Lucas Lang
Well-Known Member
Reptilandia Reptile Lagoon post a picture of this species on their FB, maybe they will show this species on exhibit?
American Herping: A Guide to Reptiles and Amphibians in US Zoos
- Thread starter Coelacanth18
- Start date
Family Crocodylidae
Part I – American Crocs
Best distinguished from alligators and caimans by their more V-shaped (rather than U-shaped) snout. They are better able to tolerate salt water due to specialized glands, and they tend to be more aggressive (though this varies by species). They are found throughout the world’s tropics, other than a conspicuous absence in the Amazon where the huge Black Caiman likely fills their niche as apex river hunter.
We’ll begin with crocodiles close to home – the four species found in the Americas.
American Crocodile (Crocodylus acutus)
Status in US Zoos: Prevalent – overall; Rare – outside Florida
Another crocodilian native to the United States, although unlike the alligator this one is limited to South Florida. It is also found throughout the coastal areas of Mexico, Central America, northern South America and the Caribbean islands – using its specialized salt glands to inhabit brackish swamps and lagoons avoided by caimans. It is one of the largest crocodiles on Earth, with males (the larger of the two sexes) reaching up to 20 ft long.
After almost going extinct in the late 20th century in the United States, the Florida population has now recovered to the point of being downgraded federally as a Threatened species rather than Endangered (meaning that it remains federally protected). A dozen or more places in the US have American Crocs, most of which are in Florida; the only northern holders I found are Omaha and Cincinnati.
Taken at Zoo Miami by @Andrew_NZP
Cuban Crocodile (Crocodylus rhombifer)
Status in US Zoos: Prevalent – overall; Uncommon – outside Florida
A smaller, peculiar species of crocodile. The Cuban croc is more terrestrial than others, with reduced foot webbing and long powerful legs. They can leap a human’s height out of the water, using their tail to thrust. They are one of the most aggressive crocodilians, and there is anecdotal evidence they possess pack hunting capabilities. In other words: if you wanted to imagine a crocodile that could one day evolve into a real terrifying future predator, this would likely be your pick.
Despite its fearsome adaptations, it seems that humans have conquered this reptile before it had a chance to do us in; the Cuban croc is critically endangered, now likely found only in one swamp of its native island country. There is a captive breeding program in the US, but a 2008 paper indicates that many of our Cuban crocodiles have American croc DNA mixed in; current reintroductions are being done using captive-bred crocodiles in Cuba.
Taken at Zoo Miami by @Pleistohorse
Orinoco Crocodile (Crocodylus intermedius) – Prevalent
A large, lightly-colored crocodile with a narrow snout; huge individuals over 20 ft once existed, but nowadays males are closer to 16-17 ft with females half that size. One of the most endangered crocodiles in the world, the Orinoco croc has been largely wiped out from its native habitat in Venezuela and Colombia.
The Dallas World Aquarium imported a pair from Venezuela under a breeding loan in 1998; this breeding first proved successful 5 years later, with the DWA pair producing several dozen hatchlings. Recently two other zoos – Miami and Gladys Porter – have also bred the species, and many of these captive-bred crocs have gone out to other American facilities that will rear them up in preparation for a release in Venezuela. This expansion has led Orinocos to rival Americans and Cubans in numbers, and if the trend continues Orinoco could become one of the most common crocodilians in US zoos.
Taken at the Brookfield Zoo by @wilson
Morelet’s Crocodile (Crocodylus moreletii) – Uncommon to Prevalent
The least common of the four mentioned today, this medium-sized croc is found in secluded freshwater bodies on the Yucatan Peninsula; lakes bordering Mayan ruins are filled with this species. It seems this animal cannot be found in any well-known urban zoos; instead it is held by an eclectic mix of ~10 aquariums, reptile zoos, Floridian crocodile parks and sanctuaries. This trend is apparent in Europe too, with few of the several holders being well-known names on the forum.
Taken at Vallazoo (Mexico) by @ralph
Part I – American Crocs
Best distinguished from alligators and caimans by their more V-shaped (rather than U-shaped) snout. They are better able to tolerate salt water due to specialized glands, and they tend to be more aggressive (though this varies by species). They are found throughout the world’s tropics, other than a conspicuous absence in the Amazon where the huge Black Caiman likely fills their niche as apex river hunter.
We’ll begin with crocodiles close to home – the four species found in the Americas.
American Crocodile (Crocodylus acutus)
Status in US Zoos: Prevalent – overall; Rare – outside Florida
Another crocodilian native to the United States, although unlike the alligator this one is limited to South Florida. It is also found throughout the coastal areas of Mexico, Central America, northern South America and the Caribbean islands – using its specialized salt glands to inhabit brackish swamps and lagoons avoided by caimans. It is one of the largest crocodiles on Earth, with males (the larger of the two sexes) reaching up to 20 ft long.
After almost going extinct in the late 20th century in the United States, the Florida population has now recovered to the point of being downgraded federally as a Threatened species rather than Endangered (meaning that it remains federally protected). A dozen or more places in the US have American Crocs, most of which are in Florida; the only northern holders I found are Omaha and Cincinnati.
Taken at Zoo Miami by @Andrew_NZP
Cuban Crocodile (Crocodylus rhombifer)
Status in US Zoos: Prevalent – overall; Uncommon – outside Florida
A smaller, peculiar species of crocodile. The Cuban croc is more terrestrial than others, with reduced foot webbing and long powerful legs. They can leap a human’s height out of the water, using their tail to thrust. They are one of the most aggressive crocodilians, and there is anecdotal evidence they possess pack hunting capabilities. In other words: if you wanted to imagine a crocodile that could one day evolve into a real terrifying future predator, this would likely be your pick.
Despite its fearsome adaptations, it seems that humans have conquered this reptile before it had a chance to do us in; the Cuban croc is critically endangered, now likely found only in one swamp of its native island country. There is a captive breeding program in the US, but a 2008 paper indicates that many of our Cuban crocodiles have American croc DNA mixed in; current reintroductions are being done using captive-bred crocodiles in Cuba.
Taken at Zoo Miami by @Pleistohorse
Orinoco Crocodile (Crocodylus intermedius) – Prevalent
A large, lightly-colored crocodile with a narrow snout; huge individuals over 20 ft once existed, but nowadays males are closer to 16-17 ft with females half that size. One of the most endangered crocodiles in the world, the Orinoco croc has been largely wiped out from its native habitat in Venezuela and Colombia.
The Dallas World Aquarium imported a pair from Venezuela under a breeding loan in 1998; this breeding first proved successful 5 years later, with the DWA pair producing several dozen hatchlings. Recently two other zoos – Miami and Gladys Porter – have also bred the species, and many of these captive-bred crocs have gone out to other American facilities that will rear them up in preparation for a release in Venezuela. This expansion has led Orinocos to rival Americans and Cubans in numbers, and if the trend continues Orinoco could become one of the most common crocodilians in US zoos.
Taken at the Brookfield Zoo by @wilson
Morelet’s Crocodile (Crocodylus moreletii) – Uncommon to Prevalent
The least common of the four mentioned today, this medium-sized croc is found in secluded freshwater bodies on the Yucatan Peninsula; lakes bordering Mayan ruins are filled with this species. It seems this animal cannot be found in any well-known urban zoos; instead it is held by an eclectic mix of ~10 aquariums, reptile zoos, Floridian crocodile parks and sanctuaries. This trend is apparent in Europe too, with few of the several holders being well-known names on the forum.
