Combining field phenological observations with distribution data to model the potential distribution of the fruit fly Ceratitis rosa Karsch (Diptera: Tephritidae)

2012 ◽  
Vol 103 (1) ◽  
pp. 60-73 ◽  
Author(s):  
M. de Villiers ◽  
V. Hattingh ◽  
D.J. Kriticos
Keyword(s):  
South Africa ◽  
South African ◽  
Relative Abundance ◽  
Potential Distribution ◽  
Fruit Fly ◽  
Global Distribution ◽  
Biological Information ◽  
Distribution Data ◽  
Suitable Habitat ◽  
Independent Distribution

AbstractDespite the potential for phenological and abundance data to improve the reliability of species niche models, they are seldom used. The aim of this study was to combine information on the distribution, relative abundance and seasonal phenology of Natal fruit fly, Ceratitis rosa Karsch (Diptera: Tephritidae), in South Africa to model its potential global distribution. Bucket traps, baited with Biolure, were used to trap C. rosa in different climatic regions of South Africa over a two-year period. A CLIMEX niche model of the potential global distribution of C. rosa was fitted using the collected trapping data and other distribution records from South Africa. Independent distribution records for elsewhere in Africa were reserved for model validation. The CLIMEX model results conformed well to the South African trapping data, including information on relative abundance and seasonal phenology, as well as to the pattern of presence records of the species elsewhere in Africa. The model suggests that under recent historical conditions a large part of South America, Central America, Mexico and southern USA may be climatically suitable for establishment of C. rosa. In Europe, climatically suitable habitat is restricted to coastal regions of the Mediterranean, in Asia, mostly to the southern and south eastern countries, and in Australia mostly to the wetter south and east. The independent cross-validation provided by South African relative abundance and seasonal phenology data, central African distribution data and relevant species specific biological information provides greater confidence in the modelled potential distribution of C. rosa.

Potential of a trap-fishery for deep-water rock lobster Palinurus delagoae off South Africa

1997 ◽  
Vol 48 (8) ◽  
pp. 993 ◽  
Author(s):  
J. C. Groeneveld ◽  
A. C. Cockcroft
Keyword(s):  
South Africa ◽  
South African ◽  
Deep Water ◽  
Linear Models ◽  
Depth Interval ◽  
Suitable Habitat ◽  
Rock Lobster ◽  
Experimental Phase ◽  
Trap Fishery ◽  
Catch Rates

An experiment to investigate the potential of a trap-fishery for deep-water rock lobster Palinurus delagoae was conducted off the east coast of South Africa between 1994 and 1996. The 75–425 m depth interval between 27°S and 32°S was stratified according to depth and latitude, and three regions (North, Central and South) were sampled systematically over the three years. Sampling by commercial vessels operating long-lines and traps included an experimental phase (fixed fishing positions) and a commercial phase (no restriction on fishing location). Generalized linear models were used to investigate the influence of year, region, sampling phase, month and soak time. Sampling phase was significant, with traps set during the commercial phase catching more than those set in the experimental phase. The effect of soak time on catch rates was not significant. The almost-50% decrease in the combined abundance index combined with a marked decrease in mean lobster size over the study period suggests a relatively low fisheries potential for this species in South African waters; this may be attributable to the relative scarcity of suitable habitat in the area.

scholarly journals The geographic distribution of Senecio glastifolius in New Zealand: past, current and climatic potential

2021 ◽  
Author(s):  
◽  
Josef Rehua Beautrais
Keyword(s):  
South Africa ◽  
New Zealand ◽  
Species Distribution ◽  
Potential Distribution ◽  
Species Distribution Modelling ◽  
Suitable Habitat ◽  
Native Range ◽  
Data Set ◽  
Distribution Modelling ◽  
Temperature Range

