THE SEASONAL MOVEMENTS OF GURNEY'S SUGARBIRD PROMEROPS GURNEYI IN THE LYDENBURG AREA,TRANSVAAL

De Swardt, D. H. 1991. The seasonal movements of Gurney's Sugarbird Promerops gurneyi in the Ly-denburg area, Transvaal. Ostrich 62: 40–44.

The seasonal movements of Gurney's Sugarbird Promerops gurneyi were studied in the Lydenburg area, eastern Transvaal, South Africa. Influx into the suburban habitat occurred durin the winter when the birds left the mountains at the end of the flowering period of Protea roupelliae. Birifs were mistnetted and each adult colour-ringed with a unique combination for individual recognition. In all, 256 Sugarbirds were ed in the mountain habitat and 50 in the suburban habitat. Of the unringed individuals 22,2 % were ted on cliffs with aloes and 79,3 % around P. roupelliae clumps late in the season. Of the ringed birds 25 (9,7%) were retrapped at sites in the mountain and 10 (3.9%) showed seasonal movements; 6 (8,3%) were recaptured in the same town localities where originally ringed. Mean distance moved was 7 km. An overall recapture rate of 7,5% was recorded during this study. When nectar became scarce the birds started moving away and utilized other food sources. Protea roupelliae showed a flowering peak from October to February which coincided with the sugarbirds' breeding season.     

PLUMAGE CHANGES IN THE MALE MACCOA DUCK

Clark, A. 1974. Plumage changes in the male Maccoa Duck. Ostrich 45: 251–254.

Maccoa Duck Oxyura mi ccoo counts made at various waters in the Transvaal and Orange Free State, South Africa, in which the numbers are separated according to plumage, are presented and discussed in the light of the work done by Siegfried (1968, 1970) on this species. Males invariably outnumber females and the indications are that Transvaal birds move out of the area during winter when most males are in non-breeding plumage. There is little difference in the pattern of plumage changes between Transvaal and Cape birds.     

6. REVIEWS AND CRITICISM OF NOMENCLATURAL CHANGES

CLARK, A. 1976. Observations on the breeding of whistling ducks in Southern Africa. Ostrich 41 59–64.

Records collected since 1954 show that Dendrocygna viduutu breeds in the Transvaal, Natal and Rhodesia, choosing for the most part a limited mid-summer period when most rains can be expected. D. bicolor records for the Transvaal and Natal show a similar pattern but in Rhodesia breeding is not so restricted. In the Transvaal and Natal most records were obtained near the more populated areas at man-made or artificial breeding grounds. Information is given on nest sites and construction, clutch and brood size, and the behaviour of nesting birds. The percentages of juveniles in flocks of D. viduuta following the breeding season are compared showing the apparent effect of rainfall on breeding success.     

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.     

Moult,breeding season,mass, wing length,and dispersal in Cape Robins (Cossypha caffra) and Olive Thrushes (Turdus olivaceus): results from mist-netting garden birds

We compared a data set from the Western Cape, South Africa (GDU, n = 170 Olive Thrushes (Turdus olivaceus), n = 475 Cape Robins (Cossypha caffra)) with our captures in the Eastern Cape, South Africa (n = 197 Olive Thrushes, n = 203 Cape Robins). In both regions Olive Thrushes began moult in December-January, while wing-moult lasted for 89 days in the Western Cape compared to 53 days in the Eastern Cape. Cape Robins began moult in early November in the Western Cape, early January in the Eastern Cape and again the duration of wing-moult was longer in the Western Cape (64 days) than in the Eastern Cape (50 days). For both species the start of moult coincided with the end of the breeding season. Cape Robins were heavier and longer-winged in the Western Cape than in the Eastern Cape. There was no significant difference in mean mass or mean wing length of the Olive Thrush between the two provinces. Both ringing and atlas data suggest that Cape Robins are relatively more common than Olive Thrushes in the Western Cape, but not in the Eastern Cape. In the Eastern Cape we observed colour-ringed robins (n = 2) and thrushes (n = 2) on their breeding territory in all months of the year, suggesting that some individuals of both species are strongly resident.     

