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Alligator reclining on rock Crocodilian CAPTIVE CARE F.A.Q.
This is a detailed care guide for serious keepers of caimans, alligators and crocodiles. If you're looking for a friendly, loving and easy to care for pet, this guide is definitely not for you!



FAQ CONTENTS

0. CREDITS

1. CONTENTS

2. INTRODUCTION

3. SPECIES

4. PURCHASING

5. HOUSING

6. FEEDING

7. HANDLING

8. HEALTH CARE

9. MISCELLANEOUS

10. APPENDICES


2. INTRODUCTION
 2.0What is the aim of this FAQ?
 2.1.0What is a crocodilian?
 2.1.2How many species of crocodilian are there?
 2.1.3Where do crocodilians live in the wild?
 2.2.1How large do crocodilians get?
 2.2.2How fast do crocodilians grow?
 2.2.3How long do crocodilians live?



2.0 What is the aim of this FAQ?

This is a document about crocodilians - alligators, caimans, crocodiles and gharials - and their care in captivity. It has two main goals. First, and perhaps most importantly, its goal is to persuade the majority of readers that crocodilians do not make good pets. Once you've read the whole thing, you might be inclined to agree. In the words of John Levell "Hopefully you're reading this document before possibly making the biggest mistake of your life." The second goal is to get essential information on crocodilian care to dedicated owners (both private and professional) of these creatures.

Through the pet trade, various crocodilian species have become more widely available in several countries, yet there is virtually no information available on the Internet or in published books on how to look after them properly in captivity - nor whether they even make good captives at all. Spectacled and dwarf caimans are the most commonly kept crocodilian species - they are the most widely available, and are promoted by pet stores as growing to small adult sizes. However, crocodilians including caimans are definitely not for beginners. They may be small and cute as hatchlings, but this does not last very long. In only a few months, never mind years, they grow considerably in size and their temper usually gets worse with every day. They also have incredibly powerful bites featuring many sharp teeth. It isn't surprising that many owners, frequently misinformed by pet stores desperate to sell the animals, end up giving them away or, worse, disposing of them in some manner that may be illegal, inhumane or both. If your dedication for keeping a crocodilian is anything less than total, you will find nothing in these pages to encourage you. Dedication alone will not be enough - you need experience, skill, and lots of money as the animals grow. If you bought a baby caiman from the pet store and were told it was easy and cheap to look after, you're in for a shock. If you're debating whether to buy a crocodilian or not, please read the entire document before you even start to consider it seriously.

The main audience for this document is serious and dedicated owners, and potential owners. You'll find hints on purchasing animals, setting up their environment, feeding them, handling them and more. An entire book could easily be written on some sections of this FAQ alone, so instead of pretending to be some kind of ultimate guide to crocodilians in captivity, this resource should be taken for what it is - a detailed source of information to get you on the right track.

The narrative of this document does not refer to any one species in particular. This was done intentionally, as all 23 crocodilian species have fundamentally similar basic requirements. Virtually all the information you'll find in here applies equally to any species. However, some differences do exist (eg. in social behaviour, growth rates, breeding etc), and these are pointed out in the appropriate section. There is also a short description of the most commonly kept species. The art of keeping crocodilians in captivity is a relatively new one, so many owners are literally learning as they go along. I hope that this document helps to speed up the learning process.



2.1.1 What is a crocodilian?

Juvenile American alligator
Juvenile American alligator
(Alligator mississippiensis)


Juvenile dwarf caiman
Juvenile Cuvier's dwarf caiman
(Paleosuchus palpebrosus)


Adult saltwater crocodile
Adult male saltwater crocodile
(Crocodylus porosus)


Adult Indian gharial
Adult Indian gharial
(Gavialis gangeticus)