<p>Senecio glastifolius (Asteraceae) is an invasive species in New Zealand, where it threatens rare and vulnerable coastal floristic communities. It has expanded its range dramatically over recent years and continues to spread. It is subject to control programs in parts of its distribution. Uncertainty over its future distribution and invasive impacts in New Zealand contribute to the difficulty of its management. To address this knowledge gap, the potential distribution of S. glastifolius in New Zealand was predicted, based on its bioclimatic niche.  Existing information on its current distribution and historic spread is incomplete, stored in disparate sources, and is often imprecise or inaccurate. In this study, available information on its distribution and spread was synthesised, processed, and augmented with new data collected in the field by the author. This data set was optimised for use in species distribution modelling.  The distribution of S. glastifolius is described in its native range of South Africa, plus invaded regions in Australia, the British Isles and New Zealand. The data set describing its distribution is of higher quality than any known previous data set, is more extensive, and more suitable for use in species distribution modelling. The historic spread of S. glastifolius in New Zealand is presented, illustrating its expansion from sites of introduction in Wellington, Gisborne, plus several subsequent sites, to its now considerable range throughout much of central New Zealand.  A predictive model of the potential distribution of S. glastifolius was created based on the three main climatic variables observed to limit its distribution: mean annual temperature range, aridity, and minimum temperature of the coldest month. MaxEnt models were trained on data from all regions for which georeferenced records of the species were available; South Africa, Australia, New Zealand and the Isles of Scilly. Predictions were evaluated using methods appropriate to the special case of range-expanding species. Models performed well during validation, suggesting good predictive ability when applied to new areas.  Analysis of the realised niche space of S. glastifolius in the two climatic dimensions most influencing its distribution: Annual Temperature Range and Aridity, indicated that it is exploiting almost totally disjunct niche spaces in New Zealand and South Africa. Of the climate space occupied in New Zealand, almost none is available to the species in its native range of South Africa.  Predictions of S. glastifolius’s potential distribution in New Zealand reveal significant areas of suitable habitat yet to be invaded. Much of this suitable habitat is contiguous with the current range and active dispersal front of S. glastifolius, suggesting that invasion is highly likely under a scenario of no management intervention. Specifically, it is suggested that control and surveillance in coastal Taranaki are required to prevent invasion of an area covering most of the northern third of the North Island.</p>

scholarly journals The geographic distribution of Senecio glastifolius in New Zealand: past, current and climatic potential

2021 ◽  
Author(s):  
◽  
Josef Rehua Beautrais
Keyword(s):  
South Africa ◽  
New Zealand ◽  
Species Distribution ◽  
Potential Distribution ◽  
Species Distribution Modelling ◽  
Suitable Habitat ◽  
Native Range ◽  
Data Set ◽  
Distribution Modelling ◽  
Temperature Range

<p>Senecio glastifolius (Asteraceae) is an invasive species in New Zealand, where it threatens rare and vulnerable coastal floristic communities. It has expanded its range dramatically over recent years and continues to spread. It is subject to control programs in parts of its distribution. Uncertainty over its future distribution and invasive impacts in New Zealand contribute to the difficulty of its management. To address this knowledge gap, the potential distribution of S. glastifolius in New Zealand was predicted, based on its bioclimatic niche.  Existing information on its current distribution and historic spread is incomplete, stored in disparate sources, and is often imprecise or inaccurate. In this study, available information on its distribution and spread was synthesised, processed, and augmented with new data collected in the field by the author. This data set was optimised for use in species distribution modelling.  The distribution of S. glastifolius is described in its native range of South Africa, plus invaded regions in Australia, the British Isles and New Zealand. The data set describing its distribution is of higher quality than any known previous data set, is more extensive, and more suitable for use in species distribution modelling. The historic spread of S. glastifolius in New Zealand is presented, illustrating its expansion from sites of introduction in Wellington, Gisborne, plus several subsequent sites, to its now considerable range throughout much of central New Zealand.  A predictive model of the potential distribution of S. glastifolius was created based on the three main climatic variables observed to limit its distribution: mean annual temperature range, aridity, and minimum temperature of the coldest month. MaxEnt models were trained on data from all regions for which georeferenced records of the species were available; South Africa, Australia, New Zealand and the Isles of Scilly. Predictions were evaluated using methods appropriate to the special case of range-expanding species. Models performed well during validation, suggesting good predictive ability when applied to new areas.  Analysis of the realised niche space of S. glastifolius in the two climatic dimensions most influencing its distribution: Annual Temperature Range and Aridity, indicated that it is exploiting almost totally disjunct niche spaces in New Zealand and South Africa. Of the climate space occupied in New Zealand, almost none is available to the species in its native range of South Africa.  Predictions of S. glastifolius’s potential distribution in New Zealand reveal significant areas of suitable habitat yet to be invaded. Much of this suitable habitat is contiguous with the current range and active dispersal front of S. glastifolius, suggesting that invasion is highly likely under a scenario of no management intervention. Specifically, it is suggested that control and surveillance in coastal Taranaki are required to prevent invasion of an area covering most of the northern third of the North Island.</p>

scholarly journals Projecting the Potential Global Distribution of Carpomya vesuviana (Diptera: Tephritidae), Considering Climate Change and Irrigation Patterns

Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 355
Author(s):  
Guo ◽  
Ge ◽  
Zou ◽  
Zhou ◽  
Wang ◽  
...  
Keyword(s):  
Climate Change ◽  
Potential Distribution ◽  
Climate Scenario ◽  
Fruit Fly ◽  
Global Distribution ◽  
Future Climate Change ◽  
Economic Losses ◽  
Economic Damage ◽  
Primary Determinant ◽  
Irrigation Patterns

