Iguanas were in Florida first––by 16 million years
FORT LAUDERDALE, Florida––Bashing or shooting the brains out of iguanas essentially for the hell of it would be illegal almost anywhere if done to pets.
Braining iguanas in the name of research, however, brought University of Florida wildlife biologist and research coordinator Jenny Ketterlin and 14 colleagues a $63,000 grant from the Florida Fish & Wildife Conservation Commission.
“Blunt force trauma”
”Most of what we’re doing is blunt force trauma,” admitted University of Florida wildlife biologist and research coordinator Jenny Ketterlin to Susannah Bryan of the Florida Sun Sentinel. “Hitting their heads very hard against a solid object.”
The Ketterlin team, elaborated Bryan on March 9 2018, “is using a tool called a captive bolt gun that sends a bolt into the brain, similar to what is used [to kill cattle, pigs, and horses] in the livestock industry. They are also smashing the creatures’ heads against solid objects, including a truck and boat they are using to track them down.”
The killing is “designed to find the best way to remove iguanas and then offer tips to homeowners on how to purge the pests from their gardens,” Bryan reported, accepting at face value the view of the Florida Fish & Wildlife Conservation Commission that iguanas are “pests.”
Most Floridians appear to disagree, variously tolerating, ignoring, or even making quasi-pets of iguanas. Charismatic, docile vegetarians, uninclined to harm either humans or pets, iguanas have become popular public mascots despite more than 50 years of hate literature urging the extirpation of iguanas published by the Florida Fish & Wildlife Conservation Commission and allies in pushing ecological nativism.
“So far,” Bryan wrote, “working in teams of two, the researchers have captured and killed 249 iguanas along a canal in Davie that runs parallel to Griffin Road. They sneak up on the creatures at night while they are asleep, then kill them on the spot.”
Said Ketterlin, “We are using flashlights to find them. They are slow at first. If they are in a tree and wake up, they’ll jump into the canal or jump onto the ground and run off.”
Bashing kills fewer than cars
Scheduled to continue until the end of May 2018, the iguana bashing might, at the present pace, kill about 1,500 iguanas altogether, probably substantially fewer than are roadkilled in Broward County in any given three-month time span, though no one seems to have kept track.
However, a 2011 study of “Wildlife Road Crossing & Mortality” by Esteban Payan, Ph.D., director of Panthera Columbia, found that the numbers of iguanas whom humans manage to see, including using camera traps, amounts to perhaps 20% of the number of iguanas who will be roadkilled in the same habitat over the same time.
This in turn suggests that Ketterlin et al are unlikely to have any significant impact on the local iguana population, no matter how much violence they and the minority of Floridian iguana-haters manage to inflict on the relatively few iguanas they catch.
Head-bashing baboon experiments
Amplified within a few days by nearly 200 other news media, the Ketterlin iguana head-bashing exercise evoked memories of the head-bashing experiments conducted by neurologist Thomas Gennarelli on baboons at the University of Pennsylvania Head Injury Clinic between 1976 and 1985.
Designed to simulate the head injuries suffered by humans in car crashes, the baboon head-bashing ended in October 1985, after nearly three years of escalating public protest. But Gennarelli resumed the experiments, with National Institutes of Health funding, in 1991, now using pigs.
The Gennarelli experiments had at least the pretext of helping to improve human health and welfare. Tens of thousands of humans per year suffer preventable head trauma in accidents of various sorts. The Gennarelli findings also had potential applications to protecting soldiers in combat.
Iguanas vs. gopher tortoises?
Discovering any substantial benefit to humans, or to native wildlife, in the Ketterlin iguana killings requires a stretch of imagination.
Iguanas do not prey upon rare or endangered species; do not compete significantly with any rare or endangered wildlife for a habitat niche; have never killed or even seriously injured anyone; and are themselves in the food chain for a variety of native species, including endangered Florida panthers and crocodiles.
Though iguanas might at times occupy burrows dug by gopher tortoises, a threatened species, bulldozing gopher tortoise habitat for development, roadkills, and malicious killing by humans all documentedly harm gopher tortoises––if iguanas harm them at all––in much greater numbers.