THE BEHAVIOUR OF EGRETTA GARZETTA AND E. INTERMEDIA

Slotow, R. H., Mendelsohn, J. M. &; Perrin, M. R. 1987. The diet of adult and nestling Blackshouldered Kites, and breeding success. Ostrich 59:150-154.

Blackshouldered Kite diet was examined at Settlers, Transvaal, by pellet analysis. Rodents made up 98% by number of the adult diet, comprising 51% Otomys angoniensis, 31% Praomys natalensis, and 16% Rhabdomys pumilio. There was no apparent selection for either prey species or age groups. As the breeding cycle progressed the chances of success increased. We found no evidence that nestling survival was related to the quality of their diet.     

NOTES ON THE BREEDING BEHAVIOUR OF MARICO AND PALLID FLYCATCHERS IN THE CENTRAL TRANSVAAL,SOUTH AFRICA

Frost, S.K. 1990. Notes on the breeding behaviour of Marico and Pallid Flycatchers in the central Transvaal, South Africa. Ostrich 61:111-116.

The breeding behaviour of Marico and Pallid Flycatchers (Melaenornis mariquensis and M. pallidus) was studied at the Nylsvley Nature Reserve, South Africa, between September 1980 and January 1981. The flycatchers are morphologically similar but occur in different although sometimes adjacent woodlands. The two species do not differ in their breeding seasons, nor in their clutch sizes. The incubation period, previously unrecorded for Pallid Flycatchers, is 14 days and the fledging period 17 days. Marico Flycatchers fed their chicks more frequently than Pallid Flycatchers and helpers were observed at two Marico Flycatcher nests.     

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.     

Polystomatidae (Monogenea) of southern African Anura: Polystoma claudecombesi n. sp. parasitic in Rana angolensis Bocage

Polystoma claudecombesi is described as a new species of the Polystomatidae (Monogenea) parasitic in the urinary bladder of the anuran host Rana angolensis. This parasite was collected at three localities in South Africa, namely Vernon Crookes Nature Reserve in Natal province, Witsieshoek Mountain Resort in the north-eastern Orange Free State and Bovenste Oog in the province of Transvaal. It is the largest African polystome described to date. Prevalence at Vernon Crookes Nature Reserve was 4.0% and 2.7% in two successive years, with a mean intensity of 1.0 (n=25 and 36, respectively). One of the two R. angolensis from Witsieshoek was infected with 5 parasites. The diversity and distribution of southern African polystomes is also discussed.     

ASPECTS OF THE ECOLOGY OF KNERIA AURICULATA (PELLEGRIN, 1905) (PISCES: KNERIIDAE) FROM THE EASTERN TRANSVAAL SOUTH AFRICA

SUMMARY

Seven natural populations of Kneria auriculata occur in tributaries of the Crocodile River (Incomati System) on the eastern Transvaal escarpment. The routes it probably used to colonize these streams are discussed and used to explain its current restricted distribution with reference to its ecological requirements. Fish up to a fork length of 2,0 cm feed on invertebrates while larger fish utilize ‘Aufwuchs’, especially diatoms. This dietary difference results in an increase in the food spectrum and possibly also serves to limit competition between smaller and larger lengths groups. Relative gut lengths increase with an increase in fork length and this is correlated with a change in diet from invertebrates to diatoms. Observations on captive fishes indicated that adult fish are able to survive on a diet of Daphnia spp. The habitat of K. auriculata is considered to be unstable due to the occurrence of unpredictable summer floods in escarpment streams. As a result the species has a prolonged breeding season (October to April) while the presence of two size classes of ova indicate that it is a multiple spawner. This breeding strategy minimizes mortality in escarpment streams. The colonization by this fish of previously unsuitable and unavailable habitat indicates that it is a generalist. Its feeding habits and reproductive strategy indicate, however, that it has developed a certain degree of specialization in order to survive in a relatively unpredictable habitat. The conservation prospects of the seven natural and one translocated population varies from uncertain to good. Medium and long term conservation measures are needed to ensure the survival of this fish in the Transvaal.     

