American Herping: A Guide to Reptiles and Amphibians in US Zoos

[Coelacanth18]

Asian Ground Vipers
Last viper post before rattlesnakes next week. Most of these species are quite rare, so this will be a shorter one.

Hundred-Pace Viper (Deinagkistrodon acutus) – Uncommon or Rare

Called by several other names – most commonly Sharp-nosed Viper – the above name was given due to a belief about how far you could make it before you dropped dead from its bite. It is quite dangerous, but its reputation is exaggerated and unfortunately leads to very short-sighted medical decisions being made like amputating limbs. The species is found in southern China and Taiwan; captively in the US it is rarely found in major zoos and snake specialist facilities.

Taken at the Hangzhou Zoo (China) by @Himimomi

Protobothrops

A group of larger Asian pitvipers, whose Latin name suggests similarities to the fer-de-lances of Latin America. Several of these species are called “habu”, a name originating from the Ryukyu Islands of Japan. However, the species most of you are probably familiar with is from mainland China.

Mangshan Pitviper (P. mangshanensis) – Common

Also called the “Mang Mountain Pitviper” (shan = mountain in Mandarin), this beautiful clover-green viper has recently became a common sight in major American zoos. Found only in a small mountainous area of southern China, its color and patterning help it to blend in on lichen-covered logs. An egg-laying viper, this species hatched in a US zoo for the first time in 2018 at the San Diego Zoo, with 39 snakes born. This feat has since been repeated by two Texan zoos, the Dallas Zoo in 2021 and the Gladys Porter Zoo in 2022. Part of a breeding program, this endangered species has recently become a mainstay in America’s top reptile houses.

Taken at the Toledo Zoo by @Lucas Lang

Other Protobothrops species (all Rare):

Fan-Si-Pan Horned Pitviper (or Horned Pitviper) (P. cornutus)
Sakishima Habu (P. elegans)
Okinawan Habu (P. flavoviridis)
Jerdon's Pitviper (P. jerdonii)
Tokara Habu (P. tokarensis)

Other Asian ground vipers (all Rare):

Malayan Pitviper (Calloselasma rhodostoma)
Halys Pitviper (Gloydius halys) – the Karaganda subspecies specifically
Humpnose Viper (Hypnale hypnale)
Tonkin Pitviper (Ovophis tonkinensis)

 

[RatioTile]

Bronx Zoo has Taiwan Mountain Pit Viper (Ovophis makazayazaya).

https://www.zoochat.com/community/media/taiwan-mountain-pit-viper-ovophis-makazayazaya.649908/full

 

[Coelacanth18]

Crotalus and Sistrurus – Rattlesnakes

One of the most iconic American reptiles, famous for loudly vibrating their hollow-scaled tails as a warning. It’s probably a blessing in disguise that most of our venomous snakes here make themselves easy to find; unfortunately, it also makes it easier for people to find and kill them out of fear. This has led to many rattlesnake populations declining, as well as an increasing proportion of silent or even rattleless rattlesnakes. Don’t think I should have to explain the downside of that to anyone!

Even so, there are still millions of these snakes throughout the country and they’re a staple of reptile houses in American zoos. Out of curiosity, I ran a full comparison of my survey results to all of the European rattlesnake listings on Zootierliste. Excluding Russia (Moscow Zoo changes the results dramatically, but I believe many of their listings are outdated or offshow), European zoos had ~200 holdings. My survey results alone yielded 447 holdings, and still didn’t include several large reptile zoos (including a handful of huge rattlesnake collections in Texas) and countless nature centers. The US also has slightly more species than Europe (excl. Russia again) with 35 to 29*, and at least 16 shared species are more than 2x as common here; in Europe only one species (the Uracoan) was more than 2x as common than in the American results. Australasia and Japan – the two other major zoo regions whose holdings are easy to check – have comparatively very few rattlesnakes. Conclusion: if you like shaky-tailed snakes, come to the States!

