Issue #25

Herpetoculturemagazine.com

erpetoculture agazine Issue #25

, d e t a r r e d n U e Th

s y x i n Ki meana ho

An Interview with

Tortuga Fontana

Are You Prepared For Winter Storms?

How It Works:

Herp

Vision!

Looking For Rattlesnakes In

Mexico!

-- On the Cover -Kinley Childress @kinelylakelyn

This Issue...

Page 5 Page 20 Page 11 Page 25 Page 13 Page 30 Copyright © 2021 by Herpetoculture Magazine all rights reserved.

This publication or any portion thereof may not be reproduced or used in any manner whatsoever without the express written permission of the publisher except for the use of brief quotations in a book review.

Twenty Fifth Edition www.herpetoculturemagazine.com Herpetoculture Magazine

THE XR-16 The gift that keeps on giving.

- Fits multiple tub sizes from Vision or Freedom Breeder!

- Upgrade your animals as they grow with bigger tubs that fit the same unit!

- Stackable.

- Belly heat included with optional dual zone heating.

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From The Publishers’ Desk

Here we are, 25 issues and 2 years deep into this publication! It’s been quite a ride for myself and the gang here at HM. There have been plenty of ups and downs throughout the years. Most of it has been us finding our way, flying by the seat of our pants as they say. Some months are a breeze from start to finish with content and design. While some issues have been a bit more difficult to say the least.

Every bit of feedback has made the tough times worth it, and helped to fuel the motivation to keep bringing this magazine to life! That being said, we’ve decided to cut magazine issues back a bit, and make the magazine the best it can be! Issues may not be monthly, but we promise consistent content from the best in our community.

Personally, it hasn’t been an easy decision. Our team of contributors and editors is working to bring you, the reader, the best magazine we possibly can with each issue!

I know I speak for the handful of us when I say that we love making this magazine happen. It’s been a wild, fun, and exciting ride thus far, and we don’t plan on quitting!

Thanks for 2 years of HM, here’s to many more!

Justin Smith -Publisher-

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Contributors

Justin Smith - Publisher -

Tyler Brooks - Contributor -

Phil Wolf - Editor -

Ryan Collister - Contributor -

Paul Donovan - Executive Contributor -

Christian Parr - Contributor -

Do you keep up with taxonomy changes? why or why not?

“I try too, but usually I just hear a new genus or species and go all angry old man mode when it doesn’t match up with my old field guides from undergrad herpetology. Also chondropython4ever!”

- Brian Whitaker “I'm a scientist... it's my job...that's what I tell myself anyway. In reality, I am an uber-nerd and love taxonomic research. If a paper is written well and based on solid science, you learn about the evolutionary history of the animals we all love. It cracks me up how heated people get over names being sunk, or new names being created. If the paper provides evidence of support, I see no problem with names being sunk, new species being described, taxa being split, etc. so long as the science that created the change is done well. Keypoint here though is the paper/science being done...WELL...with ample evidence. One thing I have noticed while writing about snake taxonomy over the past year is how little evidence some investigators rely on to describe a new species of snake - as little as a single collection of 1-3 animals from a single location and BAM - new species are split from nominate taxa. That I have a problem with - the peer review boards and associate editors of those articles that let that slide are where the problem is…” - Dr. Zac Loughman

“I started naming things after myself and just seeing what the science community accepts.”- Owen McIntyre

“Yes, but mainly just for the animals I keep or dream about keeping. It would be too daunting for me to learn them all. I guess I do it because I'm obsessed about those certain animals and want to know everything anyone has ever said or written or thought about them?” - Lisa Farinha “It doesnt change the way I keep them or what I keep in general. If I come across a paper I will read it but I don't go out of my way. We're just raising pet snakes in boxes anyways haha” - Randy Pegues

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Homeana

at home

The captive care of the Home’s Hingeback Tortoise, Kinixys homeana, is something that is not discussed enough. Hopefully, by the end of this article, you will be interested in the care and husbandry of this interesting species as much as we are at The Kinixys Working Group. Here, I will discuss the natural history, husbandry and reproduction of Kinixys homeana.

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Keeping

Kinixys homeana

With Tyler Brooks

Photos by Kinley Childress

Natural History

The Home’s Hingeback Tortoise was described

by Thomas Bell in 1827 and named in honor of Everard Home, British surgeon and Naturalist.

Kinixys homeana are a small to medium-sized tortoise from equatorial West Africa. They have been found in Ghana, Gabon, Guinea, DRC, Benin, Cameroon, Ivory Coast, Liberia, Equatorial New Guinea, and Nigeria. In their natural range, these tortoises will inhabit dense forest, lowland jungles, and seasonally flooded swampy areas adjacent to larger bodies of water.

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Captive Care Enclosures Taking what we know about Kinixys homeana in the wild and applying it to a captive situation can be difficult. Being successful with this species takes patience and the ability to set up their habitat correctly. They are shy, crepuscular, and stay hidden most of the day, but that being said, they can be very rewarding for the keeper (you) when given the opportunity to exhibit natural behaviors.

