Red-eyed Tree Frog (Agalychnis callidryas)

I picked today’s animal mostly based on its looks — colourful animals are just really fun to draw. Apparently my past self felt the same way as well, because I have a painting of a red-eyed tree frog I did six or seven years ago on my bedroom wall. We’ll have to compare the one I’ve done for today to that one and see if I’ve improved at all!

Red-eyed tree frogs are native to Central America, from southern Mexico in the north to Panama and a tiny bit of Colombia in the south. They live in rainforest habitats, particularly in places near rivers. If you haven’t figured it out from their name, I’ll tell you just to be super clear: red-eyed tree frogs like trees. They spend almost all their time in trees, and are primarily nocturnal.

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A map of the distribution of red-eyed tree frogs. Image source: Wikipedia

The stunning red eyes of this frog aren’t the only colourful part of its body. Their backs are mostly bright green, and they have yellow and blue vertical stripes on their sides. The upper part of their legs are a pretty, rich blue, while their feet are a startlingly brilliant orange or red. Altogether, red-eyed tree frogs are a wonderful melange of colours that makes them a joy to look at (and to draw!).

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My drawing of a red-eyed tree frog, contrasted with the painting I did in 2011. I think I’ve gotten a bit better! 

Tree frogs don’t get to be super large, reaching between about 3.5 and 7 centimetres in length. Female frogs are typically larger than males. Their long back legs make red-eyed tree frogs excellent jumpers, and suction cup-like structures on their toes means tree frogs can stick to pretty much any surface. That’s a pretty useful skill when you spend your life in trees.

A lot of brightly coloured animals are poisonous, their striking colours a warning to any predator that might think about eating them. This is not the case with the red-eyed tree frog. Their bright green colouring actually helps them camouflage against tree leaves. During the day red-eyed tree frogs sit on leaves with their eyes closed and their blue spots covered by their hind legs, praying no hungry animal notices them.

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A red-eyed tree frog trying to camouflage itself against a leaf. I don’t know why this one is so pale… maybe it’s the lighting? Image credit: John J. Mosesso via Wikipedia

If a predator does happen by, the frogs open their eyes suddenly, staring right at the predator. Bright red eyes coming from a green lump may startle the predator just long enough to allow the frog to leap away. I’m not quite sure how effective this defensive strategy is, but red-eyed tree frogs seem to be doing pretty well.

Reproduction in red-eyed tree frogs begins with males advertising their presence to any females in the area. They do this by calling loudly, and quivering on leaves to establish territory. Once a female shows up, all the males in the area jump on her back, vying of the best position. Occasionally multiple males will cling to a female’s back while she is trying to find a good spot to lay her eggs, and she may have to carry them around for hours, sometimes even days.

Females lay clutches of around 40 eggs, on leaves that hang over puddles or ponds. Males stay on the females’ backs while they lay their eggs, fertilizing them as they are laid. The eggs develop into tadpoles quite quickly, and the tadpoles swim around inside the eggs until they rupture. Once the eggs have ruptured, the tadpoles are washed down into the pond waiting below, where they can complete their metamorphosis and become adults.

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Coincidentally, I also had this souvenir shot glass in my office (I use it for painting), so apparently I have a thing about red-eyed tree frogs… 

Thanks to their beautiful colouring, red-eyed tree frogs are popular in the pet trade. Thankfully, they are not yet threatened, though their population has been declining. Pollution, habitat destruction and deforestation are all significant threats to red-eyed tree frogs, so we ned to keep an eye on these guys to ensure they stick around!

Cover image credit: Carey James Balboa via Wikipedia

Green Tree Python (Morelia viridis)

I definitely chose today’s animal for its looks. I was out of the country for the past two weeks for work, and couldn’t bring much with me. So I grabbed my smallest sketchbook and brought only one pen — one of those clicky ones that has multiple colours. All I had to work with was red, green, blue and black. And so I picked a snake that was mostly green, hoping I could make some kind of passable art with the supplies I had brought.