Spoiler: *caveat

numbers may be a bit off due to some recent splits not reflected in ZTL or the survey

Nearly all rattlesnakes belong to one genus – Crotalus – which (as with Varanus) confounds my easiest method for organizing this. Therefore, I’ve taken sort of a hybrid geographic-numerical approach to covering them – starting with the most common native species, working my way down to the less common natives, then doing a full post on all of the non-native species. Rattlesnakes will have 5 posts in total, which was more than I originally anticipated but I think is appropriate given their status, popularity and abundance in the US specifically.

Timber Rattlesnake (C. horridus) – Abundant

The most common snake in the entire survey, this is the only rattler found in most of the Northeast US and ranges across the eastern half of the country. They are also called canebrake rattlesnakes, as a favored habitat of theirs were bamboo thickets in the Southeast called “canebrake” – a habitat that is unfortunately mostly gone. Fortunately, unlike some other species that depended on this habitat who are now extinct or nearly (Carolina Parakeet, Bachman’s Warbler, Florida Panther) the Timber Rattler is an adaptable species found in a wide variety of temperate habitats. Most holdings are in or close to its native range in the US; this is common for rattlesnakes, as it is with many other herps.

Taken at the Salato Wildlife Education Center (Kentucky) by @TinoPup

Eastern Diamondback Rattlesnake (C. adamanteus) – Abundant
Western Diamondback Rattlesnake (C. atrox) – Very Common

The second and fourth most common rattlers in the survey. Sporting diamond patterning, these are the two largest rattlesnake species. The Eastern is found primarily in Florida and other lowland areas of the Southeast, while the Western is found in the Southwest from Texas to California.

There is a population of rattlers on Tortuga Island in the Gulf of Mexico, sometimes treated as a subspecies of Western Diamondback and sometimes treated as their own species, Crotalus tortugensis. At least one facility (Reptile Lagoon in South Carolina) has held this species recently.

Eastern Diamondback (C. adamanteus)
Taken at the Cincinnati Zoo by @ChunkyMunky pengopus

Western Diamondback (C. atrox) / Taken at the Dallas Zoo by @geomorph

 

[Antimony96]

The Philadelphia Zoo had a western diamondback that shared a tank with (and could usually be found cuddling with) a Gila monster. Unfortunately the zoo's venomous snakes are all in the process of being removed.

 

[Batto]

Given that rattlesnakes are a very popular New World genus, it would be a great surprise if there were more European than North American zoos keeping them.
The current rattlesnake collection in European zoos, however, is only the tip of the iceberg when it comes to the amount of species actually kept in Europe. At WdG, I have several rattlesnake species on display that are rare to non-existent in other zoos in Europe, but quite common in the exotic pet trade (like C. concolor or ornatus).

"Canebrake rattlesnake" has often been used solely as the common name for Crotalus horridus atricaudatus in the past, but given the taxonomic discussion about the validity of the subspecies, it's nowadays sometimes used as a synonym for all timber rattlesnakes or certain localities.

 

[Coelacanth18]

Given that rattlesnakes are a very popular New World genus, it would be a great surprise if there were more European than North American zoos keeping them.

Well I didn't say I was surprised but I did think it was noteworthy since some N. American species (alligators, turtles, Gila monsters, etc) are common in European zoos as well. The difference in types of holder was notable too, as traditional city zoos are a great place to see rattlesnakes in the US but not really so in Europe - though this seems to be a trend with venomous snakes generally, not just rattlers.

At WdG, I have several rattlesnake species on display that are rare to non-existent in other zoos in Europe, but quite common in the exotic pet trade (like C. concolor or ornatus).

That info about concolor being common in private trade over there is very interesting, for reasons I'll touch on later this week

"Canebrake rattlesnake" has often been used solely as the common name for Crotalus horridus atricaudatus in the past, but given the taxonomic discussion about the validity of the subspecies, it's nowadays sometimes used as a synonym for all timber rattlesnakes or certain localities.

My cursory reading suggested that C. h. atricaudatus was a dubious (or at least disputed) subspecies, yeah. Some zoos and nature centers here sign horridus as "Canebrake" colloquially rather than Timber, which I've seen trip people up sometimes into thinking they are two different species.

