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Posts Tagged ‘American alligator’

loggerhead sea turtle hatching

Recently, I’ve been using this space to play around with the fuzziness of “species.” Hundreds of species concepts exist, and because different researchers have somewhat different perspectives, you will sometimes get real conflicts about whether something is a species or a mere subspecies.

In canids, we get caught up in species discussions that are about what really amounts to very little genetic variation. For example, red wolves, Eastern wolves, gray wolves, dogs, dingoes and coyotes are all lineages that have only radiated in the past 50,000 or so years.

By contrast Old World and North American red foxes, including the ones allegedly derived by those set out by English colonists in the seventeenth and eighteenth, last shared a common ancestor 400,000 years ago.  This finding means that we probably should regard the red fox of North America as Vulpes fulva.

But 400,000 years of divergence is nothing compared to the 3 million years estimated for the Indo-Pacifica and Atlantic-Mediterranean populations of loggerhead sea turtle. There has been some gene flow between the populations. Matrilines have flipped around South Africa, once 250,000 years ago and an once 12,000 years ago.

So researchers who specialize in wolf-like canids are debating over very small genetic differences and relatively recent divergence times.  Red fox researchers are only just now realizing that there are likely two species in what was once thought to be a Holarctic species. And those specializing in loggerhead sea turtles don’t really care that their species has such a deep genetic difference.  The occasional gene flows between populations are enough for them to recognize only one species of loggerhead sea turtle.

This problem gets more interesting when we start talking about “living fossil species.” Take this article on Futurity.org, which is entitled “Evolution Hasn’t Revamped Alligators in 8 Million Years.” This article discusses the findings of some paleontologists at the University of Florida, who have found 8-million-year-old alligator fossils in North America, and they are remarkably similar to the ones we have today.

One of the researchers is quoted in the article says,”We were surprised to find fossil alligators from this deep in time that actually belong to the living species, rather than an extinct one.”

I would be just a hair more careful in my language. Although one can certainly see that these ancient alligators looked and probably behaved very much like the current species, 8 million years is a long time. I doubt that current alligators and those from that time could even interbreed if they encountered each other today. From a biological species perspective, it makes little sense to call them the same species, but from a paleontological perspective, it makes more sense, simply because paleontology is more interested in morphology and ecology over the entire time a population has existed.

So yes, “species” is a nebulous concept, and that is a good thing.  It makes some legal aspects with conservation difficult, because we have an Endangered Species Act that is about a hard and fast definition of a taxonomic entity.  In reality, the whole nebulous side makes for interesting levels of inquiry. If the Neo-Darwinian synthesis correctly describes the origin of biodiversity, then we would expect these discussions and debates to be commonplace.

They certainly are quite common in taxonomy and systematics. They probably always will be. Part of what defines a species are the biases of the classifier, which can often be contradictory.

For example, I have no problem with the new taxonomy of wildcats that posits the European wildcat into a different species than the Near Eastern/North African species. However, I disagree with the position of the domestic cat, which derives fro the Near Eastern/North African species, as its own unique species.

That bias may come from the simple fact that I am more familiar with domestic dog taxonomy, and I have come to accept that domestic dogs are best classified as a divergent form of gray wolf. If the domestic cat derived from its wild ancestor much more recently than the dog derived from its wild ancestor, why would it make any sense to classify the domestic cat as its own species?

So in zoology, we have all these different perspectives on how to classify species. Specialists in sea turtles are able to tolerate a genetically quite divergent species, while experts in wolf-like canids will debate over much more recently divergent lineages. These researchers really don’t talk to each about their ideas.  Indeed, the only time loggerhead sea turtle researchers worry about what specialists on the wolf-like canid side are doing is when they need to figure out how to stop coyotes from destroying the turtles’ nests. But they don’t need to know the complexity of the systematics to find an answer.