As juveniles (under a year old), the Home’s Hingeback Tortoise should be housed in a closed chamber enclosure – any enclosure that can hold and maintain humidity. This can be easily achieved by using PVC caging with sliding glass front doors with minimal ventilation. These are ideal with the only drawback being price. Young Hingebacks thrive in smaller controlled environments. To accomplish this, we have developed the “Tort Port”. These modular enclosure windows allow the keeper to utilize any size bin as an enclosed chamber habitat.

Once you have decided what type of enclosure to use, build the enclosure from the ground up. Substrate is very important, as Hingebacks spend hours digging and nosing through their substrate looking for worms and bugs. For hatchlings, I prefer

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to use fir bark nuggets, although coco husk chunks and cypress mulch will work as well. I recommend introducing isopods, springtails, and any other “cleaner” that can also be used as forage. These additions are essential to the natural diet and behavior of Kinixys homeana, and help support a bioactive environment.

The next step is to add live plants such as Pothos or Wandering Jew. I also utilize sticks and branches to give sight breaks, as well as hides or retreats where the tortoise can go to feel secure. At this stage of their lives, I do not add a water dish to the enclosure to avoid the unnecessary risk of an overturned hatchling.

Instead, they are soaked every other day under full spectrum UV lighting to address hydration and vitamin D3 synthesis.

As the tortoise grows, I will set the animal up in a bigger version of what has been described above with a few changes. I will add a shallow water dish, preferably with ramp out (plant water dishes are cheap and easy to clean) and UV lighting. Typically, I upgrade to a 110 quart bin, which allows me to safely add the lights. I have found that Arcadia’s “Shade Dweller PRO” works best in this situation as it is only 12” long and as the name suggests, it is not an overpowering light for the tortoise. These lights seem to be perfect for the species.

As Kinixys homeana reach five to seven years old, they are ready for their adult enclosure. I utilize different size cattle troughs.

A single Hingeback can be kept in a 6’ trough and will do even better in an 8’ trough. The major change in the adult habitat is the substrate, aside from it being open air. For adult females that I want to breed, I use 10” of shredded coco husk topped with 2” of coco husk chunks. The chunked topper helps keep your water dish clean and will also assist the tortoise in walking properly by providing solid footing. Adult males get several inches of coco husk or cypress mulch as substrate. Additionally, both male and female troughs get a layer of leaves, typically Magnolia.

Naturally, Kinixys homeana seem to really enjoy leaf litter, and it brings out a lot of their natural burrowing behaviors. Other than substrate, adult housing is similar to the baby habitats. They both want low lighting and lots of hides. Adults of both sexes relish a good soak, so make sure that you always provide the correct size water dish.

Diet Kinixys homeana enjoy a highly varied diet. In the wild, chitin from the exoskeleton of millipedes is found in most stool samples. It seems that millipedes are an important item in their diet, so in captivity it is important to use many forms of protein to round out their diet. Different forms of protein can include rodents, chicks, earthworms, boiled eggs, and assorted invertebrates. I offer one of the above items to babies at least

once or twice a week, depending on what is available, and to adults typically once a week.

As for the vegetable side of the equation, my base salad features dark leafy greens. In the Southeast United States, we have relatively cheap, year-round access to collards, turnips, mustard greens, and kale. These greens are good for a store-bought diet, but if you have the ability to collect weeds like dandelion, clover, plantain or mallow, it is preferable.

Next, I prepare a topper to the greens that includes zucchini, yellow squash, mushrooms and sweet potato. I microwave the sweet potato until it is the consistency of a zucchini or yellow squash (cooked but still firm). In addition to these common items, I will add okra, green beans, carrot and various assorted squashes. These items are added as I see fit or when they are seasonally available.

As you can see, I am not using true fruit in their daily diet.

If you are trying to establish wild caught adults, it will be tempting to use fruit when acclimating them, but this should be avoided as the high sugar content of fruit will lead to avoidable gut flora problems in the future.

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In addition to natural food items, I use pellets every seven to ten days. I utilize a variety at my facility: Mazuri Tortoise (5M21), Mazuri Crocodilian (5MG1), Marion Zoological Tortoise (MRFT B25) and ZooMed Aquatic Turtle (3/16” Growth Formula). Before feeding, I will soak the pellets that I am going to use in water and prep a salad that is pretty basic.

Next, I will combine the pellets and salad on the plate being fed out. I let the pellets be the star of the show on these days.

I do add supplements to their salads once a week, alternating between Repashy Calcium Plus, Repashy Calcium Plus LoD and Arcadia EarthProA. I provide adult females more supplementation during the breeding season. I strive to provide a highly varied diet to best support these amazing tortoises throughout their lives.

Reproduction If you choose to work with Kinixys homeana, I strongly suggest that you consider trying to breed them. These tortoises are not doing well in their home range due to many factors such as habitat loss, traditional medicine and human consumption, just to name a few. Added to these external pressures, Kinixys homeana do not lay large clutches. In my experience an average clutch size is two to four eggs with one to three clutches laid per year.

In October, as the temperature is changing, I start to pair my Hingebacks. I use the change in seasons to help facilitate breeding. The storms that come through in October are a great time to start your pairings as the barometric pressure drop seems to stimulate breeding. First, I remove the food and water dish from the male’s enclosure.

