Macroinvertebrate communities associated with duckweed (Lemnaceae) in two Eastern Cape rivers,South Africa

The functional feeding groups and diversity of macroinvertebrate communities associated with duckweed mats in the New Years River (two sites) and Bloukrans River (two sites), Eastern Cape province, South Africa, were assessed. Duckweed (Lemnaceae) is a ubiquitous family of floating macrophytes. A total of 41 macroinvertebrate families were collected monthly over a six-month period from February to July 2014. Duckweed biomass in both rivers was highly variable both temporally and spatially. The majority of identified macroinvertebrate taxa were predators and detritivores, with a small percentage of herbivores. An average of approximately 26% of the macroinvertebrate taxa found were from families that include species from more than one functional feeding group. Although overall measures of diversity and ecosystem health (Fisher’s α and Simpson’s index) remained constant over time in the New Years River, significant differences in macroinvertebrate community structure were seen between sites and months on both rivers, with dissimilarity being driven by a larger number of species in the New Years River. This high variability within macroinvertebrate assemblages probably reflects a combination of heterogeneous duckweed distribution, variation in physico-chemistry, opportunistic behaviours of macroinvertebrate predators and/or successional colonisation of duckweed mats.     

Effects of goat pastoralism on ecosystem carbon storage in semiarid thicket,Eastern Cape,South Africa

Abstract Intensive pastoralism with goats transforms semiarid thicket in the Eastern Cape, South Africa from a dense vegetation of tall shrubs to an open landscape dominated by ephemeral grasses and forbs. Approx. 800 000 ha of thicket (which prior to the introduction of goats had a closed canopy and a Portulacaria afra Jacq. component) have been transformed in this manner. Ecosystem C storage in intact thicket and loss of C due to transformation were quantified. Carbon storage in intact thicket was surprisingly high for a semiarid region, with an average of 76 t C ha^?1 in living biomass and surface litter and 133 t C ha^?1 in soils to a depth of 30 cm. Exceptional C accumulation in thicket may be a result of P. afra dominance. This succulent shrub switches between C₃ and CAM photosynthesis, produces large quantities of leaf litter (approx. 450 g m^?2 year^?1) and shades the soil densely. Transformed thicket had approx. 35% less soil C to a depth of 10 cm and approx. 75% less biomass C than intact thicket. Restoration of transformed thicket landscapes could consequently recoup more than 80 t C ha^?1.     

Ecological preferences and seasonal dynamics of ticks (Acari: Ixodidae) on and off bovine hosts in the Eastern Cape Province,South Africa

A total of 31,425 ticks were collected from 10 cattle and also from six drag-samples during the 12-month study period. Adult ticks were removed from the right hand side of each animal and all instars of ticks were placed in containers filled with 70% ethanol. Based on morphological traits, 10 tick species were identified: Rhipicephalus (Boophilus) decoloratus (32.5%), R. evertsi evertsi (18.8%), R. appendiculatus (17.3%), Amblyomma hebraeum (16.3%), R. simus (7.7%), Ixodes pilosus (3.8%), Hyalomma rufipes (3.5%), R. follis (0.08%), Haemaphysalis elliptica (0.04%), H. silacea (0.02%). The southern African yellow dog tick, H. elliptica, was only found on vegetation. The agro-ecological zones differ significantly in tick species and their distribution. The A. hebraeum and R. evertsi evertsi counts were higher in Kowie Thicket (KT) during summer season (2.05 ± 0.01 and 1.00 ± 0.09, respectively) compared to Bedford Dry Grassland (BDG) and Bhisho Thornveld (BT) veld types. In all vegetation types, R. appendiculatus had higher counts in KT in spring (0.91 ± 0.08), summer (0.78 ± 0.08) and winter (0.78 ± 0.08). Rhipicephalus (Boophilus) decoloratus was more frequent in the BT (1.78 ± 0.11) during the summer season. BDG had lower tick infestation with R. evertsi evertsi being the most frequent species in summer. No H. rufipes was collected in the KT. Of epidemiological interest, R. (B.) microplus was absent in the study area which needs further investigation. Within the context of this study, we found agro-ecological differences and seasonal variations to have influence on tick species distribution.     

