Archive for snake

Meet the Menagerie: Hypatia and Daedalus

Posted in Animalia with tags , , , , , , , , , , on January 24, 2012 by KarenElizabeth

As regular readers will be aware, I’ve got a particular love for colubrid snakes (snakes of the family Colubridae, which includes king snakes, rat snakes, milk snakes, and many others).  To that end, I’ve expanded the menagerie recently with two new additions:  baby corn snakes, Pantherophis guttatus guttatus.  Hypatia and Daedalus.

Hypatia

Daedalus

Since corn snakes require virtually identical care to king snakes, which I’ve already covered in a previous post about Penelope, my California king, I’ll avoid repeating myself and instead focus on some of the other interesting aspects of my new little friends.  There’s also lots of reputable websites out there with excellent basic care information, and I’ll link to a few of them at the end of this post.

Colour Morphs

Now, someone not particularly familiar with snakes might look at those photos I posted up above and say, “wait, those aren’t the same type of snake!”  But looks can be deceiving, and yes, they are both corn snakes.  Corn snakes have, however, been a popular pet species for several decades, and in that time there have been many captive breeding projects aimed at producing interesting, and incredibly varied, colour morphs.  Hypatia is what is known commonly as a “butter” corn snake, while Daedalus is a “lavender”.  Neither of these are colours that you’d be likely to see in the wild.  But in captivity, there’s been a lot of success with producing a great variety of morphs, and captive-bred corn snakes are now available in almost every colour you can think of (not in blue, yet, but I’m sure there’s someone working on it as we speak).

How these different colours are produced is actually quite interesting, if a little bit complicated.  To begin with, there are several different “wild types” of corn snakes.  These are corn snakes that, because of being geographically isolated from each other, have evolved to have slightly different colours and patterns.  The Keys corn snake is a pinkish hue, and tends to have a slightly smaller adult size.  Miami corn snakes have grey or very light tan bodies, with dark orange “saddles” (the splotches on the back) outlined in black.  Okeetee corns (found on the grounds of the Okeetee hunting club in South Carolina) have bright orange bodies with dark orange or red “saddles”, and the saddles have thick, black outlines around them.  And finally, there’s the Carolina (or “normal”)  corns, which have bright orange bodies, dark orange or red “saddles”, and thin, often incomplete, black outlines around the saddles.  Any of these “wild types” will act as dominant, while other colours may be present as recessive traits, hidden invisibly in a snake’s genetics.

In the wild, with so many snakes interbreeding with one another, it would be unlikely for two snakes with the same recessive trait to meet and produce eggs.  But get snakes into captivity, and the available gene pool shrinks considerably.  Inbreeding tends to bring out recessive traits, and in captivity, that’s what happened.

So far, we know of more than a dozen different genes that can affect a corn snake’s colour and pattern.  Several produce similar effects (there are 4 different strains of hypomelanistic, or albino, corn snakes to be found, and it’s difficult to tell the difference between them just by looking; you have to know your snake’s lineage to be sure if it’s a hypo, a sunkissed, a lava, or an ultra).  Others are quite unique (the Palmetto morph, for example, is particularly striking, and certainly hard to miss).  Other genes don’t affect the snake’s colour, but change the shape of its pattern — Motley snakes have dots instead of saddles on their backs, while Stripe morphs are, well, striped.

It doesn’t just stop there, though.  Because each of these colours or patterns is produced by a different gene, you can get snakes that exhibit multiple different recessive traits at once.  Butter corn snakes, like my Hypatia, are such a combination: a butter corn must have both the “amelanistic” and “caramel” traits.  And it’s not just as simple as taking a caramel-coloured father and an amelanistic mother and breeding them together: it takes several generations to produce a line of snakes with such a combination of traits, because you have to eliminate any “normal” genes, which would dominate over the recessive traits and thus the snake would appear just like a wild-caught specimen.  Even harder is combining 3 or 4 traits — but with patience, almost any number of combinations can be achieved.  It can be a bit of a gamble for breeders, though — while combining 4 different traits could produce something never before seen in the pet trade, it won’t do you much good if the resulting snake looks boring, or too similar to something that’s more easily produced.

A Basic Corn Snake Genetics Lesson

If the above paragraph left you feeling lost, I’ll try to make it a bit more simple here.

