Source: African Snakebite Institute 

Snakes and Hibernation 

Hibernation has been described as an inherent, regular and prolonged period of inactivity during winter. Hibernation is a term associated with warm-blooded animals (endotherms) such as mammals and refers to a period of inactivity as well as a shut down in the metabolic system to save energy.

Brumate

Reptiles on the other hand are said to brumate – become less active, but do not shut down and will be active with a slight increase in temperature.

The term brumate was coined by Wilbur Waldo Mayhen back in 1965 and referred to research he was doing on Flat-tailed Horn Lizards – he found that even if he heated these lizards up in winter, unlike other lizards, they would still not feed and become lethargic.

Strangely, Mayhen’s term does not technically apply to the standard period of inactivity in our reptiles as our reptiles will become active with a slight increase in temperature on a warm winter day. 

Snakes in cold regions of the world go into a state of torpor (inactivity) for long periods of time, up to 8 months, and often in dens where hundreds or even thousands of snakes may share the same winter shelter.

Eating habits

According to Professor Harry Greene, snakes consume between 6 – 30 meals per year and this is in summer. During winter they do not eat at all or if they do, very little. Most mammals will die within a few days if they are deprived of food but some snakes are known to have survived for more than a year without a meal. 

When seeking a hide-out for winter, snakes will carefully seek a shelter that (a) has sufficient moisture to ensure that the snake does not desiccate and (b) cannot easily be located by predators. As it cools down the snake may move deeper and deeper into its hole but they rarely remain motionless unless the temperature drops to close to zero degrees Celsius. 

Many environmental conditions appear to control snake movement. We have documented rain and warm weather increasing snake activity. There may be other factors that increase their activity, such as moon phase, barometric pressure, prey and mate abundance.

In southern Africa, snakes do not really hibernate as our winters are very mild. They may be less active and human/snake interactions decrease but on a warm winter’s day, the temperature may exceed 20°C and snakes may sneak out of their hiding spots to soak up some sun.

Most snakes appear to go underground during the colder periods as temperatures are stable a meter underground. As soon as the days start increasing in temperature, the snakes become more active. 

During winter most snakes do not eat, as they require high temperatures to digest prey. As soon as temperatures increase, snakes will be on the move in search of food. Many snakes end up around human dwellings as we often have a surplus of snake prey in our gardens in the form of rodents, lizards and geckos, frogs and birds. 

Spring is snake season 

Spring is in full swing in Southern Africa – temperatures are rising, birds are nesting, and we’ve even seen a few minor rain showers.  

Many environmental conditions appear to control snake movement. We have documented rain and warm weather increasing snake activity. There may be other factors that increase their activity, such as moon phase, barometric pressure, prey availability and mate abundance.

Reproduction 

Mating usually takes places in spring or early summer in most southern African snakes. There are a few exceptions. Black Mambas are well known for mating in autumn and winter, as are Puff Adders and Pythons. Female snakes leave a trail of pheromones to attract male snakes. The male snakes follow the scent trail of the female. Often more than one male will follow the scent and we have come across females with multiple males hoping to mate with her. This may lead to male combat, where the male snakes wrestle for the rights to mate with the female. We are often sent images of large Puff Adders or Black Mambas wrestling and many people mistake this for mating. In male combat, the two males twist around each other, each trying to pin the opponents head to the ground. The winner or dominant male gets to mate with the female and the loser leaves.

Females can mate with multiple males and store sperm. The result of this is that babies from a single clutch may have multiple fathers, increasing their chances of survival and having good genes. Eggs are usually laid in summer and take around 3 months to hatch. Most females do not guard the eggs, and the babies once they’ve hatched, are on their own to fend for themselves. So if you encounter a baby snake, there is little to no chance of finding the mother. However, you may encounter more than one baby snake until they have successfully dispersed. 

Secretive Habits

Snakes are not frequently seen, due to their secretive habits. We often talk to farmers who have “plenty” of snakes around, but when asked when they last saw one, we find they often haven’t seen a snake in a year or more. On a good day in the field, we may find more than a dozen snakes, but we must work hard to locate them. Obviously the more isolated you are and the greater the natural area around your house, the more snakes you may encounter. Built up areas may still have a few snakes that take advantage of the high abundance of water and food. These are usually snakes such as the Brown House Snake, Spotted Bush Snakes or Herald Snakes. Even Rinkhals may thrive in built up areas of Gauteng although they are almost locally extinct in the built up regions of the Cape. 

Snakebite 

Very few snake encounters end up in snakebite. Snakes are shy and avoid human conflict as much as possible. Over the whole of southern Africa, we see less than 50 deaths a year from snakebite. Our hospitals are generally well equipped to deal with snakebite. 

Many people ask if all the hospitals stock anti-venom and where they should go if they are bitten by a snake. The truth is that the vast majority of snakebites do not require anti-venom and are treated symptomatically. Therefore any hospital with a trauma unit would be good. Many rural hospitals are well practiced with snakebite treatment and often have better experience than suburban hospitals. In the short term, the most dangerous aspect of snakebite is the lack of breathing due to neurotoxic venom (found largely in the Black Mamba and Cape Cobra for example). This can be treated by putting the patient on a ventilator. 

Venom in the eyes from spitting snakes must be flushed out as soon as possible. We recommend using a running tap to wash out as much excess venom as possible. Any bland liquid can be used, but water works best. You should visit a doctor after the incident to have the eyes examined and treated with local anaesthetic and antibiotic cream to prevent corneal damage. 

Pets often get bitten by snakes, especially dogs. Due to their hunting instincts, they attempt to kill snakes and often end up getting bitten. There are no household recipes or tricks to deal with snakebites in pets and it is best to get your pet to a veterinarian. In serious cases anti-venom is needed. Cutting the tip of the ear, injecting petrol, making your pet drink milk or swallow charcoal as well as administering tablets does nothing for your pet and just causes additional stress. Pets that are spat in the eyes by Rinkhals or one of the spitting cobras need to have their eyes washed out as soon as possible. Use a running hose and flush the excess venom out as best as possible, and then get it to a vet. 

The free ASI Snakes App is available on IOS and the Android Play Store. It has the contact numbers of over 500 snake remover’s country wide. It also has a map of the local hospitals and can aid you in the case of snakebite. The Poison Information Centre contact details are also available as is a direct line to the African Snakebite Institute. This app also has over 150 profiles of snakes, scorpions and spiders and you can also send your photos through for identification.