A crocodilian is any one of 23 species of large, carnivorous, semi-aquatic reptiles that live primarily in tropical and semi-tropical environments. Although the taxonomy varies, there are three families of crocodilians: alligatoridae (alligators and caimans), crocodylidae ("true crocodiles") and gavialidae (gharial). Alligators and caimans (Alligatorids) possess a characteristically broad snout and upper jaws that normally overlap their lower jaws, hence hiding their lower teeth which fit into depressions in the upper jaw. Crocodylids have a more V-shaped snout in general, with both upper (maxillary) and lower (mandibular) teeth interdigitating outside the jaw (ie. in full view). Gavialids have the most slender (or longirostrine) jaw of any species, specially adapted to sweeping through water to catch fish. All crocodilians possess "integumentary sense organs", which appear as dark spots, across the scales of their upper and lower jaws. This gives many species a somewhat "unshaven" appearance when viewed up close, and lends them an unprecedented ability to detect small vibrations and movement through water and across the ground. However, while these spots are present all over the body scales of crocodylids and gavialids, they are absent from the bodies of alligatorids. All crocodilians are powerful reptiles with a keen bite and often a mean disposition. It is often said that alligators and caimans are generally less boisterous than true crocodiles. While this is not completely false, temperament varies greatly between individuals and species. It is no exaggeration that all crocodilian species are capable of being highly aggressive, and a calm and docile individual is extremely rare.

Sense organs on snout
Juvenile Australian freshwater crocodile
(Crocodylus johnstoni) with integumentary sense
organs visible on scales.






2.1.2 How many species of crocodilians are there?

Overall there are 23 species of crocodilians: two alligators, six caimans, 14 crocodiles and 1 species of gharial. The two alligators include the American alligator (
Alligator mississippiensis) and the Chinese alligator (Alligator sinensis). Of these, the American alligator is available in the pet trade in certain US states, and may be available in other countries typically as captive bred individuals. Chinese alligators are not available in the US pet trade, although limited numbers have made it to Europe and Asia from China's captive breeding program. Of the six caimans, the most common species in the pet trade has traditionally been the spectacled caiman (Caiman crocodilus), which some dealers mistakenly call the "speckled caiman". The spectacled caiman gets its name from the prominent bony ridge that connects each eye orbit, giving it a bespectacled appearance. Of the three subspecies, the one best represented in the pet trade is the brown caiman (Caiman crocodilus fuscus).

There are several other caiman species: the broad-snouted caiman (Caiman latirostris), the Yacare or Jacaré caiman (Caiman yacare), the black caiman (Melanosuchus niger), Cuvier's (or the smooth-fronted) dwarf caiman (Paleosuchus palpebrosus) and Schneider's dwarf caiman (Paleosuchus trigonatus). These two dwarf caimans, particularly P. palpebrosus, are fast becoming the most popular crocodilian species in captivity because of their modest size and improved temperament over the boisterous C. crocodilus. Import and interstate travel of C. crocodilus has now been largely curtailed in the US through new licensing laws, and hence it has declined in popularity. The other caiman species are difficult or impossible to obtain in the US pet trade due to their CITES trade status and US laws, although captive bred specimens are available in limited numbers in Europe and Asia.

Of the 14 species of crocodiles, very few are available in the US pet trade, but again limited numbers are represented in Europe by captive bred stock. These species include the American crocodile (Crocodylus acutus), the African slender-snouted crocodile (Crocodylus cataphractus), the Orinoco crocodile (Crocodylus intermedius) from South America, the Australian freshwater crocodile (Crocodylus johnstoni), the critically endangered Philippine crocodile (Crocodylus mindorensis), Morelet's crocodile (Crocodylus moreletii), the infamous Nile crocodile (Crocodylus niloticus), the New Guinea crocodile (Crocodylus novaeguineae), the mugger or marsh crocodile (Crocodylus palustris), the Australian saltwater crocodile (Crocodylus porosus), the Cuban crocodile (Crocodylus rhombifer), the critically threatened Siamese crocodile (Crocodylus siamensis), the relatively small African dwarf crocodile (Osteolaemus tetraspis), and the false gharial or Tomistoma (Tomistoma schlegelii). Finally, the Indian gharial (Gavialis gangeticus) with its characteristic needle-like snout represents the sole member of the family Gavialidae.

More information on the different species is available on the Internet and various books (section 9.5).



2.1.3 Where do crocodilians live in the wild?

Crocodilians are found mainly in tropical and sub-tropical regions of the world, being unable to survive and reproduce successfully in cold climates. However, the American alligator and Chinese alligator are the most cold-tolerant and are found in the highest latitudes of any species. Both breed and feed successfully during warmer months, but have adapted to survive relatively cold conditions each winter - usually hibernating in specially-constructed burrows.