The snake I chose to draw was the green tree python, a snake that is found in Australia, Indonesia, and New Guinea. These snakes are aptly named, as they are green and like to live in trees. They are found in tropical rainforests, generally staying at elevations between sea level and 2000m. Younger snakes tend to stay around the edges of the forest or in canopy gaps, while adults are perfectly comfortable in closed-canopy forests.

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My drawing of a green tree python’s eye. I think it turned out pretty well!

Green tree pythons can get pretty big, with the average length being 1.5 meters, though snakes of up to 2.2 meters have been recorded. They are long and thin, with a well-defined head. Green tree pythons are really beautiful snakes: they are bright green with white scales forming a patterned line down their backs. Juvenile snakes are easily distinguished from adults, as they are either bright yellow or red.

As I mentioned, green tree pythons are quite fond of trees. In fact, they are the most arboreal python in the world. Their long tails are prehensile, which helps them climb and navigate their forested habitat. Tree pythons have a very distinct resting posture, where they throw a few coils over a branch and then sit in a saddle position with their heads resting in the middle.

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A green tree python resting in a typical ‘saddle’ position. Image credit: Micha L. Rieser via Wikipedia

This is quite distinct from the pythons’ hunting posture. When green tree pythons are looking for prey, they extend the front part of the their bodies, ready to strike at any prey that wanders by. Snakes change between resting and hunting postures at dawn or dusk, to stay camouflaged.

Green tree snakes are carnivorous, feeding on small reptiles, amphibians and mammals. They kill their prey by constriction, and do not have any venom. Adults are nocturnal, feeding on the larger animals that emerge at night. Juvenile snakes come out during the day, and feed mainly on small reptiles. As ambush predators, green tree snakes do not actively search for prey, and don’t move very much. They are so lazy they will use the same ambush site for up to two weeks.

This strategy is quite useful for green tree snakes, as it helps them hide from predators. As adults, their green colouration and lack of movement makes them blend in to the leafy trees. Juveniles are also well camouflaged — yellow snakes camouflage well in forest edges, while brick-red juveniles blend in with tree trunks and other non-leafy backgrounds.

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A juvenile of the brick-red variety. Image credit: Johnkentucky via Wikipedia

We don’t know a whole lot about green tree python reproduction in the wild, as breeding has never been recorded in their natural habitat. What we do know we have learned from captive populations. Females lay 1 to 25 eggs, which she broods and protects for almost two months. The eggs hatch at the start of the wet season, in November. The hatchlings are about 30 cm long, and reach sexual maturity between two and four years of age.

Green tree pythons are popular snakes in captivity, and tend to do quite well once their needs are met. Because of their popularity, their population is under pressure from hunting for the pet trade. There are captive breeding programs however, so if you want to get a green tree python, just make sure you source it from a captive breeder!

Cover image credit: Mattstone911 via Wikipedia

Dusky Salamander (Desmognathus fuscus)

Some salamanders are super cool looking, and are covered in awesome bright colours and fun patterns. Others are not, and today’s animal is one of those poor unfortunate amphibians that simply looks slimy and gross. But I would be the first to stress that just because an animal got shortchanged in the looks department, that doesn’t mean it is any less amazing. And dusty salamanders are no exception.

Dusky salamanders live in North America, in the eastern parts of Canada and the United States. In different parts of their range, the salamanders prefer different habitats. In the north, they like clear mountain springs, while in the south they seem to enjoy floodplains, sloughs, and muddy streams. Dusky salamanders spend most of their time hidden under rocks or logs. They are hidden from sight for as much as 70% of their lives, so don’t expect to see these guys darting around when you go for a walk in the woods.

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See how not-interesting looking these guys are? But I guess beauty is all in the eyes of the beholder. Image source

As salamanders go, these guys are fairly average. Their average length is 9.4 cm for males and 8.6 cm for females. They range in colour from brown to grey to olive green, with some darker spots. Their colour lightens on their bellies, and is covered in speckles. As I said, dusky salamanders are really not very exciting looking.

Dusky salamanders belong to the family Plethodontidae, also known as lungless salamanders. Which means, of course, that these guys don’t have any lungs. Instead of breathing like most normal terrestrial animals, lungless salamanders absorb the oxygen they need from the air. This is done through their skin and special membranes in their mouth and throat.