However, it is amazing how different specialists come to tolerate variation within one species. That nebulous nature of the various species concepts makes for some interesting variations on what specialists accept as normal.

Specialists often have very different ideas in mind, depending upon what they are used to, and I find it beautiful, even if it a bit confusing at times.

 

 

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I always wondered how they did this:

This is in Florida, which has a very tightly regulated alligator hunting season.

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west virginia alligator

From WSAZ.com:

An alligator is such a bizarre, unusual sight in the waters of the Upper Mud River that even seeing isn’t necessarily believing.

“I didn’t even tell my wife,” says Jack Stonestreet, who was fishing on the river last Thursday. “I didn’t tell her because, to be honest, I didn’t think anyone would believe me.”

Fishermen over the past several days contacted the West Virginia Division of Natural Resources to tell them of the gator sighting. On Saturday, Nick Huffman, a field superintendent with the DNR, saw the scaled reptile with his own eyes.

“I would say he’s a half grown alligator, a total measurement of 67 inches,” Huffman says. “That’s big enough I knew not to get on him in hand-to-hand combat.”

The DNR shot the alligator and pulled it out of the water.

The alligator will now be dissected. Opening the alligator’s stomach may give the DNR some insight as to where it may have come from and how long it was in the river.

West Virginia has almost no regulations on alligator ownership– probably because most people have sense enough not to own one!

But I have seen alligators and caimans available at pet stores, and every once in a while, someone releases a pet alligator into a river or lake in hopes that it will survive in the wild (I guess).

The problem is that alligators live only as far north as northeastern North Carolina.  There is some debate about about them having an historical range into southeastern Virginia. I’ve always heard that the Great Dismal Swamp was the northern boundary, but I’ve also heard that alligators once ranged into the James River. In North Carolina, they are found only in the coastal plain, where the winters are comparatively mild. My guess is if they were found in Virginia at one time, they were never found out of the extreme southeastern part of the state, and if they did occur in the James River, my guess is they were found only near the coast.

If they aren’t found outside of North Carolina’s coast plain, how on earth could they survive in West Virginia?

People are amazingly dumb about animals. Alligators are not good pets. I’m surprised I had to type that sentence. An alligator can eat you. It has very powerful jaws and a relatively small brain.  And although they are smarter than, say,  iguanas or box turtles, they are about the same level of intelligence as a chicken.  Powerful jaws and a small brain are a combination a combination for a dangerous pet.

Oh, yeah, and you need a massive heated enclosure that contains both a swimming area and a basking area, which has to be cleaned on a regular basis.

But if you get one and live in one of these states that has an actual winter, please don’t dump it in the local river. It’s either going to freeze to death or someone is going to shoot it.

There is no “born free” scenario that works out well for the alligator.

But some people just don’t care.

***

One of the most interesting alligator populations that has been established outside their normal range is the Tennessee River in northern Alabama. Most of these are on the Wheeler Lake Reservoir.

Alligators are native to southern Alabama, but they were introduced to the Tennessee River at some point in the 1960’s or 1970’s.

These alligators are outside their native range, and they also are living in a somewhat cooler climate than they normally would experience.

However, even northern Alabama has much milder winters than West Virginia, and there is no chance of them ever becoming established here.

 

 

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Source.

It looks like this alligator got a yellow Labrador.

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Source.

This is an old story, but I somehow missed it.

Um. Contrary to what that fellow says, alligators aren’t as safe or safer than domestic dogs.

For one thing, a dog is domesticated. It also has a relatively large brain, so it can learn rules and be safe.

Alligators, not so much.

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Just a hunch:

Source.

The person who put this up on youtube has a channel called the AlligatorTrainer.

Just imagine what will happen if this thing bites an arm when it’s 3 or 4 feet long:

Source

I don’t think a 100 gallon tank’s gonna hold them:

Source.

I’m no expert on crocodilian husbandry, but these little alligators don’t look all that healthy.

I don’t think this is going to end well.

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