Wild caught Arizona elegans arenicola (Glossy Snake) from Hidalgo County Texas with SFD like symptoms
When I go herping I always wear gloves in between animals. My primary reason for doing so is to avoid transmitting diseases within and among herps. Many people are a bit confused as to why I do that. For one there is literature in Veterinary Medicine that confirms that Batrachochytrium dendrobatitis more commonly known as Bd, an amphibian disease, can be transferred to lizards. Quite a strange occurrence when diseases can pass the species barrier as typically they are specific to a group of animals.

However, more frequently I’m seeing a lot of snakes with symptoms of Snake Fungal Disease (SFD). I hear from collectors that back then they’d find milk snakes with lesions and basically they’d shed them off and be fine after a while. The question is, was it highly contagious among the rest of the person’s collection? I’m not sure how many people may have housed symptomatic snakes with others to confirm whether it was contagious or not. Now we know that SFD is highly contagious, and not to be mistaken with other conditions like water blisters.

If you’re out collecting in the field keep in mind the well-being of the rest of your collection whenever you do pick up an animal that shows SFD symptoms, as it is becoming more and more prevalent. The USGS states that for infected individuals the mortality rate in the wild is 100%. Other literature says >80% likelihood of mortality. Whatever the case may be, antibacterial between snakes may not work as this is a fungus, but the truth of the matter is that even if you do pick up a sick snake and bring it home, housing it in warmer temperatures and a dry enclosure will result in the snake likely shedding off the disease. The key being that you quarantine that snake from the rest of your collection, and that its lesions aren’t so bad that it refuses to eat, as many times the worst symptoms are around the face and chin, making it difficult for them to feed.

It requires a couple of tests to confirm the disease in an individual and we are finding it in more and more species than those initially reported by the USGS. We know it’s prevalent in Texas and is constantly being found in more species of snakes in the state, too. So continue to enjoy the field herping, but take the necessary precautions to keep your personal collection disease free.

Some things that might help are disinfecting your field equipment if you use it at home too, or having a separate set for your snake collection and one for the field. Also, if you see early signs in a snake remove the water bowl and keep the moisture level as low as you can in its enclosure. Offer the animal water every couple of days by replacing their water bowl for a few hours and then removing it again.

Western Diamondback Rattlesnake (Crotalus atrox) crossing caliche road in South TexasSo this weekend a friend of mine and I decided to go herpin here in South Texas. We left Friday afternoon around 4:30 P.M. and returned on April 2nd at around 3 P.M. We covered at least 5 counties (maybe 6) and travelled a total of 874.7 miles.

Just like back then when herpers would meet up somewhere in the Western regions of Texas we slept a few hours during the hottest part of the day between noonish and 5 P.M. then started all over again, throughout the night into the next morning, thereby allowing us to see all the night time herps and the morning herps. A few times we’d stop in for breakfast in some tiny town waiting for it to warm up before we’d go in search of the diurnal species, but also had deli meats and bread, because we got to make these road cruising trips affordable right?

We saw a total of 50 individuals of 17 different species (herps only), plus a lot of the spring wildflowers, numerous birds, and mammals too. Considering it’s relatively early in the season we considered our trip rather successful. My friend and I have different motives for what drives us to be so hardcore in the field. For some its research, others do it to find lifers, some to add to their personal collection, but all of us I think share one thing in common. Passion. An appreciation for a group of animals often misunderstood and underestimated.

Among our highlights were a slightly aberrantly colored Arizona elegans arenicola (Glossy snake), we both saw our first Mexican Hooknose (Ficimia streckeri) of the year, and we encountered a species that neither one of us had observed in South Texas, the Prairie Lizard (Sceloporus consobrinus), and well a lot of the common herps we’d expected to find. We put our lives on pause, stressed our bodies out, and all for what if nothing was collected, but data and photos? I’ll tell you. A complete feeling of satisfaction, fun, and for me, it is especially cathartic, to get away from the norm, indulge in the nature that’s still clinging on amid rows and rows of wind turbines and agricultural fields. It’s official, the herpin season is in full swing and more of these trips are underway.

In other words, lots of camaraderie, adventures, stories, encounters, networking, new friends and familiar faces all out doing the same thing. There’s always some nostalgia for the way “things used to be.” We’re a relatively small group of people and every year I look forward to encountering other herpers while meandering the back roads of south Texas terrain. Plus, we still didn’t find our target Milksnake to check off our annual list, so it’s on!
Glossy Snake Arizona elegans arenicola

Cane Toad and Gulf Coast Toad co-inhabiting in the same burrowThe Deep South Texas terrain is quite interesting. It’s mostly a delta with none to very little elevation. Hence the features of the terrain are mostly thorn-scrub, at least what is still sort of intact. The rest has become ag-land for crops or urban sprawl. The point being that there are no rock cuts, or boulders or hills or other features that are conducive to providing herps a lot of hiding spaces. As a result they’re often found around people’s houses using artificial cover.

There was one incidence when I observed a Cane Toad and a Gulf Coast Toad co-inhabiting in the same burrow. It made me wonder why they’d do so if the Cane Toad could potentially poison the gulf coast toad or even eat it. I looked around the caliche pit and there weren’t very many hiding spaces, as is the case for most of the Lower Rio Grande Valley. So, my curiosity was overwhelming and I wanted to see who was being choosy about the burrow availability.

I collected 30 Cane Toads and 30 Gulf Coast toads. With the help of a NASA engineer we designed a box with identical burrows, except one was connected to a cooler and maintained a cool 75 degrees, while the rest of the chamber was brought up to 100°F, not unusual for the region. This caused the other burrows to maintain a temperature about 10-15 degrees lower than ambient temperature, but the cooled burrow remained at 75°F. We put in pairs of toads of the same species, or one of each species all for 10 minutes at a time, never using the same toad twice during one trial. We had infrared cameras set up to look inside the burrows and digital cams above recording their movements.