Alligators and caimans are found almost exclusively in North, Central and South America, with the sole exception being the Chinese alligator restricted to eastern China. A handful of crocodiles are found in the Americas, but the majority are found throughout Africa, India and Asia. The gharial is found in India and adjacent countries. Click on the map to learn more about the distribution of crocodilians around the world.

Most species have a relatively wide distribution, and typically occupy a variety of habitat types from swampy wetlands and isolated pools to major river systems and tributaries. Most species prefer freshwater, although some are more tolerant of saline conditions, and this affects their distribution accordingly. Crocodilians are tenacious survivors, and several species thrive outside their natural range in suitable environments, or in habitats modified by humans. Spectacled caimans are the best example of this, with several feral populations already established in countries like the USA and Cuba. Many feral populations are caused by illegal releases of unwanted pets by owners that have been bitten one too many times. Such releases are irresponsible and a serious danger to the ecology of native wildlife including crocodilians.



2.2.1 How large do crocodilians get?

There is a lot of confusion and misinformation about the
maximum size of various crocodilian species, and there are many "big fish" stories that owe more to imagination than actual measurements. Conversely, less reputable or informed pet stores do the opposite, providing figures that greatly underestimate the size potential of a particular species in order to make it a more attractive purchase. After all, a 3 foot long caiman sounds far more manageable than a 7 foot caiman, doesn't it?

The fact is, growth rates and maximum size vary quite a lot in a particular species, and there are often big differences between males and females. Australian saltwater crocodiles, for example, grow relatively quickly and males reach an average size of around 15 to 17 feet (4.6 to 5.2 metres), but some males never get larger than 14 feet (4.3 metres), and some rare individuals reach 18, 19 and even over 20 feet (over 6.1 metres) in length. Females, however, typically reach only 8.5 to 10.5 feet (2.6 to 3.2 metres), although again some rare individuals can exceed this. Given that saltwater crocodile adults can reach maximum sizes between 8.5 feet (2.6 metres) and over 20 feet (over 6.1 metres) it's no surprise that there's confusion over its maximum length! The same applies to all other species, from dwarf caimans to Indian gharials. This is made even worse by stories of 33 foot long saltwater crocodiles, 20 foot long American alligators, and 24 foot long gharials. Stories make for great reading, but take them with a pinch of salt.

Here is a selection of realistic size ranges for a handful of species. Like any species, there may be very rare exceptions outside these ranges:

SpeciesAdult size (male)Adult size (female)
Paleosuchus palpebrosus4.2 - 5.2 ft
1.3 - 1.6 m
3.5 - 4 ft
1.1 - 1.2 m
Paleosuchus trigonatus5.5 - 7.5 ft
1.7 - 2.3 m
4 - 4.5 ft
1.2 - 1.4 m
Caiman crocodilus6 - 8.5 ft
1.8 - 2.6 m
4.5 - 5.5 ft
1.4 - 1.7 m
Alligator mississippiensis12 - 14.5 ft
3.7 - 4.4 m
7 - 10 ft
2.1 - 3.0 m
Crocodylus niloticus13 - 16 ft
4.0 - 4.9 m
12 - 14 ft
3.7 - 4.3
Crocodylus porosus14 - 17 ft
4.3 - 5.2 m
8.5 - 10.5 ft
2.6 - 3.2 m

Growth rates (and hence maximum sizes) in all species are influenced by environmental variables such as temperature and food intake. This has unfortunately spawned the irresponsible myth that crocodilians will only grow to the size of their enclosure, or that their growth can be stunted by keeping them in sub-standard conditions. Such thinking will kill a crocodilian, and is discussed in more detail here. Show the above table to anyone who tells you that a spectacled caiman or Nile crocodile only grows to 2 or 3 feet in length.