The ber fruit fly Carpomya vesuviana Costa (Diptera: Tephritidae) is the most destructive pests of Ziziphus spp. Carpomya vesuviana infestation causes great economic losses. We re-parameterized an existing CLIMEX model, and used the updated CliMond 30′ gridded resolution datasets within CLIMEX for the periods 1987–2016 and 2071–2100, representing historical and future climates, respectively, to predict the potential global distribution of the pest. Under the historical climate scenario, C. vesuviana had a wide climatically suitable distribution worldwide, from approximately 46° S to 50° N. Future climate change expanded the upper boundary of the potential distribution northward, and predicted that the pest would distribute approximately from 50° S to 60° N. Temperature was the primary determinant of the potential distribution of the pest among all driving variables. Irrigation was associated with a slight improvement in the climate favorability for the pest in some areas, including south-western North America, northern and southern Africa, and most of Oceania. The projections clarify the impacts of climate change on the potential global distribution of C. vesuviana, and are instructive for quarantine and management agencies for reducing economic damage caused by the fly and preventing expansion of C. vesuviana due to climate change.

scholarly journals Varroa destructor reproduction and cell re-capping in mite-resistant Apis mellifera populations

Apidologie ◽  
2019 ◽  
Vol 51 (3) ◽  
pp. 369-381 ◽  
Author(s):  
Stephen J. Martin ◽  
George P. Hawkins ◽  
Laura E. Brettell ◽  
Natasha Reece ◽  
Maria E. Correia-Oliveira ◽  
...  
Keyword(s):  
South Africa ◽  
Apis Mellifera ◽  
South African ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Global Distribution ◽  
Cell Opening ◽  
Very High

AbstractGlobalization has facilitated the spread of emerging pests such as the Varroa destructor mite, resulting in the near global distribution of the pest. In South African and Brazilian honey bees, mite-resistant colonies appeared within a decade; in Europe, mite-resistant colonies are rare, but several of these exhibited high levels of “re-capping” behavior. We studied re-capping in Varroa-naïve (UK/Australia) and Varroa-resistant (South Africa and Brazil) populations and found very low and very high levels, respectively, with the resistant populations targeting mite-infested cells. Furthermore, 54% of artificially infested A. m. capensis worker cells were removed after 10 days and 83% of the remaining infested cells were re-capped. Such targeted re-capping of drone cells did not occur. We propose that cell opening is a fundamental trait in mite-resistant populations and that re-capping is an accurate proxy for this behavior.

scholarly journals South Africa's Initiative Towards an Integrated Biodiversity Data Portal

2021 ◽  
Vol 5 ◽  
Author(s):  
Kiara Ricketts ◽  
Brenda Daly ◽  
Fhatani Ranwashe ◽  
Carol Lefakane
Keyword(s):  
South Africa ◽  
South African ◽  
Southern Africa ◽  
Integrated System ◽  
Research Assessment ◽  
Distribution Data ◽  
Free Access ◽  
The South ◽  
Biodiversity Data ◽  
Wide Range

Biodiversity Advisor, developed by the South African National Biodiversity Institute (SANBI), is a system that will provide integrated biodiversity information to a wide range of users who will have access to geospatial data, plant and animal species distribution data, ecosystem-level data, literature, images and metadata. It aims to deliver a centralized location with open access to information to enable research, assessment and monitoring; to support policy development; to foster collaboration and advance governance. Data are aggregated from multiple, diverse data partners across South Africa including, CapeNature, the FitzPatrick Institute of African Ornithology, Iziko South African museum, the National Herbarium of South Africa and the South African Institute for Aquatic Biodiversity. This newly developed and integrated system promotes a shift from tactically-based information systems, aimed at delivering products for individual project initiatives to a strategic system that promotes the building of capacity within organisations and networks. It has been developed by integrating SANBI’s existing authoring layers through a service-orientated architecture approach, which enables seamless cross-platform integration. Some of the key authoring layers that will be integrated are, the Botanical Database of Southern Africa (BODATSA), the Zoological Database of Southern Africa (ZODATSA), the Biodiversity Geographic Information System (BGIS) and SANBI's institutional repository (Opus). Biodiversity Advisor will provide users, policy and decision makers, environmental impact practitioners and associated organizations with free access to view, query and download any of South Africa's biodiversity data available on the system, providing them with everything needed to make decisions around conservation and biodiversity planning in South Africa. All sensitive species data, which are those that are vulnerable to collecting, over-exploitation, commercial and/or medicinal use, will be redacted and only granted access upon application. Biodiversity Advisor will encourage more effective management of data within SANBI, but also encourage the sharing of data by the biodiversity community to provide integrated products and services, which are needed to address complex environmental issues.

