African Birds – BOU Open-Day
16 August 1998, IOC, Durban, South AfricaÔÇ¿by Neil Bucknell
The BOU organised an open meeting on the subject of “African Birds” on the registration day of the International Ornithological Congress at Durban, South Africa – Sunday 16 August. John Croxall reminded us in his introductory remarks that the Union had made a considerable contribution to the early development of ornithology in Africa. The purpose of the open meeting, however, was to look to the future and not to the past. The speakers rose to John's challenge and in doing so highlighted a number of the underlying themes which frequently recurred in the African contributions to the main proceedings of the IOC.
The challenges that face ornithology and conservation in Africa are considerable. In the opening talk on Taxonomy, Adrian Craig highlighted some of the difficulties and problems yet to be resolved even with regards to the species which had (apparently) long been known to science. A number of apparently widespread species showed considerable geographical variation. However, information on distribution, behaviour and movements was still very limited or non-existent even for widespread species. DNA analysis would not help to resolve many of these uncertainties. Not only is it expensive but there is still considerable controversy as to the significance of degrees of variation and even the relationship of various groups which occurred in Africa, such as the Mousebirds Colius spp. or the Sugarbirds Promerops spp. He appealed to the BOU and others to ensure that the museum collections were maintained and that the African material remained accessible. The future of some important African collections (such as that at Bulawayo) was in the balance as a result of the shortage of resources.
Phil Hockey's talk indicated that as well as resolving the taxonomy of known species, there was still plenty of opportunity to discover new and unknown species. The rate of discovery of these species has not diminished in the last half-century. As many were described between 1979 and 1988 as were described between 1949 and 1958. There were a considerable number of species which were only known from one or two specimens (such as the Congo Bay Owl Phodilus prigoginei, the Mascarene Shearwater and the Kibale Ground Thrush Zoothera kibalensis). As recently as 1976 a new species (the Algerian Nuthatch Sitta ledanti) had been discovered on Europe's doorstep. There was clearly, therefore, plenty of scope for the discovery of new species by old fashioned “pith helmet and butterfly net” exploration. Phil highlighted a number of areas where little or no work had been done in the last 50 years, including the Central African Republic, Angola, Northern Mozambique and the Republic of Congo (formerly Zaire). He also gave a list of various recent sightings of unidentified species to whet the appetite further.
Having established the difficulties in identifying the range and numbers of species in Africa, Lincoln Fishpool and Gary Alport, in the last talk outlined the steps being taken by BirdLife International in identifying African IBAs. This work followed up similar work in Europe and the Middle East culminating in publications in 1989 and 1994 listing the identified areas. Lincoln Fishpool reminded us of the four criteria to be applied – those areas holding globally threatened species, those holding important biome assemblages, areas with significant numbers of endemic species or with significant congregations of birds. He outlined the process from the initial research to set up the areas, the drawing up of inventories, moving through to action planning and then monitoring protected areas. There are already ten government partnerships with countries as diverse as South Africa, Tunisia and Sierra Leone.
Three speakers reviewed various aspects of the monitoring of poor populations in South Africa. James Harrison of the University of Cape Town's Avian Demography Unit gave an overview of their work. Their mission is to study bird populations in Southern Africa, to aid conservation, to foster collaboration between amateurs and professionals and to ensure that participation is fun. The Unit was established in 1991 by Les Underhill, sponsored partly by the RSPB. James also acknowledged the debt owed to the BTO, many of whose methods had been adopted by the surveys undertaken by the Unit. Perhaps the BTO could, however, learn from the Unit when it came to devising acronyms for its surveys – CWAC for their equivalent of the wildfowl count and CAR for road counts of large terrestrial birds in agricultural landscapes. Perhaps the outstanding achievement of the Unit, however, was the publication of the South African bird atlas.
Derek Pomeroy from Makere University, Uganda, reviewed the brief history of South African bird observatories. Originally these had been established as temporary stations for monitoring the annual migration of Palearctic visitors. It was clear, however, that ringing would be a useful tool for learning more about Afrotropical birds, especially as regards longevity and movement. Dieter Oschadleus enlarged on this in his talk on Ringing. He showed how ringing data were highlighting the differences in the life style of African birds compared to those of temporal regions. The data that were accumulating highlighted that tropical and sub-tropical species tend to live much longer than their counterparts from temperate regions. By comparing species of weaver Philetairus spp., it appeared that the closer a species range lies to the Tropics, the longer its life span is likely to be – there did not appear to be any relationship with the length of any regular migration.
Steven Piper's brief but entertaining talk looked at possible explanations for the mechanisms behind this. Scientists from a temperate background tended to assume that the annual seasonal cycle was the controlling factor in breeding biology. This did not, however, appear to be the case in the sub-Tropics. Work in Africa, Australia and New Zealand had indicated that rainfall was the key. In the sub-Tropics the pattern of rainfall from year to year was highly irregular with no apparent predictable pattern. Despite all the publicity given to El Nino, the South African Weather Bureau considered that only 20% of the droughts in South Africa were attributable to its effects. Work by McLean over 30 years on the Sociable Weaver Philetairus socius in the Gemsbok National Park indicated that breeding was triggered whenever 20mm of rain occurred. This could result in the species breeding up to three times a year or going two or three years without breeding. Longevity rather than production rates was more important to the survival of the species in sub-Tropical regions.