Neither is the Ketterlin iguana killing likely to discover any information not already included in the American Veterinary Medical Association Guidelines for the Euthanasia of Animals since 1963.
The current edition of the AVMA guidelines, issued in 2013, after covering the preferred and recommended methods for killing reptiles, suggests under the headline “Acceptable with conditions” that “Crocodilians and other large reptiles can be euthanized by a penetrating captive bolt or gunshot (free bullet) delivered to the brain.
“However,” the AVMA guidelines add, “size-appropriate equipment and appropriately trained personnel are required.
“Manually applied blunt force trauma to the head,” according to the AVMA guidelines, “is acceptable with conditions, when other options are unavailable, as long as it is performed by well-trained and skilled personnel and if an adjunctive method, such as decapitation or pithing, is promptly applied to ensure death.”
“Further research is needed”
The Ketterlin killing appears to be rationalized by the concluding sentence of the passage, stating that “Further research is needed to clarify methods, taxa, and size ranges where this method is effective and humane.”
Ketterlin previously drew media notoriety for helping to capture a three-foot Nile crocodile seen by python hunters in 2012, hunting feral tegu lizards in 2013 and 2017, and hunting both Burmese and African rock pythons.
All are introduced species in Florida. Nile crocodiles, tegu lizards, and African rock pythons are potentially hazardous to humans. Burmese pythons are known to have killed 11 people since 1990 in their native habitat, which includes most of Southeast Asia, and––because they hunt crocodiles and tend to keep leopards and tigers away––are usually regarded as a benign presence, rather than as a threat.
Where Florida iguanas came from
Iguanas are also officially an introduced species, but in all likelihood have been in Florida, off and on, for thousands of years.
Of the two iguana species native to much of the Caribbean region, Cyclura, including the blue and rhinoceros iguana subspecies, historically dominated on the easternmost islands, including Jamaica, Puerto Rico, and Hispaniola, shared now by Haiti and the Dominican Republic.
The more common green iguana ranged from tropical Mexico, including the Yucatan peninsula, throughout Cuba, to the eastern islands, competing to some extent and probably hybridizing with blue iguanas to produce the many color variations noted by early naturalists.
How iguanas moved
Drawing strings across a globe between the earliest known habitats of either blue or green iguanas suggests that if they managed to colonize the many islands that each species occupied when first observed, probably drifting on floating logs after hurricanes, both species must have often come ashore in the Florida Keys and along the southern tip of the Florida peninsula, as well.
Indigenous people in the Caribbean and likely in south Florida, too, hunted iguanas for food, and may have transported some from island to island via canoe.
But iguana exploitation and movement began in earnest with Spanish colonization of Mexico, the Caribbean, and south Florida.
Treasure galleons hauled iguanas too
More than 11,000 treasure galleons sailed from Spain to Mexico and back between 1566 and 1790. Sailors on the outbound voyage ate dried beef, mutton, pork, and fish. For the return voyage, the galleons were often stocked mostly with live sea turtles and iguanas, who could be kept alive, in torpor, with their mouths sewed shut, until slaughtered for consumption.
Hundreds of galleons wrecked in storms, and occasionally by pirates or in warfare, offered thousands of sea turtles and iguanas a slim chance to escape. Since the galleons often came through the Florida Keys, many iguana refugees must have hauled up on Keys beaches, with the opportunity to mate and lay eggs, even if few survived for long.
Hunted with dogs
By the time Austrian naturalist Josephus Nicolaus Laurenti (1735-1805) published the first recognized scientific description of iguanas in Specimen Medicum, Exhibens Synopsin Reptilium Emendatam cum Experimentis circa Venena (1768), iguanas had already been commonly consumed by sailors and colonists––and hunted for sport with dogs––for more than 200 years.