Taken at Vallazoo (Mexico) by @ralph
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I'd be interested if you could share your sources for this, as the species' latest IUCN red list assessment paints quite a different picture; the reintroduced population in Lanier swamp has apparently been extirpated, and numbers seem to be continuing to decline in Zapata;
IUCN Red List of Threatened Species
I wish I could tell you, but upon re-reading none of the sources I used say this. I was working on American and Cuban crocodiles at the same time, so my best guess is that I added that in while looking at info for the wrong species. I didn't realize they were considered extirpated from one of the two swamps though, that was information I missed. I've edited the post to accurately reflect the information provided by IUCN... thanks for the catch.
Antimony96
Well-Known Member
Has the American crocodile zoo population outside Florida declined in recent years? I distinctly remember seeing them at ZooAmerica on a field trip about 20 years ago.
Not really sure. This is the kind of question that makes me wish we had an American equivalent of Zootierliste, as it would be really interesting to see how reptile collections have changed over the past decades. My knowledge for holdings is limited between 5 and 15 years ago (which is about as far back as US references on this forum go) and almost zero for anything earlier than that.
FWIW there are a couple of photos of American Crocodile from ZooAmerica in the gallery, uploaded by @zoo_enthusiast in 2011 but dated to 2008/2009. There's only one other former holder in the north I can find from that time period (Newport Aquarium, held through the 2000's) and I'm not sure if Omaha had them yet (earliest reference I found is 2012, the exhibit they're in opened in 2003).
Family Crocodylidae
Part II – African Crocs
Another day, another continent. There are three “types” of crocodiles in Africa – all three of which have been split into multiple species in recent years.
“Nile” Crocodiles (Crocodylus niloticus and Crocodylus suchus)
Status in US Zoos: Common – overall; Prevalent – AZA only, or outside Florida
One of the most famous crocodiles, the one you’ve all seen in a nature documentary pulling zebras and wildebeest into the rivers in the Serengeti or another wildlife hotspot in Africa. Found in rivers, lakes and swamps across the continent, this croc is more social than most: they will often congregate at spots and share in food kills – with larger, older males topping the hierarchy.
In the early 19th century French naturalist Étienne Geoffroy Saint-Hilaire – the namesake for every species most of you misspell as “Geoffrey’s”
– noticed that the skulls of mummified Egyptian crocodiles looked different than those from sub-Saharan Africa. This is now known to be because there is a second species of “Nile Crocodile”, C. suchus – the desert crocodile or West African crocodile. Confirmed by multiple genetic studies, the two are visually similar but differ in size, habitat preference and disposition.
There are around 20-25 holders of “Nile Crocodile” in the US; about half of those are in Florida, and also about half (somewhat overlapping) are outside of AZA accredited zoos. A 2015 study revealed that some of our “Niles” are actually suchus rather than true niloticus; the sample did not include recent imports from the niloticus range, so the exact proportions are unclear.
Taken at Disney's Animal Kingdom by @Andrew_NZP
Slender-snouted Crocodile (Mecistops cataphractus) – Uncommon to Prevalent
A candidate for “Coolest Latin Name of Any Animal”, the Slender-snouted Croc is a medium-sized, fish-eating crocodile found in jungle rivers of West and Central Africa. Yet another Critically Endangered crocodilian, there is a breeding program for this species in the US and ~10 zoos display them.
The crocodiles of Central Africa were split a few years ago into a separate species M. leptorhynchus, which means they drew the short end of the “cool name” straw. The same study cited above for Nile crocs found that likely all or nearly all Mecistops in US zoos are the West African type.
Taken at Zoo Atlanta by @ThylacineAlive
Dwarf Crocodile (Osteolaemus tetraspis and co.) – Common
The smallest crocodile in the world (and similar in size to the dwarf caimans), these small crocs share a similar range to the Slender-snouted Crocodiles – inhabiting the tropical forests of West and Central Africa. Unusually for a crocodile, they rarely bask in direct sunlight; Dwarf Crocs prefer shaded streams and pools and are often active primarily at night. Some have even taken a page from Lost and moved to the caves. O. tetraspis is rated as Vulnerable by the IUCN, although its status hasn't been updated since 1996.
Evidence suggests there are multiple, genetically distinct clades of O. tetraspis – at least three, possibly more. I won’t get too much into the taxonomy on this one as it seems complicated and unresolved. The ones in US zoos were found to be of both West and Central African origin, with some hybrids; there are ~25 holders.
Taken at the San Diego Zoo by @Julio C Castro
A citation for the 2015 paper referenced throughout this post: https://www.researchgate.net/public...e_cryptic_African_crocodile_species_complexes
Part II – African Crocs
Another day, another continent. There are three “types” of crocodiles in Africa – all three of which have been split into multiple species in recent years.
“Nile” Crocodiles (Crocodylus niloticus and Crocodylus suchus)
Status in US Zoos: Common – overall; Prevalent – AZA only, or outside Florida
One of the most famous crocodiles, the one you’ve all seen in a nature documentary pulling zebras and wildebeest into the rivers in the Serengeti or another wildlife hotspot in Africa. Found in rivers, lakes and swamps across the continent, this croc is more social than most: they will often congregate at spots and share in food kills – with larger, older males topping the hierarchy.
In the early 19th century French naturalist Étienne Geoffroy Saint-Hilaire – the namesake for every species most of you misspell as “Geoffrey’s”
– noticed that the skulls of mummified Egyptian crocodiles looked different than those from sub-Saharan Africa. This is now known to be because there is a second species of “Nile Crocodile”, C. suchus – the desert crocodile or West African crocodile. Confirmed by multiple genetic studies, the two are visually similar but differ in size, habitat preference and disposition.There are around 20-25 holders of “Nile Crocodile” in the US; about half of those are in Florida, and also about half (somewhat overlapping) are outside of AZA accredited zoos. A 2015 study revealed that some of our “Niles” are actually suchus rather than true niloticus; the sample did not include recent imports from the niloticus range, so the exact proportions are unclear.
Taken at Disney's Animal Kingdom by @Andrew_NZP
Slender-snouted Crocodile (Mecistops cataphractus) – Uncommon to Prevalent
A candidate for “Coolest Latin Name of Any Animal”, the Slender-snouted Croc is a medium-sized, fish-eating crocodile found in jungle rivers of West and Central Africa. Yet another Critically Endangered crocodilian, there is a breeding program for this species in the US and ~10 zoos display them.
The crocodiles of Central Africa were split a few years ago into a separate species M. leptorhynchus, which means they drew the short end of the “cool name” straw. The same study cited above for Nile crocs found that likely all or nearly all Mecistops in US zoos are the West African type.
Taken at Zoo Atlanta by @ThylacineAlive
Dwarf Crocodile (Osteolaemus tetraspis and co.) – Common
The smallest crocodile in the world (and similar in size to the dwarf caimans), these small crocs share a similar range to the Slender-snouted Crocodiles – inhabiting the tropical forests of West and Central Africa. Unusually for a crocodile, they rarely bask in direct sunlight; Dwarf Crocs prefer shaded streams and pools and are often active primarily at night. Some have even taken a page from Lost and moved to the caves. O. tetraspis is rated as Vulnerable by the IUCN, although its status hasn't been updated since 1996.
Evidence suggests there are multiple, genetically distinct clades of O. tetraspis – at least three, possibly more. I won’t get too much into the taxonomy on this one as it seems complicated and unresolved. The ones in US zoos were found to be of both West and Central African origin, with some hybrids; there are ~25 holders.
