ASI Newsletter - June 2020 

Snakes in the Cold

The second cold front has hit South Africa this season, with flurries of snow across much of the mountains in the Cape. Somewhere under those blankets of snow, our snakes are hiding.

The mountains near Ceres, home to Red Adders (Bitis rubida) and Black Spitting Cobras (Naja nigricincta woodi), covered in snow. Photo - Sakkie Hanekom.

Prior to winter, we see quite a peak in snake activity. Snakes are feeding up, building fat reserves and searching for a suitable hideout for the cold. Active hunters such as cobras and Boomslang will be on the move in search of prey. This means that they often end up in human settlements and there is inevitably human-snake conflict. Many snakes have a retreat that they will use every year if not disturbed. We have heard of Boomslang hiding out in the roof of old farmhouses, returning every winter. Dr Tony Phelps recorded multiple Cape Cobras sharing the same den year after year in De Hoop Nature Reserve.
Many of the smaller snakes utilise old termite mounds for the winter, as they provide safety from predators and get nice and warm in the afternoon sun, allowing the snakes inside to warm up.  Most snakes seem to go underground. The temperature underground may not be much warmer than the surface, but it is far more consistent. For many cold-blooded animals (ectotherms) that rely on the environment to control their body temperature, cold temperatures don’t necessarily kill them, but a drastic fluctuation in temperature will. By hiding out underground, the snakes can retain a constant body temperature.

Many snakes utilise holes in the ground or disused termite mounds for the colder months.

Many people refer to this period of inactivity as hibernation. Hibernation technically refers to warm-blooded animals (endotherms) and refers to the shutdown of their metabolism and other systems to allow them to sleep off the cold winters. For reptiles and other cold-blooded animals, the term brumation has been used. It is very similar to hibernation except that on a warm winter day, the increased temperatures will allow reptiles to come out of their holes or hiding spots and bask in the sun. They therefore break their “hibernation” period based on external temperatures. This is what differs between hibernation and brumation.

ASI Face Mask – Gaboon Adder  An easy to wear, adult tapered face mask, with elasticated ear loops. Price R40.00

Recently, the term brumation has come under scrutiny as the man who coined the term back in 1965, Wilbur Waldo Mayhen, had used the term to describe some lizards he was studying that showed typical hibernation, being inactive despite an increase in temperature. Currently we accept that brumation means that an increase in temperature will mean an increase in activity in reptiles. So for now, we will say that reptiles go into a state of torpor (inactivity) with reduced temperatures.

Yet, some species may become more active with a drop in temperature. We see this especially in Puff Adders and Black Mambas that start their breeding season at the end of Autumn in much of southern Africa. Both these species exhibit male combat and we see a number of great videos showing two males wrestling to win the rights to mate with a nearby female. After mating, the female will start developing eggs and can deposit them by early spring, so that the hatchlings can emerge in early summer when there is rain, brought on by warmer temperatures, and abundance in food is at its peak.

Two male Black Mambas in combat in June. Photo Ian Thomas.

The next three months will see a reduction in snake sightings due to their lower periods of activity. Construction sites may still excavate snakes hiding underground or in the walls of old buildings, but snake encounters as a whole will decrease greatly until we see an increase in temperatures and the first rains of spring.

The Dangerous Snakes of Africa Now in stock! This comprehensive book is an essential tool for all naturalists, conservationists, educators, field workers and medical personnel throughout Africa. Price R795.00

There is also a dramatic decrease in snakebites as snakes become less active. The majority of snakebites are recorded in the warm summer months, especially after some good rains. Over 80% of snakebites in southern Africa are recorded between January and April/May. Most victims are bitten in the early evening when accidentally stepping onto snakes, followed by subsistence farmers that encounter snakes while tending to their crops.

Introducing our two new online courses, The Beginners Guide to Snake Identification, and The Advanced Snake Identification Course. We recently released our two new online courses, and have had a tremendous response. In the last six weeks we've had hundreds of students sign up for these courses, and the feedback has been phenomenal. The course is fully digital, and delegates have lifetime access to the content once the course is purchased. To view more info on these courses, and the full course curriculum, click here. 

Check out our video on Snakes in the Workplace: