Saturday, December 31, 2011

Seeing Chinese Alligator

As a child we all have our trip to the zoo to see all the amazing animals that we can’t see in our backyards. We get the opportunity to go to the reptile cage or building, whatever it may be in your zoo, and get a chance to look at the alligators. Did you know there are only two types of alligators in the world? The ones we usually see at the zoos are the American Alligators, however, there is another one called the Chinese Alligator that is an endangered animal that needs protection. There are around ten thousand Chinese Alligators left in the entire world.If you think you can spot the differences in the two different alligators, I think you may be wrong. There are only two minor differences between the American and Chinese Alligators.

While the American Alligators are very long and have a higher weight, the Chinese Alligator is the smaller of the two, averaging around six feet in length and only around one hundred pounds. The only other difference is that while the American Alligator’s body armor extends the length of its body, it leaves the belly area nice and smooth. The Chinese Alligator’s body armor wraps around the entire body, including the belly area, keeping it safe from those predators that would try to get it from the underside.

The Chinese Alligator is now listed as Critically Endangered on the International Union for Conservation of Nature, or the IUCN for short. To help increase the population, they are being taken captive into zoos and rescues where they are bred and kept secure until they reach an age appropriate enough to be released back into the wild in China. Hopefully these efforts, along with the efforts of the Chinese people, will keep them from going instinct indefinitely.

Monday, December 26, 2011

Spectacled Caiman Information

Spectacled Caiman conservation status
The estimated wild population exceeds 1 million individuals.
The Spectacled caiman is one of the most common of all crocodilian species, but depletion has taken place in certain areas. The subspecies C. c. apaporiensis is for instance under severe threat in Colombia and serious depletion is reported from El Salvador. The major threat comes from illegal hunting.
The Spectacled caiman has actually been promoted by the depletion of other crocodilians within its range (chiefly the American crocodile, Orinoco crocodile and Black caiman) since this has allowed the caiman to take over new habitat from which it has traditionally been outcompeted. When the more valuable species started to become increasingly scarce in the mid 20th century, Spectacled caiman hunting did however increase.
Despite intense hunting plus collection for the pet trade, the Spectacled caiman populations are in relatively good condition in most parts of the species range. It has taken over habitat from more severely depleted species and is also making use of man-made bodies of water. Well developed sustainable use programs exist in several countries.
Spectacled Caiman range
The Spectacled caiman is native to Peru, Ecuador, Colombia, Brazil, Venezuela, Guyana, French Guiana, Suriname, Tobago, Trinidad, Panama, Costa Rica, Nicaragua, Honduras, El Salvador, Guatemala, and Mexico. The species has been introduced to Cuba and the UnitedStates (including Puerto Rico). On Cuba and Puerto Rico, you will find the subspecies C. c. fuscus.
Caiman crocodilus has the widest distribution of any species in the Alligatoridae family.
Spectacled Caiman habitat
The Spectacled caiman is an adaptable species that tolerates fresh, brackish and saltwater. It prefers still waters but is present in virtually all types of lowland wetland and riverine habitats within its range.
If necessary, the Spectacle caiman will excavate a burrow and aestivate until conditions improve.
Spectacled Caiman size and appearance
Males are normally 2-2.5 meters (6.6-8.2 feet) long, while the largest reported specimen approached 3 meters (9.8 feet). The females are smaller and will normally not exceed 1.4 meters (4.6 feet) in length, although occasional females may reach a size of nearly 2 meters (6.6 feet).
The Spectacled Caiman has a bony ridge between its eyes (infra-orbital bridge), hence the name. Another ridge (a triangular one) can be seen on the upper eyelids, which are heavily ossified. The number of teeth varies from 72 to 78.
Adult Caiman crocodilus are dull olive green, while juveniles are yellow and adorned with black spots and bands on body and tail. As the caiman matures, the markings grow less and less noticeable.
The different subspecies vary in size, colour and skull shape. The social status of an individual will also affect its size by affecting its growth rate. Submissive animals grow slower than the dominant ones and are less likely to breed.
Spectacled Caiman feeding and diet
Juvenile Spectacled caimans feed on aquatic invertebrates, such as crustaceans, insects and molluscs. As they grow larger, they gradually learn to overtake bigger and bigger prey, chiefly fish, amphibians, reptiles and water birds. Large adult caimans are capable of taking midsized mammals like wild pigs. Cannibalism also occurs, especially during dry periods when other prey is scarce. Spectacled caimans can also refrain from eating anything during the dry season.
Spectacled Caiman breeding
The female Spectacled caiman attains sexual maturity when she’s 1.2 m (4 feet) long, something which normally happens at an age of 4-7 years. The males matures at a similar age, but not until they’ve reached a size of 1.4 m (4.6 feet).
Towards the end of the dry seaon (April to May), the gonads of the male caiman begins to increase in size but they will not reach their maximal size until the wet season has commenced (May to June). Courtship occurs between May and August.
A mound nest consisting of soil and vegetation is built, usually under cover but sometimes in more open environments or on floating mats of vegetation. Inside the nest, the female will deposit 14-40 (22 is the average) eggs in July or August. Sometimes, several females will share one nest.
Females stay close to their nests in order to ward off introducers but many fail and a large share of the nests is raided by predators before the eggs hatch. The habit of sharing a nest with other mothers may be a way for the female caiman to lower the risk of her eggs getting eaten since there will be more than one parent watching over the nest.
Hatching normally takes place after roughly 90 days of incubation and the hatchlings will stay close to the female for some time and follow here wherever she goes. Sometimes one female takes care of not only her own hatchlings but the hatchlings of others as well.