Another distinct trait of lungless salamanders is a special slit known as the nasolabial groove. This is located on the snout of the salamanders and helps the salamanders with chemoreception. The salamanders use this sense to find mates and potential food items. You may now be wondering: what do dusky salamanders eat? The answer: gross things, like earthworms, slugs, a wide variety of insects, spiders and crustaceans.

As small animals, dusky salamanders are quite susceptible to predation themselves. They fall victim to raccoons, birds, skunks, shrews, snakes and other salamanders. Dusky salamanders are quick and agile, and have particularly slippery skin. This makes them quite difficult for a predator to grab. If a salamander feels really threatened, it can drop its tail and as a distraction for the predator, and then scamper away. The tail will then regrow, though it will not look the same as the original.

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I guess they are kind of cute… In a way. Image source 

Dusky salamanders mate in the spring and fall, on land, but close to streams. A male dusky salamander has a peculiar dance he uses to approach a female: he does a ‘butterfly walk’, in which he swings his front legs like a swimmer performing a butterfly stroke. This is followed by tail wags and nudges on the female’s back. He then arches his body while pressing down on the female, and then straightens quickly, so that he is thrown back, sometimes as far as five to ten centimetres away. This process is repeated until the male makes his way to the female’s head.

Once the female is enamoured (thanks to the male’s bizarre advances), it is her turn to stimulate the male. She does this by touching the base of his tail with her chin. After staying like this for a while, the male will deposit a package of sperm called a spermatophore onto the ground, which the female will walk over and then pick up with her vent. The sperm is then stored inside her body until it is needed in the summer (meaning salamanders that mate in the fall store the sperm over winter), when the eggs are laid.

Female dusky salamanders lay between 12 and 51 eggs, which she lays under rocks, logs or other debris. She lays these near water, as the young are aquatic, and mother salamanders guard their nests until hatching. This occurs after 40 to 80 days, and the young sometimes stay with the mother for days or weeks before moving to water.

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A quick little sketch I did of a dusky salamander.

Although they are quite common overall, dusky salamanders are threatened in certain areas by habitat destruction and pollution. Removal of trees lets sun shine down onto salamander habitats, which heats up the water and lowers humidity. This is a big problem for salamanders that need to stay moist so they can breathe. Still, dusky salamanders are doing quite well, and let’s hope they continue to do so.

Madagascar Day Gecko (Phelsuma madagascariensis)

I saw this little guy on the cover of one of my favourite animal websites, and he was so bright and pretty that I was immediately interested in writing about him. I will admit that I was also influenced by the fact that I knew I had to draw him. I love using fun colours so that made the Madagascar day gecko a perfect blog candidate.

Madagascar day geckos belong to the family Phelsuma, which contains about seventy species and subspecies. These are commonly known as ‘day geckos,’ as these species are active in the daytime, unlike most other gecko species. The Madagascar day gecko lives in Madagascar (unsurprisingly), along the east coast of the island. There are also introduced populations in Florida. These lizards are arboreal, and are most at home in tropical rainforests.

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Aren’t they cute?

I called them little, but that isn’t very fair. Madagascar day geckos are actually one of the largest species of geckos, reaching lengths of up to 25 cm. As I mentioned, this species is brightly coloured, with the geckos being being bright green or bluish green in colour. They have a rusty-red stripe running from their nose to their eyes, and have various red or brown stripes and spots on their bodies.

Day geckos possess flat toe pads equipped with adhesive scales, which allow them to climb and stick to smooth surfaces. This is no doubt very helpful to a species that spends most of its time hanging around in trees. Day geckos like to relax in their tree perches, soaking up the sun when they’re not looking for food.

Madagascar geckos aren’t exceptionally picky eaters; they feed on a wide variety of invertebrates, as well as fruit and nectar. They get almost all their water from that which collects on leaves, meaning they don’t have to head to the ground to drink. So very convenient.

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My drawing of a day gecko – I had fun with this one though the scales were quite tedious. Still working on getting good scan quality for my pencil crayon drawings, so apologies for that! 

