The following information is provided in response to the many questions RainForest Adventures receives from folks around the world concerning the Crocodilians. Virtually every day we receive both written and email requests from teachers, students and lots of other folks on the subject of Crocodiles and Alligators.
This page, and all of the amazing facts in contains is dedicated to all of those who wish to learn more about the incredible world of Crocodilians.
Not all species shown on this page can be viewed at Rain Forest Adventures, this information is provided as a service to students and teachers.
To view the current Crocodilians on display at RainForest Adventures please visit the Crocodilian Page
Range: Southeastern United States. Mid to southern Alabama, Southern Arkansas, Coastal North & South Carolina, Florida, Georgia (south of mid state), Louisiana, Mississippi, Oklahoma, Texas (possibly western Tennessee, Mississippi river)
Habitat: Primarily freshwater swamps and marshes, but also in rivers, lakes and smaller bodies of water. They can tolerate a reasonable degree of salinity for short periods of time, being occasionally found in brackish water around mangrove swamps, although they lack the buccal salt-secreting glands present in crocodiles. Construction of burrows is well documented in this species. The burrows are used for shelter and hibernation when the seasonal temperatures fall. Even outside their burrows, they can tolerate limited periods of freezing conditions (see "icing response" in Miscellaneous Facts, below). They modify their habitat through the creation of 'alligator holes', which provide a refuge for other animals during dry periods. These are excavated using both snout and tail. Once these dry out, however, the alligator crosses land in order to find another body of water. Alligators near human habitation are often seen crossing roads, entering suburbs and finding shelter in swimming pools during the drier months.
Size: 8-12 Feet on average (19' 2" Record) Males substantially larger than females.
Status: Stable in the majority of it's natural range. Expatriated from portions due primarily to human habitation. Original range of the American Alligator is debated, populations may have occurred as far north as Memphis, Tennessee along the Mississippi river, the Alligator is not found this far north today. The American alligator may actually occur in a higher density than ever before in some portions of it's range where predators such as Bobcats etc. have been removed. The removal of such predators may be allowing more of the eggs and hatchlings to reach adulthood than in historical times.
Rain Forest Facts: A true poster child of conservation, the American Alligator has made a remarkable comeback. Over collection for the skin trade from the early 1920's through the early 1960's nearly brought an end to this majestic creature. Wise intervention on the behalf of the United States government not only protected the American Alligator but actually assisted in the management of captive populations for an incredibly successful reintroduction program.
As is the case with most crocodilians, the American Alligator is highly nocturnal. Virtually all feeding is conducted at night. Food items for the American Alligator vary widely based on the age of the animal and available prey items. As with most crocodilians the American Alligator is highly opportunistic in it's feeding.
The American alligator is one of the most vocal species of reptiles. The bellowing call of an adult male alligator can be heard a considerable distance. Vocalization by the young alligators is typically directed at their mother.
The breeding season of the American alligator lasts from April to May, the southern portion of the range starts earlier than in the more northern populations. A female will lay 25 to 60 eggs in a mound of vegetation. The eggs are incubated by both the compost process of the vegetation and the warmth of the sun The eggs of the American Alligator typically hatch in approximately 60-70 days. The mother alligators guard their nests and protect their young for several months after they hatch. Some female alligators have been known to allow juveniles to remain near her for protection for periods up to 3 years.
American alligators often have a dramatic impact on their natural surroundings. The gator will dig excavations known as "gator holes", which support a whole community of other creatures and plants. By building up the land around the gator holes, they create new places for plants to grow.
Range:Small range in north east China
Habitat:Fresh water ponds, lakes and slow moving streams
Status:Critically Endangered, may be the next species of crocodilian extinct in the wild. (Less than 200 animals in the wild, captive populations are present in several farms and zoo)
Rain Forest Facts: Local Chinese peoples often refer to the Chinese Alligator as the "Muddy Dragon," The Chinese People have a long history of worshipping and fearing the dragon as part of their culture, it makes the precarious position the Chinese Alligator finds itself in even more ironic. This Alligator species faces virtual extinction in the wild in the very near future.
Dragons have long been a symbol of strength and
perseverance, in China and in many ways the Chinese alligator is the
country's last living dragon. Efforts are under way by the Chinese
government to continue a captive breeding program that has been in existence for
a few years. Reintroductions are planned on a very small scale.
Unlike the wide ranging American Alligator, the Chinese alligators have a
very small natural range, there is debate as to weather or not they ever had a
large natural range. Growing human populations coupled with this small
natural range have put intense pressures on the animals. The natural
range is actually in the lower Yangtze valley.
