore Zoo, they’ve used acupuncture to treat a sick dragon. It’s thought to have been successful.

Have one last photo of these beautiful animals.

Komodo Dragon

Komodo dragon, clearly contemplating the meaning of life. Image taken at the Los Angeles Zoo.

What’s going on?

Dear Backyard Zoologist readers,

You’ve probably noticed a huge drop off in posts recently and I wanted to let you know what’s going on. In all honesty, I began this blog over a year ago because I enjoy sharing information and pictures of awesome wildlife. I still do, but at the moment I have a lot of cool but time consuming things going on and creating these posts on a regular schedule is starting to become more of a chore than something I do for fun. So, I’ve decided to only write new posts when the spirit moves me instead of on a regular schedule, to eliminate the dreaded deadline of Monday and Friday. Still, I hope you’ll check in periodically to see what’s new or better yet, sign up for e-mail notifications to let you know when I do post something new.

I still have lots to share…for example, did you know that this animal:

anemone

A giant green Anemone. Image taken at Fitzgerald Marine Reserve tidepools in California.

is used as a vertebrate heart stimulant? Or that this animal:

armadillo

A 9 banded armadillo. Image taken at the San Francisco Zoo.

always gives birth to identical quadruplets? And naturally grows the bacteria responsible for leprosy on its feet? Scientists couldn’t cultivate this bacteria in a lab, so they brought in live armadillos to collect the bacteria to work with.

Or that this animal:

tree shrew

A tree shrew. Image taken at the Oregon Zoo.

Is very smart and has a larger brain size to body mass than humans do?

Or that this animal:

kingsnake

California kingsnake, Kali, my personal companion.

Is called a kingsnake because it eats other snakes, including rattlesnakes and is immune to rattlesnake venom?

Or that these animals:

rock doves

Rock doves, a.k.a. pigeons. Image taken in San Francisco.

are one of the few birds that feed their young a type of milk?

Or that this animal:

marine toad

A marine toad. Image taken at the San Francisco Zoo.

is one of the only toads that will sometimes eat vegetation and dead things? While other frogs and toads want to eat only moving things, this toad is even attracted by dog and cat food left in yards.

Or that this animal:

lionfish

A lionfish. Image taken at the California Academy of Sciences.

is covered in highly venomous barbs and that dolphins will sometimes grab these fish by their tummies and use them as weapons to catch fish hiding in crevices?

Magnificent Large Finned

Canary Rockfish

A Canary Rockfish. Image taken at the California Academy of Sciences.

This pretty fish is called a canary rockfish (or Sebastes pinniger, literally translated to magnificent large finned, hence the title). All along its back, those fin spines are actually venomous, although not as venomous as some of its relatives. Its a great defense, but its first defense is, well, to be a rock. It sits really still along rocky bottoms, on kelp leaves or along piers and man made structures. Since predators eyes are attracted to motion, sitting still really helps keep them from being noticed. But, failing that, venomous spines. Win! I suppose its major defense against humans is that it is really high in mercury and PCB’s, poisons that in excess can cause anything from numbness, memory loss and irritability to circulatory failure and permanent damage to the kidneys and the brain. And that’s in adults. Children or developing fetuses have even more health risks to worry about. Mercury accumulates in fish that live for a very long time, or are top predators because they accumulate mercury from all of the fish that they eat.  San Francisco Bay is particularly bad for mercury contamination in fish as well, because the gold miners used to use mercury to separate the gold from the rock and all of that mercury has come down the river into our estuary.

Despite containing human poison in its flesh, this animal is listed as threatened and protected under the ESA because of overfishing. Rockfish live for a very long time. From the many species of rockfish, scientists have estimated life spans from between 100 and 200 years! (This species lives to be around 75 years old) Like most animals that live a long time, these animals are late to mature and reproduce, so often they are fished before they ever have young. Which, by the way, are born alive, in a larval form, and not from eggs released into the water column. The females of this species actually have a lot more eggs than the other rockfish and can have up to 1.9 million eggs inside of them at a time. Coo-ool. Of course, many of the larva don’t survive, assuming the female even lives to reproduce.

So, if eating poisonous, threatened, protected fish doesn’t appeal to you, then you want to look out for Rock cod, Pacific snapper, red snapper and Pacific Ocean perch, all of which are just different market names for rockfish. (There aren’t even any snapper on the U.S. west coast.) And once again, kudos to Safeway for taking red snapper out of their stores.

Canary rockfish

Look me in the eye when I'm talking to you! And please don't eat me. Canary rockfish image taken at the California Academy of Sciences.

Duck-billed platypus

A duck-billed platypus specimen at the California Academy of Sciences. Part of their extreme life exhibit.

The duck-billed platypus, aside from having a hilarious name, has long been a fascination of scientists.  Upon first examining a platypus specimen, some scientists thought the animal was surely a hoax, specifically that it was several animals sewn together.

The platypus is probably most known as one of the few monotremes, or egg-laying mammals (they are still considered mammals because they produce milk, although platypus have no nipples). But in addition to its relatively weird reproductive strategy, this animal has all kinds of unique characteristics for a mammal. For example, when diving the platypus can close off its nostrils and cover its eyes and ears, but then how is it able to navigate under water with its senses shut down? Well, the answer is in their funny looking bill; they have a sixth sense. This sense is called electroreception, which is also found in cartilaginous fish like sharks and rays. In the platypus bill, there are small electricity-detecting pits, which they use to find small prey buried in the mud by the electrical pulses given off by the prey’s muscles. There is no hiding from a platypus. Further, an adult platypus has no teeth, but uses ridges and sometimes gravel it picks up to chew the food once it catches it.

Male platypus are also one of the few venomous mammals. They have venom glands in their thighs that are attached to venomous spurs on their hind legs. The females have this spur, but lose it in their first year. You can actually tell how old a young platypus is by how long its spur is. The venom is strong enough to kill a dog, and has caused a range of symptoms in humans, up to paralysis of an entire limb.

platypus spur

The venomous spur of an adult male platypus. Image taken at the California Academy of Sciences.

So despite their comical appearance, these animals are nothing to laugh at.

comedy club

A sign for a comedy club in Toronto, featuring one platypus.

Oh. Sorry little guy. I stand corrected.

One last thing. I have noticed that a number of Christian organizations are suggesting that the platypus, which appears to have features from several different animal groups, is evidence that evolution must be incorrect.  Therefore, I’m including this link which discusses the decoding of the platypus genome and how it sheds light on not only platypus evolution, but mammalian evolution, as monotremes share genes with their reptilian ancestors.

And if you like, you can adopt a platypus from the World Wildlife Fund.