THE WINTER FEEDING ECOLOGY OF THE REDSHANK TRINGA TOTANUS

The aim of the work was to find out how the Redshank which over-winter on the Ythan estuary, Aberdeenshire, adapt their feeding activities to the short daylength in winter. To achieve this, the feeding behaviour and daily routine in winter were compared with those in autumn and spring. Corophium volutator was the main prey on the estuary during the day. However, the temperature of the mud greatly affected the diet in the two areas where the feeding behaviour was studied in detail. At temperatures above 6°C, most of the biomass ingested consisted of Corophium. However, in one study area in one winter, Macoma balthica was taken more frequently at lower than at high temperatures. In the other area, Nereis diversicolor was taken more frequently at low than at high temperatures. These changes in diet appeared related to changes in the behaviour of the prey affecting their availability and not due to the birds changing their preference at low temperatures. The ingestion rate was not affected by the change in diet in the first area but decreased at low temperatures in the second. The sizes of Macoma and Nereis taken by the birds did not vary seasonally. The sizes of Corophium taken decreased in winter as a result of a reduction in the size of those present in the substrate. It was concluded that there was no evidence of Redshank increasing their ingestion rate in winter to compensate for the short daylength. The proportion of the time spent feeding on the estuary in daylight was greater in winter than in spring. Redshank continued feeding at high water in the surrounding fields and on the estuary at night during the winter but not in either autumn or spring. During the winter they obtained less than 50% of their daily food requirements from the estuary in daylight, mainly because of the short daylength. Consequently, they had to collect the balance at night and at high water. Seasonal changes in the numbers of Redshank were recorded. After an autumn decrease in numbers, no decrease in numbers could be detected during the winter. These findings are discussed in relation to the possible difficulties for Redshank in collecting their daily food requirements during the winter. The impact of the birds on their main estuarine prey Corophium is also discussed.     

THE PROBLEM OF NOMENCLATURE

Whitfield, A. K. &; Blaber, S. J. M. 1978. Feeding ecology of piscivorous birds at Lake St Lucia, Part 3: Swimming birds. Ostrich 50:10-20. The diets, foraging periodicities and feeding behaviour of the Reed Cormorant Phalacrocorax africanus, Whitebreasted Cormorant Phalacrocorax carbo and White Pelican Pelecanus onocrotalus were studied at Lake St Lucia, Natal, South Africa, during 1975 and 1976. The Reed Cormorant fishes in shallow water within 100 m of the shore and mainly caught Sarotherodon mossambicus and Solea bleekeri, while the Whitebreasted Cormorant caught Mugilidae, Rhabdosargus sarba and Thryssa vitrirostris in deeper water. The diet of the White Pelican followed three distinct phases: a pre-incubation phase when the birds followed and preyed heavily on migrating Mugil cephalus shoals; an incubation and post-incubation phase when the adults flew a round trip of 200 km to the north to obtain freshwater fish, mainly cichlids, from the Pongolo pans where fishes were concentrated and densities high; and a post-fledgling phase when both adults and juveniles fed on a variety of marine species of fish in Lake St Lucia for about a month before dispersing to other areas. The feeding and breeding of Reed Cormorants and White-breasted Cormorants is discussed in relation to wind speeds, water turbidity and flooding of backwaters. The diet and long-range foraging behaviour of White Pelicans at St Lucia are compared with data from other African lakes. The breeding season of White Pelicans at St Lucia is related to availability of fish and inaccessibility of the breeding site to predators. The latter is determined by lake levels.     

A STUDY OF THE CINNAMON-BREASTED ROCK BUNTING Fringillaria tahapisi tehepisi

Brown, C. J. &; Piper, S. E. 1988. Status of Cape Vultures in the Natal Drakensberg and their cliff site selection. Ostrich 59:126-136.

