Mass participation and monitoring

Emphasis on analysis, publication, and dissemination of data makes the ADU's outputs big and bold: the largest was the two-volume, 1 600-page, six kg Atlas of Southern African Birds (Johannesburg: BirdLife South Africa, 1997), which recently won the John FW Herschel Gold Medal of the Royal Society of South Africa that is awarded for “outstanding contributions to science in southern Africa, especially of a multidisciplinary scientific nature”. Critical for conservation efforts is The Eskom Red Data Book of birds of South Africa, Lesotho and Swaziland (Johannesburg: BirdLife South Africa, 2000) edited by Keith Barnes, providing a complete update of what we know about threatened bird species in the subcontinent.

The Unit relies to an unusual extent on members of the public, with more than 5 000 contributors to the bird atlas, for instance. The CWAC (the Coordinated Waterbird Counts) project relies on observers counting waterbirds in midsummer and midwinter at some 300 wetlands around South Africa; CAR (the Coordinated Avifaunal Roadcounts) has some 800 participants twice a year counting large terrestrial birds such as cranes, storks, and bustards over nearly 20 000 km of South African roads, mainly in agricultural landscapes. The challenge is to make the recording protocol strict enough statistically to provide reliable data on bird population trends, yet make participation enjoy-able enough for people to want to ‘own' their route and be enthusiastic about covering it every six months.

Another important ADU component is SAFRING, which tags and then monitors birds to determine survival rates, habits, and positions. After the 1994 Apollo Sea oil spill, they put rings on the flippers of over 4 000 of the 5 000 African penguins cleaned by SANCCOB (South African Foundation for the Conservation of Coastal Birds). The subsequent patient monitoring work of ADU PhD students Phil Whittington and Anton Wolfaardt among others provided evidence that birds do survive contamination (though their numbers are affected), and demonstrated clearly the conservation value of SANCCOB's de-oiling (despite the alarmingly low success of similar northern hemisphere attempts to restore seabirds to the breeding populations by cleaning them).

Systematic publication of post-Apollo Sea monitoring data paid off when, six years later, as soon as the Treasure sank, the results were available to key government decision-makers - 10 minutes of reading was all they needed to convince them that rescuing penguins was worthwhile. As a result, the rescue operation began without delay. Says Underhill, “it was in fact so quickly in place that we were in time to prevent birds from becoming oiled - which is what the Port Elizabeth operation was all about. In many oil spills elsewhere, slow reactions by uncertain authorities has led to the deaths of many thou-sands of birds.”

“From the ADU perspective, the Treasure spill demonstrated the value of careful and systematic scientific monitoring. Even more critical, it demonstrated the importance of having the results of the monitoring available at extremely short notice. This is not an easy objective to achieve; it means being continuously on top of data capture and processing. Backlogs are the pathway to disaster.” Professor Les Underhill (University of Cape Town)

For more information on ADU publications, news releases and other activities, visit their website at www.uct.ac.za/depts/stats/adu

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Coastal birds under threat

Other unexpected findings come from Prof Phil Hockey's bird conservation and research projects at the University of Cape Town.

One of them focuses on the Aldabra Flightless Rail, the only surviving flightless bird species in the tropical Indian Ocean. Confined to three islets within the remote coral atoll of Aldabra (the largest in the world) in the western Indian Ocean, this species is at risk because of its tiny range. Applying a carefully planned, soft-release technique, researchers successfully translocated a group of 18 rails to Picard Island, where the species occurred historically but had been eliminated, probably by cats (now themselves removed). Within three months of release the rails were breeding, with a success rate higher than that of the parent population on Malabar Island. The offspring of this first breeding attempt are themselves now breeding. A monitoring programme is studying the translocated birds and assessing the suitability of other islands within the species' historical range for further translocations.

The near-threatened African Black Oystercatcher is another focus of attention. Research into its breeding habits and juvenile movements have yielded information that could save this species from a conservation crisis, reports Hockey.

Confined to the southwestern Afrotropics, with a world population of fewer than 2 000 breeding pairs, African Black Oystercatchers begin life on the open coast at the height of the summer holiday season. Suspecting that human disturbance was causing low chick production, researchers compared breeding success over a range of protected and unprotected sites. They found that, whereas egg loss was similar at the different sites, hatchling survival varied considerably. It averages around 67% in protected areas, but only 27% outside the protected areas where, in many cases, pairs are producing insufficient chicks to replace themselves. It takes time to detect the effects of such reproductive failure because adults are very long-lived.

“Having narrowed the crunch period down to 40 days of the birds' life, we are now trying to quantify the key sources of juvenile mortality,” says Hockey. “If we can devise a means of reducing chick mortality outside protected areas by only 25%, we should have solved the species' looming conservation crisis.”

Three years of ‘colour-ringing' has shown movement patterns among juvenile African Black Oystercatchers that are apparently unique among birds. Whereas breeding adults remain in one area, juveniles leave the parental territory, some dispersing over relatively short distances (up to about 150 km), but about half of them undertaking what seem to be long-distance targeted migrations. Many go to ‘nursery areas' on the Namibian coast north of Lüderitz, the largest we know about (with up to 250 juveniles) being at Walvis Bay / Swakopmund. The record is held by a chick that travelled from East London to Walvis Bay - more than 2 500 km.

Says Hockey of this curious behaviour, “To date, we have found no avian analogue of a species that has a long-distance, once-off juvenile migration and, after returning to the natal area, is sedentary for the rest of its life. Typically, birds are either migratory or not for their entire lives. Our next step is to try to identify the conditions, environmental or physiological, that turn the migratory gene on and off.”

In answer to the problem of what makes birds migrate? the team's analysis of Afrotropical bird species now reveals that those staying in one place tend to eat fruit or fish, whereas those that migrate eat insects. As their prey become increasingly active or aerial, the birds that eat them are increasingly likely to be migratory. In the Americas the pattern is different, and the UCT analysis is now going global, with an international research team including members from Australia and the United States beginning a comparative study of the Asian migratory fly-away route.

Studies of specific species around a large-scale question, involving researchers from different parts of the world, yield critical, and widely relevant information. Explains Hockey, “Bird migrations have been the subject of scientific study for two millennia, yet one vital question has never been addressed satisfactorily: what environmental and ecological attributes predispose a species or population to being migratory? This is critical information, not only for understanding the evolution of migratory behaviour, but also for predicting how species' movement patterns will evolve in response to climatic change.”

More information about research activities at the Percy Fitzpatrick Institute can be found at www.uct.ac.za/depts/fitzpatrick

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Protecting African parrots

At the University of Natal (Pietermaritzburg), Professor Mike Perrin's project on the conservation of African parrots has tried to identify the key factors that cause populations to decline and that prevent natural bird populations from recovering. They have concluded that fragmentation and loss of habitat are major causes, as well as capture of the birds for the illegal pet trade.

The researchers have shown that the Cape Parrot is a distinct species (Poicephalus robustus), forming a species complex with the Grey-headed Parrot (Poicephalus fuscicollis suahelicus) and the Dusky-collared Parrot (Poicephalus fuscicollis fuscicollis), and that its conservation status is more serious than was originally recognised - ‘endangered' rather than ‘vulnerable'. Reasons include the fact that yellowwood forests are not regenerating, and both wild and captive populations suffer from psittacine beak and feather disease. As the number of these birds decreases, rarity -and market value - increase, which in turn stimulates more poaching and accelerates the demise of this species.

The research on Black-cheeked Lovebird populations, however, reveals that they have stabilised at a new, lower equilibrium, after the marked decline that followed long-term drying out of their preferred mopane woodland habitat, previous commercial trade for pet birds, and changing farming practices of rural subsistence farmers who now plant mealies rather than millet and sorghum. Recent data on breeding biology and demography show, encouragingly, that the conservation status of Black-cheeked Lovebirds can be downgraded from ‘endangered' to ‘vulnerable'.

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The economic potential of birds

'Sustainable utilisation' - the theme of a recent study headed by Dr Alan Kemp (of the Transvaal Museum) - unites the need to conserve and protect birds, with the possibilities of of developing their potential in the economic development of humans. It has emerged as the guiding international principle for conserving and managing biodiversity (including the United Nations Environmental Programme and the World Wildlife Fund), and is endorsed in South Africa's new constitution.

The African Hawk-eagle, the Giant Eagle-owl, and the Southern Ground Hornbill all produce a redundant second egg/chick, which invariably dies in the nest, and which can be harvested with no obvious effect on the parent population. The project formed the basis for four Master's programmes. Two were in biology at the University of Venda (one on predicting the size and cost of the harvest, the other on the husbandry of the harvest and rearing of the chicks) and two were in sociology at the University of the North (one on community perceptions of the birds and their utilisation, the other on conflicts in sustainable utilisation between the community and the Kruger National Park from which the birds were harvested).

The study involved the small, rural Makuleke community, who live alongside the Kruger National Park and who have joint control over one of the best birding areas in South Africa, the Pafuri Triangle at the northern tip of the Park. Second chicks of all three species were harvested and carefully raised; the economic feasibility is currently being determined. Potential markets for the chicks exist - for the eagles in falconry, for example, for owls in aviculture, and especially for the hornbills in reintroduction programmes or as traditional medicine.

The concept of using redundant chicks commercially had never been investigated, despite their unquestionable sustainability, and the work is important, says Kemp, to test practical and conceptual hurdles to sustainable utilisation on both sides of the Kruger National Park's fences. “We have established that the harvest and husbandry of these chicks are possible, that it can be done within the practical constraints of a typical rural community.”

Find the Transvaal Museum's Birds of Africa site at http://mail.nfi.org.za/Birds/Birdssa.htm

“The concept of sustainable utilisation can be viewed as the two sides of a mirror. From the side of the resources, in this case birds, it suggests that they might be sustained by utilisation. From the side of the users, in this case humans, it suggests that utilisation of the resources might provide a means of sustenance. These two sides, the one biological and the other economic, have only been reintegrated recently.” Dr Alan Kemp (Transvaal Museum)

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