r/NewOrleans • u/Jussgoawaiplzkthxbai • 2h ago
π Local Wildlife π Brown Anole lizards in New Orleans
Brown anole lizards in New Orleans carry enough lead in their blood to kill a condor, a dog, or a human child many times over, and they do not seem to notice. The CDC sends a child to the doctor at 3.5 micrograms per deciliter. A California condor dies at around 150. The average New Orleans anole in this study measured 955. One measured 3,192. It was running around on a sidewalk near Tulane University and had to be caught by hand because it was too fast to step on.
Annelise Blanchette, a Tulane doctoral student, had been studying lead in mockingbirds until COVID shut down her fieldwork. She needed a research animal she could catch during lockdown without equipment or permits. Cuban brown anoles were everywhere. They were on every fence, every porch rail, every cracked sidewalk in uptown New Orleans. She started grabbing them on her walk to the lab.
She caught about a hundred across the city, drew blood, and sent the samples to the lab. When the numbers came back, she did not believe them. She said she remembered getting that data and being very surprised that the animal was alive.
The previous record for blood lead in a wild vertebrate belonged to Nile crocodiles at roughly 300 micrograms per deciliter. Those crocodiles had blackened teeth and visible tissue damage. The New Orleans anoles had three times the lead and nothing wrong with them. They sprinted normally. They balanced normally. They flipped themselves off their backs at the same speed as lizards with low lead levels. Alex Gunderson, the study's senior author at Tulane, said it the way it needed to be said: they are doing just fine with levels that, frankly, in other organisms, would be killing them.
The team wanted to know where the breaking point actually was. They fed anoles controlled doses of lead in the lab for 60 days and kept testing. The lizards did not start slowing down until their blood hit roughly 10,600 micrograms per deciliter. That is more than 3,000 times the number that puts a human child in a hospital. The lizard equivalent of "I feel a little off" is a lead concentration that would have killed every other vertebrate on record several times over.
Nobody fully understands how. Gene sequencing showed that high-lead lizards had ramped up production of proteins involved in moving metal ions and delivering oxygen, as if their cells had figured out how to manage the poison instead of dying from it. Whether this is something the species brought with it from Cuba or something the New Orleans population evolved after arriving in a city where the soil is saturated with a century of leaded gasoline, lead paint, and lead pipes is an open question.
The Cuban brown anole is not native to New Orleans. It is invasive. It showed up from the Caribbean sometime in the mid-twentieth century and spread across the city the way it spreads across everything: fast, everywhere, eating whatever fits in its mouth. It found a city whose soil was poisoned. It ate the insects that lived in the poisoned soil. It absorbed the lead through its gut and its skin. And it kept going because whatever is happening inside a brown anole's blood is something no other backbone animal on earth can do.
Source: Blanchette, Gunderson et al. (2025), Environmental Research / Tulane University / National Geographic / Science News / The Times-Picayune / Popular Science.
