Get to know the facts about Marabous

I have been provoked to write this article because of a misleading caption of a picture that appeared in the New Vision of Thursday April 6, 1995, which stated that a tree on Kampala's Parliament avenue has lost leaves due to the presence of the Marabous. It is common knowledge that Kampala City Council is looking for ways and means of eliminating these birds within the city. But the questions are: Do these officials know what these birds are, their requirements and what attracts them to the city? 

The tree in question is the Mvule tree formerly called Chlorophora exelsa now known as Milicia exelsa an indigenous tree of the deciduous type. These types of trees shed leaves at the beginning and end of the year. This particular tree will not be expected to have full blossom of leaves till later in the year, and mind you not all the trees shed leaves at the same time. Mr. Anthony Katende, a renowned taxonomist at the Botany Department, Makerere University, said that was naive, irresponsible reporting that abused the science of the plant (tree).

Marabou chick thrown out of nests on Jinja road

These are some of the facts about Marabous (Leptoptilos crumeniferus) Marabous are residents and local migrants throughout tropical Africa from Senegal to Somalia, South to Botswana, but rare in extreme South. While mainly scavengers, they can also be active predators, catching rats and mice with a swift snap. They can swallow whole lumps of food of up to 1kg. The only other two close relatives are found in Asia, thus the Marabou is the only one of its kind we have in Africa. Marabous prefer open or semidesert areas, there are rare within forested and true deserts. They are associated with man near fishing villages. Records show that the population of Marabous has been increasing since 1969 when the first count of the breeding population was made.

In Kampala, the breeding population has increased from 11 pairs in 1969 to over 500 pairs in the 1994/5 breeding population. The total breeding population in the country is well over 1,000 breeding pairs. Marabous can be seen elsewhere on rubbish dumps and abattoirs in the towns where they forage for food. They nest in close proximity to wetlands usually swamps where they forage for aquatic prey for their young.

Today, Marabous can breed even more successfully near human settlements like towns and cities. This has been the case with Kampala, Masaka, Hoima, Masindi, also Kikube, Kakooge to mention but a few. This is associated with easy availability of food (artificial) and good nesting sites around human populated areas. They are most numerous in the areas of moderate rainfall near the equator, and central Uganda is favourable. Marabous have a breeding season regime of about 190 days, approximately 6½ months from the time of nesting to when the young become independent. This period in Uganda starts in August and ends in May the following year, that is, a bird that starts nesting in August ends the season in February or early March. Marabous begin nesting in August, through September, October and November. Early nesting is a successful timing of the food availability at the end of a dry spell and occupation of suitable nesting sites. Breeding populations compete for nesting sites.

Marabous also have a gregarious behaviour in nesting which is an advantage because pairs that have bred successfully return to the same site/colony, the young inexperienced breeders seeking sites join an already established colony as the latter's existence is an indication that the site/colony is safe in food supply, protection from predation, harassment and interference by other factors like humans. The young pairs are also poor in finding food for the young, thus would be directed to foraging areas by the experienced breeders. The factors affecting the choice of breeding habitat are governed by climate and topography. Proximate factors being adequate food supply for both adults and young, nest sites and nesting materials, and other environmental features which supply the birds’ needs. For example display points during courtship time, preening, and later in the season fledging success of the young ones. On close examination, a suitable locality, therefore, should reveal that the site supplies many of the needs.

Taking Kampala town as an example it offers the following:-

1. Easy food availability for both adults and young. People in town around Market centres, institutions and hotels have lost sense of cleanliness, proper deposition of garbage and remains which leaves the city dirty, and in some places stinking awful. This, ironically, provides easy food availability to scavengers including Marabous. God forbid, some human beings have benefited from this carelessness. Abattoirs, butcher areas, garbage heaps, rubbish dumps, dust bins are all scattered around the city. Many hotels and institutions have no proper garbage tips. This cannot be blamed on innocent birds looking for survival like everybody else.

2. Easy and good nesting sites - Marabous prefer trees with laterally interwood branches strong enough to hold twigs, weight of parents (female and male), in addition to broods which may be 2-4 in number. The total weight of a nest with all the occupants may be well over 40kg. This would be in addition to resisting strong winds and storms since the nests are usually located on topmost parts of the trees. This factor has been well covered by availability of such strong trees in the city centre. These include Mvule, a known indigenous strong, hard wood tree, Cupressus species, an exotic tree used as an ornamental tree in homesteads for shade and hedges, and other trees like Ficus which may serve as substitutes in the latter's absence. These birds also prefer open aspects to keep good watch of birds of prey, high enough to escape from some snakes and Mongooses. Indeed, nesting colonies are situated on tops of hills of Kampala city, that is Makerere, Nakasero, Rubaga, Namirembe and Mulago. Fortunate for these birds, that is where the above species of trees are mainly found, not also forgetting food resources, i.e. domestic household refuse.