Next, I introduce the female and I use a garden hose on a shower setting to simulate heavy rain. I keep an eye on the pair when they are together to make sure the male isn’t flipped and that courting doesn’t get too violent. Kinixys, as a genus, can be rather aggressive during mating rituals, so some combat is to be expected. It is important to pair aggressively and often during this time to ensure the best chance at fertile eggs. I continue to pair until the female rejects the male. In most cases, she will become much more aggressive towards him.

As the female gets close to laying, she will become very restless, constantly pacing and roaming her space to find the right nesting spot. If your female goes through all of these stages and then stops pacing, it is time to search the enclosure for eggs.

Kinixys homeana are shallow nesters, so be very cautious when turning the soil looking for eggs. It is important to be observant

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with the tortoises as you don’t have some of the advantages that you have with snakes and lizards, like sheds and swelling that can be good indicators that things are progressing in the way you want them to.

I have had success in hatching Kinixys homeana eggs utilizing passive ambient incubation, meaning that I do not use a traditional incubator. I use a Squamata Concepts SIM container with water in the bottom and I put the box on a shelf in my tortoise building to experience the temperature fluctuations. This time of year the eggs will be exposed to temperatures between mid to low 70s up to the low 80s. I caught a late second clutch of two eggs being laid on July 9th, 2020 - one of these eggs was very large and went bad quickly, while the other went full term in the SIM container and hatched on October 12th, 2020. It is not a traditional incubation method, but this is what has worked for me.

Call To Action

If you are remotely interested in working with Kinixys homeana or any other Kinixys species, I highly encourage you to seek out the Kinixys Working Group. We are a collaborative of dedicated Hingeback tortoise enthusiasts, keepers, institutions and researchers working together to ensure the future of the genus to the best of our ability. To accomplish this mission, the working group will preserve Kinixys, educate those interested in the genus and support sound research. You do not need to be a keeper in order to help the genus - there are multiple opportunities to educate, promote and bolster these amazing animals. Kinixys homeana have taught me patience, endurance and humility. I encourage anyone wanting a challenge to consider these unique tortoises for your program. If you choose to do so, you will be greatly rewarded in your endeavor.

fb.com/kiniyxswg

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Product Review by Justin Smith Zep Antibacterial Disinfectant I’m always on the perpetual search of the best disinfectant for my herp room and cages. I’ve used F10 in the past and loved it but the inconsistent availability coupled with a higher price tag left me wanting to try other options. I switched to chlorhexidine for a while but then in talking with Matt Most (of Sarpamitra fame) he mentioned a product called Zep that my local Tractor Supply Company carries. The next time I found myself in my local TSC, I grabbed a bottle.

So far this product seems to work well. Obviously, I’m not taking samples and testing for bacterial or viral loads from surfaces. Zep claims that their antibacterial kills 99.9% of germs and bacteria on hard, non-porous surfaces in 60 seconds, a much quicker contact time than we see with pretty much any other disinfectant that’s commonly used.

This particular formula has a citrus scent that is fairly strong.

Price wise, Zep is actually around the same price, if not slightly cheaper, than chlorhexidine for a gallon sized bottle.

Unlike chlorhexidine, you don’t have to mix zep with water.

You simply pour it into your spray bottle and you’re ready to go! The only downside to this is you will go through a gallon bottle faster than you would with chlorhexidine since it isn’t a concentrate that you mix with water.

I’ve been using it to clean out tubs and water bowls with no issues with my animals. I spray my water bowls, let them sit for a few minutes while I get the animal or tub separated or cleaned then I just wipe the bowl dry, refill, and move on!

Overall, it’s nice having a product that I can find locally and not be beholden to stock shortages online. There are a lot of options for disinfectants out there and I still recommend rotating between a few of them periodically but Zep is going to be a staple in my herp room!

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Emergency Prep: Power Outtages and the K

Cold

eeping reptiles in captivity is fun, rewarding and, for most of us, it's down right addicting. But the hobby is full of challenges that will always test our abilities and ways of thinking. One challenge many keepers will experience is the sudden loss of electricity or heating during cold weather conditions. With this in mind, the question for today is: What will you do when faced with the loss of power and/or heat in cold weather conditions? In this article I would like to talk about what I do to prepare for these types of situations and offer a few other ideas that you may be able to use in your home.

The first thing to keep in mind is that not all situations will be the same and not all animals have the same requirements, so it's important to know exactly what your animals require. Winter storms can cause power failures.

It could also be a failure with your home's electrical or heating system. There are many situations that can, and most likely will at some point, cause you to make adjustments so that you can keep your animals safe from cold temperatures. It's also possible that our own good intentions for back-up plans may fail. For example, if your only emergency plan is to have a generator, what happens when your generator won't start? It's best to give yourself multiple options to handle these cold weather situations.

My goal is to have a plan in place so that my animals are affected as little as possible. I don't want to be moving

By Christian Parr

things around or rushing to get things set up when the power goes out. I want things to be as easy as possible while still being effective.

Ok, let's talk generators. Generators are a common solution for power loss. But not all generators are the same and there are many different options to choose from. Additionally, we all will have very different power level needs. It's absolutely critical for you to know how much power you need to run everything for your reptiles safely. The purpose of this article is not to figure out what generator best fits your needs, but I will share a few things to keep in mind.

