Mighty MikeMighty Mike:Mike: The Master of the Marsh A story of when humans and predators meet
Alligators are magnificent predators that have lived for millions of years and demonstrate amazing adaptations for survival. Their “recent” interaction with us demonstrates the importance of these animals and that we have a vital role to play in their survival.
Primary Exhibit Themes: 1. American Alligators are an apex predator and a keystone species of wetland ecosystems throughout the southern US, such as the Everglades. 2. Alligators are an example of a conservation success story. 3. The wetlands that alligators call home are important ecosystems that are in need of protection.
Primary Themes and Supporting Facts 1. Alligators are an apex predator and, thus, a keystone species of wetland ecosystems throughout the southern US, such as the Everglades. a. The American Alligator is known as the “Master of the Marsh” or “King of the Everglades” b. What makes a great predator? Muscles, Teeth, Strength & Speed i. Muscles 1. An alligator has the strongest known bite of any land animal – up to 2,100 pounds of pressure. 2. Most of the muscle in an alligators jaw is intended for biting and gripping prey. The muscles for opening their jaws are relatively weak. This is why an adult man can hold an alligators jaw shut with his bare hands. Don’t try this at home!
ii. Teeth 1. Alligators have up to 80 teeth. 2. Their conical teeth are used for catching the prey, not tearing it apart. 3. They replace their teeth as they get worn and fall out.
iii. Eating prey whole and using the “Death Roll”
1. Younger alligators eat insects, shrimps, snails, small fish, tadpoles and frogs while adult alligators eat fish, birds, turtles, other reptiles and mammals. 2. Alligators main prey are smaller animals that they can kill and eat with a single bite. 3. The “Death Roll” - Alligators may kill larger prey by grabbing it and dragging it into the water to drown. They often do this by biting and then spinning or convulsing wildly until bite-size pieces are torn off their prey. This is referred to as the 'death roll'.
iv. Body built for Stalking 1. The position of an alligator’s nose, eyes and ears are such that it can remain unseen and mostly submerged in the water as it waits for unsuspecting prey 2. Alligators are capable of short bursts of speed of up to 30 mph as they lunge to capture their prey.
c. Why are alligators important?
i. The alligator’s greatest value to the marsh and other animals within it are the “gator holes” that many adults create and expand through the years. During the dry season and extended droughts, gator holes provide vital water for fish, insects, crustaceans, snakes, turtles, birds, and other animals in addition to the alligator itself. Sometimes, the alligator may expand its gator hole by digging beneath an overhanging bank to create a hidden den. After tunneling as far as 20 feet, it enlarges the end, making a chamber with a ceiling high enough above water level to permit breathing. This is not the alligator’s nest but merely a place for the reptile to survive the dry season and winter. Below is a cross section of a gator hole.
ii. Large alligator nesting mounds provide nesting and feeding sites for species of herons and egrets. Red-bellied turtles use old gator nests for incubating eggs.
iii. Alligators eat a large number of gar, which is a predatory fish in its range. This helps maintain populations of game fish such as bass and bream.
iv. As predators at the top of the food chain, they help control numbers of rodents and other animals that might overtax the marshland vegetation.
v. Alligators have a strong immune system to help them fight off bacteria, fungi, viruses and other microbes. In recent years, scientists have begun analyzing alligators’ blood to identify compounds that could kill harmful bacteria, fungi and viruses, including those that have become resistant to commonly used antibiotics. These discoveries could lead to new medicines that might help treat a variety of human illnesses.
vi. Alligators are a tourist attraction to areas where they live and help support these regions economically
2. Alligators are an example of a conservation success story.
a. Historically, alligators were depleted from many parts of their range as a result of market-hunting and habitat loss. By the 1960’s, hunters and poachers wiped out nearly 90% of the population in Louisiana and the population in Florida’s Everglades was near extinction. Many people believed this unique reptile would never recover.
b. In 1967, under a law that preceded the Endangered Species Act of 1973, the alligator was listed as endangered, meaning it was considered in danger of extinction throughout all or a significant portion of its range. A combined effort by the U.S. Fish and Wildlife Service and State wildlife agencies in the South saved these unique animals. The Endangered Species Act prohibited alligator hunting, allowing the species to rebound in numbers in many areas where it had been depleted. As it began to make a comeback, States established alligator monitoring programs and used the information to ensure that numbers continued to increase. In 1987, the Fish and Wildlife Service pronounced the American alligator fully recovered and consequently removed the animal from the list of endangered species.