 

[Coelacanth18]

Native Rattlesnakes, Day 2

Today's itinerary: blurbs on three small, common rattlers.

Rock Rattlesnake (C. lepidus) – Very Common

The third most common rattler in the survey, and even for rattlers distinctly more common here than in Europe (where only a few reptile zoos in German-speaking countries have them). Found on rocky slopes in the Southwest (particularly in the mountains of West Texas), this is a smaller species typically ~2 ft in length. There are three subspecies, all of which have been recorded on display at US zoos in recent years: the Banded (C. l. klauberi) is by far the most common and has distinct clean bands, while the Mottled (C. l. lepidus) is uncommon and generally has more dark speckling and less distinct bands. Los Angeles has additionally held the Durango subspecies (C. l. maculosus) in recent years.

Banded Rock Rattlesnake (C. l. klauberi)
Taken at the Arizona-Sonora Desert Museum by @Coelacanth18

Pygmy Rattlesnake (Sistrurus miliarus) – Very Common

Found throughout the American South, this species is a very small 1-2 ft snake. Most have a vertical red stripe down their body, with horizontal dark bands overlaid on top of it. There are three subspecies, with the most common in zoos being the Dusky subspecies from Florida (S. m. barbouri) followed by Carolina (S. m. miliarus) and Western (S. m. streckeri).

Dusky Pygmy Rattlesnake (S. m. barbouri)
Taken at the Cincinnati Zoo by @ChunkyMunky pengopus

Carolina Pygmy Rattlesnake (S. m. miliarius)
Taken at the North Carolina Museum of Natural Sciences by @drill

Sidewinder Rattlesnake (C. cerastes) – Common

An example of convergent evolution, this rattlesnake is extremely similar in both appearance and habitat niche to the Saharan Horned Viper from earlier, and even shares the same species name (cerastes – “having horns” in Greece, and the name of a horned serpent from Greek mythology). It can be found burying itself or sidewinding across the North American sands, with a different subspecies found in the Mojave, Sonoran, and Colorado deserts respectively. Few of the holdings I found mentioned subspecies, but I can confirm that all three have been displayed in recent years.

Taken at the Orange County Zoo (California) by @Coelacanth18

 

[Batto]

I wouldn't say that Crotalus concolor is common in the European reptile trade - just more common than in European zoos (given that WdG is currently, at least according to ZTL, the only European zoo keeping one).

 

[Coelacanth18]

Native Rattlers, Part 3
Now is when we start getting into species that some of you maybe haven't seen or heard of before... exciting times! Three of the four rattlers covered today have been split in recent times, highlighting the constant flux of rattlesnake taxonomy.

Speckled Rattlesnake (C. mitchellii)
Southwestern Speckled Rattlesnake (C. pyrrhus)
Status in US Zoos: Common

Speckled Rattlesnakes were recently split into multiple species, with the US populations being split off into the Panamint (stephensi, mentioned later) and the Southwestern Speckled (pyrrhus). As this is a relatively new change, I’m not exactly sure how many pyrrhus vs mitchellii are around here – though my assumption based on cursory research would be mostly pyrrhus with a small number of genuine mitchellii. A fourth species has recently been described as distinct – the Angel Island speckled rattlesnake, C. angelensis – and was just confirmed at a rattlesnake facility in Arizona last month.

While the color is variable depending on the population (as is usually the case with rattlers), the most common and distinctive for pyrrhus is a bleached white complexion with black speckling.

Southwestern Speckled Rattlesnake (C. pyrrhus)
Taken at the Sedgwick County Zoo by @geomorph

Eastern Massasauga (Sistrurus catenatus) – Prevalent
Western Massasauga (Sistrurus tergeminus) – Uncommon

Another recent split, though fortunately every holding I found specified the type. The Eastern Massasauga was once the quintessential rattler of the Midwestern tallgrass prairies… until those prairies disappeared under a wave of agriculture. Now this snake is federally listed and protected in every range state. Meanwhile, the Western consists of two subspecies: one from the Great Plains and one from the Southwestern deserts.

