Vampire Bat (subfamily Desmodontinae)

It’s hard not to think of vampires when you think of bats, and while many bats are harmless and helpful fruit- and insect-eaters, not all bats play so nice. There are some that embrace their vampire connections, and they are known, quite unimaginatively, as vampire bats.

There are three species of vampire bat, and each is so unique that they are placed in a separate genus (Desmodus, Diphylla, and Diaemus, for those who are interested). You can find these extra-creepy bats in Central and South America. Their preferred habitats are in tropical and subtropical areas, and they require dark places for roosting, such as caves, wells, hollow trees and buildings.

A white-winged vampire bat. Image credt: Gcarter2 via Wikipedia 

Vampire bats are not overly large animals, with all species ranging in length from seven to nine centimetres. They have greyish brown fur, and in general, look fairly bat-like. They do not have nose leafs life fruit bats — they make do with naked nose pads with grooves in them. Vampire bats are also more suited to moving on the ground than other bat species, using their wings to propel them across the ground in a bounding gait.

You may have guessed — or already know — why vampire bats are named after the mythological Transylvanian monsters. Yes, these bats do suck blood. Common vampire bats feed primarily on mammalian blood, while hairy-legged vampire bats and white-winged vampire bats are more partial to bird blood. They feed only at night, so you don’t need to worry about being attacked by vampire bats (or vampires) when the sun is out.

Vampire bats have distinct skulls and teeth that make feeding on blood easier. Image credit: Mokele via Wikipedia 

Subsisting solely on blood is a very specialized diet, and vampire bats have some amazing adaptations as a result. They have thermoreceptors in their noses, which are used to locate areas where blood flows close to their prey’s skin. There’s even an area in vampire bats’ brains that is similar in appearance and location to infrared receptors in snakes, as the bats are capable of using infrared to find blood on their prey.

Once the blood is located, the bats have to find a way to access it. They do this with their razor sharp teeth — teeth that lack enamel so they are always incredibly sharp. Once they slice into their poor victim’s skin, vampire bats use their saliva, which is full of anticoagulants, to keep the wound bleeding.

Vampire bats also have a special digestive system to cope with their sanguine diet. To get the nutrients they need, bats typically drink about 20 grams of blood per feeding — which is a lot for creatures that weigh an average of 40 grams. That added weight is a problem for flight animals, so the bats have to jettison some of that extra cargo before they take off and return home. Therefore, their digestive system is designed to digest the blood as soon as possible, and pass on the extra liquid to the kidneys so it can be excreted. Typically, vampire bats start to urinate within two minutes of feeding. That’s some pretty quick digestion!

Vampire bats roosting together in a colony. On cold days, even non-resident males are invited into the colony to help keep the other bats warm. Image source

While the picture I’ve painted of vampire bats is one of evil, blood-sucking monsters, vampire bats aren’t all bad. At least, they’re nice to (most) members of their own species. Highly social animals, vampire bats live in colonies consisting groups of females and a few resident males. Non-resident males are shunned and live in separate groups.

Within colonies, vampire bats may share food with bats that are related to them, or bats that they know. A vampire bat can go only two days without feeding, so often a starving bat will beg another for food when sources of meals are scarce. The donor bat will then regurgitate a bit of blood for the beggar to consume. The exact nature of these relationships is still being studied, but it just goes to show that vampire bats are not self-serving, malicious creatures.

I had a lot of fun drawing this guy for today. I like bats! 

Vampire bats have been known to carry rabies, but it is very rare for a vampire bat to pass the disease on to humans. So don’t be afraid of these amazing animals! They are also medically useful, with compounds in their saliva being used in medicine to increase blood flow in stroke patients. See, vampires are friendly after all!

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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.

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!).

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.

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.

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

Motmot (family Momotidae)

I think motmot is a great name for an animal. I love the name, but I think these birds are a misnamed – to me it sounds like motmots should be cute, fluffy little things, but this isn’t the case. No, these birds are quite stunning animals, with bright colouration and big tails. Motmots deserve a grander name than what they’ve got. Still, they aren’t the worst named species on this blog.

