WATERFOWL AND WADERS AT PORT BEAUFORT,C.P. (Part III)

Sibley, C. G. &; Ahlquist, J. E. 1974. The relationships of the African sugarbirds (Promerops). Ostrich 45: 22–30.

Certain characters of the sugarbirds (Promerops) seem to suggest that the genus may be a geographically isolated derivative of the Australo-Papuan Meliphagidae or a separate group of unknown ancestry, the Promeropidae. Both theories have received support to the present day.

New data from comparisons of the egg whi te and red blood cell proteins, using the technique of isoelectric focusing in acrylamide gel, indicate that Promerops is a specialized starling and that an appropriate taxonomic treatment is to include the subfamily Promeropinae in the Sturnidae. This discovery not only explains the characters of Promerops but solves one of the most contentious zoogeographic problems in ornithology.     

2. WADERS,DIKKOPS, COURSERS AND COMMON LARKS AT OUDTSHOORN

Eggleton, P. &; Siegfried, W. R. 1979. Displays of the Jackass Penguin. Ostrich 50:139-167.

The paper describes the displays of the Jackass Penguin Spheniscus demersus. It also covers aspects of the species' comfort behaviour. Observations were made at several islands off the South African west coast from 1973 to 1976, although most were made on 130 individually-marked adults at Bird Island (Lambert's Bay) in 1975.

The Jackass Penguin has an extensive repertoire of aggressive displays including Point, Gape, Alternate Stare, Sideways Stare, Peck and Beak Slapping. Other displays are Vibratory Head Shaking (VHS), Ecstatic Display, Mutual Ecstatic Display, several bowing displays and displays associated with copulation. The functions of the displays are discussed and comparison is made with displays in other penguins as documented in the literature. In general the displays of the Jackass Penguin resemble those of other penguins, excluding the genus Aptenodytes. There are, however, variations commensurate with the environment and habits of S. demersus.     

2. A WONDERFUL NESTING COLONY OF SACRED IBIS,HERONS AND OTHERS WADERS AT JOHANNESBURG

Skead, D. M. 1974. Roadside counts of Blackshouldered Kites in the central Transvaal. Ostrich 45: 5–8.

From August 1967 to November 1970 roadside counts of Blackshouldered Kites Elanus caeruleus were made along the Great North Road from the Pienaar's River Irrigation Settlement, near Hammanskraal, to Warmbaths, Transvaal. The mean density for this period was 10 km per bird. Counts were also made along the same route, but for a shorter distance to the farm Vaalbosch. The mean density for this route was 17 km per bird. Relative density was higher than in the Cape Province.     

WADERS (CHARADRII) AND OTHER SHOREBIRDS AT CAPE RECIFE,ALGOA BAY,SOUTH AFRICA: SEASONALITY,TRENDS, CONSERVATION,AND RELIABILITY OF SURVEYS

Spearpoint, J. A., Every, B. & Underhill, L. G. 1988. Waders (Charadrii) and other shorebirds at Cape Recife, Algoa Bay, South Africa: seasonality, trends, conservation, and reliability of surveys. Ostrich 59: 166–177.

A total of 126 surveys of waders (Charadrii) and other shorebirds were made along 4 km of shore northwest of Cape Recife. The surveys were conducted bv two observers who counted independently of each other. The variability between observers was least for conspicuous species such as Whitefronted Plover, Blacksmith Plover, African Black Oystercatcher, Whimbrel and Grey Plover, but greatest for cryptic species such as Ringed Plover and for species which formed a minority in mixed flocks such as Curlew Sandpiper and Little Stint. Variability of surveys within years and between years is also considered. Turnstones and Sanderlings were the most abundant waders in summer. Of the Palaearctic waders, Turnstones, Grey Plovers, Sanderlings, Greenshanks and Whimbrels overwintered. In contrast, Ringed Plovers, Curlew Sandpipers, and Little Stints rarely overwintered. Little Egrets, Threebanded Plovers and Water Dikkops occurred mainly in winter. It is recommended that surveys to estimate numbers of Palaearctic waders in summer and winter should be conducted in December, January or February and June or July, respectively. Because of three-year cycles in breeding productivity of certain waders, surveys should be extended over at least three years. There was evidence that waders associated with rocky shores increased in numbers during the study period: this coincided with the erosion of sandy beaches near Cape Recife. Density, biomass and daily field metabolic rates, expressed on an area basis, were similar to those in eastern Scotland. Nine species of tern utilized Cape Recife. It is recommended that the bait-collecting regulations be enforced, that vehicles be prohibited on the beach, and that the tern roost and breeding site be fenced off to create a sanctuary.     

FUNCTIONALIZATION OF PYRIMIDINE AND PURINE NUCLEOSIDES AT C4 AND C6: C-NUCLEOPHILIC SUBSTITUTION OF THEIR C4- AND C6-(1,2,4-TRIAZOL-1-YL) DERIVATIVES

A study of C-nucleophilic substitution at the C4-position on pyrimidine and C6-position on 2′-deoxyguanosine to produce novel nucleosides is presented with the spectroscopic properties of their respective substitution products. C4-(1,2,4-triazol-1-yl) pyrimidine nucleosides 1 were treated with nitroalkanes, malononitrile, acetylacetone, ethyl nitroacetate, acetoacetate and cyanoacetate at 100°C in dioxane in the presence of DBU resulting in the production of novel nucleosides 2–11. To explore the application of this methodology to purine chemistry, this approach was used to produce novel analogs from 2′-deoxyguanosine. We found that the triazolo derivative 12 undergoes C-nucleophilic substitution with nitromethane, malononitrile, acetylacetone, ethyl nitroacetate and cyanoacetate in the presence of potassium carbonate (K₂CO₃) in DMF at 100°C to give novel nucleosides 13–7.     

SPATIAL AND TEMPORAL ABUNDANCE PATTERNS OF WATERBIRDS IN THE SOUTHERN CAPE PROVINCE. PART 2: WATERFOWL

Boshoff, A.F., Palmer, N.G. & Piper, S.E. 1991. Spatial and temporal abundance patterns of water-birds in the southern Cape Province. Part 2: Waterfowl. Ostrich 62:178-196.

Waterfowl (ducks, geese, moorhens, gallinules, coot) were counted, and water-level and water transparency measured, on a monthly basis from 1980 to 1983 or 1984, at the six waterbodies comprising the Wilderness-Sedgefield Lakes Complex, southern Cape Province. The fluctuating status of the submerged aquatic macrophytes, and the trophic status of the waterbodies, was documented. The counts reflect the monthly status o the birds, and allow the calculation of densities (birds/ha). Linear and logarithmic models aided the interpretation of the count data. Spatial and temporal patterns and trends are described, and discussed in relation to changes in water-level, water transparency and aquatic macrophyte biomass regimes in the study area. Cyclical fluctuation in Potamogeton pectinatus biomass, and Its effect on Red-knobbed Coot numbers, is emphasised. The monthly abundance peaks of some species occurred at water-bodies in a regular sequence each year.     

COMPARATIVE BUNDLE SHEATH AND MESOPHYLL DIFFERENTIATION IN THE LEAVES OF THE C4 GRASSES PANICUM EFFUSUM AND P. BULBOSUM

The two C₄ Panicum species examined differ in C₄ acid decarboxylation type and in developmental origin of bundle sheaths in major veins of their leaf blades. In Panicum effusum R.Br. (NAD-malic enzyme type) both mesophyll (PCA) and chlorenchymatous bundle sheath (PCR) cells are derived from ground meristem. In contrast, in Panicum bulbosum H.B.K. (NADP-malic enzyme type), bundle sheath cells are derived from procambium, while mesophyll develops from ground meristem. To test the hypothesis that the developmental divergence of bundle sheath and mesophyll cells would occur earlier when these two tissues had different ontogenetic origins (in P. bulbosum) than when these tissues had the same origin (in P. effusum), the development of major veins in each species was investigated. We measured cell length and cross sectional area, plastid and mitochondrial number, plastid area, vacuole area fraction, wall thickness and fraction adjacent to intercellular space using direct and digitizer measurements of transmission electron micrographs of leaf cross sections of successive developmental stages. Many of the statistically significant changes in the structural parameters measured occurred late in development of both species. The magnitude of developmental change in P. effusum PCR cells was sometimes more dramatic, viz. changes in cell and PCR plastid area, and in mitochondrion number per cell. However, earlier divergence of PCR and PCA length and volume, and wall fraction adjacent to intercellular space in P. bulbosum than in P. effusum indicates that ontogenetic origin of PCR cells from procambium could determine the timing of at least some developmental events.     

POPULATION,DIET AND THE ANNUAL CYCLE OF THE LAUGHING DOVE AT BARBERSPAN,PART 4. BREEDING DATA AND POPULATION ESTLMATES

Dean, W. R. J. 1980. Population, diet and the annual cycle of the Laughing Dove at Barber-span, Part 4: Breeding data and population estimates. Ostrich 51:80-91.

From 1974–1976, Laughing Doves Streptopelia senegalensis raised an observed total of 436 young in 619 nest attempts, giving a breeding success of 0,70 young per pair nest attempt, or an overall success of 0,35 young per egg. Breeding success, estimated by computing the probability of survival of an egg through the incubation period, and of a chick through the nestling period suggest that the breeding success is about 0,33 young per egg. Nests were found in every month of the year, though there was a tendency for breeding to be concentrated during the late rainy season and the dry season. The mean annual population size of the Laughing Dove in the study area was estimated at 221 adults and juveniles by one method and at 237 adults and juveniles by another method. The number of young produced each year is correlated with the estimated population size for each year.