Wednesday, December 21, 2011

Broad-Snouted Caiman Information

Broad-Snouted Caiman

The broad-snouted caiman (Caiman latirostrits) is found in South America, including Argentina, Bolivia, Brazil, Paraguay and Uruguay. Normally inhabiting tropical forests, they prefer ponds and slow moving rivers as their habitat. Broad-snouted caiman can be found mostly in freshwater marshes, swamps, and mangroves, they are also be found in man made ponds for the cattle industry.
Their common name is derived from the species most notable physical characteristic, its very broad snout, which is even broader than that of the American alligator. The snout also presents a characteristic ridge which runs down along it. Their dorsal surface is heavily ossified. Adults specimens are show a pale olive green color, with some presenting spots on the jaws.
This species can live for about 50 years, considered a medium-sized crocodile species measuring an average of 1.5 to 2.5 meters (5 to 8,2 ft). Females are smaller than males, the adult specimens have an olive green color, they have an extremely strong bite.
Broad-Snouted Caiman - Diet
Their diet consists mainly of small invertebrates, and it can crush shells to feed on turtles and their favorite food, aquatic snails. As their size increases, so does its prey size, it will then include in the diet birds, fish, and reptiles.
Broad-Snouted Caiman - Reproduction
The female lays an average of 20 to 60 eggs, and builds the nest among the vegetation near the water, after the nest is finished is covered with sand and dry leaves to protect against predators. The eggs are laid in two layers, creating a temperature difference between them, resulting in a more even ratio of males and females. After about 70 days, the hatchlings quickly seek water to protect themselves from their natural predators such as hawks and other animals. Either one or both parents will guard the juveniles for an indeterminate period.
Broad-Snouted Caiman - Conservation status and major threats
Although the hunting of this specie as been prohibited in most countries in their range, this practice still persists in some regions, as their skin is considered very valuable because its very smooth texture. However the main threat to the Broad-Snouted Caiman in nowadays is habitat destruction, due to deforestation an pollution. The latest data shows that healthy populations still exist in most areas of their habitat, the exception being the Bolivian population, which is considered to be severely depleted.

Sunday, December 18, 2011

The Black Caiman Is Found In Various Freshwater Habitats

The Black Caiman(Melanosuchus niger) has a distribution range including: Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru and Venezuela.

The Black Caiman is found in various freshwater habitats such as slow-moving rivers, streams, lakes, flooded savannahs and wetlands.

