I hope you’re sitting down, because this next part will shock you: this snake has a bad reputation.

Its alarming-sounding genus name, Tantilla, lingers a bit too close to “tarantula” or something you’d scream while fleeing a battlefield explosion, and that’s before we even get to its distinctive black head. Because as we all know, black anywhere near the mouth of a snake spells doom. We’re not the only ones to think so, though.

Native knowledge

Overlapping the Mexico-US range of the Yaqui black-headed snake are the Cora people, and in 1955, anthropologist Borys Malkin poked them about their local reptile knowledge. Of the animals they mentioned, they seemed to know this secretive, ruler-length snake the least, but enough to say it was rare, and also apparently everywhere.

It was ranked “lethally venomous” too, except by the guy who was bitten on the foot and managed to cure himself with a plant that was, confusingly, also known as the local word for “snake”. While all snakes were known as ku-kux, different species were still distinguished and acknowledged. Until 1964, that wasn’t always the case in the scientific community.

That’s a bit jarring

We assumed the Yaqui black-headed snake only occurred in Mexico, but one specimen, captured in Arizona in 1907, sat overlooked and misidentified in a museum jar for years under the label “plains black-headed snake (Tantilla nigriceps)”.

Well at least two parts were right.

It wasn’t until Clarence J.McCoy, Jr. took a closer look that we realised our mistake, and that like its namesake the Yaqui Indians, it was found in the US as well. Hooray for Clarence J.

The black head may as well have been a ninja-mask though, because we still weren’t much closer to learning it secrets, such as its behaviour, diet, or breeding habits. In fact, in what has to be my favourite ever closing line in an academic paper,  McDiarmid, in 1977, pointed out that its penis hadn’t been illustrated. Well, I have good news for you, Dr. McDiarmid, although probably not for anyone else: we now know that as per usual for a snake, it has two of them, the ends are globular, and there are two very large spines at the base.

Too much information?

I, on the other hand, don’t want to end this post talking about snake genitals, so let’s move on to how the Yaqui black-headed snake is thought to lay 4-20 eggs, and makes a meal of most multi-legged things smaller than it.

It can also be picked out by the white splashes on its cheeks, which are either toned down or non-existent in other Tantilla species, and while it has the dental gear for injecting venom, fear not: reported bites have seen mild swelling at worst. Helpfully, McGinnis and Stebbins’ suggestion is to “avoid handling it”, which isn’t difficult because it prefers to live underground or in crevices, only coming out to party during the rain or at night.

This probably means there are more of it than we can find, and it’s already counted as “Least Concern” in the endangered stakes. So sometimes it pays to live under a rock for a while.


Latin: Tantilla yaquia

What? Small, caramel-coloured snake with a black head and white cheek splashes.

Where? Arizona and New Mexico in the US, and Sonora, Chihuahua, Sinaloa and Nayarit in Mexico, usually in wooded areas near water or rocky cover.

How big? About ruler-length, so 17-32 centimetres / 7-12 inches from head to tail.

Endangered? Currently Least Concern, and due to its shy nature, its population is probably larger than we think.

Probable motto: I guess I don’t need a mask to be mysterious.

They look cool. Do they need my help at all?

Nope, they tend to keep out of the way, and their numbers are probably quite healthy.

Just to prove I’m not fibbing:

Editors of Encyclopaedia Britannica. No date. “Yaqui“. Britannica.com.

Frost, D.R. et al. 2007. “Tantilla yaquiaThe IUCN Red List of Threatened Species” 2007: e.T63966A12724749.

Malkin, Borys. 1958. “Cora ethnozoology, herpetological knowledge; a bio-ecological and cross-cultural approach“, Anthropological Quarterly 31(3):73-89.

McDiarmid, Roy W. 1977. “Tantilla yaquia“. Catalogue of American Amphibians and Reptiles. Society for the Study of Amphibians and Reptiles.

McGinnis, Samuel M., and Stebbins, Robert C. 2018. “Peterson Field Guide to Western Snakes and Amphibians” (fourth edition). Houghton Mifflin Harcourt Publishing.

Rorabaugh, Jim. 2013. “Yaqui black-headed snake (Tantilla yaquia)“, Sonoran Herpetologist 26(3):61-63.

Shaw, Charles E., and Campbell, Sheldon. 1974. “Snakes of the American West“. Alfred A. Knopf.

Featured image credit: “Yaqui Black Headed Snake”,  © Devin Bergquist