Eastern Massasauga (S. catenatus)
Taken at the Brookfield Zoo by @Andrew_NZP

Black-tailed Rattlesnake (C. molossus and C. ornatus) – Prevalent

A native species that in 2012 was split into western (molossus) and eastern (ornatus) species. I’m not sure the origin of most captive snakes, so I’ve kept them lumped together; as far as I can tell they are visually very similar, if not indistinguishable. They are found in the Southwest, from Texas to Arizona.

Taken at the Arizona-Sonora Desert Museum by @Coelacanth18

Prairie Rattlesnake (C. viridis) – Prevalent

A generally light-hued rattlesnake with brown bands, its range stretches across the Great Plains from Canada to Mexico. Due to how far north it goes, it is the only venomous snake in much of its range. Most holdings are the nominate subspecies, but a few places in Arizona and New Mexico hold the Hopi Rattlesnake (C. v. nuntius) named for the Native American tribe who hail from its habitat there.

Taken at the Pueblo Zoo (Colorado) by @Ituri

 

[Coelacanth18]

Native Rattlers, Part 4
The final post for native rattlesnakes, and last post of the week.

Mojave Rattlesnake (C. scutulatus) – Prevalent

This small rattler possesses the most lethal venom (both a hemotoxin and a neurotoxin!) of any rattler in the US. While it can be found commonly in the desert it’s named for, it ranges much further east to Texas and south to Mexico. It is often called “Mojave Green” colloquially as it can have a greenish tinge to it – though this is not ubiquitous, and another species (C. basiliscus) is more consistently a greenish hue than Mojaves. It has a diamond pattern on its back – very similar to its conspecific, the Western Diamondback.

Taken at the San Juan de Aragon Zoo (Mexico) by @carlos55

Ridge-nosed Rattlesnake (C. willardi) – Prevalent

Named for its upturned snout, it’s the official state reptile of Arizona despite only being found in the southeast corner. This snake is found in mountain pine forests of sky islands from south of Tucson well into Mexico. The young’s diet consists largely of centipedes, a random fact that I nonetheless felt the need to share because it’s neat. At least four of its five subspecies – Arizona, New Mexico, Chihuahuan and Del Nido – were found in the survey, which is a lot for one of the rarer rattlers.

Arizona subspecies (C. w. willardi) / Taken at the Phoenix Zoo by @Ituri

Northern Pacific Rattlesnake (C. oreganus) – Uncommon
Southern Pacific Rattlesnake (C. helleri) – Uncommon

These two have historically been considered the same species, but in recent years the Pacific rattlers of southern California have been treated as a distinct species. While uncommon in captivity across most of the country, they are by far the most commonly seen wild rattler in California due to their coastal range and they are common in both major zoos and local nature centers throughout the state.

Southern Pacific Rattler (C. helleri)
Taken at the Living Desert Zoo (CA) by @ThylacineAlive

Other native rattlers found in the survey:

Prevalent:
Arizona Black Rattlesnake (C. cerberus)
Red Diamond Rattlesnake (C. ruber) – notable for its pale red hue

Red Diamond Rattlesnake (C. ruber)
Taken at the Orange County Zoo by @Coelacanth18

Uncommon:
Tiger Rattlesnake (C. tigris)
Great Basin Rattlesnake (C. lutosus) – also spun off from Pacific Rattlesnake
Panamint Rattlesnake (C. stephensi) – found in the Owens River Valley of California (where much of LA’s water comes from )

Rare
Twin-spotted Rattlesnake (C. pricei)
Midget Faded Rattlesnake (C. concolor) – the only native rattler to not be held by any facility in the survey recently. The last major zoo I found with concolor was ASDM in early 2018, but they are gone now; other places held it earlier in the 2010's. Recently one was reported from a rattlesnake collection at a Kansas natural history museum, so it's possible they are kicking around unreported in a few smaller places

 

[zoo_enthusiast]

Reptile Gardens in South Dakota had a large collection of Australian elapids in the mid-2010's, but I don't know how many they still hold today.