A few years ago when I started keeping just a few geckos I had a 3600 watt generator. This worked perfectly for what I needed. It would run the two racks of geckos as well as a few enclosures I had set up. It could also run a small 1500 watt space heater when needed as well. In addition, I could run a few lights in the house and the refrigerator which kept my wife happy! However as my group of animals grew and I got a chest freezer for my feeders, I found the limit of the generator, as well as a very major flaw with my emergency plan.

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Specializing in Morelia & Old World Ratsnakes.

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I use herpstat thermostats for all my temperature control needs.

Herpstats have a low voltage shut-off, so that in the event the thermostat doesn't have sufficient power levels to operate, the thermostat will shutdown to protect itself from damage. So what would happen is every time my fridge or freezer would cycle, they would draw enough power from the generator that the power levels would drop low enough to kick all of my herpstats into the low voltage cut-off mode, killing all the heat in all my enclosures and racks. Thankfully, it's not my only plan (more on that later).

Having discovered this, I needed a bigger generator to run everything since my needs had grown. Also worthy of remembering is that generators are machines. I know, shocker right? Keep in mind, machines require maintenance and upkeep.

They will fail (Murphy's Law and all), and of course at the worst possible time. The last thing you want is for your generator to fail in the middle of a winter storm, so it's best to make sure it's kept in the best working condition at all times. With all that in mind when you have the right generator for your situation it is a wonderful tool to have.

Now, how exactly will the power from your generator get to where you need it? The best and most expensive way is to have a whole home generator system installed. These systems are designed so that when the power goes out, they automatically turn on and will power your entire house. These systems are often thousands of dollars, but they are extremely convenient if you live in areas that lose power often. In my opinion the best way to use a traditional portable generator is to have your generator connected to a switch panel that feeds your home’s load center (panel box). This way in the event of power failure you can flip a switch, start the generator, and your house will be powered. Depending on what size generator you have, you may need to turn a few breakers off to things that use a lot of

electricity. Well pumps, hot water heaters, heat pumps, things like this that use a lot of energy that may not be absolutely essential in an outage so you don't overload your generator.

Though this works, installing a switch panel and plug for a generator to be properly connected to your panel can be an expensive, labor intensive process and could be extremely dangerous if you don't know what you're doing. If it's not something you completely understand and know how to do, it's always best to call an electrician to install it for you. Please don't electrocute yourself! If this method isn't something you want to do, you'll need to run extension cords from your generator to your set-ups, likely requiring a few chords and power strips here and there, depending on your setup.

"...what would happen is every time my fridge or freezer would cycle, they would draw enough power from the generator that the power levels would drop low enough to kick all of my herpstats into the low voltage cut-off mode, killing all the heat in all my enclosures and racks."

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The next area I would like to talk about is heating your room in the event your main heating source fails or goes off when you lose power. One option is to use a portable space heater.

If you have a total loss of power, you can power the electric space heater using a generator. But what about a heat source that doesn't require any electricity?

In Northeast Pennsylvania, where I live, it's common for people to use natural gas or propane fireplaces to heat their entire house. The best thing about gas fireplaces in my opinion is in most cases they require no electricity to run as most of them start via battery power..

In the event of a power outage in cold weather, I can now simply turn the fireplace up.

I use a wall mounted unit that can easily heat my room to well over 80 F degrees if needed. Most reptiles can spend a good amount of time with ambient temps in the low 80's. This has become my favorite tool when dealing with cold weather emergencies, to the point where I'm installing another one to heat the rest of my house. This was fairly inexpensive to install (under $1000). Again, if this isn't something you're comfortable installing, seek professional help. After all, it is gas and fire you're dealing with--don't burn your house down or blow yourself up! Now, I understand that wall space is at a premium in most of our reptile rooms, so having a heater taking up a few feet of wall space isn't ideal.

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So for situations like this, they do make small portable propane burning space heaters that are safe for indoor use, and are typically less than $200. Most will run off of small 1lb canisters or a 20lb tank. Just make sure it is safe for indoor use. When propane burns, it gives off moisture, so it won't dry your room out. If your room isn't well ventilated you may need to crack a window or open the door to keep the humidity down to prevent condensation. I also highly recommend getting a carbon monoxide detector to ensure safety for animals and people alike.

Remember that propane is a low lying gas, so keep your detectors low. Typically the best place in this scenario is in wall outlets or power strips. There are probably other options out there to heat your room in emergencies, but this is something I use and have had extremely good results with thus far.

One last thing I would like to touch on is your room in which the animals are kept. Some of us keep our animals in our basement; others, in a spare bedroom or perhaps even an attic. But it's important to know and understand your room or area you keep your animals in. Check windows, doors, air gaps, insulation and other areas for spots cold air can get in or let the warm air out. It's a good idea to make your room as energy efficient as possible. If it doesn't hold heat well this will make keeping the room warm in an emergency difficult to manage. It's also a good idea to check for potential hazards as well such as outlets, plugs and places with a lot of wire. These are the common places electrical fires can start when a lot of power is being transferred. Each room is different so you will have to examine yours to determine if there is something you can improve.