Ground, aerial and questionnaire surveys on the status of the Cape Vulture Gyps coprotheres in the Little and High Drakensberg mountain ranges of Natal were carried out from 1981–1983. The area supported at least 1325 Cape Vultures, 60% on the High Drakensberg in 17 nesting colonies (mean of 31 birds per colony) and 38 roosts (mean of 7 birds). In the Little Drakensberg 17 sites were found, six of which were confirmed nesting colonies (mean of 53 birds) and seven were roosts (mean of 16 birds). A minimum of 215 nests was recorded while the actual number of breeding pairs was probably about 325. In the Natal Drakensberg 84% of nests and 77% of roosting birds occupied ledges that faced between east and south, on the lee side of the generally westerly and northwesterly “Bergwind”. Nesting ledges in the High Drakensberg were on average about 100 m lower than roosting ledges. The northern Drakensberg supported the largest numbers of Cape Vultures (19 birds per 10 km of cliffs), while the smallest numbers were recorded in the south (8 birds per 10 km of cliffs). In the south smallstock farming predominates and the availability of carrion is higher than in the north where mainly largestock are farmed. The use of poisons (mainly strychnine) for killing mammalian predators on farms is considered to be the main reason for fewer birds occurring in the south, and is the main threat to Cape Vultures in the Natal Drakensberg.     

THE PRESENT AND PAST DISTRIBUTION OF THE BALD IBIS IN THE PROVINCE OF THE CAPE OF GOOD HOPE

Tarboton, W. R. 1981. Cooperative breeding and group territoriality in the Black Tit. Ostrich 52:216-225.

In a small, colour-ringed population of Black Tits Parus niger in central Transvaal, 11 of 19 observed breeding units comprised pairs with one to three helper-males. These pairs and groups defended permanent territories, the size of which correlated with the size of the group. There were significantly more territorial disputes during winter when less food was available than in summer. Breeding occurred in summer and the female alone built the nest, incubated the eggs and brooded the young while they were small. During this time she was fed by the alpha male and helper males, although before egg-laying the alpha male prevented helpers from courtship-feeding her. On average, unassisted pairs reared 0,88 young/season whereas pairs with helpers reared 1,55 young/season. However the feeding rate of nestlings of pairs with helpers was not higher than that of unassisted pairs and the number of young reared per group did not correlate with the number of helpers within the group.

The helper system in Black Tits was associated with a skewed sex-ratio (1,7:1 males: females) in the adult population and the data are consistent with the “hopeful reproductive” hypothesis for cooperative breeding.     

Evidence for altitudinal migration of forest birds between montane Eastern Arc and lowland forests in East Africa

Burgess, N.D. & Mlingwa, C.O.F. 2000. Evidence for altitudinal migration of forest birds between montane Eastern Arc and lowland forests in East Africa. Ostrich 71 (1 & 2): 184–190.

In this paper we assess the evidence for altitudinal movements of forest birds from the montane forests of the Eastern Arc mountains of East Africa to nearby lowland forest patches. For 34 montane species, including all the Eastern Arc endemics except Banded Green Sunbird Anthreptes rubritorques there is no evidence that they undertake seasonal movements to lower altitudes. An additional 26 montane species, of somewhat wider distribution, have been recorded at low (<500 m) altitudes during the cold/dry season (June to September). Most records of these montane birds at lower altitudes are from sites adjoining montane forest areas, although a few records are from lowland coastal forests at 100–240 km distance from montane areas. Only five of the 26 species (White-chested Alethe Alethe fulleborni, White-starred Forest Robin Pogonocichla stellata, Orange Ground Thrush Zoothera gurneyi, Evergreen Forest Warbler Bradypterus mariae and Barred Long-tailed Cuckoo Cercococcyx montanus) are regularly and commonly reported in the lowlands. They are also found in the lowlands in small numbers during the warm/wet season (October to February), when they may breed. The abundance of at least four, and probably more, of the forest birds with a more widespread distribution in the lowland and montane forests of East Africa declines greatly at high altitudes from the onset of the cold/wet season (February) and only increases again at the start of the warm/wet season (September). It is not known how far these species move as they cannot be easily separated from resident populations in lowland forests, and there are no ringing recoveries in different forests. Altitudinal migration of a proportion of the Eastern Arc avifauna is the most likely explanation for available data, although source-sink metapopulation theories may be helpful to explain the distributions of some species. As the movement of forest birds from the Eastern Arc to the lowland forests does not involve the rare endemics, they are of lower conservation concern, but the presence of montane and lowland forest may be important for the long-term survival of some more widely distributed forest species.     