Hunting iguanas with dogs actually extirpated blue iguanas from Puerto Rico and all but the most inaccessible parts of Jamaica. On other islands, however, settlers and slave traders introduced green iguanas as a ready replacement. A. Deans Peggs, the proto-Bahamian historian, in A Short History of the Bahamas (1959) described both the importance of iguanas to the Bahamian diet in the 18th and early 19th centuries, and the extensive commerce of that era between the Bahamas and eastern Florida.
How many iguanas made, and survived, the westward voyage?
This seems not to have been mentioned.
The official history
Tampa Bay Times reporter Craig Pittman, summarizing the official history of iguanas in Florida, on December 5, 2017 recounted that the first wild iguana sighting in Florida “dates back to Miami-Dade County in 1965, according to Sarah Lessard, a spokeswoman for the state Fish and Wildlife Conservation Commission.
“Now they are found,” Pittman wrote, “all along the Atlantic coast from Martin County down to the Keys and in isolated instances have been found on the state’s west coast as well.
“The next official sighting,” Pittman said, “from 1979, came from the island community of Boca Grande, near Fort Myers. Local legend says a Boca Grande resident brought a pair back from Mexico as pets, then either turned them loose or lost them, and they became the Adam and Eve of a huge Florida iguana colony.
16,000 iguanas killed in two years––in one place
“By 2007 the island was overrun by thousands of the lively lizards,” Pittman continued, summarizing years of his own coverage. “Finally Lee County assessed a tax to pay for a trapper, making it the only place in America with an iguana tax. In just his first two years on the job the trapper caught 16,000 iguanas. As of last year he was still averaging about 2,000 captures a year.”
This was, like the Ketterlin killing, not even visibly impacting the south Florida iguana then guesstimated at 100,000 by Bill Kern, a University of Florida associate Professor in the Department of Entomology & Nematology.
The online resource NewspaperArchive, however, posting searchable PDF versions of the microfilm holdings of the Library of Congress, demonstrates that while Pittman’s summary of recent Florida iguana history is accurate, most of the official version of what occurred earlier is ill-informed fiction.
The case that iguanas were introduced to Florida by humans in relatively recent times rests largely on four items of circumstantial evidence:
- The lack of evidence of iguanas from the recent fossil record. Yet iguanas seem to have been common along the northern Florida peninsula, which then extended only as far south as Polk County, from about 16 million to 4.5 million years ago.
- The lack of written references to iguanas in Florida in the 19th century and earlier, when the entire estimated human population of Florida was barely 500,000, according to the U.S. Bureau of the Census, and written documentation of anything was correspondingly sparse.
- The absence of iguanas from the list of species found in Florida in The reptile book; a comprehensive, popularised work on the structure and habits of the turtles, tortoises, crocodilians, lizards and snakes which inhabit the United States & northern Mexico, by Walter Ralston, published in 1907;
- The similar absence of any mention of iguanas in A contribution to the herpetology of Florida, by Archie Fairly Carr, published in 1940.
Archie Carr missed the obvious
That Carr (1909-1987), hugely influential in saving Florida sea turtles, omitted even any transient discussion of iguanas seems most telling.
Yet NewspaperArchive shows that some iguanas, if not a familiar species to most Floridians, were practically right under Carr’s nose.
Even manatees, though known to still exist, were seldom seen by 1940.
Smithsonian Institution scientist Frederick W. True wrote of the disappearance of manatees as early as 1884, recounts Pittman in Manatee Insanity (2010).
Manatees barely documented before 1949
After Florida authors of books for children Julia McNair and Kirk Munroe mentioned the plight of manatees in two of their books, published in 1892, real estate mogul Fred Morse, a friend of Munroe, secured passage of the first law protecting manatees in 1893.
Yet as recently as 1949, when Joe Moore (1926-2018) began studying manatees, neither any manatee counts nor even a method of counting manatees existed. Like iguanas, manatees spend much of their time munching vegetation in murky water, and are difficult to distinguish from each other. Moore was first to realize that manatees can be recognized––and counted––by identifying their scars from boat propellers.
Other Florida species also became scarce during the late 19th century, as developers drained swamps and logged forests.
“Alligators wanted,” headlined a Boston Transcript news item in May 1898.