Finally, let's talk about the small, simple things that can work for smaller collections. These may not be ideal methods, but if you're in a pinch they'll work if you only have a few animals. It is be very easy to keep heat packs you can use.

One idea is to keep a cooler big enough that you could put all your animals in bags or deli cups and then put a few heat packs in the cooler with them. Just make sure they can't get in direct contact with the heat packs and they have plenty of oxygen. Also, if you only have a few animals you can find ways to use your body heat to keep them alive.

You can put your animals in bags or cups and put them under a blanket with you. Things like this will work, but I wouldn't necessarily recommend it because it will likely put unnecessary stress on your animals. The last thing you want is a cold stressed animal. It would be much more wise to create a better plan so the animal can stay in its enclosure.

"The question is, are you set up and prepared yet? What steps do you need to take to keep your animals safe?"

These few things are my main tools I use for cold weather emergencies-- they haven't let me down, and honestly I can't see how they could. I have gone a few days without power in the winter and these tips has proven to work extremely well. In fact, my animals almost see no effects when the power goes out, because I took the time to plan and prepare for situations just like this. Of course, each time I deal with a situation I try to learn new ways to improve on how I can better protect my animals in cold weather emergencies. Are there better ways and better tools? Maybe. I'm sure there are plenty of other ways to achieve the same goals. This is simply what works for me.

The question is, are you set up and prepared yet? What steps do you need to take to keep your animals safe? I hope this helps you start thinking of ways to prepare for emergencies of this nature. Maybe you already have something in place, but can you make it better? There are also many other types of emergencies we should be prepared for, but for this article I decided to focus on cold weather emergencies (tis the season!). Do yourself a favor, don't wait until that unexpected, bad storm knocks the power out. Make a plan. Test that plan, and make sure you're prepared. That's it for now my friends. As always, enjoy your reptiles.

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! n o

p r

e H

i s i V There has been much written regarding the extent to which reptiles rely on vision as a primary sense of their surroundings, with many people believing them to be blind or having poor visual perception at the best. It is true that some snakes and lizards, such as burrowing snakes of the family Typhlopidae, Thread snakes, Leptotyphlopidae, and Worm lizards in Amphisbaenidae, are blind or have very rudimentary eyes capable of detecting perhaps only minor changes in light patterns, but by and large reptiles have good vision.

Living a subterranean lifestyle would make the need for vision redundant: A) because light levels would be so low that unless the eye was highly evolved with the equivalent of night vision capability, it would be incapable of picking out enough light to form an image, and B) there would be nothing to see anyway.

With Paul Donovan This then brings us to the remainder of the reptile orders - those living on the surface (terrestrial) and those living in the trees (arboreal). Almost certainly, within the thousands of snake, lizard, chelonian and crocodilian species, there must be great disparity in visual acuteness. From examination of the makeup of the eye, arboreal snakes and crocodilians have the most sophisticated eye structures.

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Structure Outwardly and although the reptilian eye would bear a resemblance to the mammalian eye, they are structurally very different. One of the major differences of the reptilian eye, is the lack of muscle structure that physically alters the shape of the lens to bring about focusing. Focusing is then achieved by contractions of the surrounding ciliary muscles which increase pressure on the vitreous body and physically moves the fixed focus lens backwards and forwards away from the retina which lacks in all but one species, (Ahaetulla), no fovea.

In effect, the lens works in a similar fashion as to focusing a magnifying glass. In this respect vision could be described as being poor. However, the makeup of the retina is highly sensitive, as it is in humans, to movement and so could technically be regarded as being very responsive.

Furthermore, a snake’s eyes can focus on an image falling on the retina, but the detail of that image is not as clear as that of higher vertebrates.

Within the different reptilian orders, vision will vary greatly, from those only being able to distinguish light from dark, to those capable of seeing color. Many snakes have both rods and cones in their eyes as humans do, but there are some diurnal species such as the European Grass snake, Natrix natrix, which have just cones that are sensitive to blue, red and green, though not in any significant numbers. Although sensitive to color, the Grass Snake's eyes lack the range of colored oil droplets, as do many other snakes, in the photoreceptors that further filter the light, thereby restricting the range of colors seen detectable.

Grass snake can see a restricted range of colors

It is thought that the absence of this oil was due partly to early snakes being subterranean, where the need for vision was superfluous. As they evolved to a terrestrial way of life, vision began to evolve parallel to this, but in some species the oil droplets remained absent.

To help protect the eye, many diurnal snakes have a yellow filter inside the lens that helps absorb ultraviolet light; in crepuscular species this yellow filter is absent. The presence of rods and cones in crepuscular species does indicate that vision is good even at very low lighting levels.

As for nocturnal species, they have the capacity to see exceptionally well in the dark, due in part to the presence of a vertical pupil (technically called a stenopaic pupil), a clear lens, and a retina rich in rods. The light gathering ability of

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nocturnal species is further enhanced, by the fact that because the pupil is like a vertical slit running from the top of the eye to the bottom, as it opens, it allows proportionally more available light to penetrate the eye.

In contrast, the photoreceptors of lizards and turtles show a high degree of multi-colored oil droplets affording superior color vision. Within the cones of the retina are proteins called opsins.

These proteins are sensitive to varying wavelengths, and afford some species the ability to see into the UV spectrum range, far beyond the capabilities of the human eye.

Tiny Mirrors Vision in crocodilians on the other hand, is even more intriguing. I am sure that you have all watched documentaries where crocodile researchers go out at night with spotlights and shine them in the water. If it picks up a crocodile, its eye will glow. This is due to the presence of ‘mirror-reflecting’ cells called tapetum lucidum.

Although popularised in crocodilians, the presence of tapetum lucidum is widespread in many vertebrate species, particularly nocturnal hunters, as well as deep-sea dwelling animals.

The tapetum lucidum lies directly behind the retina and reflects light back through it thus maximising the exposure time to the photoreceptors. This light gathering property significantly enhances low-level light vision, but does have one drawback; because the light is reflected back into the eye, the image seen can be blurred.

The retina is also occupied predominantly by a mass of cone photoreceptors that are sensitive to varying wavelengths of light.

Given this, the crocodile has first-rate daytime vision, and may even have superior color vision even when compared to that of humans.

Interestingly, ‘eye-shine’ in those animals where tapetum lucidum are present, may actually exhibit a wide range of varying colors.

However, because the resulting color is brought about through iridescence, the angle at which the light is shone into the eye tends to give rise to a silvery appearance. That being said, the color of the bulb within the torch or spotlight can also have an impact on the eye's color.

Do not be under the misconception that a similar effect takes place in humans when you take a photograph - a condition called red eye.

The redness you see is caused by the camera's flash bouncing off the retina, which is rich in blood vessels.

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Location The location of the eyes on the head is dictated to a certain degree by the type of habitat the reptile lives in. For example, many desert snakes and crocodilians have large eyes positioned more towards the top of the head, whereas many reptiles have smaller eyes positioned lower down. The positioning of the eyes on the side of the head, opposed to being in the front, as is the case with humans, opens up the reptile’s depth of field quite considerably.

A number of snakes may actually have what is commonly referred to as ‘binocular vision’. The Vine Snake, Ahaetulla nasuta, is amongst several snake species that have very distinct pupils that are neither circular nor vertically slit-like as they are in many nocturnal species, but horizontal and shaped like a figure eight. In accompaniment to this, the region anterior and posterior to the eye is channelled. This channel enables light to be directed, say from the rear of the snake, onto the extreme anterior region of the retina where there is a fovealike area and thus maximise the image seen. It also enables the snake to see potential predators or prey more readily.

Binocular vision allows these snakes greater perception of depth and distance giving them a field of vision in the region 130-degrees.

When we talk about vision and eyes, we cannot fail to mention the chameleons. Surely, a group of lizards with the most bizarre eyes of all reptiles. The extraordinary cone structure, which covers the eye, is formed by the fusing together of the upper and lower eyelids. This not only protects the rather bulbous eyes, but also prevents them from drying out. The eyes can be moved independently from one another, and in any direction. This gives the chameleon a 360-degree field of vision; greater than just about all other animals. Therefore, when one eye is looking up, the other can look backward. This

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is of great benefit to the chameleon, for it can search for prey with one eye, while looking out for predators with the other.

Although the aperture formed by the eyelids is very small, and therefore only a limited peripheral field of vision is available when static, this is more than compensated for in the ability to roll the eye through 360 degrees. Furthermore, the size of the eyes, and the way the eyelids form a small aperture, give each eye the equivalent of a telephoto lens with a focal range of around 100 to 150mm. These features provide the chameleon with exceptional visual perception in the detection of food or predators, which few other animals can compete with.

This is an overly simplified view (no pun intended) regarding the state of color vision in reptiles, as there are many exceptions to the examples I have given. Of course as with any animal species, be it vertebrate or invertebrate, the eyes respond to movement, and in snakes how they respond to this will vary from species to species. Take the cobra for example. Its response to movement is to rear up off the ground and display a wide hood as a warning.

Stay still and the snake drops back to the ground and moves off. Move again and it will rear up. Others will simply move

off without giving away their presence before you even knew they were there. Although some snakes may remain motionless and wait until trouble has passed, this is not the case with lizards. At the first sign of movement, the lizard scurries off to the most accessible place of safety. Only when it is confident that the threat has passed, does it emerge from its retreat.

It is true to say then, that while movement is of obvious importance to the snake, it does not play as important of a role as say the olfactory sense does. This can be witnessed by the way the snake uses its tongue to ‘smell’ the air.

Still, vision rarely works alone, and either proceeds, or is accompanied by other senses; i.e. heat detection in rattlesnakes and some pythons and boas.

Protection

retina, though it is not capable of visual perception. In some species, such as the Tuatara, it is well developed.

The presence of a parietal eye may account for the reason why many lizards are very skittish. The eye is responsive to shadow movement, so as you move towards the individual the shadow you or your hand casts, alerts the individual to your presence and it will act accordingly.

Vision, then, in all reptile groups is far superior than many people imagine. Adaptations to the eyes in the form of distinctive pupils have enabled snakes, lizards and crocodilians, to evolve a diurnal or nocturnal way of life. And while we humans may not have good night time vision, nocturnal species, with their reflective retinal cells, do. In this regard, they sport a far more superior sight than we do.

One difference you will notice between snakes and other groups of reptiles, is that they lack moveable eyelids which offer protection and a method, blinking, of keeping the eye moist and free from irritants. It would be foolhardy in the snake’s evolution to omit some method of protecting the eye from damage, and this has come about by the evolution of a transparent scale called a brille or spectacle covering the eye.

This is not a separate scale, like a contact lens, but actually forms part of the snake’s skin and is shed periodically when the snake sloughs. The brille is particularly evident when the snake approaches a slough when it turns a milky white color due to secretion being released to separate the old skin from the new.

Many aquatic or semi-aquatic species such as the crocodilians, have a third eyelid called the nictitating membrane which covers the eye when the animal is submerged beneath the water. This semi-transparent membrane allows the animal to see while submerged, almost as though it were wearing a pair of goggles, though the image detected will not be in such clear detail.

I want to finish off by talking about another type of eye, and that is the parietal eye, or third eye; sometimes inaccurately referred to as the pineal eye. The parietal eye is visible on top of the head of many lizard species such as Iguanas, as a small whitish ‘spot’. It is a light-sensitive photo-sensory organ present in many animal species, including, but not limited to, lizards, frogs and some fishes. It is associated with the pineal gland and functions in regulating the circadian rhythm, hormonal production for reproduction, and ultimately thermoregulation. Structurally it resembles a primitive eye in that it has a small rudimentary lens and

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Notes From the Field: Expedición de Cascabelitos Article & Photos by Ryan Collister

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Mexico’s herpetofauna is among the most diverse and exciting of any country in the world, and its proximity to my home state of Texas has always been tantalizing to herp enthusiasts here, myself included. Having spent a large part of my career working with Mexican species in a captive zoological setting, I found it was time to take the next step and encounter some of these truly special animals on their home turf.

I cut my teeth in field herpetology within a stone’s throw of the border in west and south Texas as well as the mountains of southeastern Arizona, where most, if not all, of the species present there can be found on both sides of our arbitrary man-made boundaries. So, when I was offered the opportunity to accompany a group expedition to the northern border states of Coahuila, Nuevo León, and Tamaulipas, I was immediately on board.

The northern Sierra Madre Oriental, the mountain range that runs up much of eastern Mexico, is mostly arid terrain, with more mesic conditions at higher elevations, including small portions of cloud forests a bit further south from our destinations. May of 2016 found us beginning our trip before sunrise, where a private shuttle service conveniently picked us up in Del Rio, Texas, where our cars were left in a public parking lot, and took us across the border to our rental car in Ciudad Acuña, which boasted

Mexican plates that greatly increased our safety while traveling.

For obvious reasons, this is not a subject to be taken lightly in this part of the world and was a frequent topic of conversation before and during the trip.

After experiencing the chaos of Mexico’s highways for a few hours, we stopped to stretch our legs on a rocky mountainside just off the road, where one of our crew found our first animal, a juvenile Lugo’s alligator lizard (Gerrhonotus lugoi). This little lizard could easily be called the rarest find of the entire trip and was a personal highlight for me, after a childhood encounter with a Texas alligator lizard (Gerrhonotus infernalis) forever cemented my interest in this genus and its relatives.

The next morning, on the extreme southern side of the state near the border of Nuevo León, we combed some hillsides in search of an uncommon locality of Tamaulipan rock rattlesnakes (Crotalus morulus), but to no avail. Luckily, the first two snakes of the trip did show themselves - immaculate specimens of Mexican blacktailed rattlesnake (Crotalus molossus nigrescens) and Mexican pine snake (Pituophis deppei jani), the latter of which was a literal last-minute find that was waiting for us back at the car! This habitat was still fairly arid, and was interspersed with a variety of interesting cacti, including some form of giant barrel cactus and a smaller one with hot pink spines. Unfortunately, some of these spines made their way into me after I took a tumble on some sliding rocks, a constant possibility on this type of terrain.

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Moving southwest into higher elevations in Nuevo León, we explored a grassy area surrounded by tall pines, entering the elevational range of eastern twin-spotted rattlesnakes (Crotalus pricei miquihuanus). It didn’t take too long before one was found in a pile of small boulders, along with the first of many imbricate alligator lizards (Barisia ciliaris) that we would see under rocks. Next on the list was an area near the little mountain town of Pablillo, which greeted us with a thick layer of morning fog and the greenest habitat we would visit on this trip.

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Epiphytic vegetation covered the branches of the many old oaks, including some interesting Mexican varieties of Tillandsia that happened to be in bloom. A large variety of spiny lizard (Sceloporus torquatus) could be seen frequently here among the rock piles, and a surprise encounter with a yellow-throated garter snake (Thamnophis pulchrilatus) had us scratching our heads, as we had never heard of this species which so closely resembled the black-necked garter snakes back home. After a pleasant run-in with the landowner, who actually distantly knew a member of our party and decided to accompany us for a bit, we finally found two examples of our main target species, the Tamaulipan rock rattlesnake. One of them required some assistance shedding (this was done extremely carefully and without using bare hands!) and was revealed to be an absolute stunner, almost appearing to be made of silver, nicely complimenting another find we would make later.

