Thursday 28 January 2016

Reptiles found in the Kruger - The Brown house snake

Brown house snake
Adult brown house snake. 
Brown house snakes are one of many species of African house snakes found across sub-Saharan Africa. They are medium in size and non-venomous with a variety of patterns and may be striped, spotted or even solid in colour. African house snakes are sexually dimorphic, meaning that females grow to be larger than their male counterparts, with females reaching up to 783 mm and males up to 656 mm in length.  

Brown house snakes are light brown to reddish brown in colour and darken with age on top while their underparts are an off white colour. There are two distinctive pale yellow streaks running across each side of the head from the tip of the snout through the eye but do not run down more than a third of their body length. 

Habitat

African house snakes, as mentioned are found throughout sub-Saharan African, are able to adapt and live in a variety of habitats. They are referred to as ‘house’ snakes due to often being found settled under stones or in rocky areas of gardens and in the homes of people. These snakes live in underground borrows, scrublands, woodlands, savannah and mountainous areas.

Behaviour

African house snakes that have ventured from the wild are often very nervous if approached by humans and will try to slither away in response. Brown house snakes and their relatives are said to make good pets and make for the perfect first choice of snake for a beginner.

Some may become aggressive during feeding, eating all the food for themselves and preventing others from feeding. In some cases, ravenous hatchlings will eat their smaller brothers and sisters, so it is suggested that all hatchings are best kept apart.

Brown house snake
Juvenile brown house snake. 
Diet

Adult brown house snakes eat mostly rodents but will also feed on frogs, lizards and birds while juvenile snakes eat lizards and geckos.

These snakes are powerful constrictors; able to snatch rodents in their jaws before unleashing a strong and deadly grip around the prey. Once the rodent is no longer alive, the grip is released and the unfortunate victim is eaten head first.  

Reproduction

House snakes lay up to 16 eggs in the summer month among vegetable debris or compost, on average 2 months after mating. Females usually stop eating after the first month of gestation and begin a shed cycle before laying her eggs 5 to 10 days later. Hatchlings take between 60 and 75 days to develop within the egg before hatching. When born, hatchings are around 20 cm in length and begin to shed within a week of leaving their eggs.

Did you know?

Those that prey on brown house snakes are larger snakes and birds of prey. 

Thursday 21 January 2016

Reptiles found in the Kruger - The African rock python

African Rock Python
An African rock python.
The African Rock Python is the largest of all snakes found slithering around in Africa and may reach or exceed an impressive length of 6 metres (20 ft). However, males from this non-venomous species of snake, usually reach 5 metres while female reach 4.25 metres in length. There are two subspecies of this incredibly large snake; one is found in Central and Western Africa while the other is found in parts of Southern Africa. The species from Southern African is generally smaller than its relative living in Central and Western Africa.

This snakes' thick body is a grey-green or brownish colour covered in blotches, ranging from a mix of brown, olive, chestnut to yellow colours, often merging up into a wide and asymmetrical stripe. On the crown of their heads they are marked with a large spearhead shape while a triangular shaped marking of dark and light bands run from each eye to their lip. Their scales are small and smooth and their teeth sharp and curved backwards, delivering a painful bite anchoring into the victim, that if left untreated may lead to a nasty infection. Pythons have two functioning lungs unlike the majority of snakes only have one. They also have small and visible pelvic spurs which are believed to the remains of hind legs from prehistoric times. 

Habitat

Both sub-species are found in sub-Saharan Africa, with Northern African rock pythons living in parts of Central and West Africa and the Southern African rock python found living in parts of Southern African countries such as Kenya and South Africa among others.

African Rock Python
African rock python.
Depending on which subspecies of African rock python, they live in a wide range of habitats, which include savannahs, woodlands, grasslands, forests, semi-deserts and rocky areas, avoiding very dry desert areas. They often live in areas where a permanent source of water can be found such as swamps, lakes or along river banks.

Behaviour

They are solitary animals and will only seek out other pythons during breeding season. Due to their large size they mainly stay on ground but are able to climb if need be. They are great swimmers and can even stay submerged under water for long periods of time. Although mostly nocturnal they will bask in the sun during the day soaking in the sun’s rays for thermoregulation purposes. These snakes have a reputation for being aggressive and unpredictable, and will bite and constrict if feeling very threatened or unable to escape.

Diet

The African Rock python has heat-sensitive pits positioned near their lips, which are used to detect the location of warm-blooded animals that could be potential prey and are even able to pick up their location in the dark.

After capturing the prey, the python coils around it, tightening its grip with each breath of the victim, causing crushing of internal organs and suffocation; this method is called constriction. It will then eat the prey whole which leads to large meals taking months to digest.

African Rock Python
Submerged in a swamp.
They have a carnivorous diet, feeding mostly on large rodents, monkeys, warthogs, antelopes, fruit bats, monitor lizards and even crocodiles in the wild but if they find themselves in suburban areas they will eat rats, poultry, dogs and goats.

Reproduction

Once reaching the age of sexual maturation between 3 to 5 years, African rock pythons seek out one another when the mating season arrives in spring. Females lay between 50 to 50 hard-shelled, elongated eggs in the safety of an old animal burrow, termite mound or cave. 

She coils around the eggs in order to protect them from predators till they hatch around 65 to 80 days later. The mother will also guard her python babies from predators for up to 2 weeks after hatched. Juvenile African rock pythons appear like duplicates of adult pythons expect more brightly coloured.