Nest boxes for Cape Parrots Poicephalus robustus in the Hogsback area,Eastern Cape,South Africa

Breeding propensity of tree-cavity nesting bird species are often limited by a shortage of natural nesting sites. Artificial nests can be used to provide alternative nest sites. Cape Parrots Poicephalus robustus are nationally endangered and nest in existing tree-cavities in high-altitude fragmented Afromontane forests in South Africa, assumed to be in short supply due to historic and current logging practices. To increase nest site availability, 179 wooden bird boxes and 28 bee boxes (to ‘pull’ bees) were erected during 2011–2012 in Hogsback, Eastern Cape. In 2016, no bird boxes were occupied by Cape Parrots. A total of 43% were used by other species, 51% were unused and 6% could not be inspected due to tree instability and inaccessibility. Two bird boxes were inspected by two pairs of Cape Parrots, but were never occupied. Occupancy of boxes by birds was not associated with nest, tree or habitat characteristics. However, occupancy of boxes by bees was associated with habitat type and tree species. Future conservation efforts will include locating natural Cape Parrot nesting sites and reforestation efforts to ensure the long-term availability of natural nesting sites.     

Activity patterns of springhares from the Eastern Cape Province, South Africa

The activity patterns of springhares Pedetes capensis ( Rodentia: Pedetidae ) from the Eastern Cape Province, South Africa, were investigated by counting the number of springhares active above ground at regular intervals throughout the night at different times of the year and under different weather conditions and phases of the moon. A combination of time of year, time of night and level of illumination best explained springhare activity, accounting for 43% of the variation in springhare numbers. Springhare activity generally reached its peak soon after dark, thereafter remaining fairly constant throughout most of the night and only decreasing in the 2–4-h period before sunrise. On those nights when the moon either rose or set during the night, this pattern was modified by the level of illumination. Springhares responded to moonlight by reducing above-ground activity, shifting activity to dark, moonless periods of the night, and by reducing their use of open space. Except for extremes, other weather conditions had no significant effect on springhare activity.     

Diet of Anguilla mossambica (Teleostei,Anguillidae) elvers in the Sundays River,Eastern Cape,South Africa

The southern African crab Hymenosoma orbiculare was recently split into five distinct species, of which three are estuarine/coastal and have peripatric distributions that are linked to temperature-defined marine bioregions. This suggests that the species’ ranges may be limited by physiological adaptations to their thermal environment. We explored this hypothesis by rearing the larvae of the warm-temperate lineage of H. orbiculare and the warm-temperate/subtropical H. longicrure at a range of water temperatures, and found clear temperature-dependent differences in the duration of larval development. Our study contributes to the growing body of evidence that stresses the importance of adaptation to regional environmental conditions, rather than physical dispersal barriers on their own, in limiting the mixing of marine species between temperature-defined biogeographic regions.     

Risk factors of porcine cysticercosis in the Eastern Cape Province, South Africa

There is a high prevalence of Taenia solium taeniosis/cysticercosis in humans and pigs in the Eastern Cape Province (ECP) of South Africa. The objective of this study was to identify risk factors of porcine cysticercosis in select districts of the ECP. Data were collected in 2003 by interviewing 217 pig producers from the area. Blood samples were collected from 261 of their pigs, which were tested using two enzyme-linked immunosorbent assays (ELISA) for the presence of antibodies to cysticercosis. Frequencies of both owner- and pig-level characteristics were determined. For pig-level analysis, all bivariable and multivariable associations were determined using the surveylogistic procedure of the SAS/STAT? software to accommodate for the intraclass correlation that exists for clusters of pigs within one owner and for clusters of owners within a district. All tests for significance were performed at the α?=?0.05 level, and adjusted odds ratios (aOR) and 95% confidence intervals (CI) were determined. Among the respondents, 48% of their households lacked a latrine, 98% slaughtered pigs at home, and 99% indicated that meat inspection services were not available. On bivariable analysis, there was a significant association between porcine infection and district (p?=?0.003), breed (p?=?0.041) and the absence of a latrine (p?=?0.006). On multivariable analysis, the absence of a latrine was the only variable significantly associated with porcine infection (aOR?=?1.89; 95% CI?=?1.07, 3.35) (p?=?0.028). The increased odds of porcine infection with households lacking a latrine contributes to our understanding of the transmission of this parasite in the ECP. Determining and addressing the risk factors for T. solium infection can potentially lower the very high prevalence in humans and pigs in this endemic area.     

