Thursday, March 12, 2015

Alligators and Crocodiles Part 1

Florida is the only state in the US that has crocodiles, and the only place in the world inhabited by both alligators and crocodiles. Although crocodiles are not native to Pinellas County, one infamous crocodile visitor found in Tarpon Lake made headlines across the US. More details in Part 2.

American Alligators and American Crocodiles are very different.

American Alligators
1. are darker with black or gray bodies. 
2. have a powerful U-shaped, shorter snout to exert the downward force needed to crack turtle shells. However their jaws are weak to open like all reptiles.
3. are typically smaller and lighter, averaging 8-12 ft long and weighing 400-600 lbs
4. have partially webbed toes on hind legs.
5. have an overbite so that only the upper teeth visible when jaw is closed.
6. have sense receptors on their jaw only.
7. Florida has 1.25 million alligators.
8. are not very aggressive and prefer to flee humans except for ones that lose their fear as they have either been fed or threatened by humans.
9. prefer fresh or brackish water found in canals, streams, large shallow lakes etc.
10.The range of the American alligator is in 10 southeastern US states, including the southern parts of Georgia, Alabama, and Mississippi, coastal South and North Carolina, East Texas, the southeast corner of Oklahoma, and the southern tip of Arkansas, with the most found anywhere in Louisiana and Florida. Unlike the crocodile it can withstand temperatures as low as 45 degrees.

There is only 2 species of alligators. The other is the Chinese alligator which lives near the Yangtze River in China.

American Crocodiles
1. are lighter with olive green or tan bodies and with darker markings on their back.
2. have longer, V-shaped snout to eat a more varied diet. His jaws are strong to open, but can be held shut with a rubber band.
3. are typically larger and heavier, but the American crocodile is only 7-12 ft long.
4. have a jagged fringe on the back of their hind legs and have five toes on their front feet and four on their back feet..
5. both upper and lower teeth are visible when jaws are closed and has two protruding front teeth.
6. Have touch receptors on their whole body to detect their prey.
7. As of 2014 about 2000 crocodiles are estimated to live in southern Florida.  
8. The American crocodile is not very aggressive, although its relative, the Nile crocodile (two 4 foot ones were found in Florida recently) is very aggressive. 
9. prefer blackish saltwater in the mangroves along the coastal areas, but can also survive in freshwater. They only reason they are confined to Southern Florida is they .
10. They live only in southern tip of Florida in the United States, but are also found in coastal wetlands in the Caribbean along the Pacific Ocean from Mexico to Ecuador and along the Atlantic Ocean from Guatemala to Florida.  

Of the 14 species of crocodiles, Charles Darwin University found that the Saltwater crocodile was the most aggressive crocodile. It is also the largest at 23 ft, a record set in 2006 and lives in Australia and throughout SE Asia. The Nile Crocodile is also very aggressive and lives in Africa.