Range:The Spectacled caiman is found in Brazil, Colombia, Costa Rica, Ecuador, El Salvador, French Guiana, Guatemala, Honduras, Mexico, Nicaragua, Panama, Peru, Surinam, Tobago, Trinidad, and Venezuela. It has been introduced into Puerto Rico, Cuba, and the United States The Spectacled caiman has the largest geographical distribution of any Crocodilian species
Habitat:Slow-moving rivers; backwaters of rivers, lakes, ponds, swamps, highly adaptable the Spectacled Caiman appears to be capable of living virtually anywhere fresh water and proper temperature requirements are met. The Spectacled Caiman is not as cold tolerant as the American Alligator and will most likely have a difficult time expanding it's introduced range in the United States based on temperature.
Size:4-7 feet (male Spectacled Caiman have been recorded to 8.5 feet) Social standing appears to affect the growth rate and possibly the maximum size of the Spectacled Caiman.
Status:Declining (Not listed)-For several reasons including large geographical range and remoteness of some regions the actual status of the Spectacled Caiman is very difficult to determine. Estimates put the wild population in excess of 2,000,000 animals. The Spectacled Caiman may be benefiting from the decline of otherwise healthy populations of such crocodilians as the Black Caiman. A decrease in the competition from larger crocodilians for both food and nesting locations may well be benefiting the more adaptable Spectacled Caiman. This species of Caiman is exported in huge numbers on an annual basis to support the pet trade worldwide.
Rain Forest Facts:The Spectacled Caiman derives it's name from the bony ridge that runs between the eyes, closely resembling a pair of "spectacle glasses" worn by people.
This smaller member of the crocodile family is known for its aggressive behavior. Even a small female will stand her ground when defending her nest. The young grow rapidly and mature in about five years, half the time required for larger crocodilian species.
Female Spectacled Caiman will deposit up to 35 eggs (normally a smaller number, 22 appears to be the average. Size of the adult female and her relative health has a great bearing on the clutch size) in an excavated nest. The Tegu lizard, along with many other predators account for a very heavy loss of eggs in the nest. Some estimates put the chances of a Spectacled Caiman reaching adulthood at less than 2% with the vast majority of mortality occurring either in the nest or shortly after hatching.
The Spectacled Caiman will estivate in certain parts of it's range when water becomes scarce.
Like the majority of its crocodilian cousins, the caiman is heavily exploited for its hide. Millions have been killed for the exotic leather trade. It has been speculated that due to the loss of larger animals such as the Orinoco Crocodile to over collection that the Spectacled Caiman has actually expanded it's range. The Black Caiman and the Spectacled Caiman seem to co-exist in many of their shared habitats.
Habitat:Slow-moving rivers; backwaters of rivers, lakes, ponds, swamps
Size:Medium sized crocodilians (6.5 to 10 feet) with brownish mottling on a yellowish background fading to cream color along the underside.
Rain Forest Facts:Broad-nosed caiman are found in the sluggish streams and muddy bayous of south-east Brazil, reaching inland to Paraguay and Argentina.
In the wild, these carnivores eat a very generalized diet that includes snails, turtles, aquatic insects and their larvae, crustaceans, amphibians, and small fish, including piranhas.
Broad-nosed caiman are endangered.
Beginning in the middle of the century, commercial hunting took a significant
toll on this species. The skin was prized because it is more suitable for
tanning than the skin of other crocodilians. Today, although protected, illegal
hunting still persists. Equally dangerous to the species is the on-going threat
of habitat destruction. Deforestation and water pollution are major problems in
most areas of their range. In evolutionary terms, this species has been highly
successful, first appearing in the fossil record more than 54 million years ago.
Range: Argentina, Brazil, Bolivia, Paraguay
Habitat:Slow-moving rivers; backwaters of rivers, lakes, ponds, swamps
Size: Averages 5-7 feet with exceptions reaching 8-9 feet
Status: Accurate numbers are poorly known, smaller range than the common Caiman contributes to smaller numbers in the wild. Probably between 75,000 and 175,000 specimens in the wild
Rain Forest Facts:Nicknamed the “Piranha Croc” this species of Caiman has very pronounced teeth contributing to a menacing look. The natural range of the Yacare Caiman is smaller than the common Caiman contributing to additional pressure on its numbers. Loss of habitat is the greatest threat to this species. Poaching of the animal for its hides still occurs in the majority of the Caiman’s range.