3. Security - these rather docile creatures have lived with people for long without any problem until recently when KCC decided to discredit them, just as a displacement act of their negligence. The birds are harmless and have learnt how to associate with people. This can be realised by the location of their nesting sites close to most densely populated areas around Kampala city. Others are located on less expected public places like City Square, Nile Hotel, Standard Chartered Bank and Stanbic Bank, CPS, Uganda High Court, Makerere University and others. Feeding places are anywhere remains, uncovered dust bins, uncovered KCC rubbish skips can be found.

4. Fledging success. Nesting sites of marabous are located on such places that when the young fledge they easily find food, thus near food sources. These places must have no predation pressure for both young and adults, also should minimize natural hazards like wind breaks because of storms and winds. Kampala City Council should have appreciated the work the Marabou is doing in the City. These birds being scavengers, eat virtually every piece of tissue whether rotten or fresh.

The residents of Kampala seems to have learnt to live with their garbage. Food remains are scattered everywhere in now the latest way of deposing waste, that is wrapping and packaging waste in polythene bags which are then thrown anywhere along main roads, streets, floors and yards of flats. Its only the responsible marabou that picks and cleans the potential health hazard! It’s only that Marabous are a little few with a small capacity that they cannot cope with the 1,000 metric tones of waste deposited daily in Kampala.

In some pastoral nomad societies, Marabous and Vultures have been associated with the time of much death in domestic animals. This is because these animals being scavengers flourish when other animals are dying. The appearance of large numbers of these birds close to human settlements is believed to forecast an approaching mass death of domestic livestock on people due to drought or war. This is definitely not the case with Kampala, but it is an indication that the garbage waste has reached a dangerous level and poses a great health hazard to Kampala city.

Marabous ,therefore, become indicators of the pollution level in town. Birds can be used as a source of material for the chemical analysis of environmental pollutants. Avian eggs, in particular, have been used widely for the analysis of residue levels of organochlorides. This is a rather destructive way of collecting information since it affects the breeding success of the birds in question. Although it is a valuable approach for monitoring the temporal trends of organochlorides, it is only limited and valid to only compounds with a high affinity for lipids. Heavy metals (another class of pollutants of major interest) are not deposited in eggs. One approach is obviously to measure levels in tissue but a much less destructive approach is the use of feathers as a monitoring device. This can give reliable trends of dangerous metals like lead, mercury and others.

Therefore, these birds can be good bio-indicators of the level of our environmental problems. This, therefore, takes me to my next point and that is research. As described above, the Marabou is a potential bird for research especially pollution, baring in mind its behaviour as a scavenger. Birds continue to provide vital data as the complex mechanism of atmosphere pollution and the effects of pesticide residues are slowly unravelled. On the other hand, the value of birds to human society is now widely recognised and can be extensively traced beyond their immediate products.

In recent years, the 'cash value' of wildlife has featured increasingly in the arguments for conservation. Wildlife tourism, ranching and sustainable utilisation of natural resources are promoted as sources of foreign exchange for developing countries. In many industralised countries the revenue from birdwatching, and related 'industries' can be counted in millions. People come all the way from Europe, America to watch these birds, but we are here talking of eliminating them and tomorrow we talk of promoting tourism. What a contradiction! It will be unfair if I do not mention the value of nature conservation.

As previously mentioned, Marabous are part and partial of our environment (nature), and are attracted to places because of the favourable feeding and breeding conditions that prevail. It would be very unfair to us (KCC) to blame these birds for what they have not done or created. It’s our duty to protect and preserve our natural heritage. It’s now general knowledge that there are many more scavengers than Marabous. These include street kids who forage through mounds of unbearably filthy garbage, mentally deranged people some with innocent children who earn their living through the same process. This is not to forget domestic and wild cats, dogs, goats and sometimes cows in the periphery of the city. There are also domestic fowls that forage in the same places and of course other birds like Vultures, Crows, Kite, Sparrows which survive from such garbage tips.

I have watched many times school children who get material for balls like diary milk plastic bags. All these share the refuse tips with marabous. It will be unfortunate if KCC resorts to means like poisoning the Marabou as these garbage areas would be some of the target places. Of course the stench in air from such contaminated places can be dangerous to people like hawkers where they normally take refuge from KCC officials' harassment, and indeed other people around the garbage heaps. Remember that the poisoned marabou would not die from the very place it has been poisoned thus the affect would cover as big area as the Marabous range. Remember also that poison-contaminated water that seeps out of the garbage bins ends up in channels like Nakivubo already being used by people. The recent water shortage that hit the Kampala area demonstrated this very clearly. On the other hand, all this water finally ends up in big systems like Lake Victoria where the foodweb becomes more complicated affecting many other organisms. This is only one case of poison that I have mentioned, but even others would have adverse side effects.

There is only one positive, environmentally friendly and easily acceptable solution, keep the City clean and Marabous will go by themselves. Lack of transport to ferry the rubbish will not be a reason for prosecuting and exterminating the population of the innocent creatures. Failure to cover, burn, incinerate all the rubbish on KCC’s depository areas will not stop scavengers from making use of them.