Taken at the San Diego Zoo by @Julio C Castro
A citation for the 2015 paper referenced throughout this post: https://www.researchgate.net/public...e_cryptic_African_crocodile_species_complexes
Antimony96
Well-Known Member
Family Crocodylidae
Part III – Australian and Asian Crocs
Finishing out the true crocodile family today with the remaining 7 species.
Saltwater Crocodile (Crocodylus porosus)
Status in US Zoos: Uncommon to Prevalent (overall); Uncommon (outside Florida)
With males growing up to 20 ft long and weighing over a ton, this is the largest living crocodilian and one of the largest reptiles on the planet. An apex predator that will target just about any prey it comes across, this huge broad-bodied croc makes use of its salt tolerance by camping out in deltas, estuaries and mangrove swamps. Its ability to cross swaths of sea have given it a wide distribution throughout tropical Asia, Melanesia and northern Australia; it can even be found out on South Pacific atolls. In the US it can be found in a few Florida crocodile parks and a handful of other zoos throughout the country.
Taken at the Toledo Zoo by @Rhino0118
Freshwater Crocodile (Crocodylus johnstoni) – Rare to Uncommon
Also called the Johnstone’s Crocodile, *not* Johnston’s (despite the Latin name’s spelling). Smaller and less aggressive than salties, “freshies” are found in the billabongs and other water bodies of northern Australia. Light brown in color with dark bands, these are quite common in Australian zoos but can only be found in a handful of places around the US.
Taken at Wild Life Sydney (Australia) by @Hix
Siamese Crocodile (Crocodylus siamensis) – Uncommon to Prevalent
A medium-sized, average-looking crocodile, and the primary freshwater crocodile of Southeast Asia. The wild population is critically endangered, but hundreds of thousands are kept in crocodile farms in the region. There are ~10 zoos scattered throughout the US that display Siamese.
Taken at Utah's Hogle Zoo by @Ituri
Philippine Crocodile (Crocodylus mindorensis) – Rare
This smaller (usually under 10 ft) freshwater crocodile is endemic to the Philippines, and is likely the most severely threatened crocodilian in the world with possibly fewer than 100 adults in the wild. There is work within the country on captive breeding and release of juveniles, with mixed results. Unfortunately for such an endangered species, there are few holders here in the US; the only ones currently I know of are St. Augustine, Omaha, Pittsburgh and Gladys Porter.
Taken at the Zurich Zoo (Switzerland) by @TheoV
And now, a quick overview on a couple of rarer crocs from the region:
New Guinea Crocodile (Crocodylus novaeguineae) and Hall’s New Guinea Crocodile (C. halli) – Rare/Regional
Pretty straightforward: a smaller crocodile found throughout the island of New Guinea. It was split into two species – a northern and a southern – in 2019 based on both genetics and morphology. It is held at the St. Augustine Alligator Farm, as well as a small number of other crocodile parks/reptile zoos in Florida and South Carolina.
Mugger Crocodile (Crocodylus palustris) – Rare
A medium-sized crocodile with a broad snout, native to the Indian subcontinent. The only holder in the US I’m aware of is the St. Augustine Alligator Farm.
Part III – Australian and Asian Crocs
Finishing out the true crocodile family today with the remaining 7 species.
Saltwater Crocodile (Crocodylus porosus)
Status in US Zoos: Uncommon to Prevalent (overall); Uncommon (outside Florida)
With males growing up to 20 ft long and weighing over a ton, this is the largest living crocodilian and one of the largest reptiles on the planet. An apex predator that will target just about any prey it comes across, this huge broad-bodied croc makes use of its salt tolerance by camping out in deltas, estuaries and mangrove swamps. Its ability to cross swaths of sea have given it a wide distribution throughout tropical Asia, Melanesia and northern Australia; it can even be found out on South Pacific atolls. In the US it can be found in a few Florida crocodile parks and a handful of other zoos throughout the country.
Taken at the Toledo Zoo by @Rhino0118
Freshwater Crocodile (Crocodylus johnstoni) – Rare to Uncommon
Also called the Johnstone’s Crocodile, *not* Johnston’s (despite the Latin name’s spelling). Smaller and less aggressive than salties, “freshies” are found in the billabongs and other water bodies of northern Australia. Light brown in color with dark bands, these are quite common in Australian zoos but can only be found in a handful of places around the US.
Taken at Wild Life Sydney (Australia) by @Hix
Siamese Crocodile (Crocodylus siamensis) – Uncommon to Prevalent
A medium-sized, average-looking crocodile, and the primary freshwater crocodile of Southeast Asia. The wild population is critically endangered, but hundreds of thousands are kept in crocodile farms in the region. There are ~10 zoos scattered throughout the US that display Siamese.
Taken at Utah's Hogle Zoo by @Ituri
Philippine Crocodile (Crocodylus mindorensis) – Rare
This smaller (usually under 10 ft) freshwater crocodile is endemic to the Philippines, and is likely the most severely threatened crocodilian in the world with possibly fewer than 100 adults in the wild. There is work within the country on captive breeding and release of juveniles, with mixed results. Unfortunately for such an endangered species, there are few holders here in the US; the only ones currently I know of are St. Augustine, Omaha, Pittsburgh and Gladys Porter.
Taken at the Zurich Zoo (Switzerland) by @TheoV
And now, a quick overview on a couple of rarer crocs from the region:
New Guinea Crocodile (Crocodylus novaeguineae) and Hall’s New Guinea Crocodile (C. halli) – Rare/Regional
Pretty straightforward: a smaller crocodile found throughout the island of New Guinea. It was split into two species – a northern and a southern – in 2019 based on both genetics and morphology. It is held at the St. Augustine Alligator Farm, as well as a small number of other crocodile parks/reptile zoos in Florida and South Carolina.
Mugger Crocodile (Crocodylus palustris) – Rare
A medium-sized crocodile with a broad snout, native to the Indian subcontinent. The only holder in the US I’m aware of is the St. Augustine Alligator Farm.
Family Gavialidae – Gavials/Gharials
Today will be the last post in this guide covering individual species, and what better way to finish this off than with a couple personal favorites of mine? An offshoot of the crocodiles, this family of two large crocodilians both have long narrow snouts.
Indian Gharial (Gavialis gangeticus) – Prevalent
One of the longest crocodilians in the world (although most of the ones in the US are younger and fairly small), this species is native to the northern rivers of the Indian subcontinent. Gray in color, it is named for the bulbous shape at the end of their narrow snout – which resembles an earthen pot called a ghara. The Indian gharial is primarily a fish-eater, and can coexist with the Mugger Crocodile thanks to different preferences in food and nesting sites.
Critically endangered due to a combination of past overhunting, habitat disruption, pollution and increased use of fishing nets, there have been captive breeding and reintroduction efforts underway since the 1970’s. A big player in captive breeding has been the Madras Crocodile Bank Trust in India, which is the source for at least some of the captive gharials in the US today. There are ~10 zoos with Indian gharials in the US currently, all major AZA zoos mostly in the South and West.
Taken at the Los Angeles Zoo by @Julio C Castro
Taken at the Fort Worth Zoo by @Ding Lingwei
Sunda Gharial (Tomistoma schlegelii) - Prevalent
Also called the tomistoma or the False Gharial, the latter being a name from a recent time when this species was thought to only look like Indian gharials (they are now known to be part of the same lineage). A fairly large crocodilian also – and some of our individuals here are quite massive – this species is from Southeast Asia. Its snout broadens out near the base, it lacks a notable bulbous shape at the nostrils, and its color is frequently a richer or brighter green – all physical differences from Indian gharials. Despite having a similarly long and narrow snout, they also have a much broader diet than just fish – eating things as large as ungulates.
