TALK REPORT FOR DECEMBER 2016
10 December 2016: George and Margo Branch on “Creatures of the fynbos”
This was a very well attended morning talk with some children present. It was a pity that there were not more children there to listen and learn and enjoy this presentation which George and Margo shared.
Originally from Zimbabwe, George and Margo met at UCT while studying Zoology and Biology respectively. Being well qualified to talk on fynbos creatures, their talk was enlivened by personal experiences. On one occasion while diving near Hermanus, George had his leg playfully grabbed by an otter for several minutes!
Fynbos is not only one type of vegetation, but includes many different vegetation types. A lovely photo of a rocky section of our beach illustrated this – plants in the background, otter prints on the sand, and the water in a stream coloured golden brown by tannins and phenols leached from the surrounding fynbos plants. David Winter’s photo of six otters looking at the camera was beautiful. Three-quarters of the otter’s diet is now rock lobster.
Fynbos thrives in the Western Cape’s adverse conditions of hot dry summers, winter rain, fire and nutrient-poor soil. There are four divisions that make up this plant kingdom. There are Proteas with several subdivisions, Ericas with over 650 varieties, all having four joined petals and eight stamens, Restios where stems do the work of leaves, and Geophytes – the numerous bulbs species, many of them hibernating underground during summer.
The animals underground also have to cope with these conditions. Mole rats, bulb eaters, have underground homes. Golden moles, whose tunnels we find on our beaches, are insect eaters. Also mentioned were tortoises and porcupines whose habitat and restaurant is the fynbos.
There are numerous insects important for pollinating certain species. Ericas are isolated in pockets with their pollinators. Tubular ericas are pollinated by sunbirds and bumble bees who make a side hole in the flower. The cup-shaped ericas have bees, the hairy ericas attract insects that feed from them, and those with tiny flowers need the wind to assist with pollination.
Proteas have extended pollen presenters that dust pollen onto sugarbirds as they feed on the nectar.
What is the difference between a protea and a pincushion when not in flower? A pincushion leaf is toothed at the top, with a waxy looking glandular swelling at the tip of each tooth. These glandular swellings are thought to provide nectar that is attractive to ants.
Pincushions need ants to assist with seed dispersal. Ants love to eat the protein rich, oily elaiosome that is attached to pincushion seeds, so they take the seed underground to their cool, moist chambers, eat the elaiosome and leave the seed safely buried in their nests where the seed will be stimulated to germinate when conditions are right, such as after a fire.
The Red Disa we see in Disa Kloof is visited by the Table Mountain Beauty butterfly which also visits other similar red flowers. Flies are attracted to the ‘rotten meat` smell of stapeliads (carrion flowers). Citrus Swallowtail butterfly larvae feed on the Blister Bush and become poisonous themselves. By the way, If you are ‘brushed’ by a Blister Bush, cover the part of your body that touched the Blister Bush immediately, as sunlight activates the poison that Blister Bush leaves brush off on you, giving you an itchy, sometimes quite painful welt or blister.
When alien invasive plants burn, the intense heat generated penetrates the soil and destroys seeds stored underground as well as the roots of plants that usually resprout after they have been burnt.
Fire in natural fynbos is not as hot as fire in alien invasive vegetation. The less intense heat of fire in natural fynbos produces ash which supplies nutrients for the soil, encouraging the germination of many different fynbos plants such as Ericas and Proteas. Safe from fire underground, bulbs resprout in the ash enriched soil and re-flower within months. Fire in natural fynbos also enables the cones on cone bushes to open in the heat and scatter their seed, ensuring the next generation of cone bushes.
What else lives in our fynbos? There are frogs in the wetlands, some rare and endangered. Spiders – have you seen the beautiful web of the Golden Orb-Web spider? The green caterpillar (larva) of one of the many hawk moths has large ‘painted eyes’ on its hindquarters that make it look like a snake to scare away predators.
There is so much happening in this wonderful world of fynbos. I remain amazed that invasive aliens are left untouched on some private properties. Such aliens are fire hazards and water guzzlers, and provide no food or protection for our wonderful ‘Creatures of the Fynbos’. If these creatures disappear, will we be next?
Thanks George and Margo for all the books you brought along with you. Wonderful Christmas presents!