“Now that the Florida alligator has largely been killed off, the people of that state are very sorry they have done it,” the article continued. “They are writing nowadays to the fish commission, and asking that the raising of alligators may be experimented upon, so as to refill the swamps and streams from which the great lizard has nearly disappeared…Among the commercial reptiles are also to be considered the boa constrictor and python…Beautiful leathers are furnished likewise by the hideous iguana and the chameleon.”
Iguanas farmed & traded
Though that hint that iguanas might be farmed in Florida seems to have come to nothing, the syndicated gossip columnist Graham McNamee in February 1929 mentioned “an enterprising citizen who has a lot in Florida which he thinks would do beautifully for an iguana farm. The iguana, he informs me, is a big green lizard which tastes like chicken.”
Already, according to William T. Hornday (1854-1937), who was first director of the Bronx Zoo, 1896-1926, in Hornaday’s American Natural History (1927), green iguanas were abundant in captivity, apparently kept both as pets and for food.
“Owing to the ease with which these creatures are captured, their price in New York is about $2 each,” Hornaday wrote.
Hornaday did not mention where the captures for sale occurred, but the Philadelphia Inquirer had mentioned some trade in live iguanas from Central America, accompanying imports of bananas, as early as October 1890.
Wherever the iguanas came from, some soon turned up in unusual places, including one found alive in a woodshed in Richmond, Indiana, just before Christmas in 1930, and one found dead in Lawrenceville, Georgia, in June 1934.
The Hurricane Monster
The first green iguana documented in the wild in Florida was photographed near Fort Myers by Lewis Reynolds of Selma, Alabama, on September 17, 1935, about two weeks after the Great Labor Day Hurricane of 1935 killed 423 people in the Florida Keys.
Though the Reynolds photo was widely distributed by Associated Press, Reynolds “was unable to convince residents here that his photographs of the lizard taken then were true to life,” Associated Press updated, until a 54-inch iguana was captured and put on display in a Fort Myers city park in October 1937.
The assumption then was that the captured iguana, dubbed the “Hurricane Monster,” was the same iguana Reynolds had photographed, primarily because other iguanas were not known to be in the vicinity.
Captured or bred for the pet trade by 1957
But barely 40,000 people inhabited the whole of Lee County, much of which was then still relatively trackless swamp.
While Carr did not see fit to mention the “Hurricane Monster,” commercial traffic in Florida green iguanas existed by 1957, when one Herb Wendt purchased a 5-foot-three-inch green iguana in Florida “as a possible pet for his Pi Kappa Phi fraternity” in East Lansing, Michigan, according to United Press International. Escaping, the iguana “had this college town in a state of panic,” the account continued.
A year later, in 1958, J.K. Ellsworth of the Sarasota Herald Tribune profiled local exotic animal dealer Bill Smith, illustrating the article with a photo of Smith holding a rhinoceros iguana.
“We’re probably not going to eradicate them”
“The iguanas are here, and we’re probably not going to eradicate them,” Florida Museum of Natural History herpetologist Kenneth Krysko told Tamara Lush of the St. Petersburg Times in July 2005, after having helped to catch 1,000 iguanas on Key Biscayne.
“Krysko said the lizards were first reported in Miami in 1964,” Lush wrote. “At some point, they were spotted in the Keys.”
Reality, though, is that iguanas have probably lived in Florida, or at least been frequent visitors, even during the 4.5 million years when little record of them existed, hiding out here and there in small numbers, until conditions favored them.
Possibly significant is that iguanas began to proliferate and be noticed just as the manatee population reached low ebb––or that at about the same time, Florida developers built thousands of miles of roads, lawns, and golf courses alongside drainage canals that afforded iguanas ideal habitat and relatively safe places to sun themselves in plain sight.
The likelihood of Ketterlin et al accomplishing much to discourage iguanas, at this point, is about the same as the likelihood of violent crime in Fort Myers having increased to about 950 incidents per year discouraging human migration to the community––and means that all her work really amounts to is bashing a relative handful of presumed immigrants as symbolic “scapegoats.”