Common Adder (Vipera berus)

I hadn’t planned on writing about adders today. But I was looking for cool pictures of rattlesnakes to draw, and came across a lovely picture of an adder’s face. Before I knew it, I had started drawing, and so the subject of today’s blog post was chosen. So it goes.

Common adders are found in a large area, from the UK in the west to the China and Korea in the East. They are notable for being found further north than any other species of snake, and are also the only venomous snake species the UK. As you can imagine for such a widespread animal, they live in many different types of habitats. They are known to inhabit woodlands, hills, moors, meadows, grasslands and wetlands. Adders do require spots suitable for sunbathing, as well as ground cover so they can hide from predators.

680px-Vipera_berus_distribution.svg

The distribution of the common adder in Europe. Image source: Wikipedia

Adders are reasonably large snakes, reaching lengths of up to 80 cm. They vary in colour, and can be grey, cream, pale yellow or reddish brown. Most adders have some kind of zig zag pattern on their backs and sides, though some snakes are entirely black and so have no visible pattern at all. Female common adders tend to be bigger than males, and have more reddish colouring.

Activity in adders varies depending on their location — in the north they tend to be most active during the day, while in the southern part of their range they come out at in the evening or at night. Cold-blooded animals don’t do so well when temperatures drop below freezing, so adders in colder areas hibernate during the winter. They hibernate in groups, drawing warmth from one another, as well as from the burrows they sleep in. Even with these precautions, not all snakes survive the winter: 15% of adults and 30-40% of juveniles will not make through hibernation.

Hugorme

A normal and black common adder, posing wonderfully for an awesome picture. Image source: Wikipedia

Common adders are venomous, but they aren’t particularly scary snakes. Their venom isn’t super deadly to humans, with only intense pain and swelling occurring at the bite site. It is very rare for humans to die from common adder bites, with the most vulnerable population being small children. These snakes are also quite shy — they prefer to run away rather than bite. However, they are quite common in human inhabited areas, so bites aren’t that uncommon, and medical treatment is required after each bite. On the bright side, there is plenty of antivenin available!

Their venom may not be super effective against people, but it works pretty well on the snakes’ preferred meals. Adders will either wait to ambush prey while it walks by, or actively hunt an animal using their keen sense of smell. Mice, voles, shrews, lizards, birds and frogs all fall victim to common adders. Adders themselves fall prey to foxes, badgers, and birds of prey. Their colouration helps them hide, and any potential predator does have to be wary of the snakes’ bites.

Benny_Trapp_Vipera_berus

A common adder showing off its pretty face. Image credit: Benny Trapp via Wikipedia

After spending a long winter curled up with other snakes, adders emerge in a pretty good mood. They start to mate soon after coming out of hibernation, in the spring. Male snakes wait patiently for females to emerge, and then try and convince them to engage in copulation. They do this by relentlessly following females, for hundreds of meters if need be. When they do catch up to a lucky girl snake, the males will flick their tongues along her back and lash their tails excitedly. They also have to chase away any rival males, and fights do sometimes occur.

Females give birth to three to twenty young, after a three to four month gestation period. The young snakes are fourteen to 23 cm long, and are born in a sac that they must emerge from. They also have a yolk sac that they can use for nutrients during the first few days of life. This is important, as the young snakes are independent from birth. They take three to four years to reach sexual maturity.

Adder

My drawing of a common adder, done in charcoal. I love drawing snakes! 

Despite their large range and hefty population, adders are a protected species in some countries, such as Britain and Norway. Thanks to habitat fragmentation, human fear of the species, and collection for pets, adder populations are declining. It’s a shame because these are some lovely snakes, despite their venom. Yes, I wouldn’t want to get bitten by an adder, but the same rule applies to adders as to all snakes: leave them alone, and likely you won’t have any trouble. So don’t go pestering these pretty guys!

Cover image source: Wikipedia

Green Sea Turtle (Chelonia mydas)

I try and be as diverse as possible on this blog, writing about as many varied and wonderful animals as I can. Unfortunately, sometimes animals fall through the cracks, either because of personal feelings (I don’t like primates, and I’m terrified of spiders), or simply by accident. One of those accidental oversights is sea turtles, of which I’ve only written about one – the hawksbill sea turtle. Today I’ll add another lovely aquatic reptile to the list, the green sea turtle.

