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American Alligator

Alligator mississippiensis


Alligator mississippiensis is a robust crocodilian with a total length of 1.8-5 m (6-16.5 ft), and a record length of 5.84 m (19 ft 2 in) (Conant and Collins, 1998). American alligators can be distinguished from Crocodylus acutus, the American crocodile, and Caiman crocodilus, common caiman, by the presence of a broad, rounded snout, without conspicuous teeth protruding while the mouth is closed (especially the lower 4th tooth) (Behler and King, 1979; Conant and Collins, 1998; Powell et al., 1998). Unlike C. crocodilus, alligators lack a prominent bony ridge in front of and between the eyes (Behler and King, 1979; Conant and Collins, 1998; Powell et al., 1998). See the species accounts titled "Crocodylus acutus (Cuvier, 1807)" and "Caiman crocodilus (Linnaeus, 1758)" on this website for comparison. The general dorsal coloration is black, but light juvenile markings may be present in adults; young have bold, yellowish crossbands on a black background (Grenard, 1991; Conant and Collins, 1998). The voice of both males and females is a throaty, deep, bellowing roar (McIlhenny, 1935; Elliott, 1994; Conant and Collins, 1998). Elliott (1994) has made a recording of this penetrating roar available on a CD. Females may grunt like pigs when calling to their young (McIlhenny, 1935; Conant and Collins, 1998).


Native Range: The indigenous range of A. mississippiensis is from coastal North Carolina south to southern Florida and the Keys, and westward through the Deep South to central Texas and extreme southeastern Oklahoma (Martof, 1956; Duellman and Schwartz, 1958; Webb, 1970; Mount, 1975; Stevenson, 1976; Martof et al., 1980; Lohoefener and Altig, 1983; Garrett and Barker, 1987; Groombridge, 1987; Moler, 1988; [Sievert] and Sievert, [1988]; Carpenter and Krupa, 1989; Dundee and Rossman, 1989; King, 1989, 2000; Lazell, 1989; Ross and Magnusson, 1989; Ashton and Ashton, 1991; Carmichael and Williams, 1991; Gibbons and Semlitsch, 1991; Grenard, 1991; Ross and Ernst, 1994; Palmer and Braswell, 1995; Conant and Collins, 1998; Bartlett and Bartlett, 1999a, b; Behler, 1999; Dixon, 2000; Meshaka et al., 2000). American alligators may eventually be found in Mexico in localities adjacent to the Texas border (Smith and Smith, 1976, 1977, 1993; Ross and Ernst, 1994). Over much of its range A. mississippiensis has been eliminated, making an accurate determination of its modern distribution difficult (Ross and Ernst, 1994; Conant and Collins, 1998).


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mystified45 9 years ago

This was in Estero. One of our favorite birding areas!

mystified45 9 years ago

I tried to add the link . .but it said that is wasn't acceptable.

Maria dB
Maria dB 9 years ago

Nice spotting! Where did you see it? The information is great; perhaps you could put a link to all the reference material.

Spotted by

Florida, USA

Spotted on May 12, 2012
Submitted on May 25, 2012

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