SOME NOTES ON THE BIRDS OF THE ISOKA DISTRICT OF THE NORTHERN PROVINCE OF NORTHERN RHODESIA

Dean, W. R. J. 1978. Moult seasons of some Anatidae in the western Transvaal. Ostrich 49:76-84.

Spurwinged Geese Plectropterus gambensis, Egyptian Geese Alopochen aegyptiacus, Yellow-billed Ducks Anas undulata, Redbilled Teal A. erythrorhyncha and Southern Pochard Netta erythrophthalma have a flightless moult mainly during the dry season, from April to August, in the western Transvaal. South African Shelduck Tadorna cana moult during October to February after breeding during July and August. The Cape Shoveller Anas smithii has two main flightless periods, April-May and October-January. Cape Teal A. capensis have been recorded in flightless moult in October, December and January.

The duration of the flightless period correlates with wing length; larger and longer winged Anatidae require proportionally more time for wing moult than do smaller and shorter winged Anatidae.

Geese and shelducks moult on large open lakes with an open shore. Ducks have been recorded flightless on lakes and dams, with or without emergent vegetation.     

OBSERVATIONS ON THE BREEDING OF THE GREATER FLAMINGO PHOENICOPTERUS RUBER LINNAEUS IN THE BREDASDORP DISTRICT,SOUTH AFRICA

Clark, R. A. 1979. Seasonal levels of body fat, protein, ash and moisture in the Sacred Ibis. Ostrich 50:129-133.

Sacred Ibises Threskiornis aethiopicus in Pretoria, Transvaal, were analyzed for body composition throughout the year. Body fat levels in adults and immatures were approximately 7% of feather-free empty body mass in the winter. Just prior to breeding the levels of fat were approximately 12% in adults and 6% in immatures. Lowest levels were recorded for adults and immatures in January (3,5%). In contrast to fat, levels of moisture, protein and ash did not appear to vary significantly between seasons.     

A possible role for flowering locus T‐encoding genes in interpreting environmental and internal cues affecting olive (Olea europaea L.) flower induction

Olive (Olea europaea L.) inflorescences, formed in lateral buds, flower in spring. However, there is some debate regarding time of flower induction and inflorescence initiation. Olive juvenility and seasonality of flowering were altered by overexpressing genes encoding flowering locus T (FT). OeFT1 and OeFT2 caused early flowering under short days when expressed in Arabidopsis. Expression of OeFT1/2 in olive leaves and OeFT2 in buds increased in winter, while initiation of inflorescences occurred i n late winter. Trees exposed to an artificial warm winter expressed low levels of OeFT1/2 in leaves and did not flower. Olive flower induction thus seems to be mediated by an increase in FT levels in response to cold winters. Olive flowering is dependent on additional internal factors. It was severely reduced in trees that carried a heavy fruit load the previous season (harvested in November) and in trees without fruit to which cold temperatures were artificially applied in summer. Expression analysis suggested that these internal factors work either by reducing the increase in OeFT1/2 expression or through putative flowering repressors such as TFL1. With expected warmer winters, future consumption of olive oil, as part of a healthy Mediterranean diet, should benefit from better understanding these factors.     

THE NEST OF THE KNYSNA SCRUB WARBLER (BRADYPTERUS SYLVATICUS) AND SOME NOTES ON PARENTAL BEHAVIOUR

Von Maltitz, F., Schmitt, M. B., &; Biggs, H. C. 1984. Measurements, moult and abundance of the Lizard Buzzard in the Transvaal. Ostrich 55: 177–181.

During a 12-year study 51 Lizard Buzzards Kaupifalco monogrammicus were captured in the Transvaal. South Africa. They occurred sporadically, with peaks in the years 1972, 1975, 1979 and 1983 and were significantly more common in winter. Moult was completed between January and June. Mass is given and recaptures documented.