Listed as Vulnerable by the IUCN, there is a breeding program for this species in North America; ~15 zoos and aquariums hold Sunda Gharial, and while the majority are found in the South or in California there are a handful of more northerly places that hold them also.
Taken at the Los Angeles Zoo by @Julio C Castro
And with that, the very last species in the guide has been covered. Round of applause? No?
I will post a crocodilian summary on Wednesday, then next week I will close things out with a summary/conclusion post for the entire guide and survey. I will also work towards getting a table of contents published on the first page, so that past and future readers can go back and find specific passages more easily.
Today will be the last post in this guide covering individual species, and what better way to finish this off than with a couple personal favorites of mine? An offshoot of the crocodiles, this family of two large crocodilians both have long narrow snouts.
Indian Gharial (Gavialis gangeticus) – Prevalent
One of the longest crocodilians in the world (although most of the ones in the US are younger and fairly small), this species is native to the northern rivers of the Indian subcontinent. Gray in color, it is named for the bulbous shape at the end of their narrow snout – which resembles an earthen pot called a ghara. The Indian gharial is primarily a fish-eater, and can coexist with the Mugger Crocodile thanks to different preferences in food and nesting sites.
Critically endangered due to a combination of past overhunting, habitat disruption, pollution and increased use of fishing nets, there have been captive breeding and reintroduction efforts underway since the 1970’s. A big player in captive breeding has been the Madras Crocodile Bank Trust in India, which is the source for at least some of the captive gharials in the US today. There are ~10 zoos with Indian gharials in the US currently, all major AZA zoos mostly in the South and West.
Taken at the Los Angeles Zoo by @Julio C Castro
Taken at the Fort Worth Zoo by @Ding Lingwei
Sunda Gharial (Tomistoma schlegelii) - Prevalent
Also called the tomistoma or the False Gharial, the latter being a name from a recent time when this species was thought to only look like Indian gharials (they are now known to be part of the same lineage). A fairly large crocodilian also – and some of our individuals here are quite massive – this species is from Southeast Asia. Its snout broadens out near the base, it lacks a notable bulbous shape at the nostrils, and its color is frequently a richer or brighter green – all physical differences from Indian gharials. Despite having a similarly long and narrow snout, they also have a much broader diet than just fish – eating things as large as ungulates.
Listed as Vulnerable by the IUCN, there is a breeding program for this species in North America; ~15 zoos and aquariums hold Sunda Gharial, and while the majority are found in the South or in California there are a handful of more northerly places that hold them also.
Taken at the Los Angeles Zoo by @Julio C Castro
And with that, the very last species in the guide has been covered. Round of applause? No?
I will post a crocodilian summary on Wednesday, then next week I will close things out with a summary/conclusion post for the entire guide and survey. I will also work towards getting a table of contents published on the first page, so that past and future readers can go back and find specific passages more easily.
Muggers were the ones I was wondering about. I've talked to many reptile people, both owners and workers, and none of them no of holders outside St. Augustine. Interestingly enough St. Aug bred them back in early 2010s but I have not been able to find out where they were sent.
Excellent write up as well
Excellent write up as well
CROCODILIAN RECAP
The Topline Numbers
Note: for all stats, Dwarf Crocodile is counted as 1 species
25 species from 3 families
Family with Most Species:
Crocodylidae (true crocodiles) – 15 species
Family with Most Survey Holdings:
Alligatoridae (alligators and caimans) – 217 holdings for 8 species, of which over 60% belong to a single species
Species abundance breakdown:
- 1 Abundant (40+ holders)
- 0 Very Common (30-39 holders)
- 3 Common (20-29 holders) (counting Nile and Desert Crocodile together as 1)
- 10 Prevalent (10-19 holders)
- 4 Uncommon (5-9 holders)
- 5 Rare (1-4 holders) (counting New Guinea Crocs together as 1)
Crocodilians are the first group to really diverge from the typical species holding distribution seen in earlier herp groups; rather than 50% or more of the group being considered Rare, the median species is actually Prevalent (though on the low end – somewhere around 10-12 holders). This could be due to the much shorter list of species, combined with the group’s overall popularity. Despite the higher median, there is a noticeably enormous gap between the only Abundant species (American Alligator) and all other species, with none qualifying for even the next tier down.
Top Performers
The most common crocodilian in the survey was obviously the American Alligator, which was also the most common species in the entire survey with 76 holders (which actually represents around half of its total 150+ holdings nationally). Far behind were three small species numbering about 25-30 holders – the Cuvier’s Dwarf Caiman, Dwarf Crocodile, and Chinese Alligator. All three are popular options for aquariums and zoos that have chosen not to invest in larger tropical crocs. The Nile Crocodile group (C. niloticus/suchus) also qualified as Common when combining the two species – but Nile Crocs are poorly distributed compared to alligators, dwarf species and some other crocs, with most being located in the Southeast and in crocodile parks or other non-traditional zoos.
One of our two native crocodilians takes up a lot of available crocodilian space, especially in smaller zoos across the country
Taken at the Los Angeles Zoo by @Julio C Castro
Most other crocodilians are concentrated in the southern half of the country as well. It seems that the rarity of large tropical crocs in northern states stems from a combination of two factors: 1) nearly all smaller zoos and several major ones (Minnesota, Milwaukee, Detroit, Columbus, Boston, Seattle, etc) have chosen to only keep alligators and/or dwarf crocodilians; and 2) the major zoos that *do* keep large tropical crocs often only keep 1 species (Lincoln Park, Louisville, Cincinnati, Indianapolis, Cleveland, Toledo, Maryland, etc) and few of them keep the same species – the 7 examples I just gave have 7 different species!
Notable Facilities
As previously mentioned, the GOAT of American croc facilities is the St. Augustine Alligator Farm Zoological Park, a US Historic Site founded in 1893 in the earliest days of Florida’s now enormous tourism industry. For a time prior to recent species splits and the buildup of Europe’s big crocodile zoos, St. Augustine was the only place in the world to see every recognized species of crocodilian. The zoo remains a key player in breeding and management of captive crocodilians in the US.
Land of Crocodiles path at St. Augustine, where one can see every crocodile under the sun
Typical crocodile enclosure at St. Augustine
Both photos taken at St. Augustine Alligator Farm by @snowleopard
The US has several other alligator/crocodile parks with smaller but still sizable species collections, nearly all located in Southern states like Florida, South Carolina, Louisiana and Texas. None except St. Augustine are AZA accredited, and their standards may vary. Reptile specialist facilities from outside the South stand out as well – Reptile Gardens in South Dakota with 10+ species of crocodilians, and the Phoenix Herpetological Society in Arizona with an unknown but apparently sizable and interesting collection.
As far as traditional zoos go, as mentioned many major zoos only have 1 or 2 large crocodilians with several not bothering to go beyond American Alligators and the dwarf species. There are a few that pull their weight here though. Two typical culprits, the Omaha’s Henry Doorly Zoo and the San Diego Zoo, both have 6 species of crocodilian with a few others like Bronx Zoo and Saint Louis Zoo sitting right behind them.
Rising Stars
This section highlights species that are becoming more common on the scene.
Orinoco Crocodile (Crocodylus intermedius)
In what is shaping up to be a pretty successful herp program for US zoos, Orinoco Crocs only arrived on the scene in the 1990’s; since then they have gone from only 1 or 2 holders to 15+, with much of that growth in the past couple or few years alone. Most of these are juveniles that will see their way back to Venezuela in a couple years as part of the reintroduction program, but if this success can be replicated with more breeding pairs and more holders the experience caring for juveniles could prove to be a foundation for future permanent holders. Either way this is a species to watch in the coming decade.