Female Caiman build nests of vegetation during the rainy season. An average egg clutch will produce 27 eggs, the size and overall health of the female has a direct bearing on the clutch size, clutches of 40 eggs have occurred on rare occasion. The female Caiman will generally protect her nest, incubation is influenced by both ambient air temperature as well as the construction material used in the nest. Average incubation time is 80 days.
As with the majority of smaller crocodilians the vast majority of the Caimans diet is fish and invertebrates such as mollusks.
The future for this species of Caiman is uncertain; the local governments’ inability to enforce protection measures continues to cause the animals’ numbers to decline. Some farming of this species is occurring but fears on integration with other caiman on the farms could render the stock produced useless for potential reintroduction programs. Lack of commercially viable skin also negatively effects this species of Caiman.
Range:The Black Caiman is found throughout much of the Amazon Basin. The Black Caimans former range included virtually all of northern and central South America, but the known range as of 2005 has diminished substantially. Habitat: Slow-moving rivers; backwaters of rivers, lakes, ponds, swamps
Size:Largest of all Caiman, the Black Caiman is often thought of as very similar in size and physical shape to the American Alligator. The largest recorded size is 19 feet for a male Black Caiman, the average is is 10-14 feet.
Status:Listed as Cities 1, the Black Caiman is rapidly being lost to illegal hunting of it's hide. Some believe as much as 98% percent of the original population has been destroyed.
Rain Forest Facts:An impressive crocodilian, the Black Caiman is capable of growing as large as the American Alligator. The similarities are striking between the role the American Alligator and the Black Caiman play in their respective ecosystems. The fate of the two species appears to be as divergent as the physical similarities are in commonality.
The diet of the young Black Caiman is similar to all crocodilians, small vertebrate and insects make up much of the diet for the first year or so of life. Growing rapidly the Black Caiman switches to larger fish species such as the plentiful catfish and piranha species that share it's river ecosystem. As large adults the Black Caiman begin to prey on animals as large as the Capybara, the largest rodent on earth, carrion is also consumed willingly by Caiman of all sizes. The roll the Black Caiman plays as a predator becomes increasingly important as the animal matures.
Obtaining accurate information on the current status of the Black Caiman is difficult for a number of reasons, the flooding of the Amazon (typically late May through July) will disperse many animals including the populations of Black Caiman. When the annual dry season returns the Black Caiman and many other species of animals tend to congregate near the shrinking, and or permanent, water supplies. Counting the Black Caiman during the dry season can yield some relevant data but is by no means totally accurate. Guyana reports very healthy populations within it's borders. While surrounding nations release conflicting data on the status of the Black Caiman.
Fear on the behalf of local natives that the Black Caiman presents a serious risk to economically important fish populations is founded in rumors and false information. As a keystone species the Black Caiman undoubtedly performs many of the very beneficial functions that the American Alligator does in the United States. The loss of the Black Caiman would have far reaching negative implications for fish stocks as well as many other creatures in the ecosystem of South America. It is highly unlikely that species such as the Spectacled Caiman can assume the full roll played by such a large and important member of this complex ecosystem as the Black Caiman.
Local governments in South America could learn much from the financial success of the American Alligator, if the Black Caiman were allowed to repopulate to the extent the American Alligator has the economic benefits would be substantial not only from an ecotourism perspective but from controlled hunting for hides and meat as now occurs in the south east United States.
Habitat:Slow-moving rivers; backwaters of rivers, lakes, ponds, swamps
Rain Forest Facts:
Range: Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Surinam, Venezuela.
Habitat:Slow-moving rivers; backwaters of rivers, lakes, ponds, swamps
Size:Shares the title of the smallest of the Caiman species with most adults reaching less than 5 feet in length. Rarely adults reach 6+ feet. Record is reported at 7’ 8” On average is slightly larger than Cuvier's Dwarf Caiman
Status:Estimates place the wild populations in excess of 1,000,000. Extensive captive populations worldwide supported by large annual exports for both zoos and the pet trade.
Rain Forest Facts:Large bony plates called osteoderms are found in a very high number on the smaller species of Caiman, this fact alone may be the primary reason their numbers having remained relatively high compared to historical numbers. The skin is of little value compared to other species of crocodilians, thus significantly reducing poaching for their hides. Working against the Dwarf Caiman is it’s breeding requirements; it appears most females must be at least 8-10 years old to breed and produce a small number of eggs relative to the larger species. On average a female may lay only 10-12 eggs per season. These factors may play a key roll in the caimans future in the event loss of habitat or other external factors begin to significantly reduce the populations of these animals. .