Say a corn snake has 4 different genes that can code for 4 different colours (they have a lot more, but I’m reducing it here to make the example a lot more simple).  We’ll call those genes N (for normal, like a wild-caught snake would be), a (for amelanistic), c (for caramel), and l (for lavender).

Now, each snake would have two copies of each gene — one from their mother, and one from their father.  Because N is dominant, while the other genes are recessive, a snake needs 2 copies of the same recessive gene in order to express (show) the colour for which that gene codes.  Otherwise the dominant N would be the thing that ends up showing.

In this example, Daedalus (my lavendar corn snake) would have two l genes coding for lavender, but only N genes in the places that might code for caramel or amelanistic.  So a chart of his genetics would look like:

amelanistic    NN

caramel           NN

lavender          l l

Hypatia, on the other hand, would have double-recessive genes for both amelanistic and caramel — but since she doesn’t express a lavender trait, she’d have N genes there:

amelanistic    a a

caramel           c c

lavender          NN

Now we’re going to complicate matters.  If Hypatia and Daedalus were to have babies together, their babies would all look like normal, wild-caught corn snakes, because each one would receive one recessive trait from one parent, and one dominant trait from the other.  The dominant Ns would be what showed up — but all of the babies would be what is called “heterozygous” for all 3 traits, since they’d have the recessive traits still hidden, unexpressed, in their genetic codes.

__________from Dad      from Mom

amelanistic    N                          a

caramel           N                          c

lavender          l                           N

But if we were to breed those babies together with each other, that’s where it gets really interesting, because now there are many options for what each parent could contribute to the genetic mix.  This website is great for calculating the odds of what you’ll get from parents with known genetics, and from that we can see that there’s a 1 in 64 chance that you’d get a baby with all 3 traits expressed: caramel, lavender, and amelanistic together.  The vast majority of the babies (27/64) would be just like their parents — normal in appearance, but with hidden genetics lying unexpressed beneath the surface.  Some would have one, or even two of the traits expressed, giving you some amelanistic babies (9/64), some caramel (9/64), some lavender (9/64), some butter (3/64), some caramel/lavender combos (3/64), and some opal — a combination of amelanistic and lavender — (3/64).

This is, essentially, the same way that human genetics work.  Just like blonde hair and blue eyes are recessive and may be “hidden” by dark hair and eyes, so may various corn snake colour traits remain hidden for many generations, until a limited gene pool (or sometimes just random chance) brings them out.

Less Complicated Things

All right, so that was still rather complicated.  Genetics are kind of weird, although once you get the hang of it, they’re very much predictable.  But let’s move on to some of the less complicated reasons why corn snakes are so interesting.

Corn snakes are fairly common in the wild, being found all across the southern U.S. and down into northern Mexico.  They live in a huge variety of habitats, from the arid climate of Texas to the damp woodlands of Florida, from sea level to as high as 6000 feet in elevation.  In cooler areas they will hibernate through the winter, but in more temperate climes they’ll simply go into a period of reduced activity between December and March, spending more of their time hiding in rock crevices and less out hunting and basking in the sun.  This winter cooling, or “brumation”, is actually a necessary part of their breeding process — without a brumation period, snakes won’t readily breed in captivity.

Like most snakes and other reptiles, corn snakes do not care for their young the way that mammals and birds do.  After laying her eggs in a warm, moist location, the female corn snake goes away to resume her normal life.  The eggs are left to incubate by themselves (not a problem, since they incubate safely at a wide range of temperatures, anywhere between 72 and 90 degrees, which in their habitat is a relatively normal summer temperature).  Depending on temperature, the eggs will take 50-60 days to fully develop.  The baby snakes that hatch out are completely independent, ready to go out hunting almost immediately for their very first meal.

In the wild, corn snakes are sometimes mistaken for venomous snakes such as copperheads and killed by ignorant humans.  But these shy little snakes can be a great help in keeping down the numbers of pest species such as rats and mice, and so they should be encouraged to live in your yard if you happen to be in an area where they are native (plus it’s just nice to have cute little snakes in your yard!)  Corn snakes, while not endangered, are at risk from habitat destruction, and so by creating a place that is safe for them, you are protecting your local biodiversity.

