MINUTES OF THE ANNUAL GENERAL MEETING OF THE SOUTH AFRICAN ORNITHOLOGICAL SOCIETY,HELD AT CAPE TOWN ON 17 May 1969

Earle, R.A. &; Oatley, T.B. 1983. Populations, ecology and breeding of the Orange Thrush at two sites in eastern South Africa. Ostrich 54:205-212.

The two populations of the Orange Thrush Turdus gurneyi studied represented two races, the nominate gurneyi in Natal and disruptans in Transvaal. In the Transvaal there was a large influx of individuals during the winter but numbers stayed constant during the breeding season with one pair/ha. Natal birds were more sedentary. Food seemed to be a major factor in regulating the winter population size of both the Orange Thrush and the Olive Thrush T. olivaceus in the Transvaal forest as the number of earthworms showed a peak just before the bird numbers peaked. In Natal the Orange Thrush showed a higher degree of specialization in diet than the Olive Thrush which his a mixed diet. Clutches consisted of two eggs and incubation lasted IS days. Chicks were brooded frequently, virtually to the time of fledging, thus protecting them from the cool, wet conditions of the forest. The nestling period was 15–18 days. The Orange Thrush preferred areas in the forest where little vegetation occurred at 1,0-1,5 m and where a good layer of leaf litter was present.     

The comparative morphology and anatomy of Dioscorea sylvatica Eckl. from Natal and the Transvaal

The morphology of Dioscorea sylvatica from Natal and the hills in the Lydenburg district of the Transvaal is described, as well as the anatomy of the leaf and stem. Differences were noticed between the Natal and Lydenberg types which are inconsistent with Burkill's classification of the species. From the differences it is suggested that the Lydenberg type be designated as D. sylvatica subspecies lydenbergensis subsp. nov.     

Identification of an isolate of bean common mosaic virus from the Transvaal and Natal

The BCMV isolates most common in the Transvaal and Natal were identified from field collected samples. The isolates belong to pathogenicity group V, to which the recessive gene bcl²confers resistance.     

1. PELICANS BREEDING ON SEAL ISLAND

Clark, A. 1974. The status of the whistling ducks in South Africa. Ostrich 45:1-4. Since the 1920's the status of Dendrocygna viduata and D. bicolor has changed from that of an irregular to that of a regular species in the Transvaal, Zululand, Natal and Orange Free State. In more recent years their numbers have shown a steady increase and breeding has been established. D. viduata numbers built up more quickly than D. bicolor and it has become an established resident whereas D. bicolor is primarily a summer visitor.

In the Western Cape Province there has been little change in the status of either species but there are indications that D. viduata is appearing mote regularly in the Eastern Cape Province. The position in East Griqualand and the Transkei is obscure. In South West Africa, excluding the north east corner, D. viduata remains irregular and D. bicolor rare.

The preference shown by both species for areas where sewage effluent is disposed of and for new storage dams inevitably links their spread and increase with that of the human population.     

THE BREEDING STATUS OF THE CAPE VULTURE IN THE TRANSVAAL DURING 1980—1985

Benson, P. C., Tarboton, W. R., Allan, D. G. & Dobbs, J. C. 1990. The breeding status of the Cape Vulture in the Transvaal during 1980–1985. Ostrich 61: 134–142.

Ten of the 11 extant Cape Vulture Gyps coprotheres colonies in the Transvaal were censused using aerial and/or ground census techniques in the 1980–1985 breeding seasons. Minimum counts were obtained and best estimates of total numbers of “active nests” were determined using correction factors to compensate for incomplete photocoverage in the aerial technique and nest failures prior to the census dates. In 1985, the year when the most complete data were available, a minimum of 2741 and a best estimate of 2987 active nests were determined to be present in the Transvaal. At the large colonies, which were intensively monitored, breeding numbers did not fluctuate greatly from year to year, and it is thus estimated that about 3000 pairs of birds bred yearly in the Transvaal during the study period. Although the data indicate that the total numbers are greater than previously thought this is due to improved census techniques, rather than an increase in the population. Ninety-eight percent of breeding occurred at six colonies and 82% at three (Kransberg, Blouberg and Manutsa). The large colonies are associated with communal grazing (homelands) Private cattle and game farming and nature conservation areas, where the use of poison for predator control is minimal. The vulnerable status afforded the Cape Vulture in the South African Red Data Book—Birds (Brooke 1984) is justified because of the bird's disappearance from some breeding colonies, reduction in numbers at others and its vulnerability to poisoning.     

BREEDING SEASONS OF BIRDS IN DECIDUOUS WOODLAND AT ZIMBABWE,RHODESIA, FROM 1970 TO 1974

Vernon, C. J. 1978. Breeding seasons of birds in deciduous woodland at Zimbabwe, Rhodesia, from 1970 to 1974. Ostrich 49:102-115.