One additional interesting note concerning the reproductive habits of this species is the divergence from the normal 70-80 day incubation period noted in virtually all species of crocodilians. The dwarf caiman can require as long as 120 days for incubation, this difference is little understood.
Range:Found in 17 countries from the Southern tip of Florida to northern South America, including all Central American countries. May be expatriated from several Central American countries. Habitat: Salt Water estuaries, fresh water inlets.
Size:To 20 Feet, Largest Crocodilian in the United States. Males average 12-14 feet, females average 7-11 feet. Weight in excess of 1,500 pounds for large adult male American Crocodiles.
Status:Not fully understood, wide geographical range presents many challenges to obtaining an accurate estimate of remaining animals. It is believed the population is declining in virtually all of the American Crocodiles natural range.
RainForest Facts:Highly prized for it's leather the American Crocodile faced extreme pressure from over collection of it's skin during the middle of the 20th century. The advent of the power boat added significantly due the decline as more efficient means of hunting and gathering of the crocodiles for the skin developed from approximately 1920-1960. Today many factors continue to put pressure on the wild populations of the American Crocodile, from the construction of hydroelectric dams to deforestation the future for this crocodile is uncertain.
The vast majority of countries where the American Crocodile lives have implemented conservation programs, isolated populations remain very strong in certain areas. Farming and controlled commercial exploitation remain a viable option to help preserve the remaining numbers of the American Crocodile.
Female American Crocodiles build a wide variety of nests largely dependant upon their geographical location. Some female American Crocodiles will excavate a sand nest while others have been observed building mound nests from available vegetation. This species appears not to defend it's nest quite as vigorously as other crocodilians. Nest sizes have been noted to average 20-25 eggs with 75-80 days as an average incubation.
A highly nocturnal hunter, the American Crocodile feeds on a wide variety of vertebrates including fish and birds. As the adult American Crocodile increases in size the food types will change to include larger vertebrate. Birds appear to be a favorite food item for mid-sized American Crocodiles.
Range:Central and West Africa including (but not limited to) Angola, Benin, Cameroon, Central African Republic, Chad, Democratic Republic of Congo, Equatorial Guinea, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Nigeria, Senegal. Reported to be expatriated from Sierra Leone, Tanzania, and Zambia
Habitat: Considered to be one of the more secretive and aquatic of the crocodilian family, the Slender Snout Crocodile is found almost exclusively in fresh water in spite of the fact that the animals range includes coastal countries in western Africa. Size Medium size crocodilian averages 6-9 feet in total length
Size:Medium size crocodile 6-9.5 feet on average.
Status: Poorly known, current numbers of wild stock is approximately 40,000
Rain Forest Facts:Primarily fish and aquatic invertebrates make up the majority of this smaller crocodiles diet, the slender snout indicates similar feeding habits to the Gharial (or Gavial) family.
Several factors have led to recent declines in this species; most notably loss of habitat coupled with reduced populations of other crocodilians has led to increased poaching. Little if any real government involvement has led to almost unrestricted poaching for skins.
This crocodilian appears to be one of the least studied of the crocodiles of west Africa.
Range:As the name would imply the Orinoco crocodile is found in the middle and lower parts of the Orinoco River in the Llanas Savannah of Venezuela and Colombia, South America
Habitat:They prefer freshwater, but do have a tolerance for high salinity, as evidenced by the sighting of Orinoco crocodiles on the island of Trinidad, over 150 miles north of Venezuela, that had been washed out into the ocean by a flood and had survived. Orinoco crocodiles had at one time a much larger range, being found in tropical evergreen forests and in streams in the Andes.
Size:To 23'. The Orinoco Crocodile is the largest predator in South America.
Rain Forest Facts:Orinoco crocodiles are extremely rare. Reintroduction programs are under way but appear to be having limited success. Native peoples are still poaching the animals for their hides. It is estimated that there are only between 250-700 left in the wild. The Colombian government declared the Orinoco Crocodile endangered and protected the animal in 1998.
The difficult years for the Orinoco Crocodile are very similar to other crocodilians around the world, the early and mid 20th century saw mass killings for skins. Due in part to their large size and easy accessibility on the large Orinoco river and related tributaries, the Orinoco Crocodile was very hard hit by collection for skins. Additionally the Orinoco Crocodile lacks the osteoderms found on many of the Caiman species it shares it's habitat with, as a result the Orinoco was hunted extensively while the Caiman did not experience such dramatic decline in numbers.
