First Red-billed Quelea breeding record in the winter rainfall region of South Africa

The Red-billed Quelea Quelea quelea is a serious pest of agricultural crops throughout most of sub-Saharan Africa. Since the 1980s, it has expanded its range into the Eastern Cape and Western Cape, South Africa, facilitated by changes in agricultural practices. This note documents the first breeding of Red-billed Quelea in the winter rainfall region of South Africa. A colony of 350–600 nests was found, with evidence of recent breeding. Red-billed Quelea numbers were low in this region, but if numbers increase in the future in the Western Cape, winter crops could be under threat.     

Traditional capture of Red-billed Quelea Quelea quelea in the Lake Chad Basin and its possible role in reducing damage levels in cereals

Mullié, W.C. 2000. Traditional capture of Red-billed Quelea Quelea quelea in the Lake Chad Basin and its possible role in reducing damage levels in cereals. Ostrich 71 (1 & 2): 15–20.

Three traditional methods of capturing Red-billed Quelea Quelea quelea practised by different ethnic groups, were studied in the Lake Chad Basin in Chad and Cameroon: capture of birds by triangular hand-held nets by Hadjeraï piégeurs (trappers); with standing fishing nets of the “mist net” type by Gambai; and by cast nets (épervier) by Massa and Mousgoum fishermen.

The Hadjeraï net was found to be both selective for queleas and highly efficient. As many as 1.2 million birds were captured from 13 June to 21 August 1994 around N'Djamena, Chad, alone, until activities ceased due to heavy rains. Birds were trapped in tree roosts during moonless periods of the night. They were plucked and fried the following morning, subsequently dried in the sun, and eventually transported to the market in N'Djamena to be sold. The piégeurs operated in teams of about 6 men and each team could process about 20 000 birds per day. Once this number had been captured, they withdrew from further trapping. The catches were almost entirely composed of queleas, with sometimes a small percentage (<1%) of Golden Sparrow Passer luteus. It was estimated that annually at least 5–10 million queleas were trapped, with a market value of about 19–38 million FCFA (USA37 500–75 000).

The impact of trapping on the population of queleas in the Lake Chad Basin, estimated at about 200 million individuals in 1976/77, was insignificant. Since activities of piégeurs are aimed at maximising revenues, and not at minimising damage levels, there is no causal relationship between crop damage and number of birds trapped. However, compared to crop losses in pearl millet due to quelea damage, revenues from selling quelea are up to 40% of capitalized crop losses due to quelea in the same area.     

Is climate change causing the range contraction of Cape Rock-jumpers (Chaetops frenatus)?

Species distribution models often suggest strong links between climate and species' distribution boundaries and project large distribution shifts in response to climate change. However, attributing distribution shifts to climate change requires more than correlative models. One idea is to examine correlates of the processes that cause distribution shifts, namely colonization and local extinction, by using dynamic occupancy models. The Cape Rock-jumper (Chaetops frenatus) has disappeared over most of its distribution where temperatures are the highest. We used dynamic occupancy models to analyse Cape Rock-jumper distribution with respect to climate (mean temperature and precipitation over the warmest annual quarter), vegetation (proportion of natural vegetation, fynbos) and land-use type (protected areas). Detection/non-detection data were collected over two phases of the Southern African Bird Atlas Project (SABAP): 1987–1991 (SABAP1) and 2008–2014 (SABAP2). The model described the contraction of the Cape Rock-jumper's distribution between SABAP1 and SABAP2 well. Occupancy probability during SABAP1 increased with the proportion of fynbos and protected area per grid cell, and decreased with increases in mean temperature and precipitation over the warmest annual quarter. Mean extinction probability increased with mean temperature and precipitation over the warmest annual quarter, although the associated confidence intervals were wide. Nonetheless, our results showed a clear correlation between climate and the distribution boundaries of the Cape Rock-jumper, and in particular, the species' aversion for higher temperatures. The data were less conclusive on whether the observed range contraction was linked to climate change or not. Examining the processes underlying distribution shifts requires large datasets and should lead to a better understanding of the drivers of these shifts.     

SOME NOTES ON BIRDS OF SOUTHERN RHODESIA

Cyrus, Digby P. 1986. Seasonal and spatial distribution of Redheaded Quelea (Quelea erythrops) in South Africa. Ostrich. 57: 162–169.

There are 48 records of Redheaded Quelea Quelea erythrops occurring in South Africa. Most are for the summer and early autumn months from October to April and all are restricted to the low lying eastern coastal areas. The pattern of occurrence in South Africa is similar to that in adjoining countries to the north; the species does not however occur as regularly in the south. Breeding or attempted breeding has been recorded on six occasions. This shows the typical pattern of occurrence of a species at the southern limit of its distribution.