Did you know?

These carnivorous snakes are preyed upon by hyenas, wild dogs and big cats such as leopards. 


Wednesday 13 January 2016

Reptiles found in the Kruger - The white throated monitor

White throated monitor
White throated monitor lizard.
Monitor lizards include various types of the world’s largest lizards known for their long necks, powerful tails and strong, muscular limbs. These are diurnal animals and almost all monitor lizards are carnivorous.

The white-throated monitor, commonly known as a rock monitor, is the second largest monitor found in Africa and can live up to between 12 and 20 years.

This large lizard, which can reach an impressive 6 feet in length, has a grey or brown head while their throat is white. Their body has dark coloured rosette-like patterns with a cream coloured centre and as they age the centre merges with the rosettes creating bands around their ribcage. Their limbs are sometimes a spotted pale yellow and their tails have a pattern of dark brown and off-white bands. Colours of individual white-throated monitors can vary. 

These monitors have a distinctively blunt and bulbous snout. Monitors tails, which can grow to be twice as long as their body, have many uses such as that of a rudder to steer while swimming or for grasping prey and as a weapon used against predators.

Egyptian legend

The story goes that in the early days of Egyptian civilization, monitor lizards were chained up to boulders along the edge of the Nile River. If the lizard was calmly basking in the sun, the water was believed to be safe from crocodiles but if the lizard was thrashing and struggling to escape the chains, it meant that crocs were about. The superstition believed that these lizards monitored the whereabouts of crocodiles hence the name ‘monitor lizard’.

White throated monitor
White monitor lizard in its natural habitat. 
Habitat

White throated monitors are found in savanna or semi-desert regions of southern and central Africa including parts of South Africa, Angola, Zambia and Mozambique among others.  

They are seen existing within many of Africa’s diverse habitats, including savannas, shrub lands, woodlands, grass lands, rocky outcrops and combinations of these habitats.

Male monitors are super territorial about their domain of about 11 km (seven miles), engaging in battle with any other male they encounter, while females make a home of only just over 3 km (2 miles) in size.

Behaviour

White throated monitors climb trees in order to hunt prey, escape the heat during a hot African summers day, find protection from predators or sleep safely at night.

If they come face to face with a predator on the ground, monitors will puff up their throats and body to appear larger, while striking with their powerful tail and biting fiercely.


Diet

White throated monitors enjoy a varied diet of mostly insects, such as millipedes, grasshoppers and beetles, but also eat anything from snails and snakes through to birds and eggs.

They swallow their food either whole or in large pieces and are able to dislocate their hyoid bone in order to expand their throat.
White throated monitor
The white throat of the monitor. 

Reproduction

During the mating season an approachable female will almost always climb up a tree in wait for a male to discover her. The attracted pair mate, for one to two days, after which the male leaves in search for another female monitor.

In the early summer months up to 50 eggs are laid in a clutch by a female monitor, dependent on her size. She will use her long and sharp claws to dig her own hole or even use a termite mound or rodent den to lay the eggs.

Did you know?

Monitor lizards shed their teeth and grow new ones throughout their lives. 

Thursday 7 January 2016

Reptiles found in the Kruger - The southern tree agama

southern tree agama
Male southern tree agama. 
There are 37 different species of these long tailed lizards found throughout Africa, which vary in an assortment of colours and many sizes.

The southern tree agama is considered a large agama with a broad head and can reach lengths up to 35 cm (13 inches) and in some cases even more.

Breeding male’s heads are bright blue in colour, while their front limbs are yellow and tints of orange are seen on their backs with tail tips that looked as if they were dipped into blue paint. Females vary in different shades of grey with light coloured markings of green, orange and yellow on their backs and tails.

Habitat
southern tree agama
Female southern tree agama well camouflaged. 

Southern tree agamas are found in most of central Africa down into southern Africa including the countries of Ethiopia, Kenya, the Congo, Angola and Namibia. Within South Africa they are seen mostly along the coast of Kwa-Zulu Natal and up towards the eastern bush-veld such as in the Kruger.

They make their home in habitats from forests to savannahs and even in residential areas such as gardens. 

Behaviour

This creature often basks in the sunshine on trees or on rocks in gardens or in the wilderness. They are active during the day and can tolerate higher temperatures more than most reptiles. However when the temperatures reach a sizzling 38°C (100°F) they will find a shady place to keep cool.

Fights often break out between male southern tree agamas that involve head bobbing and weaving in an effort to scare their rival. Battles will sometimes evolve into using more intense actions such as lashing out using tails and threatening one another with open jaws, occasionally ending in broken tails as a result. Females are also known to fight and chase one another.

Diet

Southern tree agamas munch on small creatures such as caterpillars, grasshoppers, beetles, termites and ants using their incisor-like front teeth for quick cutting and chewing.

southern tree agama  
Incisor-like teeth. 
Reproduction

Most species of agamas are polygamous with males having up to six or more females within their territory for breeding purposes. Males bob their heads in an effort to impress females while occasionally the females may initiate mating by showing off their hindquarters and then running for the males to give chase.

The mating season is from March through to May after which between 5 to 12 oval shaped, soft-shelled eggs are laid within a hole dug in the moist soil during the months of June to September. The young hatch 90 days later and are 7 to 8 cm in length.

Did you know?

The southern tree agama can give a painful bite.