Large concentrations of the Orinoco Crocodile were often encountered by hunters as the animals would tend to congregate at shrinking water sources during the dry season, this factor coupled with many others led to the virtual extinction of the Orinoco Crocodile.
Ritual combat by adult male Crocodiles precedes mating. Like many other Crocodile species, the Orinoco lays a single clutch of eggs per year. The timing of the Orinoco Croc clutch coincides with the coming of the rainy season. On average 35-40 eggs are deposited in an excavation made by the female, clutches can, and do very in size from as few as 15 to as many as 70 eggs. The clutch size appears to be larger dependant upon the physical size of the adult female crocodile. Incubation of the Orinoco Crocodile eggs often varies based on soil temperature, but averages 65-70 days. As is the case with all Crocodilians the temperature the eggs are incubated will determine the sex of the hatchling crocodiles.
Juvenile Orinoco Crocodiles are preyed upon by a host of predators. Snakes, predatory birds, and other carnivores pose a threat to Crocs under 3' in length. The eggs of the Orinoco Crocodile are consumed by Tegu lizards as well as Coatimundis and other creatures.
Range:Northern Australia, found in Queensland
Habitat:Fresh water estuaries, can be found in creeks and lakes. Tends to avoid salinity.
Size:6-9 feet. Males tend to be larger by as much as 35%
Status:The Freshwater Crocodile appears to be making a comeback from historically low numbers. As estimated wild population of 75-100 thousand animals appears to be expanding it's range to areas once expatriated.
Rain Forest Facts:Native Australians often refer to this animal as the "Freshie"
Like it's distant relative the Gavial, the Freshwater Crocodile is highly adapted to eating primarily fish. The thin, elongated snout of the Freshwater Crocodile does not prevent it from eating other vertebrates and invertebrates however these items probably make up a smaller percentage of the Crocodiles diet than in the majority of other Crocodilian species. In very similar hunting techniques to the Gavial, the Freshwater Crocodile uses blinding speed to thrust it's head to either side and grab a fish.
As with virtually all species of crocodilians the hatching of the eggs coincides with the coming of the seasonal rains. Females will deposit a small number of eggs compared to most crocodilians, usually around 15 (clutch sizes have been noted as small as 5) in a sand nest excavated near the permanent source of water. The normal time from mating to egg laying is very similar in most crocodilians, approximately 45 days. The incubation time varies slightly based on soil temperatures but averages about 70 days. Females guard the nest against predators such as the local monitor lizards as well as introduced species such as cats and feral pigs. On average it is estimated that 50% percent of all nests are destroyed by predators. All female crocodilians show a remarkable maternal instinct compared to other reptile species, female Freshwater Crocodiles are no different. A female Freshwater Crocodile will allow the juveniles to remain with her for an extended period of time for protection from predators. In spite of protection from the adult female it is estimated that less than 5% of all eggs laid reach adulthood.
As with all crocodilians the actual incubation temperature will have an impact on determining the sex of the animal.
Range:Once common throughout much of the Philippines the Philippine Crocodile now faces eminent extinction unless drastic measures are taken to educate the population concerning this animal.
Habitat: Strictly freshwater species.
Size: 7-10 feet, relatively small crocodile.
Status: Critically endangered assumed less than 100 living in the wild.
Rain Forest Facts:The Philippine Crocodile is recognized by the IUCN/SSC Crocodile Specialist Group (CSG) as the most threatened species of crocodile in the world and is listed by the IUCN as Critically Endangered. It is generally agreed that no more than 100 adults remain in the wild.
General life history is poorly known and current knowledge is mostly based on captive observations. Courting and mating occurs from January to May, with eggs laid between February and October, and a peak in the April-July period. This species is a mound nester, with the females using sand, dry grass, rotting leaves and twigs, which they scrape together with their back feet. Eggs are hard-shelled and clutch size ranges from 8-35 eggs. The young crocodiles hatch after about 80 days at an incubation temperature of 30-31?C and hatchlings average 270mm in total length. As in some other crocodile species, females have been observed opening the nest and carrying hatchlings to the water.
It was only the early 1980's that the Philippine government publicly recognized the fate of this once wide ranging anima. Surveys conducted at the time indicated less than 1,000 adults in the wild (juvenile crocodiles are rarely if ever counted in censuses based on the high mortality rate). As is often the case loss of habitat coupled with unsustainable hunting by the local peoples led to the significant decline in the wild population . This led to the establishment of a captive breeding program at Silliman University in Dumaguete City, Negros Oriental, and a joint venture with the Japanese Government to create the Crocodile Farming Institute (CFI) at Puerto Princesa City on Palawan. Breeding has been successful at both locations and the CFI now holds just over 1,200 Philippine Crocodiles. Worldwide interest in contributing to the conservation of the species resulted in agreements with, and transfer of crocodiles to Melbourne Zoo, Australia, and Gladys Porter Zoo in Brownsville, USA, through Memoranda of Agreement (MOAs). These developments provided the foundation for subsequent provision of funds and other support, captive breeding at Gladys Porter, and active promotion of the crocodile and its conservation in both countries (including funding a community awareness poster in the Philippines by Melbourne Zoo).