Motmots make up the family Momotidae, which contains fourteen species in six genera. They are spread through the tropical regions of Central and South America, with the greatest number of species found in Central America. They prefer wooded areas, and nest in tunnels in river banks.

A motmot showing off its tail feathers. Image source: Wikipedia

Motmots are very colourful birds, with different species having varying amounts of blues, greens, reds and yellows. Their bills are fairly large, though not nearly as big as those of their relatives, the kingfishers. One of the most striking features of motmots is their long tails, which in most species have paddle-like tips. This tail shape is not entirely natural — in several species the feathers on the shaft of the tail are quite weak, and so fall off during preening, creating this distinctive shape.

These tails are used for a bit of a strange purpose; a motmot will wag its tail back and forth when a predator is nearby. This lets the predator know that the motmot is aware of the threat, saving both the predator and motmot time and energy, since the predator will likely not chase the motmot, and thus the bird will not have to flee.

A tody motmot, one of the only species that does not have a large flashy tail. Image source: Wikipedia

A second purpose of motmots’ fancy tails is thought to be for attracting mates, as males have slightly larger tails than females. Pair bonds in motmots can last several years, so those tails must look good. As I mentioned earlier, motmots nest in river banks, digging burrows that can be up to 2.4 meters long. Some species will nest in colonies, with up to 40 pairs nesting in the same area. Females lay around four eggs, which hatch in 20 days. Both parents care for the young, who leave the nest a month after hatching.

While motmots might not be the furballs I pictured them as, they are still pretty wonderful birds. They are most certainly prettier than what I imagined!

Artist’s rendering of what a motmot should look like.

Cover image credit: Dominic Sherony via Wikipedia

Bagheera Kiplingi (Bagheera kiplingi)

As much as spiders terrify me, they are fascinating creatures. I can’t help blogging about such diverse and amazing creatures, even though looking at pictures of them makes me squirm with anxiety. Today’s spider, Bagheera kiplingi, is perhaps not quite as scary as most, thanks to its diet.

Bagheera kiplingi are a species of jumping spider, and are named after Bagheera the panther from The Jungle Book, and the author, Rudyard Kipling. They are mainly found where their food is found, in Central America. They are present in Mexico, Costa Rica, and Guatemala.

Like most jumping spiders, kiplingi are quite small, only reaching sizes of five to six millimetres. Males and females are different in appearance, with the cephalothorax in males being green and red; and red and black-brown in females. The two genders can be further told apart by the shape and size of their abdomens: they are thin and small in males and wide and large in females.

A male kiplingi spider. Image credit: Maximillian Paradiz via Wikipedia

Kiplingi spiders are known for having an ethically acceptable diet, as they are almost completely vegetarian. This is very unusual for a spider, and Bagheera kiplingi is the most herbivorous species of spider in the world. They feed on what are known as Beltian bodies, which are protein, lipid, and sugar rich nubs that grow on the leaves of acacia trees and related plants. When Beltian bodies are scarce, the spiders will also feed on nectar, ant larvae, and other kiplingi spiders. So they aren’t entirely vegetarian, but they do their best in a tough world.

Acacia trees have a lovely symbiotic relationship with certain species of ants. The ants feed on the nutrient rich Beltian bodies on the trees, and guard these food sources vigilantly. For their efforts, the trees get a well equipped army to protect them from nasty herbivores. Of course, this doesn’t work too well when kiplingi spiders are around.

A kiplingi spider munching on a Beltian body. Image source

While most jumping spiders use their agility and speed to catch prey, kiplingi are experts at avoiding ants. They will jump from leaf to leaf to avoid ant patrols, and stay away from any buds that are too well protected.  To ensure they aren’t ambushed in their sleep, kiplingi build their nests on old dead leaves, where there are no ants.

I usually have a favourite animal in every group — for example, my favourite fox is the fennec fox, and my favourite large cat is the cheetah. Until now, I have not had favourite species of spider. They have been sorted into Terrifying and Slightly Less Terrifying. But I think I can say that Bagheera kiplingi is probably my favourite spider species. After all, there isn’t much to fear from a vegetarian spider, is there?