Later that night, some nocturnal road-cruising of some mid-elevation hills and lowland deserts yielded many common Chihuahuan desert species that are easily found back in Texas. Unfortunately, most of these were roadkills, including a desert kingsnake (Lampropeltis splendida), Texas coral snake (Micrurus tener), and a Baird’s rat snake (Pantherophis bairdi), a species which appears much different in color and pattern down in Mexico than it does north of the border. Our specimen resembled a yellow rat snake from Florida with the head of a green rat snake from Arizona, a far cry from the gray and black stripes and orange highlights of Texas specimens.

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The next morning we concluded our trip with a quick jaunt just across the state border into Tamaulipas into a remote canyon deep in the mountains, with a small village and its surrounding agricultural fields nestled deep within the valley. A rare species of montane garter snake, Thamnophis exsul, could be found nearby, but did not turn up for our group. However, another Mexican black-tailed rattlesnake and eastern twinspotted rattlesnake appeared during a stop on the way in, both of which were stunning and quite different in appearance from the ones seen days prior. Once we arrived in the valley, another variety of spiny lizard, Sceloporus minor, was often seen flitting back and forth between the massive agaves dotting the landscape.

Specimens at this locality exhibited orange bodies, blue bellies, and green tails, but are often solid blue in color in other parts of their range.

Ultimately, our team scoured the valley surrounding the little town and turned up a total of thirteen Tamaulipan rock rattlesnakes! The prettiest of which were brought back to the car to be photographed by the group before release, including my personal favorite, a knockout gold specimen with crisp black bands that remains one of the most beautiful wild snakes I’ve ever seen, and a nice contrast to the silver specimen found earlier.

Each individual looked vastly different from the last, with various levels of clean or messy patterns, and some combination of greens, grays, pinks, and yellows.

Following this epic day in the field, some final meals of street tacos and pollo asado sent us back home happy, if not exhausted, and hungry to return to this heartbreakingly beautiful and dangerous region.

Expeditions such as this are imperative to collecting scientific data and are at the backbone of the Highlands & Islands mission. By documenting, studying, and raising awareness for these amazing animals and their declining populations we hope to maintain a future for them and their habitats. To learn more about Highlands & Islands Conservatory, follow us on social media or visit our website at https://www.highlandsandislandsconservatory.org/

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Herpetoculturemagazine.com

t ee M

a g u t or a T ontan F KA A ! s k o o r B er l y T

Tyler Brooks, or “@TorugaFontana” (his Instagram handle) is an avid tortoise fanatic and Kinixys aficionado. He keeps a wide assortment of reptiles and amphibians, but his passions lie with hingebacks. Tyler has been keeping and breeding reptiles for many years and shows a true commitment to our hobby and our community.

Caiman lizards, giant skinks, and tortoises with a hinge in their back. Just a few of the many things that make Tortuga Fantana tick!

HM: Tell us a little about yourself Tyler. What got you into reptiles?

TB: Typical story, I was always drawn to reptiles. I started by ‘snake hunting’ when I was a kid. Not hunting to kill, just herping. In my 9th grade biology class we did a vertebrate study and I helped maintain an aquarium and terrarium all year. And at the end, I took home most of the animals. Marbled salamanders, eastern king snake, corn snake and a box turtle. It was off to the races from there.

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HM: What species are you currently focused on?

TB: I’m mainly focusing on 4 species of Kinixys hingebacks : K. erosa, K. homeana, K. spekii and K. nogueyi. I also keep an assortment of other reptiles such as Corucia zebrata (Solomon Island Giant skinks) and Dracaena guianensis (Caiman Lizards).

HM: What species have proven to be the most difficult and or rewarding?

TB: The Kinixys project as a whole has been very challenging and rewarding. We’re working to establish wild caught imports. This can be incredibly challenging, all the way to hatching babies.

HM: What is the Kinixys Working Group? And how did you get involved?

TB: The Kinixys Working Group or, “KWG,” is a group of Kinixys enthusiasts. We’re composed of private keepers, zoo keepers and public facilities, all working to share information to help the tortoises in the wild. We also educate and raise awareness about the genus as a whole.

It costs nothing to join and you don’t have to be a keeper.

We love people to help educate and spread awareness just as much as keeping the animals themselves. We welcome anyone who wants help and join.

HM: What are some future plans for the KWG? TB: A goal of the KWG we have discussed is buying land in situ for habitat preservation and also to sponsor researchers who are focusing on Kinixys. We’re also considering turning the KWG into a 501c3. We have done t-shirt and sticker drives in the past, and all proceeds were donated to Kinixys researcher, Flora Ihlow. Flora is a German national who has spent considerable time in South Africa studying Kinixys.

Raising money to sponsor research is the main goal for now.

HM: What advice would you give someone looking to get into hingebacks?

TB: If you want to get into Kinixys, please reach out to the KWG! We always advise going captive bred if you want to keep Kinixys! Just do your research and reach out. We want people to keep Kinixys, so we’re more than willing to help!

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Photo >> Kinley Childress

Special Thanks to our Patreon Supporters for this issue!

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Thank you!!

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In The Incubator...

- Shingleback Skinks - Herp Life in the desert - 5 more herp room must haves!

And More!

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