Green seas turtles are found around the world, in the Pacific, Atlantic, and Indian Oceans. They prefer warmer waters, living in tropical and subtropical areas. Populations in the Pacific Ocean are genetically distinct from those in the Atlantic, with each group having separate feeding and nesting grounds. Adult sea turtles tend to stay near coastal areas, while young turtles are found in the deep waters of the open ocean.

1920px-Total_internal_reflection_of_Chelonia_mydas

A green sea turtle swimming happily along (I assume). Image credit: Brocken Inaglory via Wikipedia

As far as sea turtles go, green sea turtles look pretty normal. They aren’t even green — they’re named that because of the green colour of fat deposits under their shell. Their shells start off black, and then lighten with age. They grow to be quite large, reaching shell lengths of 100 to 120 cm, which makes green sea turtles the second largest sea turtles in the world, behind leatherback sea turtles. The largest green sea turtle ever measured had a shell length of 153 cm, and weighed 395 kg. That is one big turtle!

Adult green sea turtles are gentle, herbivorous creatures. They feed on sea grass, algae, and mosses. Hatchlings are bit of a different story: they are carnivorous, feeding on marine invertebrates and other small creatures. As they grow, green sea turtles move to a more plant-based diet, and move closer to the coast.

800px-Green_sea_turtle_portrait

Look how cute it is!!!! Image credit: Alexander Vasenin via Wikipedia

In terms of predators, adult green sea turtles are pretty safe; they’re a bit too large for most ocean-dwellers to bother with. There are some sharks, particularly tiger sharks, that enjoy a green sea turtle meal. Other than sharks, the most significant predator of adult sea turtles is humans. The same can’t be said for younger turtles, which fall victim to a myriad of predators, including crabs, marine mammals, and shorebirds, to name a few.

Green sea turtles come to shore to lay their eggs, after mating near the coast. Copulation in green sea turtles can last quite a while, the longest recorded copulation being 119 hours long. Poor turtles! Females are quite selective about what beach they lay their eggs on, usually returning to the beach they themselves were born on, or finding a beach with similar sand texture and colour. Females dig a hole at the high tide line of the beach, depositing 75-200 eggs in a single clutch. Though females only breed every two to four years, they lay between one and nine clutches each season that they choose to breed in.

Hatchling sea turtles get a very rough start to life. They are left on their own after the eggs are laid, and hatch after about 30 to 90 days. The young turtles are about 5 cm in length upon hatching, and have to make a treacherous walk to the ocean. Numerous predators await the hatching of the turtles with glee, and glut themselves on the poor young turtles. Many baby turtles do not make it to the ocean; only 1% of hatchlings reach full sexual maturity, which is estimated to take 20 to 50 years. Green sea turtles are a long lived species, with wild turtles living up to 80 years.

green sea turtle

I decided to do a simple drawing for this week, and had fun playing with squiggly lines. 

These sea turtles migrate long distances from their feeding grounds to their nesting sites. The key to migration is that you have to be able to find your way from one place to the other, and green sea turtles have a number of super cool ways of doing this. They use wave direction, sunlight, and temperature to find their way around. As well, they have magnetic crystals in their brains that allow them to navigate using Earth’s magnetic field. Animals that can navigate with magnetism always amaze me — we had to invent compasses, but some species are born with them in their brains. Nature really is the coolest.

Unfortunately green sea turtles have not fared well recently, mainly thanks to human activities. They are actively hunted for their meat, skin and eggs. Turtles also get caught in fishing nets and drown, are prone to pollution and habitat destruction. They are currently listed as endangered and are protected both worldwide and by individual countries, but serious threats to these magnificent turtles remain.

Cover image source: Brocken Inaglory via Wikipedia

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.

Red-eyed_Treefrog_Agalychnis_callidryas_distribution_map_3

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!).

red eyed tree frog comparison

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.

Agalychnis_callidryas_-_camouflage_mode

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.

Photo 2017-05-09, 8 48 43 AM

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.

Green tree python

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.

Morelia-viridis

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.

JBR_7494

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.

d-fuscus-ky-mccreary-08-3a

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.

dusky17_jason

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.

dusky-salamander

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.

madagascariensis2

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.

day-gecko

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/