Mating in Madagascar day geckos takes place between November and April. Males attempt to court females by approaching them with their heads moving back and forth. If he is feeling good about his courtship, the male with then grasp the female’s neck with his teeth. After this, the male’s colour darkens, and rests his throat on her head while emitting a soft noise, presumably to comfort her after the trauma of having her head bitten.

Females lay clutches of two eggs, and can lay more than one clutch in a year. The eggs hatch after an incubation period of 47 to 82 days, at which point they are on their own. Like many reptiles, the gender of the young is influenced by temperature; eggs incubated at high temperatures produce males, while lower temperatures produce females. Young geckos are pretty much just tiny versions of the adults, though they are slightly different in colour. They become sexually mature after one or two years of age.

As is so often the case with brightly coloured lizards, Madagascar day geckos are popular as pets. You have to be careful with these guys though — they are very territorial and will act aggressively towards each other if kept in the same tank. Despite their popularity, day geckos are still doing just fine in the wild, which is great news.

Cover image source: Tambako the Jaguar via https://www.jigsawexplorer.com/puzzles/madagascar-day-gecko-jigsaw-puzzle/

Saltwater Crocodile (Crocodylus porosus)

During the past two weeks I watched all four Jurassic Park movies, so I’m in a bit of a dinosaur mood. Unfortunately, Our Wild World is a blog about extant animals, so dinosaurs are right out. I’ve decided instead to write about a species of crocodile, because they’re basically the next best thing.

The species I’m going to focus on is the saltwater crocodile, because they are super cool. Saltwater crocodiles have a broad range, and are found from eastern India to Indonesia, Australia, and even around some Pacific islands, like Vanuatu and the Solomon Islands. As their name implies, saltwater crocs can tolerate high levels of salinity, and are often found in rivers, estuaries and coastal areas. More than any other species of crocodile, saltwater crocodiles are found in the ocean; they often travel long distances in the open ocean and can spend months at sea.

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The range of the saltwater crocodile. Image source: Wikipedia 

Saltwater crocodiles are big. You definitely don’t want to meet one of them in a murky river. In fact, saltwater crocodiles are the biggest of all crocodiles and are the biggest reptiles in the world. Males can reach lengths of six to seven meters, though females only grow to a paltry three meters. The largest male ever recorded weighed 1,075 kg. Adults are a dark greenish colour, with lighter bellies. Young crocodiles have more exciting colouring, being yellow with stripes and spots on them.

Crocodiles are big (as I mentioned), and they have large, pointy teeth. Saltwater crocodiles have between 64 and 68 teeth, the longest of which can measure up to nine centimetres in length. They use these massive teeth to hunt, feeding on a wide variety of animals such as fish, turtles, snakes, buffalo, birds, wild boars and monkeys. Crocodiles are ambush predators, hiding below the water’s surface with only their backs, nostrils and eyes visible, until an unlucky victim stumbles along.

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A very fat looking saltwater crocodile. Image credit: fvanrenterghem via Wikipedia

When a prey animal does happen to wander too close to a saltwater crocodile, the crocodile strikes. They are surprisingly fast when striking from the water, using both feet and their tails to launch themselves at their prey. They can swim in bursts of 24 to 29 km/hr, so you really don’t want to be stuck in the water with a saltwater crocodile.

Once the crocodiles have an animal in their strong jaws, it is either swallowed whole, or, if it is too large, the crocs drag their prey underwater and drown it. Crocodile teeth are not made for shearing, so crocodiles rip chunks of meat off their prey by rolling in the water while gripping the prey to twist off pieces of flesh, or by jerking their heads to remove hunks of tasty meat.

If you do end up getting bitten by a saltwater crocodile, good luck getting away; saltwater crocodiles have the highest bite force of any animal, measuring a maximum of 16,414 N (which I’m guessing is a lot). Part of the bite strength of saltwater crocodiles comes from the design of their jaw muscles; they can clamp down extremely hard, but have weak muscles when it comes to opening their jaws. Apparently a few layers of duct tape is sufficient to hold a crocodile’s mouth shut. The tricky part, of course, is getting the duct tape on the crocodile in the first place.