The spawning behaviour of the endangered Eastern Cape rocky, Sandelia bainsii (Anabantidae), in South Africa

Sandelia bainsii is an endangered freshwater fish species which only occurs in short sections of several Eastern Cape river systems in South Africa. The spawning behaviour of S. bainsii is described for the first time. Female S. bainsii remained a light grey colour. Males exhibited distinctive nuptial coloration consisting of an intense black with a white bar on their caudal fin and white windows on the posterior areas of their dorsal and anal fins. There was a darkened post orbital contact organ of ctenoid scales on the reproductively active males. The spawning behaviour was recorded on a video recorder and analyzed during frame by frame replay. Sandelia bainsii are uniparental substrate breeders. The male prepared a spawning area by clearing the substrate with rapid body movements (sweeps). There were a number of preliminary courtship movements, several trial embraces by the male before the actual final embrace. The male underwent a U bend around the female, anchored himself with the contact organ, squeezed the abdominal area of the female with a quick head movement. Courtship and spawning all took place near the substratum. Twenty one separate mating bouts were filmed and analyzed. The duration varied from 1.44 to 5.11 seconds with an average embrace of 3.39 seconds. During the mating clench the female was not normally turned over, as in some anabantoids, but remained upright. The male then guarded the spawning area. Eggs were light yellow, adhesive, demersal and 1.28 mm in diameter with 0.61 mm oil globules. The breeding behaviour of S. bainsii has some similarities with both breeding behaviourial groups, the bubble nesters and the free spawners, within the other African anabantid genus, Ctenopoma. Sandelia bainsii have acquired some temperate specializations with regard to their reproductive style. Free spawning and the release of buoyant eggs is the plesiomorphic anabantid reproductive style. The demersal eggs and male substratum nest sites of S. bainsii are considered apomorphic.     

The feeding habits of six pelagic and predatory teleosts in eastern Cape coastal waters (South Africa)

A four-year study of the feeding habits of six pelagic teleost species in eastern Cape coastal waters of South Africa is analysed. These predators are Lichia amia, Pomatomus sallatrix, Seriola lalandi, Atractoscion aequidens, Katsuwonus pelamis and Thunnus albacares. All species occur in inshore coastal water (< 1 -8 km from shore) for at least part of the year. The tunas were also sampled from the edge of the continental shelf (40–50 km from shore). The use of squid 'beaks' and fish otoliths allowed accurate prey identification and size estimates. Variations in prey taken are attributed to differences in locality, predator species and size. Three pelagic fish species are important to all the predators: Sardinops ocettata, Etrumeus teres and Engraulis capensis. The inshore squid, Loligo reynaudi, is another major prey item. Offshore tuna samples revealed a different prey spectrum, viz. oceanic squid and saury, Scomberesox saurus, being taken frequently.     

Aspects of population dynamics and feeding by piscivorous birds in the intermittently open Riet River estuary,Eastern Cape,South Africa

Aspects of the population dynamics and feeding activity of piscivorous birds in the small (c. 5 ha) intermittently open Riet River estuary, on the south-eastern coastline of South Africa, were investigated monthly from August 2005 to July 2006. A total of 188 birds of 13 species were recorded, of which six were wading piscivores, four aerial divers and three were pursuit swimmers. The Reed Cormorant (Phalacrocorax africanus) was the numerically dominant species, with a mean of 8.25 (SD ± 7.90) individuals per count. Mean numbers of the Pied Kingfisher (Ceryle rudis) and Giant Kingfisher (Megaceryle maximus) were 3.42 (SD ± 1.20) and 1.17 (SD ± 0.60) individuals per count, respectively. The remaining 10 species revealed mean values <0.5 individuals per count. Breaching events were associated with a change in feeding groups from waders to pursuit feeders, and a decrease in total bird numbers, most likely due to loss of potential littoral zone foraging habitat for waders resulting from reduced water levels. The highest bird numbers were recorded in winter reflecting the migration of large numbers of Reed Cormorant into the system. Monthly food consumption by all piscivorous birds showed large temporal variability, ranging from 26.35 to 140.58 kg per month.     

The Griqua of Campbell, Cape Provice, South Africa.