c. Although the American alligator is secure, some related animals—such as several species of crocodiles and caimans —are still in trouble. For this reason, the Fish and Wildlife Service continues to protect the alligator under the ESA classification as “threatened due to similarity of appearance.” The Service thus regulates the harvest of alligators and legal trade in the animals, their skins, and products made from them, as part of efforts to prevent the illegal take and trafficking of endangered “look-alike” reptiles. The story of the American alligator is one of both drastic decline and complete recovery. A story of State and Federal cooperation, it is truly one of the prominent successes of the Nation’s endangered species program.
d. Today, the greatest environmental threats to alligators are habitat loss and pollution. As Florida’s human population continues to encroach on alligator habitat, encounters between the two species are inevitable. Human fatalities due to alligators are rare, but 12,000 to 14,000 nuisance gators are reported to the state each year and licensed trappers kill 5,000 of these.
e. As the human population grows, encounters between humans and alligators are increasing. Increasing people’s awareness of them and how to interact with them is important.
3. The wetlands that alligators call home are important ecosystems that are in need of protection f. Why are wetlands important? vii. Water quality and hydration viii. Wildlife habitat ix. Natural barriers for flood and hurricane protection x. Shoreline erosion prevention xi. Economic Value xii. Recreation and Aesthetics
What Does it Take to be the Master of the Marsh
Here are some of the behavioral and physical adaptations American Alligators have that allows them to keep their place at the top of the food chain in the wetlands where they are found.
Strong Jaws - Their strong jaws with up to 80 cone-shaped teeth can bite down with 2,100 pounds of pressure to catch and hold their prey. They have the strongest bite of any known land animal!
Sensors – Sensory pits along their snout help them detect the smallest vibrations made in the water by potential prey.
Eyes - Eyes on top of their head help them see their prey while the rest of their body is underwater.
Second eyelid - A second, clear eyelid (called a nictitating membrane) protects their eyes but allows them to still spot their prey.
Ears, Nose and - Special valves close their ears, nose and throat when they dive so they don't take in water when they catch their prey.
Immune system - Their immune system can fight off bacteria, fungi, viruses and other microbes that live in swamps & wetlands. What scientists are learning about their blood could help make new medicines for humans.
Death Roll - Alligators spin underwater with their prey in their mouth to bite off chunks to eat. This is called the "Death Roll."
Short bursts of speed - They can move up to 30 miles per hour in short bursts to catch their prey
Thick scales - Thick, pointy, bony plates called osteoderms help protect them. You can easily feel the difference between the scales on their back and those on their side and belly.
Strong tail - A strong tail helps move them through the water and launch them up to 5 feet out of the water to catch their prey.
Camouflage – Alligators are born with bands or yellow on their darker blackish/green skin. These bands help the young blend in with the grasses where they are commonly found. These bands fade as they get older. The resulting dark coloration allows them to blend in with the mud and water of the wetlands where they wait to ambush their prey.
The Gators at JBZGators JBZ Mighty Mike Length: ~13 feet, 1 inch in length (missing ~5 inches of his tail Weight: 596 (~600) pounds (weight upon arrival at JBZ) Approximate age: 40-50. Because he was wild caught, his age cannot be accurately determined. Mighty Mike was a nuisance alligator that was caught by a license nuisance alligator trapper after a resident placed a complaint with the Florida Fish and Wildlife Conservation Commission. The trapper wanted to keep him alive rather than kill him as is done with most nuisance alligators. They are eaten and their hide and skulls sold. He was brought into captivity. Written by Bruce Shwedick: Word spread fast that a licensed alligator trapper had captured a giant alligator in Lake Talquin, west of Tallahassee, Florida. The alligator was captured after a private citizen had filed a complaint with the Florida Fish and Wildlife Conservation Commission. Mighty Mike, named after the trapper who caught him, was declared a nuisance alligator because he was extremely large and had been frequenting the local public boat dock. “I really hate to kill this alligator,” declared Tony Hunter. Tony has been a licensed nuisance alligator trapper for the past twenty years. “Every year, it gets harder for me to kill them, I hope that someone can keep them alive.” Tony’s son, Mike. Had actually had captured the alligator. “I was hoping for a twelve footer.” Mike told me as he had never caught one that big before, but the alligator he caught measured 13 feet, 1 inch, and was missing about 5 inches of his tail. Florida’s nuisance alligator trapper are required to kill any nuisance alligators they capture that are over 6 feet in length. They only hunt a particular animal after a complaint has been filed with the game commission. They do not always know if the alligator they capture is the source of the complaint but their hunting activity may frighten other alligators away from the area, at least for a little while. Unless they have a buyer immediately willing to purchase the alligator alive, the nuisance alligator trappers are paid for their services by selling their meat, belly skin, skull, and feet and a $35 fee is paid to the fund by alligator farmers and management programs. Trappers provide a needed public service. The state of Florida has an estimated population of over 17 million people which encroach on the habitat of the close to 2 million alligators in the wild.