Taken at Zoo Miami by @MountainBongo
Coely’s Highlight Species
With every major group I will highlight at least one personal favorite of mine.
Indian Gharial (Gavialis gangeticus)
I won’t wax too much on this one since I just covered it two days ago, but there’s a lot to like about this crocodilian. Their super narrow snout, bulbous nose and crooked teeth make them look more comical than terrifying, despite being one of the largest reptiles on Earth. They are an iconic animal of the Indian subcontinent, a large swath of tropical Asia that is often overshadowed a bit in US zoos compared to species and exhibits from further east. Their critical status in the wild offers an opportunity for American zoos to highlight them as a flagship species and contribute to their conservation.
This was a great year for Indian Gharial in the US: in August the Fort Worth Zoo hatched 4 gharials, the second successful breeding in US history and the first to result in multiple offspring. As many of the country’s recently imported juveniles also grow larger in the next several years, there is hopefully a bright future for this unique species in our collections.
Taken at the Bronx Zoo by @red river hog
***********************************************************************************************
The conclusion/summary for the guide is still a WIP, but I’m hoping to throw it up here early next week so that I can get closure on this thread before the Thanksgiving holiday. If there’s any specific information that any of you would like to see addressed in that post, feel free to mention it in the next few days and I’ll see if I can work it in
otherwise this would be an ideal time for any closing thoughts or questions about the crocodilian family.
The Topline Numbers
Note: for all stats, Dwarf Crocodile is counted as 1 species
25 species from 3 families
Family with Most Species:
Crocodylidae (true crocodiles) – 15 species
Family with Most Survey Holdings:
Alligatoridae (alligators and caimans) – 217 holdings for 8 species, of which over 60% belong to a single species
Species abundance breakdown:
- 1 Abundant (40+ holders)
- 0 Very Common (30-39 holders)
- 3 Common (20-29 holders) (counting Nile and Desert Crocodile together as 1)
- 10 Prevalent (10-19 holders)
- 4 Uncommon (5-9 holders)
- 5 Rare (1-4 holders) (counting New Guinea Crocs together as 1)
Crocodilians are the first group to really diverge from the typical species holding distribution seen in earlier herp groups; rather than 50% or more of the group being considered Rare, the median species is actually Prevalent (though on the low end – somewhere around 10-12 holders). This could be due to the much shorter list of species, combined with the group’s overall popularity. Despite the higher median, there is a noticeably enormous gap between the only Abundant species (American Alligator) and all other species, with none qualifying for even the next tier down.
Top Performers
The most common crocodilian in the survey was obviously the American Alligator, which was also the most common species in the entire survey with 76 holders (which actually represents around half of its total 150+ holdings nationally). Far behind were three small species numbering about 25-30 holders – the Cuvier’s Dwarf Caiman, Dwarf Crocodile, and Chinese Alligator. All three are popular options for aquariums and zoos that have chosen not to invest in larger tropical crocs. The Nile Crocodile group (C. niloticus/suchus) also qualified as Common when combining the two species – but Nile Crocs are poorly distributed compared to alligators, dwarf species and some other crocs, with most being located in the Southeast and in crocodile parks or other non-traditional zoos.
One of our two native crocodilians takes up a lot of available crocodilian space, especially in smaller zoos across the country
Taken at the Los Angeles Zoo by @Julio C Castro
Most other crocodilians are concentrated in the southern half of the country as well. It seems that the rarity of large tropical crocs in northern states stems from a combination of two factors: 1) nearly all smaller zoos and several major ones (Minnesota, Milwaukee, Detroit, Columbus, Boston, Seattle, etc) have chosen to only keep alligators and/or dwarf crocodilians; and 2) the major zoos that *do* keep large tropical crocs often only keep 1 species (Lincoln Park, Louisville, Cincinnati, Indianapolis, Cleveland, Toledo, Maryland, etc) and few of them keep the same species – the 7 examples I just gave have 7 different species!
Notable Facilities
As previously mentioned, the GOAT of American croc facilities is the St. Augustine Alligator Farm Zoological Park, a US Historic Site founded in 1893 in the earliest days of Florida’s now enormous tourism industry. For a time prior to recent species splits and the buildup of Europe’s big crocodile zoos, St. Augustine was the only place in the world to see every recognized species of crocodilian. The zoo remains a key player in breeding and management of captive crocodilians in the US.
Land of Crocodiles path at St. Augustine, where one can see every crocodile under the sun
Typical crocodile enclosure at St. Augustine
Both photos taken at St. Augustine Alligator Farm by @snowleopard
The US has several other alligator/crocodile parks with smaller but still sizable species collections, nearly all located in Southern states like Florida, South Carolina, Louisiana and Texas. None except St. Augustine are AZA accredited, and their standards may vary. Reptile specialist facilities from outside the South stand out as well – Reptile Gardens in South Dakota with 10+ species of crocodilians, and the Phoenix Herpetological Society in Arizona with an unknown but apparently sizable and interesting collection.
As far as traditional zoos go, as mentioned many major zoos only have 1 or 2 large crocodilians with several not bothering to go beyond American Alligators and the dwarf species. There are a few that pull their weight here though. Two typical culprits, the Omaha’s Henry Doorly Zoo and the San Diego Zoo, both have 6 species of crocodilian with a few others like Bronx Zoo and Saint Louis Zoo sitting right behind them.
Rising Stars
This section highlights species that are becoming more common on the scene.
Orinoco Crocodile (Crocodylus intermedius)
In what is shaping up to be a pretty successful herp program for US zoos, Orinoco Crocs only arrived on the scene in the 1990’s; since then they have gone from only 1 or 2 holders to 15+, with much of that growth in the past couple or few years alone. Most of these are juveniles that will see their way back to Venezuela in a couple years as part of the reintroduction program, but if this success can be replicated with more breeding pairs and more holders the experience caring for juveniles could prove to be a foundation for future permanent holders. Either way this is a species to watch in the coming decade.
Taken at Zoo Miami by @MountainBongo
Coely’s Highlight Species
With every major group I will highlight at least one personal favorite of mine.
Indian Gharial (Gavialis gangeticus)
I won’t wax too much on this one since I just covered it two days ago, but there’s a lot to like about this crocodilian. Their super narrow snout, bulbous nose and crooked teeth make them look more comical than terrifying, despite being one of the largest reptiles on Earth. They are an iconic animal of the Indian subcontinent, a large swath of tropical Asia that is often overshadowed a bit in US zoos compared to species and exhibits from further east. Their critical status in the wild offers an opportunity for American zoos to highlight them as a flagship species and contribute to their conservation.
This was a great year for Indian Gharial in the US: in August the Fort Worth Zoo hatched 4 gharials, the second successful breeding in US history and the first to result in multiple offspring. As many of the country’s recently imported juveniles also grow larger in the next several years, there is hopefully a bright future for this unique species in our collections.
Taken at the Bronx Zoo by @red river hog
***********************************************************************************************
The conclusion/summary for the guide is still a WIP, but I’m hoping to throw it up here early next week so that I can get closure on this thread before the Thanksgiving holiday. If there’s any specific information that any of you would like to see addressed in that post, feel free to mention it in the next few days and I’ll see if I can work it in
otherwise this would be an ideal time for any closing thoughts or questions about the crocodilian family.