There is some evidence to suggest that its occurrence may be associated with “wet” years when rainfall is above average. The Redheaded Quelea may be considered as a rare and irruptive summer vagrant to South Africa, which only breeds when conditions are suitable.     

Montane forest birds in winter: do they regularly move to lower altitudes? Observations from the Eastern Cape,South Africa

Seasonal altitudinal migration to lower altitudes including the coast has been ascribed to a number of forest birds, of which 14 species occur at Fort Fordyce Reserve in the Eastern Cape, South Africa. Based on our observations and ringing at this site (2007–2017), as well as concurrent data from the South African Bird Atlas Project (SABAP2), we suggest that in this region only three species, the African Dusky Flycatcher Muscicapa adusta, White-starred Robin Pogonocichla stellata and Barratt's Warbler Bradypterus barratti, are regular altitudinal migrants. For two other species, the Grey Cuckooshrike Coracina caesia and Yellow-throated Woodland Warbler Phylloscopus ruficapilla, local movements apparently occur, but these may take place within the coastal zone rather than between the coast and inland forests.     

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.     

Bucking the trend: the African Black Oystercatcher as a recent conservation success story

The African Black Oystercatcher Haematopus moquini is a charismatic, southern African near-endemic, wader species, that is often seen as a flagship species for coastal bird conservation, as it was recently down-listed regionally to Least Concern on the IUCN Red List of Threatened Species. To celebrate this rare conservation success story, BirdLife South Africa named it the 2018 Bird of the Year and ran a year-long programme in collaboration with the Nature’s Valley Trust highlighting aspects of the species’ biology, current threats, and conservation success. We used data collected by the Southern African Bird Atlas Project (SABAP1 and SABAP2) to examine changes in the species’ range and relative abundance, both in the records between the two projects, as well as trends within the SABAP2 sampling period (2008–2017). This case study enabled us to assess whether such metrics can accurately reflect abundance and distributional changes in a species. We found increases in the reported range and the reporting rates between the two Atlas projects, and that the SABAP2 reporting rate was stable. Regionally, across four coastal categories, the reporting rate was lowest in KwaZulu-Natal, though this region also showed an increase in the probability of reporting during the SABAP2 period. While corroborating the recent change in the species’ conservation status, we also provide good evidence that the long-term SABAP data can be used successfully to assess population trends and range changes over time.     

Cryptic speciation in the southern African vlei rat Otomys irroratus complex: evidence derived from mitochondrial cyt b and niche modelling

The vlei rat Otomys irroratus has a wide distribution in southern Africa with several datasets indicating the presence of two putative species (O. irroratus and O. auratus). In the present study we use mitochrondrial cyt b data (～950 bp) from 98 specimens (including museum material) collected throughout the range of the species to determine the geographical limits of the two recognized species, and we link this to niche modelling to validate these species. Phylogenetic analysis of the DNA sequence data, using maximum parsimony, neighbour joining and Bayesian inference, retrieved two divergent statistically well‐supported clades. Clade A occurs in the Western and Eastern Cape while Clade B occurs in the Free State, KwaZulu‐Natal, Northern Cape and Mpumalanga provinces of South Africa and Zimbabwe. Mean sequence divergence between the two clades (A and B) was 7.0% and between sub‐clades comprising clade B it was 4.8%; the two clades diverged during the Pleistocene. Within Clade A the mean sequence divergence among specimens was 1.91%. Niche modelling revealed that the incipient species occupy distinct bioclimatic niches associated with seasonality of precipitation. Our data allow insightful analysis into the factors that could have led to cladogenesis within this rodent. More significantly, the new data enable us to pinpoint the Eastern Cape province as a contact zone for the divergent species. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 192–206.     

Invasion history of Lycium ferocissimum in Australia: The impact of admixture on genetic diversity and differentiation

Aim

We investigated the invasion history of Lycium ferocissimum, a spine-covered shrub native to South Africa that was introduced to Australia in the mid-1800s, and has since developed into a damaging invasive plant of undisturbed landscapes and pastures. In addition to identifying the provenance of the Australian plants, we tested for evidence of admixture, and contrasted genetic diversity and structuring across the native and introduced ranges.

Location

Samples were collected across South Africa (24 localities) and Australia (26 localities).

Methods

We used genotyping-by-sequencing (3117 SNPs across 381 individuals) to assess population genetic structuring in L. ferocissimum across Australia and South Africa. Coalescent analyses were used to explicitly test contrasting invasion scenarios.

Results

Clear geographic genetic structuring was detected across South Africa, with distinct clusters in the Eastern and Western Cape provinces. The L. ferocissimum plants in Australia form their own genetic cluster, with a similar level of genetic diversity as plants in South Africa. Coalescent analyses demonstrated that the lineage in Australia was formed by admixture between Eastern Cape and Western Cape plants, with most of the genetic material from the Australian lineage originating from the Western Cape. Our analyses suggest that L. ferocissimum plants were originally introduced to South Australia, though it is unclear whether admixture occurred before or after its introduction to Australia. We detected little evidence of geographic genetic structure across Australia, although many of the populations were genetically distinct from one another.