Range:Central America (including Belize & Guatemala), southern Mexico
Habitat:Fresh water bodies, some coastal salt marshes
Size:8-10 feet with pronounced dimorphism between the larger males and smaller females
Status:Appears to be stable in protected areas, greatest threat appears to be in Mexico with less control on poaching. Eco tourism in places like Belize may have very positive impact on local populations.
Rain Forest Facts:Once confused with the Cuban and American Crocodile the Morelet's Crocodile is smaller than the other two species.
Producing a surprisingly large clutch of eggs for a smaller species of Crocodilian, the Morelet's Crocodile can lay as many as 40 eggs per clutch (average 28). A nest is excavated near the bank of a source of freshwater, the typical incubation period is 65-70 days. As can be frequently observed in most crocodilian species the female will not only protect the nest but will respond to the calls of the juveniles as they hatch out. The majority of hatchings occur at night, this apparently in response to predatory birds sleeping while the young escape the nest. Females will often assist the young crocodiles to the waters edge by carrying the young in her mouth. The young crocodiles are allowed to stay near their mother for as many as 2 years while they grow large enough to defend themselves.
The greatest risk facing the Morelet's Crocodile is loss of habitat, as areas in Belize and Guatemala develop the animals are being forced out.
Range:Wide ranging in much of Africa south of the Sahara, populations exist on the western side of Madagascar
Habitat:Due to the Nile Crocodiles extensive natural range the habitat varies widely. Fresh water is a must for the crocodile but the source varies widely from rivers to lakes and estuaries
Size:Averages 13', accounts of animals over 20' have been reported but not verified, undoubtedly one of the largest of living crocodilians. Male Nile crocs in excess of 1,500 pounds have been verified.
Status: In certain countries the Nile Crocodile faces expatriation, in others farming and conservation have produced very healthy populations.
Rain Forest Facts:Much has been written about this amazing predator of Africa, this Crocodilian is arguably the most studied of all Crocodilian species, with the possible exception of the American Alligator. Widely believed to be a man-eater the facts are very difficult to establish, this crocodile shares it's natural habitat with hippopotamus as well as lions and other large predators that compete with humans for both food and water. Encounters with these animals are inevitable over time for the local populations.
Female Nile Crocodiles produce large clutches of eggs, up to 60 have been reported. The female builds a nest of vegetation, or excavates a sand nest, depending on location. Incubation is reported to average 80 days, with variations of 10 days reported on either side of the average. Nest temperature has an impact on the sex determination of the babies.
Female Nile Crocodiles guard their nest as vigorously as any species of crocodilian. Predators still manage to account for high mortality among both eggs and hatchlings. Humans will often trick the female away from the nest to gather the much coveted eggs. Monitor lizards as well as predatory birds will dig nests, large carnivores such as hyenas often are able to grab young crocodiles as they exit the nest. Male Nile crocs have been seen assisting in both the guarding of the nest and assisting the babies to the water.
Young Nile crocodiles will remain with the female for an extended period of time, as with most species of crocodilians the young will avoid adult male crocodiles, cannibalism is not unheard of with all species of crocodiles.
Growing fairly rapidly, the young Crocodiles will begin to consume larger and larger food items. Fish and aquatic creatures such as turtles comprise a large portion of their diets until they reach very large sizes. Much has been documented of certain Nile crocodiles awaiting the annual migration of the zebra and wildebeest, an adult Nile Crocodile is capable of consuming very large percentages of it's own body weight. An adult zebra may weigh in excess of 600 pounds, several adult Nile Crocodiles have been observed feeding on the carcasses of both adult zebras and water buffalo. Occasionally Nile Crocodiles will submerge with prey and secure the food item under water with the aid of rocks or tree branches. Much debate exists about the reasons for such behavior, one school of thought is that the crocodile is hiding its food item from other carnivores. Another school of thought is that the crocodiles use the water to soften the food item for ease of consumption.