I will get to finishing the Phoenix Herp species list soon on its own thread. It is a gem of a herp facility and would like to get it some more publicity. Out of the 6 (7ish) reptile facility I visited this year it was arguably my 1st or 2nd favorite (I go back and worth between them and Iguanaland)
Komodo Dragon
Well-Known Member
I'd be interested in what facilities, both reptile specialists and "typical" zoos, have the most species.
Hold on to your butts! This is going to be the longest post of the thread, but you know what they say – save the wordiest for last!
American Zoo Herp Guide – Conclusion/Summary on the Herp Survey
TOPLINE NUMBERS for Reptiles and Amphibians in 137 US zoos & aquariums
6,920 holdings of 1,012 species from 81 families
35 species added from reader contributions to this guide – so it’s thanks to all of you that we passed the 1,000 mark!
Largest Family by Species and Holdings: Viperidae (vipers) with 925 holdings from 120 species
Close to 1 in 7 holdings in the survey was a viper, which sounds like a lot… but then you see a puny Sidewinder staring daggers at everyone from its sandbox and you decide the extra representation is appropriate
Taken at the Detroit Zoo by @Zoological Point
Group Breakdowns
Amphibians: 226 species from 31 families
Lizards: 243 species from 25 families
Snakes: 342 species from 9 families
Turtles: 176 species from 13 families
Crocodilians: 25 species from 3 families
Species Abundance Breakdown
- 34 Abundant (40+ holders) (3%)
- 31 Very Common (30-39 holders) (3%)
- 39 Common (20-29 holders) (4%)
- 134 Prevalent (10-19 holders) (13%)
- 148 Uncommon (5-9 holders) (15%)
- 617 Rare (1-4 holders) (61%)
Species Abundance Breakdown (Simplified):
Common to Abundant (20+ holders): 104 species (10%)
Uncommon to Prevalent (5-19 holders): 282 species (28%)
Rare (under 5 holders): 617 species (61%)
Overall the survey showed that – although there is a tremendous amount of diversity in zoo herp collections across the US – most of that diversity consists of very limited holdings, with only 3 holders for the median species. Only 1 in 4 species was found in 10+ zoos, and only 1 in 10 species was found in 20+ zoos. That being said, the more commonly-seen herps make up the majority of holdings: though species with 10+ holders made up only 25% of total species, they made up over 60% of survey holdings. Many rarities are also singletons blipping in and out of the zoo scene, rather than a nucleus for a new breeding population – although a few do belong in that latter category.
10 Most Common Species in Survey
#1: American Alligator (Alligator mississippiensis) – most common herp, reptile, crocodilian and native species
#2: Green-and-black Poison Dart Frog (Dendrobates auratus) – most common amphibian and exotic species
#3: Gila Monster (Heloderma suspectum) – most common lizard and venomous reptile
#4: Dyeing Poison Dart Frog (Dendrobates tinctorius) (includes Blue Poison Dart Frog)
#5 (tie): Alligator Snapping Turtle (Macrochelys temminckii) – most common turtle
#5 (tie): Timber Rattlesnake (Crotalus horridus) – most common snake
#7: Prehensile-tailed Skink (Corucia zebrata)
#8: Common Box Turtle (Terrapene carolina)
#9 (tie): Green Tree Python (Morelia viridis)
#9 (tie): Yellow-banded Poison Dart Frog (Dendrobates leucomelas)
The fact that the top six US zoo herps in the survey were all toxic, venomous or giant swamp monsters tells you pretty much everything you need to know about Americans
Taken at the Sedgwick County Zoo by @Ituri
You’ll notice a few species that might be surprisingly absent from the top of the list, and this would be a good time to discuss the limitations of the survey. My goal in amassing lists for the 137 zoos and aquariums was as follows
1) to capture the full diversity of herp species found in American collections;
2) to get a large enough sample size to accurately reflect species abundance;
3) to prioritize facilities for which I could get recent, comprehensive and accurate on-display holdings; and
4) to prioritize facilities with larger herp collections for the sake of expedience and data management
With nearly 7,000 holdings and 137 facilities, I was satisfied with my sample size. I also felt largely vindicated by the fact that 96% of species featured or mentioned in this guide were species I found in the survey, as this suggests that I more or less succeeded in capturing the diversity held in US collections.
The relative abundance calculations I found to be less accurate – although it appears to vary widely by species. Some species that may actually belong in the top 10 would be Aldabra and African Spurred Tortoises, Ball and Burmese Pythons, Corn Snakes, Green Iguanas, and possibly others; I found these species to be undercounted in the survey due to their prevalence in under-represented facilities such as nature centers, roadside zoos, safari parks and science museums (as two off-the-top examples: the survey missed ~50% of Aldabra holders, and the missing data test alone doubled the holdings I had for Green Iguana).
Did you know that the Catawba Science Center in Hickory, North Carolina has Green Iguana? At some point you just have to stop counting
Taken by @SusScrofa
Overall I didn’t find these data omissions to be problematic for the guide, and I opted not to change much besides slightly adjusting the abundance category up for a couple dozen or so species. The reality is that most American forum members visit primarily large and mid-sized AZA-accredited zoos, so the bias towards these facilities accurately reflects what most people reading this guide would see. However, it does mean that some native and common pet herps are easier to find in zoos than this guide may suggest (though I did my best to note when this was the case).
Top Collections in the Survey
Many of you have probably been wondering what the best places to see herps in the US are. At every summary post I’ve talked about high-ranking zoos for specific groups, but this time I will do a more comprehensive summary of which zoos should be high priority for herp nerds.
Traditional Zoos and Aquariums
The following were the top 8 major AZA zoos by species count. Keep in mind that all numbers are estimates based on single snapshots in time (all snapshots roughly within the last 2 years), so take the exact numbers and ranks with a grain of salt and not as definitive.
#8: Fort Worth Zoo (108 sp) (25 amphib, 28 liz, 33 snake, 18 turtles, 4 crocs)
#7: Toledo Zoo (109 sp) (24 amphibs, 19 liz, 51 snakes, 14 chelonians, 1 croc)
#6: San Antonio Zoo (110 sp) (22 amphib, 24 liz, 45 snakes, 13 turtles, 6 crocs)
#4 (tie): Brookfield (114 sp) (23 amphib, 33 liz, 37 snake, 20 turtle, 1 croc)
#4 (tie): Omaha (114 sp) (23 amphib, 32 liz, 32 snake, 22 turtle, 5 croc)
#3: Dallas (117 sp) (20 amphib, 27 liz, 53 snake, 15 turtle, 3 croc)
#2: Bronx (123 sp) (23 amphib, 31 liz, 31 snake, 34 turtle, 5 croc)
#1: San Diego (140 sp) (21 amphib, 31 liz, 45 snake, 37 turtle, 6 croc)
Ultimately – as is so often the case – the San Diego Zoo stands on top with one of the largest herp collections on public display in the US. The Bronx Zoo – the East Coast’s most species-rich major zoo – is pretty on-par with SDZ in every group other than snakes. That being the case, it’s also clear from the numbers that SDZ and Bronx are not trouncing other herp leaders by huge margins. Dallas and Toledo both have more snakes than San Diego at 50+ species; San Antonio and Omaha both have roughly half a dozen crocs; and the amphibian and lizard counts for SDZ and Bronx are in line with some other zoos near the top of the list. Some places with sizable collections of one group don't make it into the top ranks as well: Detroit Zoo's ~40 amphibian species well surpasses any zoo in the top 8, Tennessee Aquarium's ~55 turtles and tortoises bests any outdoor city zoo, and no traditional park can hold a candle to St. Augustine Alligator Farm's near-complete croc collection.