I have visited Reptile Gardens last week and can confirm that they still have great collection of Australian elapids. I plan to post their species list in the next few weeks, once I finish sorting through my pictures, but they do have Death Adder (don't remember the species, but I did take a picture of the sign), Inland Taipan, 2 subspecies of Coastal Taipan, Collett's Snake, Eastern Brown Snake, Red-bellied Black Snake, Tiger Snake, and King Brown Snake.

 

[King of Komodo Dragons]

I have visited Reptile Gardens last week and can confirm that they still have great collection of Australian elapids. I plan to post their species list in the next few weeks, once I finish sorting through my pictures, but they do have Death Adder (don't remember the species, but I did take a picture of the sign), Inland Taipan, 2 subspecies of Coastal Taipan, Collett's Snake, Eastern Brown Snake, Red-bellied Black Snake, Tiger Snake, and King Brown Snake.

Wow, I didn't think there were any Eastern Browns, Red-Bellied Blacksnakes, or Tiger snakes left in the US! Definitely have to visit Reptile Gardens at some point

 

[Coelacanth18]

I have visited Reptile Gardens last week and can confirm that they still have great collection of Australian elapids. I plan to post their species list in the next few weeks, once I finish sorting through my pictures, but they do have Death Adder (don't remember the species, but I did take a picture of the sign), Inland Taipan, 2 subspecies of Coastal Taipan, Collett's Snake, Eastern Brown Snake, Red-bellied Black Snake, Tiger Snake, and King Brown Snake.

Thanks for the update @zoo_enthusiast! I'd hoped all those elapids were still around - a full snake lifespan hadn't passed since they were last reported - but I couldn't say for sure due to lack of information about Reptile Gardens (a common problem for American reptile zoos, which don't seem to be well-visited by forum members). I'll look forward to seeing that full species list when you have the time to share

 

[Coelacanth18]

Welcome to the last week of snakes! Only two posts left to go on serpents before their recap; today's will conclude the viper family and rattlesnakes more specifically.

Exotic Rattlers

I decided to group all of the non-native rattlers together; I thought this would be useful organization so that people know not to expect these species in nature centers or other native-focused collections.

Santa Catalina Island Rattlesnake (C. catalinensis) – Prevalent

Absent from Europe save for a Swedish science center, this is one of the two most common non-native rattlesnakes in US collections. Found only on a 15 square mile island off the coast of Mexico, this critically endangered species is notable for being a rattleless rattlesnake. It has been subject to a formal breeding program in AZA zoos.

Taken at the Toledo Zoo by @birdsandbats

Mexican Lance-headed Rattlesnake (C. polystictus) – Prevalent

The other most common non-native rattlesnake in zoos here; in Europe it is only present in two reptile zoos in Germanic countries. Distinguished by its large brown spots, there has been an active breeding program for this species in AZA zoos as well.

Taken at the San Diego Zoo by @ThylacineAlive

Aruba Island Rattlesnake (C. unicolor) – Prevalent

Another non-native species subject to a US breeding program. Found only on a small dry portion of a Caribbean island, this small rattlesnake is often pink in coloration.

Taken at the Los Angeles Zoo by @Julio C Castro

South American Rattlesnake (C. durissus) – Prevalent

Also called the Tropical or Neotropical Rattlesnake, this large 5-foot rattler is found from the Yucatan all the way to Argentina; its range being so vast and fragmented, multiple subspecies have been spun off it in recent years. Two species/subspecies – the Tzabcan and Northwestern – are both held in US collections in addition to undisputed durissus.

Cascavel Rattlesnake (C. durissus terrificus) / Taken at the Pittsburgh Zoo by @Lucas Lang

Uracoan Rattlesnake (C. vegrandis) – Rare

I mention this rarer species because it’s the only rattler that’s significantly more common in Europe than here, which is a shame because it’s a beautiful snake with a bedazzled scale complexion. It is only found in one savanna in Venezuela. There seems to be dispute about whether it should be just a subspecies of Neotropical, but it seemed unique enough to mention it separately.