The birds in Brachystegia woodland bred in the spring and 98% of 1645 breeding records occurred between September and November. 90% of the records, and 43 of the 71 breeding species, were of insectivorous passerines. The breeding seasons of individual species lasted for between less than two months to more than three months, and their peak breeding periods varied between early September and the middle of October. The breeding season started earliest in 1974 and latest in 1973, and the start of two species was related to the timing of leaf emergence of the dominant tree in the woodland and to rainfall the previous rainy season. Food supply may be the proximal factor influencing the onset of breeding.     

UNCOMMON VISITORS TO MARANDELLAS DISTRICT

Schmitt. M. B. 1976: Observations on the Cape Rail in the Southern Transvaal. Ostrich 47: 16–26.

For five years a population of Cape Rails Rallus caerulescens has been studied on a vlei in the southern Transvaal. Morphological differences between male and female are discussed, the breeding season is indicated and the development of chicks is described. In autumn a migration possibly of birds from drier areas invades the study area. The breeding population appears to be resident. The Cape Rail moults all flight feathers simultaneously during its breeding season.     

6. SHORT NOTES

Schmitt, M. B. 1975. Observations on the Black Crake in the Southern Transvaal. Ostrich 46:129-138.

During a four-year study period, several pairs of Black Crakes Porzana flavirostris and their progeny have been studied on a vlei in the southern Transvaal. Morphological differences between male and female are discussed, a double-brooded breeding season is indicated, the development of chicks is described, and the moult cycle is indicated. The Black Crake moults all flight feathers simultaneously and during its breeding season.     

Occurrence and distribution of Dolops ranarum Stuhlmann, ectoparasite of freshwater fish in the Transvaal, South Africa

During 1982–83 fish parasitological surveys were carried out in 15 dam reservoirs in the Transvaal. The fish ectoparasite Dolops ranarum was found on eight different fish species of which Oreochromis mossambicus. Clarias gariepinus and Barbus marequensis are regarded as main hosts. Distribution records and infestation statistics are presented. It was found that D. ranarum is restricted to the Limpopo Drainage System. An evaluation of site preference on host fish reveals that the mouth cavity, in the case of O. mossambicus , and skin and fins, in the case of C. gariepinus , were the sites most intensively infested by this parasite.     

Mountain streams of the Barberton area,Eastern Transvaal. Part I,A survey of the fauna

Summary This paper records the results of a faunistic survey of the mountain streams of the Barberton area of the Eastern Transvaal. Sampling was carried out in five different biotopes; cascades, sprayed flanking regions, stickles, backwaters and pools.Netting of the adults and imagos and breeding out of the larvae of Chironomidae, Odonata and Ephemeroptera was done.The faunal affinities were assessed by a comparison of the mayfly fauna of this area with that reported in other surveys conducted in Africa.     

NOTE ON THE LONGEVITY OF THE VULTURINE SEA.EAGLE,CYPOHIERAX ANGOLENSIS (Gm.)

Herremans, M. &; Herremans-Tonnoeyr, D. 1994. Seasonal patterns in abundance of Lilacbreasted Rollers Coracias caudata and Purple Rollers Coracias naevia inferred from roadside counts in eastern and northern Botswana. Ostrich 65:66-73

The relative abundance of rollers (Coraciidae) in 45933 km of roadside counts made in eastern and northern Botswana between May 1991 and April 1994 was assessed by season and biome. Lilacbreasted Rollers appeared to move from breeding grounds in the northern Botswana woodlands into the northern Kalahari, and north-westward from breeding grounds in the Transvaal into the Limpopo drainage system and adjacent eastern Kalahari, during winter. Purple Rollers showed an influx during autumn and winter over most of eastern Botswana, but birds did not remain during the drought winter of 1992. The pattern indicated a large scale west-east or southwest-northeast migratory movement, from breeding grounds in the drier parts of the Kalahari to wintering grounds in the more humid periphery of the Kalahari.     

Role of breeding and natal movements in lifetime dispersal of a forest‐dwelling rodent

The lifetime movements of an individual determine the gene flow and invasion potential of the species. However, sex dependence of dispersal and selective pressures driving dispersal have gained much more attention than dispersal at different life and age stages. Natal dispersal is more common than dispersal between breeding attempts, but breeding dispersal may be promoted by resource availability and competition. Here, we utilize mark–recapture data on the nest‐box population of Siberian flying squirrels to analyze lifetime dispersal patterns. Natal dispersal means the distance between the natal nest and the nest used the following year, whereas breeding movements refer to the nest site changes between breeding attempts. The movement distances observed here were comparable to distances reported earlier from radio‐telemetry studies. Breeding movements did not contribute to lifetime dispersal distance and were not related to variation in food abundance or habitat patch size. Breeding movements of males were negatively, albeit not strongly, related to male population size. In females, breeding movement activity was low and was not related to previous breeding success or to competition between females for territories. Natal philopatry was linked to apparent death of a mother; that is, we did not find evidence for mothers bequeathing territories for offspring, like observed in some other rodent species. Our results give an example of a species in which breeding movements are not driven by environmental variability or nest site quality. Different evolutionary forces often operate in natal and breeding movements, and our study supports the view that juveniles are responsible for redistributing individuals within and between populations. This emphasizes the importance of knowledge on natal dispersal, if we want to understand consequences of movement ecology of the species at the population level.     