The future for the Nile Crocodile looks good, as more and more nations embrace ecotourism and understand the economical reasons to protect wildlife keystone species such as the Nile Crocodile will benefit from this positive trend. Not all nations protect their natural resources in the same fashion and the Nile Crocodile will undoubtedly fair better in certain geographical regions then others, the animals wide natural range will have far reaching positive implications for it over time.
The recorded bite strength for this species of crocodilian is 3,000 pounds per square inch, over 10 times stronger than a human.
Range:Indonesia, Papua New Guinea. Assumed to be expatriated from several regions including the Aru islands
Habitat:Fresh water species, frequenting lakes, ponds and slow moving streams.
Size:7-9 feet with females approximately 20% smaller than males
Status:Reasonably sound in certain regions with estimated populations at 75,000 in the wild. Extensive farming for skins is taking place in several locations around the world.
Rain Forest Facts: Fortunately this Crocodiles future looks reasonably bright compared to other species. The remoteness of the location couple with suitable habitat have significantly reduced the probability this Crocodile will face serious issues in the immediate future.
Farming of this species is also underway to supply the leather trade with the highly sought after skin of the New Guinea Crocodile. The future management of wild populations is essential to ensure poaching does not occur to any great extent.
Range: Southern regions of the Mideast to Burma and Sri Lanka
Habitat: Exclusively fresh water species. Known to aestivate given the geographical range which includes arid regions of the Mideast.
Size:Large crocodilian. Males average 11-13 feet with females somewhat smaller.
Rain Forest Facts:
Range:Very large natural range including Australia, China, India Indonesia, Malaysia, Papua New Guinea, Philippines, Singapore, Sri Lanka, Solomon Islands, Thailand, Vanuatu (Banks Islands), Vietnam.
Habitat: The most adaptable of all crocodilian species. These crocodiles can be found in ocean sea water (often seen many hundreds of miles from the mainland) fresh water ponds, lakes and even rivers. Like many fish species the young actually spend the first few years of life in and around fresh water. Sub-adults and adults can, and do move vast distances over dry land to search out coastal regions. It is assumed that the fresh water habitat offers less threat from large predatory fish and sharks than does the open oceans
Size:The Saltwater crocodile is the largest crocodilian alive today. Weighing in at over one ton (2,000 pounds) the giant Saltwater Crocodile is the heaviest of all living reptiles. The title of longest still belongs to the snakes as 20 feet or greater is a truly massive crocodile. The longest acceptable measurement for the Saltwater Crocodile is 23 feet. Female crocodiles of all species are smaller than the male, the female Saltwater crocodile generally measures 20-25% smaller than the males.
Status:Extremely large natural range has provided some degree of protection from over collection for skins. An estimated 250,000 animals are thought to exist in various states of concentration throughout the extensive natural range. Australia in particular boasts large, protected concentrations of crocs.
Rain Forest Facts:There is good news and bad news for this species of crocodilian, thanks to the protective Australian government populations in Australia are very stable and probably expanding back into regions where the Crocodiles numbers were reduced due to over collection for the skin trade. The bad news is that other parts of this animal’s massive natural range are not doing such a good job of protecting the species. As a result it is probable that the saltwater crocodile will become expatriated from many regions.
Crocodiles in general are opportunistic feeders; the Saltwater Crocodile is no different, highly aquatic specimens will feed primarily on fish, while fresh water individuals living near forested regions will eat more vertebrate from land. The fear on behalf of some farmers that these crocodilians will decimate domestic animals such as cattle appears to be largely unfounded. Stomach contents of even the largest of Crocodilians contain surprisingly small food items. Unfounded fear of loss of livestock has reduced populations in the northern territories unnecessarily.
Given the large nature of this crocodile, females produced correspondingly large clutches of eggs. The average adult female will deposit up to 70 eggs per clutch, although the average appears to be closer to 40. As is the case with virtually all reptile eggs, predators’ account for a high mortality rate of the un-hatched eggs. Introduced species of animals including the pig have had devastating impacts on some nesting areas, mortality in the nest for this species of crocodile may be as high as 80%. Natural predators of the eggs include the local species of monitor lizards (Varanus sp.) (called goannas in Australia) as well as native peoples of Australia and surrounding lands.
