If you want to discover the truth about someone, don’t ask them because you will get a contrived or evasive answer. Look at their waste disposal, where the truth can not be hidden. Habits and attitudes are reflected in what one leaves behind. In wild areas, even if we do not see any animals, we can tell by signs where they have been and what they have done.
Marks left by their passing and ‘spoors’ of their feet, together with their droppings, will tell us much of where they have been, what they have done and what they have eaten. The contents of animal droppings are sometimes very obvious on close inspection. From a distance the size and colour are more noticeable. The position of the droppings will indicate its activity at that time.
The colour of the droppings will often indicate the type of meal eaten. The white droppings of carnivores indicate excess calcium from, mainly, bone meals, while dark droppings indicate meals of flesh and blood. Hair will often indicate the species consumed.
The dark coloured droppings of ungulates and pachyderms indicate mainly grass meals and the reddish-brown droppings indicate leaf and twig meals. The remains of browse meals, because of the tannin content, oxidise brown and grass remains oxidise black or dark grey.
Therefore one can often identify the browsers and grazers from the colour of their droppings. Grazers eat grass and browsers eat leaves and twigs. Elephants generally eat 80 percent grass during the wet season and 80 percent leaves and twigs during the dry season.
Impala are one of many species that vary their diet according to seasonal food availability. Dung beetles and other insects are active during the warm season and droppings from that period will be quickly broken up and scattered. Dry season droppings tend to remain intact for longer.
Marketing And Communication
As with many domestic animals, droppings, urination and rubbing may be used to communicate or mark territories. The communal piles of droppings of rhino, impala and other animals are referred to as ‘middens’. When a species is established in an area they will use communal ‘toilet areas’ which play a similar role to our post offices. It is here that animals will deposit and receive various messages from each other. Civets, genets, mongooses and other small mammals frequently do the same.
The same applies to rubbing posts - trees or rocks of convenient shape and height - that are sometimes worn down by the abrasion from sand in mud-caked animals or shined up by the oil from their skins. Hairs adhering to or dropped near these rubbing posts will often indicate the species involved. During the mating season, male ungulates often rub their facial and head scent glands on chosen objects and batter trees with their horns, leaving visible marks.
Indications Of Feeding On Plants
Apart from the broken branches and fallen trees left by feeding elephants, there are many less obvious signs indicating where herbivores have fed on various plants. The manner in which grass stems and leaves have been nipped off can often indicate the grazing species.
The leafless ends of new branches can indicate where giraffe have stripped off leaves with their ‘toothbrush’ type lips. Kudu and eland bulls will frequently use their horns to break high branches down so they can lower the food supply. Most browsers will feed to their maximum height leaving signs where they have bitten off the nutritious tips of branches.
The taller species are more easily able to compete with smaller species for limited food supplies. Many species co-operate in feeding methods. Baboons and monkeys, with feeding habits that are inefficient and wasteful to our thinking, frequently drop food from the tree tops to animals following them below in a feeding succession.
The same happens where larger animals break down branches or dig up roots. Within a community, many species make food available for other species and are necessary for their survival. Where numbers of herbivorous animals are excessive or where certain species are confined by various environmental factors, palatable plants species will show signs of overuse.
Not all plants are palatable and many species may give the impression of an unlimited food availability. The preferred food plants will show horizontal ‘browse lines’ up to the reach-height of browsing species. Where tall animals, such as giraffe, can reach over the tops of trees, overbrowsed plants will show signs of ‘hedging’. The rounded or ‘hour glass’ shaped trees (normally acacia species) are a common sight in national parks and private game reserves and, among other signs, are an indication of excessive animal pressure.
Coppice, Browse Lines And Hedging
Trees normally grow with one stem or trunk, while some shrubs are naturally multistemmed. Where tree stems are damaged by animals or fire, the plant will produce two or more stems as a survival reaction to the damage. Single stemmed trees in the lowveld are becoming increasingly scarce, indicating that the majority of our trees have been damaged by some means - usually fire. Many of these multi-stemmed trees stand on bare ground where no fire could presently occur - indicating the deterioration in veld condition.
Frequent fires kill off the lower branches of many trees, reducing a potential food source for browsers. The fires also create ‘fire scars’ on the sheltered side at the base of large tree trunks. These fire scars increase in size with each subsequent fire until the mature trees are killed. Browse lines are created by excessive removal of leaves by browsers and such continued browsing will kill the lower branches. Hedging of plants is caused by excessive browsing of branch tips.
This excessive ‘pruning’ will cause the plant to put out more shoots as a protection against the intrusive mouths, until it thickens into an impenetrable ‘hedge’. Horticulturalists are well aware of the process. Where the ‘hour glass’ shape is observed, the tree has been able to outgrow the browsers and develop freely once more. The growth mechanics of hedging and coppice may be of interest to botanists and veld managers.
Bud Removal And Replacement
Plants have growing points tipped with ‘buds’ at the end - or apex. These ‘apical’ buds contain ‘meristem’ cells in the first couple of millimetres of the tip. These meristem cells produce ‘hormones’ called auxins that inhibit the development of many buds that lie dormant lower down the branch. This physiological process is called ‘ apical dominance’.
The lower buds, because they normally occur in the ‘axils’ of leaf growth, are called axillary buds. As long as apical buds are present they suppress the growth of axillary buds that are within the area of dominance lower down. Below this area of dominance other branches are able to develop.
Trimming of the apical bud, as is done by browsing animals, eliminates the source of auxin and its inhibiting effect on the other dormant axillary buds, allowing them to grow. Each time the suppressive effect of an apical bud is removed an increasing number of axillary buds grow new branches. Axillary buds, in their turn, become apical, with inhibiting auxin production, until they are removed, compounding the process until the ‘hedge’ effect is produced.
The same type of mechanics are involved in the coppice production of multi-stems. The more some plants are attacked the more they fight back. Some types of plant grow with only one apical bud and when this bud is damaged the whole stem dies. Most palms belong in this category although some will send up new shoots from the base of the plant.
Assessing Veld Condition
When travelling around the area take note of the amount of coppice growth and hedging that indicates overuse or faulted management practice. In many areas the skyline silhouette indicates that a whole generation of trees is absent due to burning or destruction by large herbivores during a certain period.
The young generation of trees are nearly all hedged by heavy browsing. Veld management must be carried out with a long term vision of the objective. The lowveld vegetation climax is woodland, not grassland - except in areas of heavier soils - and burning for grassland is a temporary measure that will inevitably be re-invaded by thick scrub.
Proper management will maintain a healthy savannah woodland and, hopefully, the perennial grasses that supported healthy sable herds not so long ago. When the sable antelope die out, like the proverbial ‘canary’, it is a warning that we need to take action before we are also affected. Liberals can escape from the problem or afford to comment from a distance. Realists live with the problem - there is no escape - and have to deal with it. We need to all pull together for the optimum future of this region.