FIRST RECORD OF THE SNAKE CATFISH CLARIAS THEODORAE (WEBER, 1897) (CLARIIDAE: PISCES) FROM THE TRANSVAAL,SOUTH AFRICA

SUMMARY

Two new distributional records of the snake catfish Clarias theodorae (Clariidae: Pisces) from Transvaal tributaries of the Limpopo River are documented. This is also the first record of the snake catfish from the Transvaal. The habitat preference of this species is briefly discussed and brief comment is made on probable migration routes.     

Molecular genetic variation across the southern and eastern geographic ranges of the African lion, <Emphasis Type="Italic">Panthera leo</Emphasis>

We examined sequence variation in the mitochondrial cytochrome b and NADH dehydrogenase subunit 5 genes (2,360 bp total) for 26 lions from eleven locations throughout sub-Saharan Africa. Six distinct haplotypes were observed in the combined sequences, forming two clades: the eastern and the western savannas. The Uganda-Western Kenya haplotype grouped at a basal position with the eastern clade of lions from Tsavo south to the Transvaal and Natal regions. The phylogenetic position of the haplotype from Sabi Sands in the southern part of Kruger National Park remained poorly resolved. The haplotypes found in Namibia and Botswana formed the western clade. The modest genetic variation documented here argues against taxonomic distinctions among living African lions.     

Observations on circular purple scaleChrysomphalus aonidum (Linn.), and two introduced parasites in western Transvaal citrus orchards

Circular purple scale,Chrysomphalus aonidum (Linn.) is localized in its appearance in South African citrus orchards. It mainly occurs along the Natal Coast, the Western Transvaal and the Transvaal Lowveld. In the Western Transvaal its importance was highlighted by the development of biological and integrated programmes chiefly directed against red scale [Aonidiella aurantii (Mask.)]. This paper reports on an attempt at the biological control of circular purple scale in the Western Transvaal by introducingComperiella bifasciata. The eggs ofC. aonidum, at 26.7°C and 50% relative humidity, hatches within two to three days. The female has two and the male four moults. The first eggs are laid approximately 43 days after settling of the crawler.C. aonidum has 4 broods a year. C. bifasciata, circular purple scale strain, is uniparental. The adults can live for only one day without food, but from 3–22 days in the laboratory when fed on honey. The photopositive adults lay the eggs internally in female scales, male scales being seldom parasitized. The eggs hatch in 3–4 days of which a female parasite lays an average of 37. The larval stages occupy 13–15 days and the pupal stage 7 days. Superparasitism does occur in which case only one larva reaches maturity. The length of the life cycle varies in various stages ofC. aonidum, the shortest was in scales 25–35 days old. ThoughC. bifasciata was established after release in citrus orchards, it maintained itself at very low levels or disappeared in competition withAphytis holoxanthus.     

Relationships between some genetic parameters and test environments in open-pollinated families of Pinus elliottii in South Africa

Summary Growth traits, stem form and branch characteristics in three series of well-replicated trials, comprising open-pollinated families of Pinus elliottii Engelmann, were analysed to investigate whether the absolute value of the component of variance for family effect and its relative value (which is equivalent to one-quarter of heritability on individual values) were related, with trial averages of the traits studied taken as productivity indices of the sites tested. The first series, called the foreign selection series, consisted of four trials comprising open-pollinated families from single clones from a Florida seed orchard and from selected trees in Queensland, Australia. Two trials were established in the eastern Transvaal, at Tweefontein and Frankfort State Forests (SF), and two in Zululand, at Dukuduku and KwaMbonambi SF. The second series, called the Zululand selection series, consisted of open-pollinated families from single trees selected in Zululand that were compared in three trials: in the eastern Transvaal at Wilgeboom SF, in Zululand at Dukuduku SF and in the southern Cape at Lottering SF. The third series, called the South African selection series, consisted of open-pollinated families from single trees selected in the different forest areas of South Africa and compared in four trials: two trials in the eastern Transvaal at Tweefontein and Mariti SF and two in the Natal province at Dukuduku and Weza SF. Some positive and linear relationships between absolute sizes of the variance component for family and trial average for all traits studied, except stem form, were discernible for the foreign selections and for the Zululand selections. The South African selections presented a more erratic pattern of variation. However, when the origin of the genetic material was disregarded, the positive trends were undeniable. Curvilinear relationships between relative values and site averages were discernible, when the origin of the genetic material was disregarded. Further research is needed in order to confirm the suggested effect of site on genetic expressivity of open-pollinated families of slash pine grown in South Africa.