While corn snakes usually like to stay on the ground, they are excellent climbers.  In the wild they may climb up trees to get at bird eggs or other delicacies, while in captivity they will explore every inch of their tank and may even amaze and baffle you by climbing up the bare glass, like Hypatia is in this picture:

They are also incredibly good at finding absolutely any hole or gap in their enclosure through which they might escape, and so it’s very important, if you want to have a corn snake as a pet, to buy a tank that is specifically designed for keeping snakes, and to check it carefully for any little gaps and spaces (note the bit of duct tape on Hypatia’s tank in the photo above — that’s covering up a tiny space where the lid clips on to the tank).  Corn snake escapes are unfortunately rather common, and they can be hard to find again once they do get out.  Protect your baby (and show courtesy as a pet owner) by making sure they can’t pull a Houdini on you.

More Information

Care sheet and basic information

Another care sheet

Pictures of hundreds of different colour morphs

TheCornSnake.co.uk (information, links, and forums)

Corn Snake Calculator (figure out what morphs you’ll get by breeding your snakes)

Advertisements

So Frickin’ Cool! Snake Digesting a Rat

Posted in Animalia, Ramblings with tags , , , , , , on September 26, 2010 by KarenElizabeth

This is one of the more interesting things I’ve seen in my travels around the Internet, recently, so I felt the need to share it.  Click the picture to see the rest of the images.

Using a combination of computer tomography (CT) and magnetic resonance imaging (MRI), scientists Kasper Hansen and Henrik Lauridsen of Aarhus University in Denmark were able to visualize the entire internal organ structures and vascular systems (aka “guts”) of a Burmese Python digesting a rat.

By choosing the right settings for contrast and light intensity during the scanning process, the scientists were able to highlight specific organs and make them appear in different colors. The non-invasive CT and MRI scans could let scientists look at animal anatomy without the need for other invasive methods such as dissections.

Not only does the snake owner/lover in me think that this is entirely awesome, I’m also mind-boggled by the possible applications of this sort of technology.  As a diagnostic tool for difficult digestive disorders (Crohn’s disease comes to mind) this could really be invaluable, since it gives a much more comprehensive picture than a colonoscopy could offer.  Anything that shows more details of soft tissues is  really important, since those things are often hard to see without actually opening up the body surgically.

Biology is so neat, and technology just makes it cooler.

Meet the Menagerie: Penelope

Posted in Animalia with tags , , , , , , , on March 21, 2010 by KarenElizabeth

In this, the fourth installment of my “Meet the Menagerie” posts, I’m introducing you to my California Kingsnake, Penelope.

For years I’ve had a special love for colubrid snakes, and kingsnakes in particular.  When I was in high school, I had a friend whose older sister had a pet red kingsnake.  Every time I visited their house, I’d find an excuse to go stare at the snake tank for a while.  He was a fun snake to watch — very active, and very pretty.  So when I decided last fall to get myself a pet snake, kingsnakes were first on the (longish) list.

Basic Info

Kingsnakes (genus Lampropeltis) are non-venemous, constricting snakes that are common in much of the United States and Mexico.  They have shiny, unkeeled (non-ridged) scales, sleek heads, and long, thin bodies.  There are many different subspecies of kingsnake, from the brightly coloured red kingsnake with banding that imitates the venomous coral snake, to the dark chocolate-coloured Mexican kingsnake.  California Kingsnakes like Penelope (Lampropeltis getula californiae) are, as the name suggests, most commonly found in California — but they’re also seen in Arizona, southern Nevada, southern Utah,  southern Oregon, and northwestern Mexico.  There are several regional colour variations within the California Kingsnake species; Penelope exhibits what is commonly known as the “Newport-Long Beach” phase, with a broken-up pattern that looks almost like a cross between bands and stripes.  Banded snakes with either black and white or yellow and brown bands are more commonly seen, and snakes with longitudinal stripes are also found in the wild.  The thickness of the bands or stripes can also vary, creating different-looking snakes.  Check out some photos of different morphs here.