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Saltwater crocs can breach out of the water to try and catch food, so don’t think you’re safe just because you’re in a tree. Image credit: Matt via Wikipedia

Saltwater crocodiles breed during the wet season, from September to October. Though they often live in saltwater, saltwater crocodiles move to fresh water to breed. Males are very territorial in general, but are especially aggressive during the breeding season, chasing away any other males that encroach on their territory.

Female saltwater crocodiles lay between 40 and 90 eggs in mounds placed on river banks and shores. The eggs are laid raised from the ground, to prevent them from being washed away during floods. The eggs hatch after around three months, at which point calls from the young prompt the mother to help unearth the eggs. She then carries the hatchlings in her mouth to the water, and stays with her brood for a few months. Very few survive to adulthood, and those that do disperse at eight months of age. Sexual maturity is reached when crocodiles are 10 to 16 years old, and these remarkable reptiles can live to be over 70 years of age.

Because saltwater crocodiles are highly valued for their meat, eggs, and skin, this species was once hunted extensively. They have since come under protection in most of their range, and have made great recoveries. Thankfully they are not currently endangered or threatened, but habitat destruction is a concern for these magnificent beasts.

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My drawing for the week (I apologize for the poor quality of the image – I’m away and do not have access to my scanner) – this is all you would see of a crocodile hiding in the water. 

I’d like to say a few last things about the saltwater crocodile. First, they are big, with large teeth, and are territorial and aggressive. So yes, they can and do eat people who come into their waters, so watch out. And secondly, even though these guys are giant man-eaters, you shouldn’t hate them, because not only are they very cool, they are also supposed to be very intelligent. They have extensive means of communication, can learn tasks quite quickly, and track the migratory patterns of their prey. So don’t hate saltwater crocodiles, and definitely don’t swim with them.

Cover image credit: Djambalawa via Wikipedia

Colorado River Toad (Incilius alvarius)

Toads in general are fairly odd looking animals. I don’t think I’ve seen a toad and thought to myself ‘wow, what a beautiful animal,’ but beauty is in the eye of the beholder. Still, today’s animal, the Colorado River toad, is not one of the best-looking toads out there.

Colorado River toads are not just found in the Colorado River — they also live in the Gila River, which means you can find these toads in California, New Mexico, Arizona, and Northern Mexico. They primarily live in semi-arid and arid habitats, and are especially abundant near sources of water, such as streams, canals, and drainage ditches. These toads have a patch of skin on their bellies that absorbs oxygen from any water the toad is sitting in.

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The distribution of the Colorado River toad. Image source: Wikipedia

Colorado River toads get pretty big for toads, and are the largest native toad in the United States (only being surpassed by the invasive cane toad). They grow to be 19 cm long, and have super attractive olive green skin with warts on their hind legs. River toads have large parotid glands behind their eyes, and a light green eardrum just below these glands.

River toads are nocturnal, spending the daytime sequestered in rodent burrows. They come out at night to feed, munching on a variety of tasty insects, including snails, beetles, spiders and grasshoppers. River toads will also eat other vertebrates, such as lizards, small mammals, and other amphibians.

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See how ugly these guys are? Image source: Wikipedia

Colorado River toads don’t have to worry too much about predators; they have glands on their legs and on the corners of their mouths that secrete toxins. These are enough to deter most predators, as animals as large as dogs have been paralyzed or killed by the toxins. Some animals have learned to work around the River toads’ secretions — raccoons in particular are known for pulling a toad by its leg and then flipping it over, so they can feed on the toxin-free belly.

While the toxins produced by the Colorado River toad can be deadly, they are also hallucinogenic. The main compounds in River toad secretions are 5-MeO-DMT and bufotenin, both of which are used recreationally. Smoking these substances avoids their toxic effects, and gives the user a sense of euphoria as well as hallucinations. There are laws restricting the use of toad toxins, however, as the toxins are controlled substances.

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I got to test out my new watercolour pencils to draw these guys! You can check out my website for more art. 

While its overall population is doing quite well, in California and New Mexico, the Colorado River toad is endangered or threatened. It is therefore illegal to capture a River toad from the wild in those states. Hopefully these measures work and prevent this funny little toad from going through widespread population decline.