Two speakers highlighted some of the conservation problems facing African birds. Munir Virani (whose attendance was funded by the BOU) presented a paper showing the effects of the intensification of agriculture around the shores of Lake Niavasha in Kenya. He had investigated the effect on raptors at the top of the food chain where they were particularly vulnerable to a loss of habitat and to the concentration of contaminants. In Kenya 30% of raptors were in the three categories of threat identified in local governmental red data lists (compared to an average of 9% throughout the world). In his study area there had been a rapid growth in population accompanying a considerable intensification of both cultivation and grazing by the local Masaia population. The population of African Fish Eagles Halliaeetus vocifer, for example, had declined from between 120 to 200 in the early 1970s to probably no more than 50 at present. There were still some protected areas (although enforcement had not been reliable and contamination of the Lake continued from agricultural chemicals despite its designation as a RAMSAR site in 1995). Despite this, there were startling differences in mortality rates. In Auger Buzzards Buteo augur, this varied from 13% per annum in protected acacia areas to 60% in agricultural areas with direct persecution responsible for a considerable proportion of this.
Christine Dranzoa looked at the impact of forest management in East Africa. Although Africa still holds 20% of the world's tropical rain forest, the forest suffered from three underlying African problems – the lack of a capital base, the lack of technology and the lack of skilled manpower. In Uganda since independence there have been seven changes of policy, on the change of each government, which had resulted (for example) in the human population of Kibale Forest increasing from 30 households in 1976 to over 71,000 people in 1988. Not only was forest cleared for timber, but undergrowth was also cleared for uses as diverse as charcoal burning and providing the raw materials for basket weaving. Christine emphasised that the difficulties of reconciling conservation with local economic needs were hindered by the fact that the costs of rainforest clearance were generally under-estimated and not appreciated. Malaria incidences are increasing in clear areas and bacterial infections are spreading amongst women engaged in agriculture. Uganda has now embarked upon a campaign of education aimed both at policy makers and children including an ecological literacy program and community conservation projects in areas around the forests. Emphasis was being placed on the potential benefits from eco-tourism in preserved rain forests with a view to changing attitudes and ensuring that a more positive view was taken of this valuable resource.
The two remaining speakers looked at positive action being taken for conservation in very different circumstances. Les Underhill from Capetown University looked at steps being taken to combat the effects of oil pollution amongst the penguin colonies off the eastern Cape coast. This population was already under pressure. Guano extraction since 1900 had already removed the burrows formerly used for nesting leaving the penguins to nest in the open where they were exposed to some rain and predation by Kelp Gulls Larus dominicanus. The world population of African Penguins had been reduced from 1,000,000 to 180,000. Oiling regularly occurs on the coast which is on one of the world's busiest sea lanes, but a concerted campaign of rounding up and cleaning oiled penguins had been undertaken at the main colonies of Dassen and Robben Island. In contrast to the very low success rate revealed by studies of cleaning following oiling incidents in Europe and North America, the South African experience was that a very high success rate could be achieved. Each bird was given a thorough 90-minute wash, it was then put into clean water for an hour and then every feather track was examined for water penetration. Monitoring through ringing had shown that 72% of birds cleaned up following the Apollo Sae incident in 1994 were still alive in July 1998 (see Underhill et al in this issue of Ibis). Indeed, of eight birds known from ringing recoveries to be more than 20 years old, three are rehabilitated oiled birds – a greater survival rate than that amongst the population as a whole!
Deon Coetzee reviewed the action taken by the Sandton Bird Club in protecting the breeding areas of the White-winged Flufftail Sarothrura ayresi, a scarce and widespread bird dependent upon waterlogged sedge areas in highland grassland areas. Such areas were threatened by drainage and over grazing. The group had secured protection firstly at Middelpunt and now had an agreement in place having offered to rent the site until 2005. A management regime had been instituted which included limiting access to two times a year. The Middelpunt Trust had been established and had now secured two further sites. The species were also know to occur in Ethiopia and the Trust had sent Barry Taylor there who had reported that it had occurred more in mixed grass than sedge areas. As a result such habitat was investigated in South Africa and a further nine sites for the species had been discovered. There was now a regular exchange of expertise with workers in Ethiopia, and the Trust had paid for an Ethiopian to come to South Africa for a month to study methods there.
In his concluding remarks, John Croxall thanked the speakers for their contributions. Even though the BOU may not make such a large impact in future, it still had much to offer through its Checklist Series, through papers in Ibis and through grants. The contributions had highlighted that much still needs to be learnt but that there were promising signs of co-operation and progress throughout Africa. The meeting provided an up-beat introduction to the main conference, and Chris Fear and Barry Taylor are to be congratulated and thanked for their efforts in bringing together the program for the meeting.
From Ibis 141 (1) January 1999