Gomek, 17.9 feet of saltwater crocodile
 Where would you keep Gomek, 17.9 ft of Crocodylus porosus?
Do not buy a crocodilian unless you are capable of housing it comfortably when it reaches its maximum size. Where are you going to keep your hatchling Nile crocodile when it reaches 15 feet in length? Certainly not the 4 foot glass aquarium it starts off in. Thinking about the future of the animal, rather than your own short-term satisfaction, is what separates a serious and responsible crocodilian keeper from the irresponsible and thoughtless. Large species like Nile crocodiles and saltwater crocodiles are highly unsuited to captivity outside of professional zoological establishments and highly resourceful private keepers.



2.2.2 How fast do crocodilians grow?

Compared with many other animals, crocodilians grow rapidly. Many species increase in length at least 20 to 30 times from hatchlings, and increase in weight by at least 1,000 times within 10 to 20 years. However, growth rate varies significantly between species, and also between individuals of each species. Key factors including temperature, frequency of feeding, quality of food and even social factors can result in major differences in growth rates and hence maximum size. Poor growth rates can often indicate problems with husbandry, but it is not so simple. Even a group of individuals kept in identical conditions will exhibit a certain degree of variation.

Despite this variation, all crocodilians show a fairly typical growth pattern: initial growth rates are rapid, often for several years, but slowly begin to decline as the animal matures. It takes many years for growth to cease entirely and many larger crocodilians appear to grow continuously over their lives, albeit very slowly in later life.

Larger species such as American alligators or saltwater crocodiles can initially grow at least a foot a year, and a few individuals can achieve sizes of nearly 4 feet after only 12 months. Smaller species usually grow more slowly. The following table is a very rough guide to growth rate in the spectacled caiman, Caiman crocodilus, assuming it is kept under normal conditions. Variation from these figures is not unusual.

Spectacled Caiman (Caiman crocodilus)
AgeTotal length (cm)Total length (inches)
Hatchling18 - 217 - 8
1 year40 - 4516 - 18
2 years65 - 7526 - 30
3 years90 - 10535 - 41
4 years110 - 12543 - 49
5 years135 - 15053 - 59
6 years155 - 17061 - 67
10 years175 - 19569 - 77

For comparison, the following table shows growth rates for a male saltwater crocodile, Crocodylus porosus, kept under optimal conditions in captivity. This results in a very fast-growing individual. Wild saltwater crocodiles normally grow far less quickly due to their lower overall food intake (e.g. only 200 cm / 79 inches at 10 years).

Saltwater crocodile (Crocodylus porosus)
AgeTotal length (cm)Total length (inches)
Hatchling27 - 3211 - 13
1 year70 - 10028 - 39
2 years140 - 19055 - 75
3 years180 - 22071 - 87
4 years210 - 26083 - 102
5 years250 - 28098 - 110
10 years320 - 360126 - 142



2.3 How long do crocodilians live?

This is a very difficult question to answer! There is virtually no information on maximum age of different species in the wild, and nobody really knows whether animals in captivity live normal lifespans or die prematurely. The main problem is that crocodilians live long lives, often outliving their caretakers and those scientists who study them! Marked individuals in the wild can be studied by different generations, but no studies have been ongoing for enough time to provide any conclusive answers. Old animals can be aged by looking at growth rings laid down in bone, but this technique is notoriously unreliable.

From the information we have, it appears that smaller species live around 30 to 50 years, and larger species live at least 50 to 70 years. There is enough reliable information from long-term captive saltwater crocodiles to conclude that some individuals can reach at least 70 years of age. One zoo in Russia claims to have held a crocodile (species unknown) that was 115 years old when it died - they obtained the animal as a young adult in the 1890s. This would have made it at least 100 years old when it died. The claim has never been properly verified however, and would seem to be highly unusual.

The point here is that all crocodilians are long-lived animals. If you buy a dwarf caiman when you're 30 years old, expect it to be alive and healthy when you're pushing 70! That's a serious long-term commitment. Many people purchase crocodilians expecting to give them away once they get too large, but this is a misguided philosophy! Not everyone wants a 6 foot long, foul-tempered crocodilian with a propensity to bite the hand that feeds it, and don't rely on giving a spectacled caiman or American alligator away to a zoo overburdened with them already. In short, think carefully about your long-term plans before you buy any crocodilian. Read
this section if you need further convincing of this.


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