Although overlapping with the range of other caiman species in South America, it appears to occupy different habitat niches. The Black Caiman is the largest species in the family 'Alligatoridae'. The Black Caiman can grow to 20 feet long (6 metres), making it the largest member of the Caiman family and the largest predator in the Amazon basin.

The Black Caimans general appearance is similar to the American Alligator (Alligator mississippiensis). As their common name suggests, Black Caimans have a dark colouration.

A Black Caimans lower jaw has grey banding (brown in older animals) and pale yellow or white bands are present across their flanks of the body, although these are more prominent in juveniles. This banding fades only gradually as the animal matures. The Black Caiman has a bony ridge over red eyes and black, scaly skin. A Black Caimans skin colouration helps with camouflage during its nocturnal hunts, but may also help absorb heat.

The Black Caimans eat fish, including piranha fish and catfish and other animals, including birds, turtles and land-dwelling animals like the capybara (Hydrochaeris hydrochaeris) and deer when they come to the waters edge to drink. Larger specimens can take tapirs and anacondas. Their teeth are designed to grab but not rip, so they swallow their food whole after drowning it. Juveniles eat crustaceans and insects before moving onto larger, terrestrial prey. Healthy adult black caimans have no predators other than humans and Jaguars and are one of the apex predators (predators that, as adults, are not normally preyed upon in the wild in significant parts of their range by creatures not of their own species) in their habitat. Their main predator is humans, who hunt them for leather or meat.

The female Black Caiman constructs a mound nest (1.5 metre in diameter) during the dry season into which 30 to 65 eggs are laid. Nests can be found in both concealed and open locations. Females remain close to their nests.

Once the eggs are ready to hatch, she will open the nest and assist in the hatching process. Hatching is reported to occur between 42 and 90 days, coinciding with the beginning of the wet season.

As many females often nest within close proximity, the number of hatchlings in one area can be high. This leads to safety in numbers. Black Caimans sometimes eat their young.

Wednesday, December 14, 2011

The Black Caiman Is An impressive Crocodilian

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 American alligator is experiencing an incredible come back from the brink of extinction while the future for the Black caiman is much less certain. Captive farming of these magnificent animals is underway in a limited capacity and should have some positve impact on both the reduction in demand for wild caught specimens as well as provide a safety net of genetics in the event the wild populations are decimated.

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.

Saturday, December 10, 2011

Cuviers Dwarf Caiman

The Cuviers Dwarf Caiman(Paleosuchus palpebrosus) has a distribution range including: Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Surinam and Venezuela. The Cuviers Dwarf Caiman prefers freshwater forested riverines (drainages between and including the Amazon and Orinoco rivers, in addition to those in Paraguay) and flooded forests around larger lakes.

This Caiman also inhabits rivers and small streams in Bolivia (exposed shoreline and around dead wood). Although Cuviers Dwarf Caiman generally prefers clean, faster-flowing stretches of river, it does occur in very nutrient-poor waters in southeastern Brazil and Venezuela. The Cuviers Dwarf Caiman uses burrows as shelter for long periods during the day. The Cuviers Dwarf Caiman covers large distances terrestrially at night. It may be more tolerant of cooler water conditions.

Cuviers Dwarf Caiman Characteristics

The Cuviers Dwarf Caiman is the smallest of the crocodilian family. Males reach a maximum of 1.5 or 1.6 metres in length and females rarely exceed 1.2 metres in length. Cuviers Dwarf Caimans have heavy, hardened armour on both dorsal and ventral surfaces which is used for protection and which makes up for its small size. The armour reduces injury in more fast-flowing riverine habitats, as well as from obstacles and predators during terrestrial forays which are common in the adults.

The Cuviers Dwarf Caiman has one of the most remarkable head shapes of any crocodilian, being short, very smooth and concave (high skull, upturned snout), with a pronounced overlapping of the lower jaw by the upper.

