In my go-with-the-flow-garden I hope to provide a space for myriad natural processes – only some of which I even notice. I have been thinking about some of the more obvious interactions that allow the garden to sustain itself and its network of visitors and residents.

It can seem that we humans regard the array of plants and creatures existing in nature (and by extension in gardens) as an à la carte menu from which we can pick and choose. On this menu of biodiversity apparently served up for our pleasure we may find favourites and pet hates that are shaped by our personal whims and knowledge systems. We have a tendency to want to nurture our favourites and even actively persecute those we dislike.

Some people regard swallows as favourites and allow them to nest under the eaves of their houses, whereas others who hate swallows for being ‘messy’ prevent them from nesting or go as far as destroying existing nests. Above is a Greater Striped Swallow (Cecropis cucullata), a notable hawker of insect prey on the wing

But when taking a broader view rather than pick and choose it becomes possible to back off a little and observe. What is going on is complex and we can choose to try to cooperate rather than intervene. As an approach to a garden, cooperation makes for a much more relaxed lifestyle.

Intervening and using pesticides to get rid of insects and spiders we dislike kills both target and non-target species. Killing a broad range of insects and spiders is detrimental for many reasons, including the widely recognized problem of declining numbers of pollinators and the depletion of insects and spiders as food sources for birds. Even birds that mostly eat plant material include insects and spiders in their diet when raising their young, and for many species of birds spiders webs are necessary components of nest building.

A fork-tailed drongo (Dicrurus adsimilis) with insect prey in our garden

Many pesticides are neurotoxic and even if not immediately fatal to birds, exposure over time can weaken birds and affect their efficiency when flying, feeding and raising their young. Of course some pesticides are more immediately lethal to birds that are contact with poisons through their skin or on their feathers, in water sources or though inhalation of sprays. Some pesticides if ingested, for example if eaten when in the form of granules or pellets or via contaminated water, can kill birds very quickly.

A Chorister robin-chat  (Cossypha dichroa) on its way to its nest to feed its young

In addition to some species of insects acting as pollinators, species of insects also play a role in the control of other insects by hunting and eating them directly or by parasitizing them by laying their eggs on the nests or on the bodies of other insects.

A case in point is wasps, a class of insects often disliked and killed as they are regarded as having ‘no purpose’. The fact that wasps have the capacity to sting may be used as a rationale for their persecution, but then honey bees also sting!

Wasps

Wasps are predators of note – by predating on other insects they play an important role as natural ‘pest controllers’. Both parasitoid and hunting wasps, and both solitary and social wasps play a role in regulating the populations of other insects. Some wasps are specialists in the species they parasitize or hunt and others are generalists. Seiran Sumner, in an extremely interesting article titled “Wasps: why I love them, and why you should too”, discusses the impact of wasps as sustainable, non-toxic and effective biocontrol agents.

A paper wasp (Polistinae family) with caterpillar prey that the wasp has disabled by stinging

Wasps are pollinators too. Wasps parasitize or hunt other insects or spiders that are used to feed their offspring (although a few species of wasps feed their young with a mixture of pollen and nectar). Most adult wasps visit flowers for food. Some plants, including many orchids, have co-evolved with specific species of wasps to be entirely dependent on them for pollination. But many species of wasps are generalists in the flowers they visit. As Seiran points out, in the face of the apparent decline in pollinators such as honey bees and hoverflies, we would do well to take wasp pollination more seriously.

A paper wasp visiting flowers on a perennial basil plant, illustrating the role wasps play as pollinators. If you look carefully you may spot the spiny flower mantis well camouflaged higher up on the same flower stem to the left of the wasp

An unidentified little wasp, probably one of the solitary wasps, eating pollen from a feverfew flower in our herb garden

Flies

As I have mentioned before, species of flies also play an overlooked but significant role as pollinators.  A former post discussing flies as pollinators (and bubble blowers!) references a research project that notes that blow flies can be significant pollinators improving the yield in mango plantations in countries such as India, Israel and Pakistan, so much so that flies are specially bred to assist in the pollination of such fruit plantations.

A blow fly (Calliphoridae family) feeding on the tiny flowers of a tassel-berry tree (Antidesma venosum)

Another species of fly, possibly a Tachinid, taking nectar from a flower

In addition to their role as pollinators some species of fly are part of nature’s clean-up crew assisting in the decomposition of decaying animal material. Blow flies and their maggots can be used as forensic indicators, for example when investigating the time of death in murder cases. Blow fly maggots have been used in medicine to help clean and heal infected wounds. Other species of fly such as Tachinid flies parasitize insects that include significant agricultural pests, and so the role of flies as biological control agents can have a considerable positive economic effect.

Fungi

The role of fungi in complex networks with other organisms is a vast subject, but I am only mentioning here that they are another significant agent in the important process of decomposition and consequently in soil enrichment. (In addition many fungi are very beautiful too and some are deliciously edible. Of course the toxic ones should not be eaten!)

