THE SURVIVAL RATES OF SOME SOUTHERN AFRICAN PASSERINES

Yom-Tov, Y., McCleery, R. & Oatley, T. 1994. The survival rates of some southern African passerines. Ostrich 65:329-332.

Little information is available on survival rates of southern hemisphere passerines, but two recent studies indicate that Australian passerines tend to live longer than their northern hemisphere relatives. The aim of this paper is to provide data on survival of some South African passerines and compare them with Australian data. The survival rates of eleven species (eight genera) of South African passerines were calculated using recapture data provided by the South African Bird Ringing Unit for birds whose retraps occurred more than 12 months after the original ringing. Survival did not depend on either the length of the study or body mass. Mean survival rate was similar to that of 32 species of Australian passerines, which is at least 1,2 greater than that of British passerines.     

THE DISTRIBUTION OF THE PIED STARLING,AND SOUTHERN AFRICAN BIOGEOGRAPHY

Craig, A. J. F. K. 1985. The distribution of the Pied Starling, and southern African biogeography. Ostrich 56:123-131.

The Pied Starling is restricted to South Africa, Lesotho and Swaziland, but within this region it occupies a variety of habitats. Its modern distribution is certainly influenced by its association with man. However, a comparison with other vertebrate species, and with patterns of plant distribution, suggests that its geographical distribution has been determined primarily by its evolutionary history. A hypothesis for the origin of this species leads to several predictions concerning biogeography in southern Africa.     

COMPARISONS OF THE VOCALIZATIONS AND SOCIAL BEHAVIOUR OF SOUTHERN AFRICAN PYCNONOTUS BULBULS

Lloyd, P., Hulley, P.E. & Craig, A.J.F.K. 1996. Comparisons of the vocalizations and social behaviour of southern African Pycnonotus bulbuls. Ostrich 67: 118–125.

Vocalizations and associated behaviour of three Pycnonotus species are described, based on field observations and tape recordings from which sonagrams were produced. These species, which are locally sym-patric and hybridize, have similar vocalizations and displays; differences are most apparent in their contact calls and songs. Quantitative analysis of the songs showed that P. barbatus and P. capensis are easily distinguished, whereas the song characteristics of P. nigricans overlap those of both the other species. Playback experiments with territorial male P. barbatus in an area of allopatry showed similar responses to songs of conspecifics and of P. nigricans, but almost no response to the song of P. capensis.     

THE ROLE OF LARGE-SCALE DATA COLLECTION PROJECTS IN THE STUDY OF SOUTHERN AFRICAN BIRDS

Underhill, L.G., Oatley, T.B. & Harrison, J.A. 1991. The role of large-scale data collection projects in the study of southern African birds. Ostrich 62:124-148.

The major ornithological data collections in southern Africa (checklists, migration enquiry, atlas projects, censuses, bird ringing and recoveries, biometric data, nest record cards, moult cards and beached birds) are described. For each project, current volumes of data are tabulated. The Southern African Bird Atlas Project database contained 5,0 million records in December 1990. 1,25 million birds of 810 species had been ringed with South African Bird Ringing Unit rings by June 1989, resulting in 22 000 recoveries. There were more than 100 recoveries for 27 species. The nest record card scheme of the Southern African Ornithological Society had 117 000 cards on file in February 1990, representing 696 species, with more than 1 000 cards for 18 species. There were 4 040 cards of 380 species in the moult record scheme. African Seabird Group beach patrols had found 10 057 seabirds by the end of 1985. A selection of published applications for each data set is given. The potential of the data sets for further analyses is considered, especially in relation to key demographic characteristics such as abundance, productivity and survival. It is recommended that volunteer participation projects should concentrate on monitoring and that indices for change in the demographic characteristics be developed. Most of the projects could be incorporated into an Avian Demography Unit.     

SUBSPECIATION IN THE SOUTHERN AFRICAN POPULATIONS OF THE SABOTA LARK MIRAFRA SABOTA SMITH

Howard, G. W. &; Aspinwall, D. R. 1984. Aerial censuses of Shoebills, Saddlebilled Storks and Wattled Cranes at the Bangweulu Swamps and Kafue Flats, Zambia. Ostrich 55: 207–212.

Aerial counts of three wetland species of uncertain conservation status were made in Zambia when the opportunity arose during Lechwe Kobus leche censuses. A portion of the Bangweulu Swamps was estimated to have a minimum population of 232 Shoebills Balaeniceps rex, 275 Saddlebilled Storks Ephippiorhynchus senegalensis and 1718 Wattled Cranes Bugeranus carunculatus. An estimate of 3282 Wattled Cranes on part of the Kafue Flats was very similar to that calculated in a count there nine years previously. Further censuses are recommended.     

ADDITIONS TO THE CHECKLIST OF SOUTHERN AFRICAN FRESHWATER FISHES AND A GAZETTEER OF SOUTH-WESTERNANGOLAN COLLECTING LOCALITIES

SUMMARY

An additional 13 species of freshwater fishes recorded from south-western Angola, mainly from the Cunene Basin, are added to the checklist of southern African freshwater fishes, including five species of marine origin permanently resident in the fresh water of the Cunene River mouth. In addition, attention is drawn to a number of doubtful records from the region. A gazetteer of collecting localities in the region is presented.     

ADDITIONS TO THE CHECKLIST AND RECENT CHANGES TO THE SCIENTIFIC NAMES OF SOUTHERN AFRICAN FRESHWATER FISHES

SUMMARY

Alterations and additions to the checklist of southern African freshwater fishes are given based on recent findings and the latest literature. Name changes are given for 13 taxa, and 25 species and subspecies are added to the list. Several species of marine origin (peripheral species) which form an integral part of continental fish communities in coastal lakes and low salinity lagoons are included in the checklist.     

THE PROCESSING OF UNCONFINED,NATURALLY ENTRAINED LEAVES IN TWO LOW-ORDER SOUTHERN AFRICAN MOUNTAIN STREAMS

Summary

Breakdown of unconfined and confined leaves of the riparian tree Brabejum stellatifolium L. was investigated in two low order mountain streams (Window Stream and Langrivier) in the southwestern Cape, South Africa. At both sites, 5000 unconfined leaves were released in April and another 5000 in December 1990. The leaves were marked and half of them presoaked in river water prior to release. Leaves reaching a net 100 m below the point of release were removed periodically. On termination of the experiments, the study reaches were cleared of the remaining marked leaves. The distance which these leaves had travelled, and the retentive feature at which they were found were recorded. All leaves were weighed after recovery. In December 1990, leaves confined in coarse-mesh bags were placed on the stream beds of the two sites. Decay rates of unconfined leaves differed between streams and seasons but not between wetted and dry leaves or those of contrasting initial size and weight. In winter, breakdown of unconfined leaves was rapid (t₅₀ of 6.6d and 23.9d for Langrivier and Window Stream respectively). In summer, breakdown of unconfined leaves was slower (t₅₀ of 58d, Langrivier), but more rapid than leaves confined in mesh bags (t₅₀ of 77d, Langrivier). Distance travelled downstream had no significant effect on leaf breakdown. Different retentive features resulted in different rates of decay. Leaf weight loss in winter and summer at both sites was greatest in riffles (17–80%) and runs (21–78%). In all cases, stranded (exposed and out of the water) leaves lost the least weight (4–38%).