Patrick E Hulley

Timing of moult and breeding in the Cape White-eye, Zosterops pallidus, from three different geographical regions in South Africa

Abstract Cape White-eyes are widespread in South Africa, occurring in different climatic regions. We analysed primary moult data for large samples of this species from three geographical regions. There were no apparent long-term changes in duration or timing of moult during the nine years that the Western Cape results were collected, but sites within this region had different mean starting dates for primary moult. The Eastern Cape and Free State birds began moult about a month later than those in the Western Cape. This correlated well with the earlier breeding season in the Western Cape, and there was no evidence of overlap between moult and breeding. Mean primary moult duration was not significantly different among the sites or regions, and may be a species-specific trait. There was no evidence of regular long-distance movements in this species.

SUNBIRD MOVEMENTS: A REVIEW, WITH POSSLBLE MODELS

Summary Craig, A.J.F.K. & Hulley, P.E. 1994. Sunbird movements: a review, with possible models. Ostrich 65: 106–110. Based on current fieldwork, we propose four possible models to explain the winter influx of sunbirds which we have observed: the birds may be (1) “winter residents”, which move annually to a wintering area and remain there; (2) “shoppers”, which periodically investigate feeding areas within their home range and feed opportunistically where nectar is most abundant; (3) “tourists”, which successively visit a series of sites on a regular itinerary; (4) “nomads”, which move unpredictably to new areas whenever food supplies decline. and have no home base. Current data on sunbird movements are reviewed, and in a few cases the winter resident model is unlikely, but generally it is not yet possible to eliminate any of the hypotheses. Moult cycles based on both field and museum studies may provide additional information, as movements are unlikely while active wing-moult is in progress; some species ...

NESTING OF SYMPATRIC REDWINGED AND PALE WINGED STARLINGS

Summary Craig, A. J. F. K., Hulley, P. E. & Walter, G. H. 1989. Nesting of sympatric Redwinged and Pale-winged Starlings. Ostrich 60:69-74. Observations were made over four breeding seasons at Cradock, South Africa, where Redwinged Starlings Onychognathus morio and Palewinged Starlings O. nabouroup nest on the same cliffs. Nests were not accessible, and the stage of breeding was determined by the behaviour of the birds. Both species reuse the same nest sites, and only the females incubate, but both sexes feed the young. The timing of breedingMaybe more variable in the Palewinged Starling. A review of the available data on nest site selection and nest construction shows apparent species-specific differences: Redwinged Starlings usually nest on ledges, often on buildings, and use mud in the nest base; Palewinged Starlings favour vertical crevices, and do not use mud.

The importance of winter-flowering Aloe ferox for specialist and generalist nectar-feeding birds

Abstract The abundance of consumers and the availability of resources are often linked, and birds are known to track food resources at a variety of spatial and temporal scales. This study describes the seasonal influx of nectar-feeding birds during flowering in a 51-ha stand of Aloe ferox in the Eastern Cape, South Africa, over 5 years (2008–09 and 2011–13). Bimonthly point counts of birds were conducted before (April—May), during (June—July) and after (August) flowering, which occurs during the austral winter. The abundance of nectar-feeding birds increased significantly during flowering each year, whereas monthly abundances of non-nectarivores were unrelated to flowering. Models fitted to bird count-data revealed a significant interaction between feeding guild (nectarivorous versus non-nectarivorous species) and the percentage of flowering A. ferox over the 5 years of the study, confirming that these guilds responded differently to flowering events. Malachite Sunbirds (Nectarina famosa), which are specialist nectarivores, responded consistently to flowering of A. ferox each year, despite the low sugar concentrations of A. ferox nectar. The arrival of nectar-feeding birds en masse during flowering, and the number of bird species (16) observed feeding on A. ferox nectar, suggest that this plant is an important source of nutrition for birds at a time when other food resources are likely to be scarce.

The Behavior of Palewinged Starlings and a Comparison with Other Onychognathus Species

Craig, A.J.F.K., Hulley, P.E. & Walter, G.H. 1991. The behaviour of Palewinged Starlings, and a comparison with other Onychognathus species. Ostrich 62:97-108. Pairs of Palewinged Starlings associa...

Comparative perch selection in Southern Fiscal Lanius collaris and Fiscal Flycatcher Sigelus silens at Amakhala Game Reserve, South Africa

The Southern Fiscal Lanius collaris and the Fiscal Flycatcher Sigelus silens are common, widespread and sympatric in much of southern Africa. They are similar in plumage and ecology, which may predispose them to competition and interspecific territorial aggression but this has not been tested to date. Here we tested for evidence of competition for perch space. At Amakhala Private Game Reserve, Eastern Cape, South Africa we monitored the occurrence and perch use of both species along transects. The birds do co-occur locally but there is evidence of small-scale spatial separation possibly a result of interspecific territoriality. Perch selection differed in respect of perch type but not perch height. Both species perched prominently in the majority of observations. Southern Fiscals make greater use of Searsia and Gymnosporia trees, whereas the Fiscal Flycatcher makes near-equal use of Vachellia karroo, Searsia and Gymnosporia trees. This may be an example of niche partitioning, though it remains unclear whether the birds actively compete for perch space, or if the separation is a product of different perch preferences, territoriality and the local plant community.

Primary wing-moult and site fidelity in South African mousebirds (Coliidae)

Based on large samples of birds mist-netted in the Eastern Cape and the Western Cape, moult of the primary remiges in both Speckled Mousebirds Colius striatus and Red-faced Mousebirds Urocolius indicus occurred throughout the year with no regional or seasonal patterns evident. The same picture emerged for the White-backed Mousebird Colius colius in the Western Cape. This aseasonality of wing-moult for all three species in South Africa was further supported by the full data set of moult records available in the Safring database. We were thus unable to use the Underhill–Zucchini model to estimate the moult parameters for these species, but an extended moult period seems likely. Recapture data for the Eastern Cape strongly suggest that Speckled Mousebirds are resident or revisit sites frequently, whereas this is not the case for Red-faced Mousebirds.

Group displays in pale-winged starlings

Cliff-nesting pale-winged starlings (Onychognathus nabouroup) gather on the cliff tops to perform Group Displays which include both aggressive and courtship elements: Hopping, Wing Stretching, Wing Drooping, Wing Flicking, Staring, Head Forward Threat and Butterfly Fluttering. These displays occur throughout the year, most frequently in the late afternoon. We suggest that this behaviour may be important in pair formation, and in establishing dominance relationships between birds breeding at the same site.