Taken at the Staten Island Zoo by @zoo_enthusiast

Other exotic rattlers found in the survey:

Prevalent
Tamaulipan Rock Rattlesnake (C. morulus) – Mexican species recently split from Rock Rattlesnake (C. lepidus); mostly held by major zoos

Uncommon
Mexican West Coast Rattlesnake (or Mexican Green) (C. basiliscus)

Rare
Baja California Rattlesnake (C. enyo)
Queretaro Dusky Rattlesnake (C. aquilus)
Western Dusky Rattlesnake (C. armstrongi)
Middle American Rattlesnake (C. simus)
Mexican Pygmy Rattlesnake (C. ravus)
Mexican Dusky Rattlesnake (C. triseriatus)

 

[zoo_enthusiast]

Thanks for the update @zoo_enthusiast! I'd hoped all those elapids were still around - a full snake lifespan hadn't passed since they were last reported - but I couldn't say for sure due to lack of information about Reptile Gardens (a common problem for American reptile zoos, which don't seem to be well-visited by forum members). I'll look forward to seeing that full species list when you have the time to share

Do not mean to derail this excellent thread, but I did finish my species list from Reptile Gardens, and it's now available on ZooChat

 

[Astrotom3000]

Welcome to the last week of snakes!

Does this mean turtles are next?

 

[Coelacanth18]

I did finish my species list from Reptile Gardens

Excellent - and much appreciated, as now I can include your findings in the snake recap to be posted later this week!

Turns out Reptile Gardens had 10 species not picked up by the survey initially - nine more snakes (six venomous) and a frog:

Australian Scrub Python (Morelia kinghorni)
Yellow-tailed Cribo (Drymarchon corais)
---
Eastern Brown Snake (Pseudonaja textilis)
Red-bellied Black Snake (Pseudechis porphyriacus)
Tiger Snake (Notechis scutatus)
Rough-scaled Snake (Tropidechis carinatus)
Midget Faded Rattlesnake (Crotalus concolor)
Siamese Peninsula Pit Viper (Trimeresurus fucatus or Trimeresurus sabahi fucatus)
Slender Hognose Viper (Porthidium ophryomegas)
---
Tiger Striped Leaf Frog (Callimedusa tomopterna)

Does this mean turtles are next?

That was meant to be a surprise but yes, turtles are the next group and starting in September there will be over a month's worth of guide posts chronicling the shelled reptiles we have here.

 

[birdsandbats]

Tiger Striped Leaf Frog (Callimedusa tomopterna)

Must have forgot to mention this earlier, but this species is kept at Sanctuary Aquatics in Oshkosh, WI, a facility that is something between a pet store and an aquarium.

 

[Coelacanth18]

Miscellaneous Snakes

Yes, it’s that time again – miscellaneous time! As nearly all captive snakes belong to one of the three major groups already covered, this will only require one post.

Family Acrochordidae

A small group of aquatic ambush predators from tropical Asia and Australia; their most recognizable feature is their loose, baggy-looking skin. Only one of the three species was found in the survey:

Elephant Trunk Snake (Acrochordus javanicus) – Rare

This nocturnal snake is found in the coastal wetlands of Malaysia and Indonesia. The survey only found two places with this species in recent years, the Memphis Zoo (where yours truly failed to find it in the tank ) and Reptile Gardens in South Dakota. They are sometimes sold as pets, but they are difficult to care for and don't seem well-suited for captivity.

Taken at the (now closed) Dusit Zoo (Thailand) by @Chlidonias

Family Loxocemidae
Mexican Burrowing Python (Loxocemus bicolor) – Rare

The only member of its family, a cryptic and usually underground species from Mexico and Central America. Though found in a handful of zoos, this is a rare animal and probably doesn’t have much exhibit appeal as a fossorial species.

Taken at the Kishinev Zoo (Moldova) by @Zaz

Family Homalopsidae

Stout-bodied, mildly venomous water snakes from tropical Asia. Two species were found in the survey:

Tentacled Snake (Erpeton tentaculatum) – Common

Found in lakes and rice paddies of Thailand, Cambodia, and Vietnam; its name derives from the unique feature of two sensory tentacles on its snout. These snakes also have a unusual hunting method; they anchor themselves with their tail in an upside-down “J” position, trigger flight responses in fish passing underneath their head, then strike at the predicted location of the fish’s escape route rather than at the fish’s immediate position.