The 5 Younger Gators in the Exhibit Age: They range from 3-5 years old 2 males and 3 Females: Largest gator is one of the females Where they came from: They were born at an alligator farm in Florida. The eggs may have laid by gators at the farm or the eggs could have been have been collected from the wild. Collection of eggs is allowed by permit in the state of Florida.
DIET at the ZOO: Meat and poultry including but not limited to gator chow, rats, mice, chicken, turkey, pork shoulder. The frequency of feedings will vary with the temperature since that is what changes their metabolism. The frequency of feedings will range from once to ~3-4 times each week. American Alligator Basic FactFactFactsFactsss
Common Name: American Alligator Scientific Name: Alligator mississippiensis Diet: Alligators are nocturnal and feed primarily at night. Younger alligators eat insects, shrimps, snails, small fish, tadpoles and frogs. Adult alligators eat fish, birds, turtles, other reptiles and mammals. Habitat: Freshwater swamps and marshes, lakes, rivers and smaller bodies of water. Range: Southeastern United States - Alabama, Arkansas, North & South Carolina, Florida, Georgia, Louisiana, Mississippi, Oklahoma, Texas
Approximate Life Span: ~50-70+ years Conservation Status: Least Concern (IUCN), Threatened in US because of similar appearance to crocodiles.
What's the difference between a crocodile and an alligator? (Information from http://www.flmnh.ufl.edu/cnhc/cbd-faq-q1.htm)
Crocodiles and alligators - two creatures that share many similarities. But what are the real differences between them? This is probably the most frequently asked question when it comes to crocodilians, and while the answer may appear straightforward the real truths lie in the details.
AMERICAN SIAMESE ALLIGATOR CROCODILE
1. Different families: There are three groups (families) of crocodilians: the alligatoridae, which includes the alligator and the caimans; the crocodylidae, which includes the "true" crocodiles; and the gavialidae, which contains only the gharial. So, the first difference is that alligators and crocodiles are actually in different families.
2. Shape of the jaw: The easiest way of telling apart crocodiles from alligators, however, is to look at their noses. Alligators (and caimans) have a wide "U"-shaped, rounded snout (like a shovel), whereas crocodiles tend to have longer and more pointed "V"-shaped noses. This is illustrated in the diagram to the left (C = alligator, D = crocodile). The broad snout of alligators is designed for strength, capable of withstanding the stress caused to bone when massive force is applied to crack open turtles and hard-shelled invertebrates which form part of their diet. Of course, alligators eat softer prey too, but hard-shelled prey are ubiquitous in their environment and it's a big advantage to be able to eat them. Conversely, the pointed snout of a crocodile isn't quite as strong as the alligatorine shape, but the crocodile is still capable of exerting massive biting power. Crocodile jaws can be thought of as being more generalized - ideal for a wide variety of prey. The full extent of the way jaw shape influences diet isn't particularly well studied in crocodilians, but it's obvious that a very thin nose like a gharial's is much better at dealing with a fish than a turtle! There are 23 species of crocodilians, though, and this simple broad vs. narrow rule doesn't always work. 3. Placement of teeth: In alligators, the upper jaw is wider than the lower jaw and completely overlaps it. Therefore, the teeth in the lower jaw are almost completely hidden when the mouth closes, fitting neatly into small depressions or sockets in the upper jaw. This is particularly apparent with the large fourth tooth in the lower jaw (see [A] in diagram on right). In crocodiles, the upper jaw and lower jaw are approximately the same width, and so teeth in the lower jaw fit along the margin of the upper jaw when the mouth is closed. Therefore, the upper teeth interlock (and "interdigitate") with the lower teeth when the mouth shuts. As the large fourth tooth in the lower jaw also fits outside the upper jaw, there is a well-defined constriction in the upper jaw behind the nostrils to accommodate it when the mouth is closed (see [B] in diagram on right). This constriction occurs at the boundary of the premaxilla and the maxilla in the upper jaw. 4. Lingual salt glands: Crocodiles and gharials also differ from alligators and caimans in having functioning salt glands on their tongue. Structurally, these are actually modified salivary glands, and while alligators and caimans also have these structures they appear to have lost the ability to use them for excreting significant amounts of salt. This makes crocodiles more tolerant to life in saline water, including sea water in some species. Moreover, it suggests that crocodiles have a more recent marine ancestry: the ability to migrate across wide marine bodies, and even live there for extended periods, would certainly explain their current wide distribution across different continents. If ancestral species could live in marine environments, this ability has not been completely lost in modern crocodiles. Species such as saltwater crocodiles (C. porosus) can survive for extended periods in tidal estuaries, around the coast, and even out to sea. Alligators and caimans have lost much of this osmotic ability to secrete excess salt through the tongue glands, and can only tolerate it for short periods of time, prefering to remain in freshwater areas when possible. However, it is not unknown for large alligators to find their way into tidal mangroves and very rarely into coastal areas.
5. Integumentary sense organs: Both crocodiles and alligators have small, sensory pits dotted around the upper and lower jaws - take a close look on a photograph, and you'll see small, black speckles almost like unshaven stubble. These are capable of detecting small pressure changes in water, and assist in locating and capturing prey. These were originally called ISOs, or Integumentary Sense Organs, although recent research has renamed them DPRs (Dermal Pressure Receptors). Crocodiles have similar organs covering virtually every scale on their body, but alligators and caimans only have those around the jaws. Although it's been known for years that sense organs on the jaws are involved in pressure detection, nobody is quite sure what those organs covering the rest of the body in crocodiles actually do. They probably extend the sensory surface over the crocodile's entire body, but previous researchers have suggested they may assist in chemical reception, or even salinity detection. The confusion lies over why crocodiles have them, but not alligators and caimans. Regardless of their role, they're very good at telling apart crocodile skin from alligator skin. Crocodile and alligator skin wallets, handbags, boots etc are easy to tell apart - if the scales have a small spot or dimple close to the edge, you know the skin is from a crocodile and not an alligator or caiman. This is illustrated below - the alligator on the left does not have any sense organs, but the crocodile on the right does.
GULAR REGION (NECK) OF GULAR REGION (NECK) OF AMERICAN ALLIGATOR AMERICAN CROCODILE
Other differences: The above points are amongst the most obvious differences between crocodiles and alligators in terms of external appearance. However, each species is unique, and to list all the possible differences would be like comparing a jaguar with a lion. Differences in behaviour are also apparent. Most people regard crocodiles as more aggressive than alligators, and this is true of some species. For example, alligators are relatively docile next to saltwater crocodiles, but there are many species with many different kinds of behaviors and temperaments. A general rule that crocodiles are more aggressive than alligators just isn't possible to make. Alligators can often reach at least 14 or 15 feet in length, which is larger than some crocodile species, but not others. The largest crocodile species is the saltwater crocodile, which can get to at least 17 or 18 feet - some rare individuals exceeding 20 feet after many years. The African dwarf crocodile, as a contrast, doesn't grow larger than 4 or 5 feet.
The two images below show an exception to the "jaw shape" rule. The Indian mugger (Crocodylus palustris) breaks the crocodile convention of having narrow jaws - its jaws are superficially very similar in shape to those of an alligator, although the fourth lower tooth is still visible. When all the above criteria are considered, the mugger is definitely a crocodile. Always bear the details in mind when faced with general questions like what's the difference between crocodiles and alligators. As you can hopefully see, the simple answer is not always the most interesting!
AMERICAN ALLIGATOR INDIAN MUGGER