Only once did I spot a colony of tiny bird’s nest fungi (Cyathus striatus) in our garden. These were growing in sawdust in a flower bed. Bird’s nest fungi have such curiosity value that they are the subject of their own post

Reptiles

For some reason many people are fearful of reptiles – perhaps because they are ectothermic (“cold-blooded”) and so have to use the environment to thermoregulate, for example basking in the sun to warm up or burrowing in the soil to cool down. Perhaps another reason that some people fear even completely harmless reptiles is because their eyelids are transparent – some have moveable transparent eyelids and others, such as snakes have fused eyelids. Generally, humans seem to prefer creatures that blink! 

In our garden reptiles are represented by geckoes, skinks (including the beautiful striped skinks) , southern tree agamas (also known as blue-headed lizards) and snakes (including the Natal green snake). All of these reptiles are predators although, sadly for them, they may themselves also be preyed upon.

Cape dwarf geckos (Lygodactylus capensis), such as the one in the photo above, eat a variety of small insects. This one was about to jump onto the vertical surface of a pole; the minute hairs on the pads of their feet enable them to adhere to vertical and even ‘upside-down’ surfaces. Geckos are surprisingly good at jumping – I have the impression that they use a curved tail to propel themselves

A southern tree agama (Acanthocercus atricollis) – I think this is a female rather than a male outside of breeding season – photographed waiting to ambush passing ants. We certainly appreciate the role they play in controlling the number of ants in our garden

Above is a still from a video I took of an agama eating ants in a tree in the garden. The video can be found here. Another post features video footage of rival male agamas fighting during the breeding season

The brown house snake (Lamprophis capensis) is a constrictor and has no fangs or venom. The term house snake derives from the fact that they are often found around human dwellings where they seek rodents, which form a major portion of their diet. They are effective rodent controllers and provide no threat to humans and so their presence should be welcomed. In addition to rodents they may prey on a variety of other small animals

Raptors

In our neighbourhood we have seen several raptors perching in nearby trees or flying over our garden. Those most frequently seen or heard include black sparrowhawks, African harrier-hawks (gymnogenes), wood owls, spotted eagle owls and small unidentified goshawks. And recently a breeding pair of  long-crested eagles have apparently taken up residence and they are very evident around our property.

A long-crested Eagle (Lophaetus occipitalis) flew into a tree near our garden with a freshly caught rat. I could not tell what kind of rat it was. Although its partner was nearby the eagle declined to share its prey

Subsequently I was able to photograph a rather wary eagle perched in a tree on the edge of our garden drying its wings after rain

Pond life

Our small garden pond has its own little eco-system going. I am amazed at the creatures that somehow end up there, for example small aquatic snails. Pond snails eat algae and so do other small aquatic creatures and – most importantly in our pond – tadpoles are very effective algae removers too.

Natal tree frogs reside and breed around our pond. Adult frogs eat a variety of insects

Having started writing about pond life I realise that there is so much going on that I will rather do a separate post including some recent pond-life observations.

Some more carnivorous creatures

A small crab spider is visible on a nasturtium flower where aphids accumulate on the stem. Perhaps among the best known aphid-eaters are species of ladybirds, which are small carnivorous beetles

This ladybird – more correctly ladybeetle – is the black-ringed ladybeetle (Oenopia cinctella). This specific ladybeetle feeds on small sapsucking insects and on leaf-beetle eggs and larvae, and are important biological control agents. They are another example of beneficial species that can be eradicated by the use of pesticides

A jumping spider – a tiny predator that eats a variety of little critters

A species of lynx spider waiting to ambush-hunt a visitor to its leafy territory

And back to some pollinators

To end this post, some more photos of pollinators – although in other stages of their life-cycle of course they are not pollinators. The world of insects is incredibly complex as they take their places in an amazingly interactive network.

An African common white (Belenois creona severina) butterfly nectaring from flowers on the very popular (with pollinators) perennial basil bush

I could not resist featuring again the giant carpenter bee (Xylocopa flavorufa) taking nectar from a giant salvia (Brilliantaisia subulugurica), fitting so perfectly beneath the stamens of the flower that the pollen sticks to the bee’s slightly furry back to be transferred to subsequent flowers that it visits. And below a hoverfly visits the blue flower of a tropical spiderwort (Commelina benghalensis)

Sources:

Alexander, Graham & Marais, Johan. 2007. A Guide to the Reptiles of Southern Africa. Cape Town: Struik Nature;   

Chittenden, Hugh, Davies, Greg & Weiersbye, Ingrid. 2016. Roberts Bird Guide: Illustrating nearly 1,000 Species in Southern Africa (2nd edition). Cape Town: Jacana;   

Londt, Jason. 2009. Suburban Wildlife in KZN. A Wildlife Handbook, WESSA KZN;  

Picker, Mike, Griffiths, Charles & Weaving, Alan. 2019. Field Guide to Insects of South Africa. Cape Town: Struik Nature;   

Sumner, Seirian. 2021. Wasps: why I love them, and why you should too. The Conversation, April 29. https://theconversation.com/wasps-why-i-love-them-and-why-you-should-too-155982

Posted by Carol