We found that Gulf Coast Toads will enter any hole they can inhabit to escape the heat, but Cane Toads, explored all available holes and 90% of the time chose the cool burrow. The other 10 percent of the time they chose burrows that already had a toad inside. We presented this work at the Joint Meeting for Ichthyologists and Herpetologists. The reason for this I believe is that by being in close proximity to another toad they reduce surface area and hence decrease desiccation. Another advantage is that if the “other” toad expels some water onto the substrate both the Cane Toad and the Gulf Coast toad can re-uptake it. Cane toads were sort of using the other toads as living canteens if you will, because they’re just bad-asses and excellent problem solvers.

Amplexed Gulf Coast ToadsIn evolutionary biology we always discuss animal’s basic needs and instinctual behaviors used to satisfy these needs. The Four F’s (fleeing, fighting, feeding, and well reproduction), are great drivers of some of the extreme or even awkward behaviors we sometimes see in nature. “Gotta do what you gotta do right?”

One day back in May of 2010 I was road cruising and a ton of rain had just fallen, the roads were thick with amphibians of all kinds. I drove down a dirt road on which both of the sides of the roads were flooded by ephemeral pools of water. The calls of Sheep Frogs (Hypopachus variolosus), Narrow-mouth Toads (Gastrophryne olivacea), Cane Toads (Rhinella marina), Couch’s Spadefoots (Scaphiopus couchii) and Gulf Coast Toads (Incilius nebulifer) among some were so loud the chorusing was deafening.

Shortly into my drive I found a very strange little scenario going on. Right next to the roadside ephemeral pool I noticed a pair of amplexed Gulf Coast Toads. Around the pair, like the scene out of some strange ritual, were 3-4 other male toads standing close by just watching, as if waiting for their turn. Well in fact, it turns out they probably were! They seemed to be acting out what would typically occur had they been just a few inches further in the actual water body. When a male and female amplex, satellite males sneak nearby trying to fertilize some of the eggs to pass on their own genetics. In this case they were just outside the water body.

However, what was the big deal with the deal female, how could that even work right? Well back in 2012 (Izzo et al. J. Nat. Hist. 46:47–48) observed similar behavior playing out. They termed it “functional necrophilia” in which even when the female is already dead, the male is able to massage the still viable eggs, out of her fresh body and fertilize them. Thereby, benefiting both individuals including the dead female, as her genes also get passed on along with his own.

The instinct of the fourth F, ‘reproduction,’ is a strong one. I guess one can relate, right? Nevertheless, we reported the first case of necrophilia in Incilius nebulifer in the journal Herpetological Review (2013, 44:4 pp. 655-656).

The force is strong with the four Fs! Of course since then (and prior to this publication) we’ve learned of necrophilia in lizards, snakes, other anurans, and it likely occurs in other taxa as well, and if we haven’t reported it, we’ll stumble upon it eventually. How successful the strategy is among other vertebrates is still a topic of discussion, but at least with some anurans we know it works!

As for the creepy satellite males standing by on watch, well, they’re just going to have to keep watching until the amplexed male works his magic massage!

Gulf Coast Ribbon Snake (Thamnophis proximus orarius) mating ball in January (winter) displaying stage III courtship behaviorm
In the previous blog we discussed how snakes’ breeding behavior is different in the Lower Rio Grande Valley (LRGV), and gave an example of the case of Leptodeira septentrionalis, Northern Cat-Eyed Snake, an attractive species unique to this region. Although the literature says they’re spring breeders, it seems that our field observations contradict that.

An even more drastic example of snakes that breed without brumating in the LRGV are Gulf Coast Ribbon Snakes (Thamnophis proximus orarius), they too, are supposed to breed during the spring. One day back in 2010 I was hiking through a small refuge and noticed a rather small mating ball consisting of about 8 snakes. This occurred in January, still winter, and the snakes were in full courtship behavior. Over the next few days I continued to observe them around the same “denning” site, which consisted only of a dense pile of branches. I documented this behavior and published it as the earliest reproducing snake in the country (Oyervides and Zaidan, 2014. Herp.Rev. 45(1):574). Over the course of the next few years I continued to monitor the behavior of this species in this region.

I’ve now learned that they breed year round. One would think that this would be detrimental to the snakes and they’d likely breed themselves to death in an effort to put out as many litters as possible, but it seems that’s not the case. Neonate and gravid Ribbon Snakes can be found year round in this region. In conducting my field surveys of these, I’ve also located a record size Ribbon snake, and one with a record size litter. Thus if they’re growing this large, having multiple litters per year doesn’t seem to be detrimental to them.

Their breeding behavior is also quite contrary to what the literature says, mind you, that last update on their biology was back in the 50’s by Tinkle. There is a very marked dimorphism between males and females of the species. When a female is being courted, she has several small males around her. These will follow her around and shadow her every move. Unlike in large mating balls where the males stress the females so much they practically force them into copulation, here, the female decides when she’s ready, as the males are too small to force her to do anything. These satellite males as I call them, will follow her around for days or weeks until she’s ready. Upon copulating, the males will disperse, and she will spend a lot more time up on tree branches absorbing as much sunshine as she can to speed up the process of having her first litter of the year and prepare for the next.
The advantage to this behavior is that because of the warm climate, there is a food supply for neonates year round. Moreover, their population numbers really decrease during years of drought. Having such a high number of individuals ensures that at least some will survive the droughts and restore a healthy population as soon as conditions improve. It’s amazing how sometimes we know so little of some of the most common species around!
Female with a male where the sexual dimorphism is evident.