These snakes are decently common in private husbandry, and multiple zoos breed them as well – including at least two US zoos last year, Denver and Cameron Park.

Taken at the Fresno Chaffee Zoo by @Arizona Docent

Other species:
Puff-faced Water Snake (Homolopsis buccata) – Rare

Family Lamprophiidae

A group that has undergone a lot of taxonomic revision; once thought to be colubrids, they are now known to be more closely related to elapids. They are found in Africa. Six species appeared in the survey, all of which were only in one or two zoos each except one – the Malagasy Giant Hognose Snake (Leioheterodon madagascariensis), which is somewhere around Uncommon to Prevalent.

Giant Malagasy Hognose / Taken at the Potter Park Zoo (Michigan) by @evilmonkey239

Other species (all Rare):
African House Snake (Boaedon fuliginosus)
Malagasy Leafnose Snake (Langaha madagascariensis)
Speckled Hognose Snake (Leioheterodon geayi)
Rufous Beaked Snake (Rhamphiophus oxyrhynchus)

Family Atractaspididae – Burrowing Asps

An obscure group of venomous snakes from Africa and the Middle East, also part of the greater elapid lineage. The only species found was the Small-scaled Burrowing Asp (Atractaspis microlepidota) at the Kentucky Reptile Zoo.

Taken at the Kentucky Reptile Zoo by @Batto

And with that the largest group of reptiles has been covered! As is now tradition, I will finish off with a recap of the group in the next day or two.

 

[Coelacanth18]

Time to wrap this squamate party up! As is now tradition, I will end the group with a recap.

SNAKE RECAP

The Topline Numbers
342 species from 26 families
22 species were added from contributions to this thread

Family with Most Species and Most Holdings:
Viperidae (vipers) – 925 holdings of 120 species

Species abundance breakdown (with some adjustments based on additional searching):

- 13 Abundant (40+ holders)
- 9 Very Common (30-39 holders)
- 14 Common (20-29 holders)
- 41 Prevalent (10-19 holders)
- 52 Uncommon (5-9 holders)
- 205 Rare (1-4 holders) (60% of total)

Overall snakes are a larger group than lizards and amphibians, with ~100 more species than either one. The breakdown also shows snakes to be more prevalent, with ~35 species that are common to abundant; over 90 species that are less common but still held in several or more places; and a block of fairly rare or unique species totaling three-fifths of the group’s total diversity. In terms of natives vs exotics, natives made about ~30% of species held – twice that of lizards (~15%) but lower than amphibians (~40%).

Top Performers
The most common snake in the survey was the Timber Rattlesnake (Crotalus horridus), a native species; the most common exotic snake was the Green Tree Python (Morelia viridis). Other Abundant or Very Common species in US zoos include the following (in the same order I covered them):

Spoiler: Snakes You'll Probably See Here

Emerald Tree Boas (Corallus caninus and batesii)
Boa Constrictors (Boa constrictor and imperator)
Green Anaconda (Eunectes murinus)
Ball Python (Python regius)
Burmese Python (Python bivittatus)
Reticulated Python (Malayopython reticulatus)
Milk Snake (Lampropeltis triangulatum)
Ratsnakes (Pantherophis alleghaniensis and obsoletus)
Corn Snake (Pantherophis guttatus)
Gopher Snake (Pituophis catenifer)
King Cobra (Ophiophagus hannah)
Gaboon Vipers (Bitis rhinoceros and gabonica)
Copperhead (Agkistrodon contortrix)
Cottonmouth (Agkistrodon piscivorus)
Eyelash Pitviper (Bothriechis schlegelii)
Eastern Diamondback Rattlesnake (Crotalus adamanteus)
Western Diamondback Rattlesnake (Crotalus atrox)
Rock Rattlesnake (Crotalus lepidus)
Pygmy Rattlesnake (Sistrurus miliarius)

Notable Facilities
With snakes being the most common type of herp in US captive collections, many zoos are big hotspots for snakes. The largest collection of snakes I’ve found in a major US zoo is the Dallas Zoo, which as of 2023 had over 50 species of snake in its Reptile House. I believe Dallas to also be the best major US zoo for cobras (with 7 species on display currently) and one of the best for exotic vipers. The second and third highest snake counts were at the San Diego Zoo (~45 species) and the Toledo Zoo (~40 species), both of which have well-rounded collections.