Main Conclusions

Our results illustrate how admixture can result in genetically diverse and distinct invasive populations. The complex invasion history of L. ferocissimum in Australia poses particular challenges for biological control. We suggest potential biological control agents should be screened against admixed plants (in addition to plants from the Eastern and Western Cape) to test whether they provide effective control of the genetically distinct invasive lineage.     

THE NEST OF THE CATTLE EGRET

The Red-billed Quelea Quelea quelea has been steadily expanding its range into the Western Cape province. The earliest record is of a vagrant in 1946. The next record came from 1986 in the Karoo and since 1997 there have been annual reports of the species in the province. It has become resident in the Karoo, especially in the Beaufort West to Leeu Gamka area. In April and May 2007 there was an invasion of Red-billed Queleas in the Western Cape province, particularly on the Cape Peninsula and Overberg region. Sixty-eight percent of records were within 5 km of the coast, over a stretch of 1 000 km of coastline. Adult males in breeding plumage were frequently observed, indicating that this irruption was not limited to post-juvenile dispersal. This influx was not repeated in 2008, but from April 2008 to January 2009, monthly records of queleas were higher than the combined monthly totals in years prior to the influx. The increasing occurrence of queleas in the Western Cape province is a potential threat to a major wheat-producing area and continued monitoring is required.     

WATERFOWL (ANATIDAE) ON IRRIGATION LAKES IN THE ORANGE FREE STATE

Geldenhuys, J. N. 1975. Waterfowl (Anatidae) on irrigation lakes in the Orange Free State. Ostrich 46:219-235.

The incidence and population size of fifteen duck species were determined on nine irrigation lakes in the Orange Free State, South Africa, during August 1972 to July 1973. Allemanskraal supported the highest average number of Egyptian Goose, South African Shelduck and Yellowbilled Duck. Redbilled Teal and Spurwinged Goose favoured Bloemhof. Cape Shoveller and Cape Teal concentrated on Kalkfontein, and Southern Pochard frequented Erfenis. The most common species were the Egyptian Goose, South African Shelduck, Yellowbilled Duck and Spurwinged Goose, in thit order according to average number of birds per count, Black Duck, Whitefaced Duck, Whistling Duck, Whitebacked Duck, Hottentot Teal, Knobbilled Duck and Maccoa Duck occurred sporadically. Relatively high seasonal population nuctuations were found in the South African Shelduck, Cape Teal, Southern Pochard and to a lesser extent in the Spurwinged Goose and Cape Shoveller.     

Dynamic occupancy models for analyzing species' range dynamics across large geographic scales

Large‐scale biodiversity data are needed to predict species' responses to global change and to address basic questions in macroecology. While such data are increasingly becoming available, their analysis is challenging because of the typically large heterogeneity in spatial sampling intensity and the need to account for observation processes. Two further challenges are accounting for spatial effects that are not explained by covariates, and drawing inference on dynamics at these large spatial scales. We developed dynamic occupancy models to analyze large‐scale atlas data. In addition to occupancy, these models estimate local colonization and persistence probabilities. We accounted for spatial autocorrelation using conditional autoregressive models and autologistic models. We fitted the models to detection/nondetection data collected on a quarter‐degree grid across southern Africa during two atlas projects, using the hadeda ibis (Bostrychia hagedash) as an example. The model accurately reproduced the range expansion between the first (SABAP1: 1987–1992) and second (SABAP2: 2007–2012) Southern African Bird Atlas Project into the drier parts of interior South Africa. Grid cells occupied during SABAP1 generally remained occupied, but colonization of unoccupied grid cells was strongly dependent on the number of occupied grid cells in the neighborhood. The detection probability strongly varied across space due to variation in effort, observer identity, seasonality, and unexplained spatial effects. We present a flexible hierarchical approach for analyzing grid‐based atlas data using dynamical occupancy models. Our model is similar to a species' distribution model obtained using generalized additive models but has a number of advantages. Our model accounts for the heterogeneous sampling process, spatial correlation, and perhaps most importantly, allows us to examine dynamic aspects of species ranges.     

Cover

A young Ecklonia radiata sporophyte, on a wave‐swept intertidal platform, at Double Mouth, Eastern Cape, South Africa. Photo by Robert J. Anderson. [Vol. 51, No. 2, pp. 236–246]     

New Streptocarpus species (Gesneriaceae) from South Africa

Two new rosulate species of Streptocarpus are described from the eastern seaboard of South Africa. The first is endemic to Mpumalanga Province. This species has almost actinomorphic corollas with small cylindrical tubes and was previously included within Streptocarpus parviflorus. However, molecular and morphological data and habitat preference do not support this classification. The second species is from the Msikaba River Gorge in the Eastern Cape Province. It adds to the already impressive list of endemic plant species from this region and is allied to other rosulate species of the Eastern Cape. It approaches Streptocarpus rexii in flower size but differs in its much shorter corolla tubes, which lack purple nectar guides. In addition, the corolla floors are marked with yellow bars reminiscent of Streptocarpus cyaneus and also seen in sympatric populations of the small‐flowered Streptocarpus modestus. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 743–748.     