Cuviers Dwarf Caiman Diet

The diet of Cuviers Dwarf Caiman is known to be dependent upon the habitat in which the caiman lives. Juveniles eat mainly invertebrates (crustaceans, terrestrial invertebrates such as coleoptera - beetles), whereas adults include a greater proportion of fish in their diets in addition to a variety of aquatic (e.g. crabs, molluscs, shrimps) and terrestrial invertebrates. The short, backward-curved teeth are particularly suited to taking invertebrates such as crustaceans. Prey also varies depending upon its availability.

Cuviers Dwarf Caiman Reproduction

The Cuviers Dwarf Caiman may be found singly or in pairs for most of the year, although no set breeding season has been discovered. Females are mound-nesters, using available vegetation and mud. The mound is usually built under cover, and in a concealed position. Size of the clutch is reported to range from from 10 to 25 eggs and the incubation period lasts around 90 days. Although it has been noted that adults will open the nest and move the juveniles to the water, information on parental care following hatching is lacking and implies that there may be none.

Juveniles are brown in colour with blank banding. Adults are darker. The Juveniles head is chocolate brown, with an iris colour to match. Their lower jaw is flecked with white bands.

Newly hatched young may not enter the water until the end of their first day. Until then, they are coated with a slowly-drying, protective mucus layer. Although such a covering is present in the hatchlings of all crocodilians, it has been suggested that the drying of the layer may help to reduce the growth of algae on the body of this species.

Wednesday, December 7, 2011

Orinoco Crocodile


The Orinoco crocodile is South America's largest predator. The males at one time reached lengths of 23 ft (7 m), bit due to overhunting of the larger specimens the average size is now 16.6 ft (5 m). Females are generally smaller, reaching lengths of 10 ft (3.2 m). Males weigh around 950 lbs (380 kg), and females 450 lbs (200 kg).

This crocodile spice is a very odd crocodile in that it has no subspecies and yet comes in three colour types. Each type has been given a name. If the crocodile is negro, then the skin is a uniform dark grey. Mariposo means that the skin is greyish-green with black dorsal patches. The third colour, amarillo, is the most common with a light, tan body with dark areas scattered throughout. In captivity it has been noted that the skin can change colours over time.

Like all crocodilians, the majority of the Orinoco crocodile's diet consists of fish, but as an opportunistic apex predator virtually any animal living within its range could be considered a potential meal for a large adult (including capybara, domestic animals, and even occasionally other large predators if food is scarce.) There have been reports of attacks on humans, but this is highly unlikely given the extremely low population level of the species and its relative isolation from large human settlements

The Orinoco crocodile mates during the drier period of the year and usually 14 weeks after mating, the female crocodile will dig a nest. It is a hole-nester and usually makes the nest on a sand bank. The eggs incubate for around 3 months. During the night they hatch and call to their mother who digs them out of the nest and carries them to the water. The young are defended by their mother for a year. Young Orinoco crocodiles are often at risk from American Black Vultures, tegu lizards, anacondas, caimans, and other carnivores.

They can be found in the middle and lower parts of the Orinoco River in the Llanas Savannah of Venezuela and Colombia (South America). 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.

Sunday, December 4, 2011

Freshwater Crocodile

The Freshwater Crocodile is the more timid relation of the much larger and aggressive Estuarine (Saltwater) Crocodile (Crocodylus porosus). Unlike the Estuarine Crocodile, there have been no reports of serious unprovoked attacks by Freshwater Crocodiles.

The Freshwater Crocodile is native to Australia, inhabiting rivers, creeks, permanent streams and billabongs from the Kimberley to Cape York Peninsula. Although it can tolerate the salty water of estuaries, it is usually outcompeted by the Estuarine Crocodile.

The Freshwater Crocodile is an ambush predator, lying in wait for prey to come within range, when, in a flash, it catches its prey. The long, narrow snout and sharp teeth are adaptations for catching aquatic prey, including fish, frogs, lizards and turtles but it also eats crayfish, insects and spiders. Digestion is assisted by gastroliths, stones swallowed by the animal, which aid in grinding up food. Although it has long been thought that these stones might also play a role in controlling flotation of the animal, recent work suggests that this role might be minimal.