Several of these zoos are well-known for their herptile sections specifically. San Diego’s Reptile Mesa is home to an old-school, open-air reptile house, but is probably more well-known for its large outdoor yards featuring iguanas, crocodilians, Asian turtles and a breeding herd of Galapagos tortoises. The Fort Worth Zoo is famous for MOLA (Museum of Living Art), a state-of-the-art herp exhibit and breeding building built in 2010 that houses nearly all of the zoo’s ~110 reptile and amphibian species. Other zoos with slightly smaller (though still sizable) collections are known for their showcasing of herps too – from Los Angeles Zoo’s LAIR to Nashville Zoo's Unseen New World to Saint Louis Zoo’s beautiful 1920’s Herpetarium. There is no shortage of US zoos with good herp areas, some of which have been featured in earlier posts.
Just a visual taste of the exhibit and design variety seen in herp areas across the country – from a historic 1920’s building with a planted turtle atrium to a state-of-the-art 2010 herpetarium to a naturalistic outdoor iguana yard.
Taken at: 1) Saint Louis Zoo by @Grizzly Hound 2) Fort Worth Zoo by @geomorph 3) San Diego Zoo by @Coelacanth18
Reptile Zoos
Of course reptile specialist collections must be mentioned as well, given that they frequently surpass traditional zoos in collection size. For both lizards and chelonians, the new Iguanaland facility in southwest Florida (so new that my survey research predated it!) displays 80-90 species of chelonian and ~55 species of lizard, both well higher than any other place I could find. For snakes, Reptile Gardens in South Dakota has ~80 species of snake on display; however, the Animal World Snake Farm & Zoo in Texas may be the largest on-display collection with ~110 species on display back in 2015 (unfortunately I don't have a more recent number).
There are several other reptile zoos across the country. Many are located in touristy spots or along well-traveled highways - such as Reptile Lagoon at a questionably-themed Carolinas truck stop or the Monroe Reptile Zoo in the Cascades near some ski resorts - but they can be found far out in the boondocks as well, like the Kentucky Reptile Zoo and venom lab with 60+ species of venomous snake or the new but promising Reptilandia out in the Texas scrublands. Nearly all choose to operate outside the AZA, though St. Augustine and the more generalist Reptiland of Pennsylvania are accredited. Their standards may therefore vary – especially given the general lack of animal welfare standards in the US for keeping reptiles and amphibians – but they are an undeniable presence on the US herp scene... and a well-managed reptile zoo prioritizing education, conservation and welfare can provide great opportunity to diversify our country's animal collections and showcase this group of animals.
Things can change fast in the reptile zoo scene; this facility - originally a service for training dogs to avoid rattlesnakes - constructed a new building and began doing tours by appointment just since 2021, and is among the largest collections of rattlesnake that can be seen on the continent.
Taken at Rattlesnake Ranch by @snowleopard
***
As I've noted throughout this guide, this is an exciting time for zoo herps in the US. Thanks to captive breeding there has been a dramatic rise in charismatic herps such as Komodo Dragons, leaf-tailed geckos, Titicaca Water Frogs and Mangshan Pitvipers. Recent breeding successes with other neat species like perentie, gharial, taipan and giant softshell turtle have created opportunities for showcasing magnificent species well into the future too. Several conservation programs are being developed or already underway – from breeding and release of hellbenders, indigo snakes and desert tortoises to the funding and logistical support of conservation groups like Amphibian Ark and the Turtle Survival Alliance. There is still much progress to be made in securing and protecting endangered herps, and in educating the public about them in an engaging and empathetic way – but many zoos are putting in effort, and hopefully what we are witnessing is just the beginning.
And with that this guide is complete feel free to ask questions and discuss to your heart’s content! I will also try and get a table of contents of some sort on the first page for easier searching going forward.
Much like this Aldabra tortoise, my thread took a long time to develop – but will hopefully stick around for people to look at and learn from for a long time to come.
Taken at the Smithsonian National Zoo by @Ding Lingwei
American Zoo Herp Guide – Conclusion/Summary on the Herp Survey
TOPLINE NUMBERS for Reptiles and Amphibians in 137 US zoos & aquariums
6,920 holdings of 1,012 species from 81 families
35 species added from reader contributions to this guide – so it’s thanks to all of you that we passed the 1,000 mark!
Largest Family by Species and Holdings: Viperidae (vipers) with 925 holdings from 120 species
Close to 1 in 7 holdings in the survey was a viper, which sounds like a lot… but then you see a puny Sidewinder staring daggers at everyone from its sandbox and you decide the extra representation is appropriate
Taken at the Detroit Zoo by @Zoological Point
Group Breakdowns
Amphibians: 226 species from 31 families
Lizards: 243 species from 25 families
Snakes: 342 species from 9 families
Turtles: 176 species from 13 families
Crocodilians: 25 species from 3 families
Species Abundance Breakdown
- 34 Abundant (40+ holders) (3%)
- 31 Very Common (30-39 holders) (3%)
- 39 Common (20-29 holders) (4%)
- 134 Prevalent (10-19 holders) (13%)
- 148 Uncommon (5-9 holders) (15%)
- 617 Rare (1-4 holders) (61%)
Species Abundance Breakdown (Simplified):
Common to Abundant (20+ holders): 104 species (10%)
Uncommon to Prevalent (5-19 holders): 282 species (28%)
Rare (under 5 holders): 617 species (61%)
Overall the survey showed that – although there is a tremendous amount of diversity in zoo herp collections across the US – most of that diversity consists of very limited holdings, with only 3 holders for the median species. Only 1 in 4 species was found in 10+ zoos, and only 1 in 10 species was found in 20+ zoos. That being said, the more commonly-seen herps make up the majority of holdings: though species with 10+ holders made up only 25% of total species, they made up over 60% of survey holdings. Many rarities are also singletons blipping in and out of the zoo scene, rather than a nucleus for a new breeding population – although a few do belong in that latter category.
10 Most Common Species in Survey
#1: American Alligator (Alligator mississippiensis) – most common herp, reptile, crocodilian and native species
#2: Green-and-black Poison Dart Frog (Dendrobates auratus) – most common amphibian and exotic species
#3: Gila Monster (Heloderma suspectum) – most common lizard and venomous reptile
#4: Dyeing Poison Dart Frog (Dendrobates tinctorius) (includes Blue Poison Dart Frog)
#5 (tie): Alligator Snapping Turtle (Macrochelys temminckii) – most common turtle
#5 (tie): Timber Rattlesnake (Crotalus horridus) – most common snake
#7: Prehensile-tailed Skink (Corucia zebrata)
#8: Common Box Turtle (Terrapene carolina)
#9 (tie): Green Tree Python (Morelia viridis)
#9 (tie): Yellow-banded Poison Dart Frog (Dendrobates leucomelas)
The fact that the top six US zoo herps in the survey were all toxic, venomous or giant swamp monsters tells you pretty much everything you need to know about Americans
Taken at the Sedgwick County Zoo by @Ituri
You’ll notice a few species that might be surprisingly absent from the top of the list, and this would be a good time to discuss the limitations of the survey. My goal in amassing lists for the 137 zoos and aquariums was as follows
1) to capture the full diversity of herp species found in American collections;
2) to get a large enough sample size to accurately reflect species abundance;
3) to prioritize facilities for which I could get recent, comprehensive and accurate on-display holdings; and
4) to prioritize facilities with larger herp collections for the sake of expedience and data management
With nearly 7,000 holdings and 137 facilities, I was satisfied with my sample size. I also felt largely vindicated by the fact that 96% of species featured or mentioned in this guide were species I found in the survey, as this suggests that I more or less succeeded in capturing the diversity held in US collections.