Kingsnakes in the wild live in a variety of different habitats, but are most commonly found in rocky or scrub-brush terrain where there are plenty of hiding spaces.  They’re good snakes to have around, and those who know their reptiles are happy to find kingsnakes living near their homes, because kingsnakes are immune to the venom of most rattlesnakes and will happily eat the venomous snakes.  Their taste for other snakes is why they are called “kings”.  They also eat mice, rats and other unwanted vermin, which is also appreciated by their human neighbors.

Kingsnakes are often killed by humans when mistaken for other, more dangerous species.  Red kingsnakes have a pattern that imitates the banding of the venomous coral snake, and those who don’t know the rhyme “red and yellow kills a fellow; red and black is okay, Jack” may kill the harmless and helpful kingsnake by mistake.  Other kingsnakes, like the California kingsnake, may be mistaken for rattlesnakes, because when threatened they will quickly vibrate their tails.  Despite the fact that they don’t actually have “rattles”, this vibration will often create enough of a noise to fool a predator — or a human — into thinking that they’re the real thing.  If you do live in an area where kingsnakes are common, get to know what the local species look like.  This way you’ll be able to protect both the snakes and yourself.

Kingsnakes in Captivity

In captivity, kingsnakes have a few simple requirements.  First, and most important, is a large enough tank.  With kingsnakes, as with most snakes, you want to follow the “L Rule” when selecting an enclosure:  the length of the snake should not exceed the length of two consecutive sides of the tank.  In other words, if the snake were to bend into an “L” shape, with the tip of its tail in one corner of the tank, would its head touch the opposing corner?  If so, you should get a bigger tank.  For an adult kingsnake you’ll likely be looking at a 40 gallon tank, as they grow up to about 5 feet long.  If you can afford to go even larger than that, please consider doing so:  these are very active, curious snakes, and more space will give them more mental stimulation, and allow you to observe a wider range of natural behaviours.  Speaking of mental stimulation:  making changes to their environment on a regular basis can also keep life more interesting for your animal.  I try to move at least one piece of cage furniture every week, to encourage exploratory behaviors and keep Penelope active and happy.

Always remember when keeping snakes:  a secure lid is VERY important.  Snakes are curious creatures and amazing escape artists — if they can push the lid of the tank up even a little bit, they’ll escape, and with all the multitudinous hiding places available in an average house you may never find them again.  Many large terrariums are designed with lids that lock closed, specifically to prevent snake escapes.

Kingsnakes also need a ready source of fresh, clean water — and their water dish should be large enough for them to curl up and take a bath in, if they want to.  A large margarine tub is a simple (if not very attractive) option.  There are also commercially available reptile dishes that are large enough — or you can go with any other (non-breakable) dish that’s of an appropriate size.  I specify non-breakable because if your snake is anything like mine, that dish is going to get moved around the terrarium quite a bit.  Kingsnakes are curious and will happily re-arrange their tank furniture during their exploratory missions.  You can also increase the amount of activity and exercise they’re getting by taking them out of their tank on occasions (always make sure you’re carefully supervising, as they can make quick getaways when you’re not paying attention).  Some snakes will enjoy handling more than others.  Penelope is quite personable and enjoys exploring people (and especially crawling inside of shirts and into pockets).  Other snakes may be more skittish, and so you’ll have to limit the amount of handling they get.  Respond to your snake’s personality, and do what is best for them.  If you find that your snake is extremely aggressive when handling, you may want to increase the amount you’re feeding them, since kingsnakes are usually a very docile species.

Hiding spots are also important when you’re setting up your snake’s home, as kingsnakes in the wild will find sheltered spots to curl up in when they rest.  At least one of these hides should be a “moist hide”, with some sort of moss or soil inside to retain moisture.  Snakes, like other reptiles, seek out humid places when they are shedding, as it helps them in sloughing their skin.  In Penelope’s tank I’ve used a mix of branches and PVC pipes to create spaces for her to hide.  I’ve also sectioned off one area of the tank to have soil as the substrate (to retain moisture and give a natural look to the space), and another section to contain a product called CareFresh — a recycled paper product that is commonly used as reptile or small mammal bedding.  Penelope likes to burrow under the CareFresh to hide.  The only reason I don’t recommend it as the substrate for the entire tank is that it turns to mush when wet, and so you can’t really use it near the water dish.