Freshwater Crocodiles can live for 50 or more years, most of their growth occurring in the first 20 years. Males are up to 50kg and 3m long (but typically less than 2.5m); females up to about 2m. Their growth rate (and therefore, size) depends very much on food availability. Males become sexually mature at about 16 years; females at about 12 years.

Like many other animals of the Top End, Freshwater Crocodiles move late in the wet season to spend the dry season near permanent water. Mating occurs around July (in the season that the Bininj/Mungguy people of Kakadu call Wurrgeng) in the water and about 12 eggs are laid on one night in August or September (in the season of Gurrung).

Females use the same nesting sites repeatedly and the nesting hole is dug in the sandy river bank, about 10m from the water. Good maternal instinct is vital to the survival of the brood. The location of the nest must be above flood waters before hatching or an early wet season can flood nest, drowning the embryos. The depth of the nest determines heat gain from the sun, which affects development of the embryos.

Temperature plays another role, too. As in other crocodiles, some lizards, snakes, fish and turtles, the sex of hatchlings is determined by incubation temperature: 31-33°C produces mostly males; above or below, mostly females. (Climate change may have some implications here.)

The eggs are left unprotected. In the season of Gunumeleng, after some 9-13 weeks of incubation (and, hopefully, before the first floods), the adult females return to the nest. When a young crocodile hears the female patrolling the area, it calls to her from within the egg and uses its small egg-tooth to start breaking through the shell. The female digs out the eggs, helps the hatchling out of the egg and carries the 25cm hatchlings to the water.

A large proportion of the nests are dug up by goannas and feral pigs that eat the eggs. The eggs are also a favoured seasonal food of the indigenous people. Only about 30% of the eggs laid will hatch (in some areas, it might be as low as 5%) and only about 1% result in mature adults.

Hunted for their skins until they became rare, Freshwater Crocodiles have been protected from hunting since 1963 and numbers are now estimated at around 100,000. Whilst habitat destruction is a threat, they occur mainly in uninhabited or lightly habited areas and the biggest current threat to Freshwater Crocodiles appears to be poisoning by the Cane Toad (Bufo marinus).

The other common name for this species is the 'Johnston River Crocodile'. It's not named after the 'Johnston River' but, rather, after a Queenslander named, ... well, you'll see in a moment!

The species was first named 'C. johnsoni' by Krefft in 1873 but it is often referred to as 'C. johnstoni' because Krefft (in a later letter) indicated that he had named it after Robert Johnston of Queensland. (In fact, the man's name was Robert Johnstone, so the species should have been originally named 'C. johnstonei'!)

Under the rules that govern the naming of animals (the International Code of Zoological Nomenclature, Article 32.5.1), the name cannot be automatically corrected because the ICZN does NOT regard this as a spelling error. One of the intentions of the ICZN is to maintain stability of names, so that scientists around the world can reliably refer to a particular species (which is not possible by common names which can change with place and time). Accordingly, (a very simplified version of) one of the rules is that an animal's correct name is the one it was first given.

When Krefft originally published the name, he dedicated it to 'Johnson' and the dedication to 'Johnston' occurred only LATER, not in the ORIGINAL publication. Furthermore, the validity of a proposed change via personal letter is also questionable. The problem is that 'Johnson' is a real name. Had Krefft's original publication spelled the name 'ojhnstonei' instead of 'johnstonei', the correction to 'johnstonei' would have been easy, i.e. correction of what was clearly a spelling error.

So, even though the dedication was wrong, the rules state that the earlier name takes priority over the others, making the correct name ‘Crocodylus johnsoni’. Bad luck for Krefft and Johnstone!

Although this interpretation follows strictly the rules for naming, there are people who would like to see Krefft's original intentions fulfilled.
Traditionally, the crocodiles were classified with lizards, snakes, turtles and dinosaurs into a group called the ‘reptiles’. However, evidence from molecular biology now suggests that the reptile grouping is unnatural, using superficial features and not reflecting the evolution of these animals.

Surprisingly, the nearest living relations of crocodiles are the turtles and birds; lizards and snakes are more distant relations of crocodiles!