The Griqua of Campbell in the Cape Province of South Africa are reputed to be descended from an amalgam of Khoi ("Hottentots") with various Caucasoid, Negroid and East Asian elements at the Cape of Good Hope. A stormy history of migration and deprivation has left this small residuum on the edge of the Kalahari Desert. It was hoped that a sero-genetic study of these people, who proudly preserve their identity, might provide further insights into the genetic consitution of their Khoi forebears. Despite the retention of the language of their own, an social mores distinct from of other Mixed populations, they have been shown, however, to have received an appreciable inflow of non-Khoisan genes. This has probably resulted from social factors such as the prestige attaching to Griqua membership and the willingness of the Griqua to assimilate outsiders, combined with the tendency of Campbell Griqua to migrate elsewhere. There are no significant differences between "Griqua" members of the population and those who are not recognized as "Griqua."     

Displacement of Rhipicephalus decoloratus by Rhipicephalus microplus (Acari: Ixodidae) in the Eastern Cape Province, South Africa

The objective of the study was to establish to what extent the native tick species Rhipicephalus decoloratus has been displaced by the invasive introduced tick, Rhipicephalus microplus at two communally grazed areas in the Eastern Cape Province, South Africa. To this end ticks were collected monthly from five cattle over a period of 2 years and from 10 drag-samples of the vegetation over a period of 1 year at each locality. Whereas 10 years previously only R. decoloratus and no R. microplus had been recorded in the vicinity of the two sites, R. microplus now comprised the bulk of collections at both. Furthermore, significantly more R. microplus were collected from cattle at both localities during the 2nd year of the survey than during the 1st. In addition to 83 instances of intraspecific coupling, there were 17 instances of R. microplus males coupled with R. decoloratus females. Collections made from cattle and goats on two farms close to the study sites revealed that R. microplus was present on both host species and that it significantly outnumbered R. decoloratus on one of the farms. Rhipicephalus decoloratus and R. microplus larvae as well as larvae exhibiting characteristics of both species were collected from the vegetation.     

Evidence for prey selection by spotted hyaena in the Eastern Cape,South Africa

We tested the widely accepted hypothesis that spotted hyaenas (Crocuta crocuta) are non-selective in their diet. The prey preference of spotted hyaena was studied in the Addo Elephant National Park (AENP), South Africa. Diet (frequency of occurrence of prey items in the diet) was quantified through the analysis of 55 scats, and compared with available prey. A combination of large- and medium-sized mammals (buffalo (Syncerus caffer), red hartebeest (Alcelaphus buselaphus) and common duiker (Sylvicapra grimmia) were the most preferred prey items. The most abundant species, warthog (Phacochoerus africanus) and kudu (Tragelaphus strepsiceros), were ignored and avoided, respectively. These results show that the assumption that hyaena prey on the most abundant available prey species may be overly simplistic. Predation patterns, such as the ones observed in AENP, may have important ramifications for less common species that are selected by hyaena in small enclosed reserves.     

A new species of Arctotis (Compositae, Arctotideae) from kommetjie grassland in Eastern Cape Province, South Africa

Arctotis debensis R.J.McKenzie, a new species from the Albany Centre of Floristic Endemism, South Africa, is described and illustrated. It grows almost exclusively in grassland on kommetjies, a distinctive landform of depressions and mounds associated with giant earthworms, in a restricted area west of King William's Town, Eastern Cape Province. It is the first plant taxon reported to be endemic or near-endemic to this unusual habitat. The new species appears to have been collected rarely and previous collections examined have remained undetermined to species level. The new species is distinguished from closely allied species by the combination of its usually larger dimensions in all parts, prostrate habit, coriaceous leaves that are green, scabrous, and eglandular on the adaxial surface and densely lanate on the abaxial surface, and involucral-bract morphology.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 581–588.     

Age and population group related distribution of enteropathogens in the Eastern Cape, South Africa

The frequency of Salmonella spp., Shigella spp., Campylobacter spp., Yersinia enterocolitica, Aeromonas hydrophilia and Helminths in samples from various hospitals of the Eastern Cape, South Africa, were analysed for trends involving age distribution and population group. Significant differences in the distribution of these pathogens could be attributed to hygiene and environmental difference between the age and population groups which suggests that rapid urbanization and poor water supply remain major problems in the drought prone Eastern Cape.