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.     

Bloodmeal analysis in Culicoides midges collected near horses,donkeys and zebras in the Eastern Cape,South Africa

An upsurge in African horse sickness (AHS) in the Eastern Cape, South Africa, from 2006 led to an epidemiological reassessment of the disease there. Light trapping surveys carried out near horses, donkeys and zebras in 2014–2016 collected 39 species of Culicoides midge (Diptera: Ceratopogonidae) that are potential vectors of AHS. To establish if these midges fed on equids, DNA sequences were obtained from the gut contents of 52 female midges (35 freshly blood‐fed, 13 gravid and four parous), representing 11 species collected across 11 sites. Culicoides leucostictus fed on all three equids. Culicoides bolitinos, Culicoides imicola and Culicoides magnus fed on both horses and donkeys. Culicoides onderstepoortensis fed on donkeys, and Culicoides similis and Culicoides pycnostictus fed on zebras. Bloodmeals from cows, pigs, warthogs, impalas and a domestic dog were also identified in various species, but none of the midges tested had fed on birds. These results contribute to knowledge of the vectorial capacity of several species of Culicoides with regard to AHS in the Eastern Cape and point to potential reservoir hosts, of which donkeys, zebras and domestic dogs have previously been found to harbour AHS. Blood‐fed midges were also obtained throughout winter, indicating the potential for endemic AHS in the province.     

Evidence of itinerant breeding of the Red-billed Quelea Quelea quelea in the Ethiopian Rift Valley

This paper provides evidence for itinerant breeding by Red-billed Quelea Quelea quelea in the Ethiopian Rift Valley. Queleas were mass-marked with aerially applied fluorescent particles in two separate nesting areas in southwestern Ethiopia during June 1981. Marked adults from both areas were recovered from nesting colonies in the Awash River Valley during August and September, up to 100 days post-spray and between 500 and 700 km to the north of the spray sites. In the Awash colonies, the presence of marked adults in breeding plumage with interrupted primary wing-moult, together with two age classes of juveniles, suggests that this was the second nesting. The progress of both the post-breeding and post-juvenal primary moults was consistent with an earlier breeding in May and June. The timing of the arrival and departure of birds from these nesting areas also supported the occurrence of double breeding by the same birds. Furthermore, the composition of black facial mask types of adult males was more similar between samples from the southern Ethiopian Rift and Awash Valley than between samples from either of these areas and samples from outside the Rift, providing additional evidence that the same population of birds bred in these two areas of the Rift Valley. Nesting colonies in both areas were scattered in time and space. Colonies in the Awash were distributed for more than 300 km and were established over a two-month period, which coincided with local differences in the timing of the seeding in grasses. This wide distribution probably increases nesting success in such areas of locally variable rainfall. This contrasts with a stategy of mass migration, where concentrated breeding occurs where and when suitable conditions are first encountered. Knowledge of the location and timing of previously successful nesting areas may increase the success of itinerant breeding, as Queleas seem to use the same areas in successive years if conditions are favourable. Recoveries of marked birds in the Awash were segregated according to both spray site and sex, suggesting some degree of group cohesion by sex from the first to the second nesting. We speculate that post-nesting group cohesion of adults may provide a means to maintain the integrity of collective group information on seasonal movements. Group cohesion may be facilitated by the high degree of nesting synchrony within colonies.     

830. NERINE LATICOMA SUBSP. HUTTONIAE

The South African geophyte Nerine laticoma (Ker Gawl.) T. Durand & Schinz subsp. huttoniae (Schönland) Traub from the Eastern Cape is described and reinstated at subspecific level, accompanied by details of its history, taxonomy, life cycle, distribution and habitat.     

Genetically distinct Dutch-domesticated Clarias gariepinus used in aquaculture in southern Africa

Clarias gariepinus, a catfish species widely distributed in Africa including South Africa, is naturally absent from the Western Cape and the coastal Eastern Cape provinces. Because of its potential as an aquaculture species it has been widely used in aquaculture ventures in South Africa, specifically a stock known as Dutch catfish, a domesticated strain developed in the Netherlands. Mitochondrial DNA markers indicate that this stock is genetically distinct from the natural populations of C. gariepinus in South Africa. It could potentially pose a threat to South Africa's natural biodiversity if these fish were to escape from aquaculture farms, or was deliberately introduced into inland waters.