The relative abundance calculations I found to be less accurate – although it appears to vary widely by species. Some species that may actually belong in the top 10 would be Aldabra and African Spurred Tortoises, Ball and Burmese Pythons, Corn Snakes, Green Iguanas, and possibly others; I found these species to be undercounted in the survey due to their prevalence in under-represented facilities such as nature centers, roadside zoos, safari parks and science museums (as two off-the-top examples: the survey missed ~50% of Aldabra holders, and the missing data test alone doubled the holdings I had for Green Iguana).
Did you know that the Catawba Science Center in Hickory, North Carolina has Green Iguana? At some point you just have to stop counting
Taken by @SusScrofa
Overall I didn’t find these data omissions to be problematic for the guide, and I opted not to change much besides slightly adjusting the abundance category up for a couple dozen or so species. The reality is that most American forum members visit primarily large and mid-sized AZA-accredited zoos, so the bias towards these facilities accurately reflects what most people reading this guide would see. However, it does mean that some native and common pet herps are easier to find in zoos than this guide may suggest (though I did my best to note when this was the case).
Top Collections in the Survey
Many of you have probably been wondering what the best places to see herps in the US are. At every summary post I’ve talked about high-ranking zoos for specific groups, but this time I will do a more comprehensive summary of which zoos should be high priority for herp nerds.
Traditional Zoos and Aquariums
The following were the top 8 major AZA zoos by species count. Keep in mind that all numbers are estimates based on single snapshots in time (all snapshots roughly within the last 2 years), so take the exact numbers and ranks with a grain of salt and not as definitive.
#8: Fort Worth Zoo (108 sp) (25 amphib, 28 liz, 33 snake, 18 turtles, 4 crocs)
#7: Toledo Zoo (109 sp) (24 amphibs, 19 liz, 51 snakes, 14 chelonians, 1 croc)
#6: San Antonio Zoo (110 sp) (22 amphib, 24 liz, 45 snakes, 13 turtles, 6 crocs)
#4 (tie): Brookfield (114 sp) (23 amphib, 33 liz, 37 snake, 20 turtle, 1 croc)
#4 (tie): Omaha (114 sp) (23 amphib, 32 liz, 32 snake, 22 turtle, 5 croc)
#3: Dallas (117 sp) (20 amphib, 27 liz, 53 snake, 15 turtle, 3 croc)
#2: Bronx (123 sp) (23 amphib, 31 liz, 31 snake, 34 turtle, 5 croc)
#1: San Diego (140 sp) (21 amphib, 31 liz, 45 snake, 37 turtle, 6 croc)
Ultimately – as is so often the case – the San Diego Zoo stands on top with one of the largest herp collections on public display in the US. The Bronx Zoo – the East Coast’s most species-rich major zoo – is pretty on-par with SDZ in every group other than snakes. That being the case, it’s also clear from the numbers that SDZ and Bronx are not trouncing other herp leaders by huge margins. Dallas and Toledo both have more snakes than San Diego at 50+ species; San Antonio and Omaha both have roughly half a dozen crocs; and the amphibian and lizard counts for SDZ and Bronx are in line with some other zoos near the top of the list. Some places with sizable collections of one group don't make it into the top ranks as well: Detroit Zoo's ~40 amphibian species well surpasses any zoo in the top 8, Tennessee Aquarium's ~55 turtles and tortoises bests any outdoor city zoo, and no traditional park can hold a candle to St. Augustine Alligator Farm's near-complete croc collection.
Several of these zoos are well-known for their herptile sections specifically. San Diego’s Reptile Mesa is home to an old-school, open-air reptile house, but is probably more well-known for its large outdoor yards featuring iguanas, crocodilians, Asian turtles and a breeding herd of Galapagos tortoises. The Fort Worth Zoo is famous for MOLA (Museum of Living Art), a state-of-the-art herp exhibit and breeding building built in 2010 that houses nearly all of the zoo’s ~110 reptile and amphibian species. Other zoos with slightly smaller (though still sizable) collections are known for their showcasing of herps too – from Los Angeles Zoo’s LAIR to Nashville Zoo's Unseen New World to Saint Louis Zoo’s beautiful 1920’s Herpetarium. There is no shortage of US zoos with good herp areas, some of which have been featured in earlier posts.
Just a visual taste of the exhibit and design variety seen in herp areas across the country – from a historic 1920’s building with a planted turtle atrium to a state-of-the-art 2010 herpetarium to a naturalistic outdoor iguana yard.
Taken at: 1) Saint Louis Zoo by @Grizzly Hound 2) Fort Worth Zoo by @geomorph 3) San Diego Zoo by @Coelacanth18
Reptile Zoos
Of course reptile specialist collections must be mentioned as well, given that they frequently surpass traditional zoos in collection size. For both lizards and chelonians, the new Iguanaland facility in southwest Florida (so new that my survey research predated it!) displays 80-90 species of chelonian and ~55 species of lizard, both well higher than any other place I could find. For snakes, Reptile Gardens in South Dakota has ~80 species of snake on display; however, the Animal World Snake Farm & Zoo in Texas may be the largest on-display collection with ~110 species on display back in 2015 (unfortunately I don't have a more recent number).
There are several other reptile zoos across the country. Many are located in touristy spots or along well-traveled highways - such as Reptile Lagoon at a questionably-themed Carolinas truck stop or the Monroe Reptile Zoo in the Cascades near some ski resorts - but they can be found far out in the boondocks as well, like the Kentucky Reptile Zoo and venom lab with 60+ species of venomous snake or the new but promising Reptilandia out in the Texas scrublands. Nearly all choose to operate outside the AZA, though St. Augustine and the more generalist Reptiland of Pennsylvania are accredited. Their standards may therefore vary – especially given the general lack of animal welfare standards in the US for keeping reptiles and amphibians – but they are an undeniable presence on the US herp scene... and a well-managed reptile zoo prioritizing education, conservation and welfare can provide great opportunity to diversify our country's animal collections and showcase this group of animals.
Things can change fast in the reptile zoo scene; this facility - originally a service for training dogs to avoid rattlesnakes - constructed a new building and began doing tours by appointment just since 2021, and is among the largest collections of rattlesnake that can be seen on the continent.
Taken at Rattlesnake Ranch by @snowleopard
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As I've noted throughout this guide, this is an exciting time for zoo herps in the US. Thanks to captive breeding there has been a dramatic rise in charismatic herps such as Komodo Dragons, leaf-tailed geckos, Titicaca Water Frogs and Mangshan Pitvipers. Recent breeding successes with other neat species like perentie, gharial, taipan and giant softshell turtle have created opportunities for showcasing magnificent species well into the future too. Several conservation programs are being developed or already underway – from breeding and release of hellbenders, indigo snakes and desert tortoises to the funding and logistical support of conservation groups like Amphibian Ark and the Turtle Survival Alliance. There is still much progress to be made in securing and protecting endangered herps, and in educating the public about them in an engaging and empathetic way – but many zoos are putting in effort, and hopefully what we are witnessing is just the beginning.
And with that this guide is complete
feel free to ask questions and discuss to your heart’s content! I will also try and get a table of contents of some sort on the first page for easier searching going forward.Much like this Aldabra tortoise, my thread took a long time to develop – but will hopefully stick around for people to look at and learn from for a long time to come.
Taken at the Smithsonian National Zoo by @Ding Lingwei
Antimony96
Well-Known Member
Amazing thread!
My favorite thread this year, easily. I learned lots and was always looking forward to the nest installment. All good things must come to an end.