Tent-making Bat (Uroderma bilobatum)

Doesn’t the idea of tent-making bats sound fun? I feel like they’d be excellent camping partners, because if you were ever stuck without shelter they could just whip up a tent for everyone to sleep in. Actual tent-making bats really do make tents, but they certainly aren’t large enough for people to stay in. Still, it’s a pretty cool way to build a roost.

Tent-making bats are found in Central and South America, from Mexico to Peru and Brazil. They live in forests, usually at elevations below 600 m. These bats mainly eat fruit, so they need to live in places where there are enough fruits to sustain them.

Tent-making bats are kind of cute, in a batty kind of way. They are not very large, growing to lengths of 5.9-6.9 cm. Their faces are decorated with a modest noseleaf, as well as four distinct white stripes. Each bat also has a white stripe that runs along the back to the base of the tail. The rest of their fur is grey-brown.

See they’re pretty cute! Image source

These bats are known for their roosting behaviour, which of course involves constructing tents. They do this by chewing at special spots along the middle of large leaves, so that they fold and create a tent-like structure. Tent-making bats usually choose banana or palm leaves for their roosts, and pick trees that are tall, but not overly so. It’s thought that this is because tall trees are better protected against predators, but that very tall trees are more exposed to weather.

Some tent-making bats in a nice cosy roost. Image credit: Charlesjsharp via Wikipedia

The downside about this tent-making process is that it takes a few nights, and the bats have to build a new one every couple of months, as the leaves dry out and fall off. Luckily the bats have friends to share in the work, as up to 59 bats will share a single roost.

Tent-making bats breed twice a year, in February and June. This is when plants are fruiting and flowering, which provides food for the pregnant bats and their young. The bats give birth to only one pup after four to five months. The babies are kept in communal roosts, and are independent a month after birth.

Although leaf homes might not seem like the greatest of shelters, this system seems to work pretty well for the tent-making bats. They are currently doing very well in their range, and hopefully will continue to do so.

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Mexican Burrowing Toad (Rhinophrynus dorsalis)

I was first drawn to this species when I saw a picture of it. The image of a fat, globulous toad with bright orange markings was too amusing to ignore. Blogging about funny-looking species is always a blast because I get to pepper the post with lots of fun pictures.

Mexican burrowing toads are fairly unique animals — they are the only extant members of their family, Rhinophrynidae. In fact, these guys are thought to be the most evolutionarily unique amphibian in the world. That’s a pretty cool title to have.

See how silly they look? Image source

Despite its name, the Mexican burrowing toad doesn’t just live in Mexico. They venture into southern Texas, and are also found in other Central American countries, such as Guatemala, Honduras, El Salvador, Nicaragua and Costa Rica. So if I were naming this species, I’d call it the Central American toad, but I’m sure that would be too accurate for taxonomists.

As I mentioned earlier, burrowing toads are nice plump animals. They aren’t overly large, only reaching lengths of eight centimetres. The toads have bright red-orange spots on their bodies, as well as a red stripe down their backs. Since these guys are burrowers, they require some way of digging. To this end, they have hardened, shovel-like additions to their feet, as well as stocky, muscular legs.

Burrowing is very important to Mexican burrowing toads. They spend the majority of their lives underground, only emerging to breed. Breeding season for these toads can occur at any time of the year, as there is only one required condition: rain. After heavy rains, the toads emerge from their underground lairs and go in search of breeding pools. Males call for females, using a creepy low-pitched call that kind of sounds like the word ‘whoa’. You can listen to it here.

A juvenile burrowing toad, who hasn’t quite developed the pretty orange spots yet. Image source: Wikipedia

Once the rains dry up, the adult toads head back to the safety of the underground, leaving their young to mature on their own. It only takes the eggs a few days to hatch, and they change into adults in one to three months.

For toads that spend almost their entire lives underground, where they can’t be found, these guys sure have interesting looks. I guess if you only have a few days to attract a mate, you’d better look pretty unique.

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