Some people use wood shavings or chips as a substrate for their snakes, but it’s not my substrate of choice.  Some types of wood — like pine and cedar — MUST be avoided because they contain resin that can be irritating to the snake’s skin and respiratory system, and it’s poisonous if ingested.  Wood chips of any kind are also very hard to digest if accidentally ingested, and can cause impaction, so if you’re keeping your snake on wood chips you’ll always want to take them out of their tank before feeding them.  Some snake enthusiasts and breeders swear by aspen shavings, but I’m just not a fan, and I definitely encourage you to do your research before deciding on wood (it’s not a decision to make just because “the guy at the pet store said so”).

The final requirement for your snake is, of course, heating.  Like all reptiles, snakes are cold blooded and need to regulate their body temperature by moving between warmer and cooler parts of their environment.  You’ll want it to be about 87-90 degrees Fahrenheit on the hot side of the tank, and 78-80 degrees on the cool side.  Temperatures above 90 or below 75 degrees should be avoided.  A heat lamp is the best source of heat for snakes, as they have a tendency to burrow when they are feeling too warm — many injuries have been caused because a warm snake decided to burrow closer to its under-tank heating pad, instead of moving further away.

Delicious and Nutritious Foods


While wild kingsnakes will eat a wide variety of foods, ranging from other snakes to rodents to eggs to lizards, in captivity they are most commonly fed on rats or mice.  These are easily available live or frozen from any pet store that handles reptiles, and they come in many sizes.  Choose the size of rat based on the size of the snake — the food shouldn’t be bigger around than the largest part of the snake’s body.  I prefer to buy frozen, myself, because they’re easier to buy in large quantities, and I don’t need to worry about doing the killing (it’s not really difficult, but it’s unpleasant). With frozen rats, all you need to do is thaw them out by leaving them in warm water.  Be sure the rat is thoroughly thawed, so that your snake doesn’t get frostbite, and never use a microwave to thaw out the rodents, because they may thaw unevenly or get too hot and burn your snake.  If you decide to go with live rats or mice instead (some snakes will never take to eating something that’s been frozen first), you’ll want to kill them just before giving them to your snake.  The kindest way to do this is by snapping the neck (it’s pretty much instant death), or by using CO2 gas (which puts them to sleep).  Don’t put your rodents in the freezer to kill them — it’s a long, slow, unpleasant death.  I’m also not a fan of the “whack them off a table” method … it’s brutal and not always accurate (sometimes the rodent is only stunned, and it wakes up a few minutes later and you have to do it again).  I don’t recommend feeding live rodents to any snake, as it causes unnecessary terror to the prey, and your snake might get bitten or scratched if the rodent fights back in self-defense.

If you’re squeamish about killing the prey yourself, simply ask the person you get the snake from whether they’re eating frozen/thawed prey (if they are, you’ll be able to feed them that, too).  Or you may be able to get the staff at your pet store to do the killing for you, and then just feed the rodent to your snake immediately when you arrive home with it.

Juvenile kingsnakes should be fed every 5 to 7 days.  Once they’re full grown, you can go 10 days to 2 weeks between feedings.  The only exception occurs when they are shedding: snakes are unlikely to eat when they’re preparing to shed their skin, so always check their eyes to see if they have gone “opaque” before you attempt to feed them.  A snake that is going to shed in the next few days will start to look dull and have a whitish sheen.  When their eyes appear to have a white film over them, it’s a sign that a shed is going to happen in the next day or so.  At this time the snake is more likely to be defensive and it won’t want to be handled.  Young snakes will shed about once a month; adults will shed four or five times a year.

Once your snake has eaten, try to minimize handling for the next few days.  They’re busy digesting, and undue stress can mess with that process or even cause them to regurgitate their meal.  In the wild, a well-fed snake would probably remain mostly in hiding while it digested its food, and your captive friend will want to do the same.  A few days after eating, your snake will poop (snake poop is pretty smelly, so you’ll want to clean it up right away).  After that he or she will be back to their normal, personable self, and you can resume regular handling.

A Final Note

If you’re interested in getting a kingsnake as a pet, do your research, people! They’re not difficult animals to keep, but they do need more extensive (and expensive) setups than, say, a leopard gecko.  There’s no substitute for knowing your stuff, and people at pet stores can’t always be trusted when it comes to accurate reptile information.