A combination of ecotourism dollars coupled with revenue generated from farming this species for their hides has resulted in the government of Australia taking very proactive measures to ensure the future of this amazing creature
Range:Limited to Cuba, although historical range may have included Cayman Islands
Size:Lengths reported to 15', 8-10 feet are average
Status:Less than 5,000 individuals in the wild
Rain Forest Facts:A small natural range coupled with the usual problems of over collection for the skin trade have left the Cuban Crocodile as the most threatened of all New World Crocodiles. While the numbers of wild Cuban Crocodiles is higher than the wild populations of the Orinoco Croc, threats from loss of habitat coupled with the vulnerable small geographical range (i.e. one major hurricane could potentially be devastating) place this croc at great risk. Substantial farming of the croc for skins has placed a stable number in various locations, this repository of adult animals may be called upon in the event the crocs numbers continue to decline.
Range:Cambodia, Thailand and Vietnam
Habitat:Fresh water bodies, lakes and slow moving streams and rivers.
Size:7-12 feet -Males 20-30% larger than females
Status: Critically endangered, less than 4000 Siamese Crocodiles remain in the wild with intense pressure on remaining stock in the wild. Captive populations are stable and growing, threats to the purity of the species exist as captive populations are being cross bred with other crocodilians to produce fine leather for the skin trade.
Rain Forest Facts:Unfortunately very few comprehensive studies have taken place on this species so sadly little is known of its natural history. More is known of the captive habits of this crocodile than are thought to be known of its habits in the wild. The Siamese Crocodile dines primarily on fish, but given the large size of the predator other vertebrates are included in the diet.
Female Siamese Crocodiles deposit a fairly large clutch of eggs (average 32) into a nest of mounded vegetation. The average incubation period is 80 days.
As with many animals in the South East Asia region, loss of habitat represents a major threat. Over collection for human consumption as well as the practice of selling many animal parts as medicinal or as aphrodisiacs have escalated the loss of biodiversity in this region of the world. The Siamese Crocodile is sadly one of the species that has not seen a reverse trend in the depletion of wild stocks, the future does not look promising for this magnificent animal.
Range:West Africa, Congo region
Habitat:Strictly fresh water species. The African Dwarf Crocodile appears to prefer small permanent bodies of water.
Size:3-6 feet, stout heavy bodied for it's length, the male African dwarf Croc is approximately 25% larger than females.
Status:Conflicting data seems to indicate that the wild populations of the Dwarf Crocodile are stable. This may be due in large part to the skin of the Dwarf Croc which is studded with osteoderms rendering it virtually useless for the skin trade.
Rain Forest Facts:This diminutive crocodilian appears to be losing ground to loss of habitat more than any other factor. The skin of the animal is virtually useless in the leather trade, this fact has a significant impact on the poaching factor. This very same fact though does not bode well for any attempts to farm the animal as there is little if any financial incentive for individuals to produce the croc in any number in captivity. A study in the successful history of the American Alligator points to the direct correlation between monetary gain by farmers and the success of the species in the wild.
Additional pressure from the bush-meat trade account for high mortality in the field.
False Gharial (Gavial)
Range:Indonesia, including Vietnam
Habitat:Fresh water lakes and slow moving streams, rivers.
Size:Large crocodilian, up to 15' Males 25-30% larger than females
Status:Critically endangered. Believed fewer than 2,000 remain in the wild. Limited work being conducted on farms.
Rain Forest Facts:The future for this species appears to be very bleak. Loss of habitat coupled with over fishing of the local fish populations (the primary food source for the False Gharial ) has led to dangerously low population levels.
Indian Gharial (Gavial)
Habitat:Fresh water rivers and streams
Size:A very large crocodilian the Gharial may reach 15 feet as an adult male. Females tend to be 8-10 feet as adults.
Status:Critically endangered. Estimated to be less than 5,000 in the wild, with the vast majority being reintroduced farm raised crocodiles.
Rain Forest Facts:While the future for this crocodilian is uncertain at best, the past has been very rocky. Virtually wiped out by the late 1960's the Gavial faced eminent extinction without immediate intervention. Several adults were captured and placed into farming facilities. The relatively high clutch count of large females coupled with proper husbandry techniques produced a viable breeding population. From this initial attempt to save the animal several other breeding facilities have become involved. In total over 5,000 young crocs have been returned to protected areas in the wild.
India is one of the most densely populated countries on earth with an exploding population. This human pressure is resulting in unparalleled loss of habitat. Additionally irrational fears that the Gavial is a "Man Eater" have resulted in heavy losses of wild stock. The snout of this species of croc is suited for hunting primarily fish and other aquatic species such as turtles. The probability is that rumors and legends have been passed down from generation to generation about the crocodilian. The crocodiles large size coupled with close proximity to human populations appears to have fueled suspicion on the largely uneducated populations of India.
The Indian Gharial produces the largest egg by weight and size of any living crocodilian species.