When it comes to specific types of snakes, Saint Louis Zoo and San Antonio Zoo are two hotspots for vipers, especially foreign vipers. The Staten Island Zoo is renowned for its rattlesnake collection in the East (~15 species) while out west the Arizona-Sonora Desert Museum boasts a similar number. The Phoenix Zoo has nearly 40 species of desert snakes – mostly natives, many rare – in its Arizona Trail complex. I didn't find a zoo that clearly stood out as a leader for boas and pythons... a niche waiting to be filled, perhaps?

I’d be remiss not to mention specialist facilities as well. The survey included a couple of publicly open venom labs, both of which have many varieties of rarely-seen hots – the Jack Facente Serpentarium/Mtoxins Venom Lab in Wisconsin (which is closing to the public soon) and the Kentucky Reptile Zoo. The newly opened Rattlesnake Ranch in Arizona boasts a heavy collection of rattlesnakes, as does (one assumes) the American International Rattlesnake Museum in nearby New Mexico. The largest collection of snakes on public display is likely the Animal World & Snake Farm Zoo in Texas; I don’t have a recent species list for it, but in 2015 it had well over 100 species. Similarly large is the famous Reptile Gardens in the Black Hills of South Dakota, with ~80 species on display and the country's largest collection of Australian elapids.

Reptile Gardens Sky Dome, where the majority of RG's snake collection is housed
Taken by @Milwaukee Man

Rising Stars
This section highlights species that are rapidly becoming more common on the scene. Unlike with past groups, I only know one species that has definitely become a lot more common in recent years (though many species are being bred).

Mangshan Pitviper (Protobothrops mangshanensis)

A relatively uncommon snake earlier in the 2010’s, this species only bred in a US zoo for the first time in 2018. They are now in over 20 zoos across the country, with new holders seeming to pop up every year.

Another Protobothrops species that might be on its way up is the Fan-Si-Pan Horned Pitviper, or Asian Horned Pitviper (P. cornutus) which was successfully bred by the Cameron Park Zoo of Texas just this month with the intention of bolstering the captive population.

Mangshan Pitviper / Taken at the Houston Zoo by @DannySG

Fan-Si-Pan Horned Pitviper / Taken at the San Antonio Zoo by @Ding Lingwei

Coely’s Highlight Species
With every major group I will highlight at least one personal favorite of mine. As snakes is the largest group (and since Rising Stars was much shorter than with previous groups), I will do two: one venomous, one nonvenomous.

Indigo Snakes (Drymarchon)

Beautiful iridescent giants, these native snakes are sadly threatened in the home region of the South. On the flip side, this gives them great potential as a conservation ambassador for local snakes and the benefit of keeping them around in our backyards. While not especially rare, I think this is an underrated gem of a species and I’d love to see more zoos hold them.

Taken at the Oatland Island Wildlife Center (Georgia) by @SusScrofa

Sidewinder Rattlesnake (Crotalus cerastes)

I have a soft spot for rattlesnakes of all kinds (which shouldn’t surprise you, given I spent 5 posts talking about them!) but if I had to choose just one, this is a solid pick IMO. Their adaptations to a sandy desert ecosystem are impeccable, and these little vipers are fun to see half-buried in their enclosures or coiled up with an inexplicably grumpy expression.

Taken at the Omaha Henry Doorly Zoo by @DesertTortoise
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And that’s a wrap for snakes! I’m taking next week off from posting content, so the guide will continue again on Labor Day with our next group of reptiles…

An Eastern Ratsnake (Pantherophis alleghaniensis) posed with a Gopher Tortoise (Gopherus polyphemus)
Taken at the Tennessee Aquarium by @Astrotom3000