scholarly journals Predicting the Potential Distribution of Non-Native Mammalian Species Sold in the South African Pet Trade

Diversity ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 478
Author(s):  
Ndivhuwo Shivambu ◽  
Tinyiko C. Shivambu ◽  
Colleen T. Downs
Keyword(s):  
South Africa ◽  
South African ◽  
Potential Distribution ◽  
Mammalian Species ◽  
Management Strategies ◽  
House Mice ◽  
Invasion History ◽  
Pet Trade ◽  
Human Footprint ◽  
Baseline Approach

The pet trade is one of the main pathways of introduction of several mammals worldwide. In South Africa, non-native mammalian species are traded as pets, and so far, only four of these species are considered invasive. We used a list of 24 companion mammalian species compiled from a previous study. We selected a subset of 14 species for species distribution modeling (SDM) based on their trade popularity, invasion history and potential economic and socio-economic impacts. We aimed to estimate their potential distribution using their distribution records. Our SDM indicated that climate in South Africa was suitable for most traded species. However, commonly and easily available species had the broadest areas of suitable climates, such as house mice (Mus musculus) and Norwegian rats (Rattus norvegicus). In addition, the model with a human footprint suggested a high risk of invasion for Norwegian rats but less for house mice distribution. This assessment suggests the need of strict trade regulations and management strategies for pet mammals with broader suitability, which are already invasive, and most available for sale. In addition, our results provide a baseline approach that can be used to identify mammalian pet species with a potential risk of invasion so that urgent preventive measures can be implemented.

Reframing Xenophobia in South Africa as Colour-Blind: The Limits of the Afro Phobia Thesis

2020 ◽  
Vol 17 (3) ◽  
pp. 433-444
Author(s):  
Amanuel Isak Tewolde
Keyword(s):  
South Africa ◽  
South African ◽  
Analytical Framework ◽  
Conflict Theory ◽  
Black African ◽  
South Africans ◽  
Theoretical Perspectives ◽  
Online Newspaper ◽  
Close Proximity ◽  
Realistic Conflict Theory

Many scholars and South African politicians characterize the widespread anti-foreigner sentiment and violence in South Africa as dislike against migrants and refugees of African origin which they named ‘Afro-phobia’. Drawing on online newspaper reports and academic sources, this paper rejects the Afro-phobia thesis and argues that other non-African migrants such as Asians (Pakistanis, Indians, Bangladeshis and Chinese) are also on the receiving end of xenophobia in post-apartheid South Africa. I contend that any ‘outsider’ (White, Asian or Black African) who lives and trades in South African townships and informal settlements is scapegoated and attacked. I term this phenomenon ‘colour-blind xenophobia’. By proposing this analytical framework and integrating two theoretical perspectives — proximity-based ‘Realistic Conflict Theory (RCT)’ and Neocosmos’ exclusivist citizenship model — I contend that xenophobia in South Africa targets those who are in close proximity to disadvantaged Black South Africans and who are deemed outsiders (e.g., Asian, African even White residents and traders) and reject arguments that describe xenophobia in South Africa as targeting Black African refugees and migrants.

Region of Birth and Child Mortality among Black Migrants to South Africa: Is there a foreign-born advantage?

2016 ◽  
Vol 13 (3) ◽  
pp. 359-376 ◽  
Author(s):  
Tiffany L Green ◽  
Amos C Peters
Keyword(s):  
South Africa ◽  
South African ◽  
Child Mortality ◽  
Southern Africa ◽  
Strong Relationship ◽  
Developed Countries ◽  
Black Immigrants ◽  
Foreign Born ◽  
Region Of Origin ◽  
Child Deaths

Much of the existing evidence for the healthy immigrant advantage comes from developed countries. We investigate whether an immigrant health advantage exists in South Africa, an important emerging economy.  Using the 2001 South African Census, this study examines differences in child mortality between native-born South African and immigrant blacks.  We find that accounting for region of origin is critical: immigrants from southern Africa are more likely to experience higher lifetime child mortality compared to the native-born population.  Further, immigrants from outside of southern Africa are less likely than both groups to experience child deaths.  Finally, in contrast to patterns observed in developed countries, we detect a strong relationship between schooling and child mortality among black immigrants.

Some Reflections on Reparation in Post-Apartheid South Africa, using a Couple Therapy Intervention as a Microcosm of South African Society

2011 ◽  
Vol 1 (2) ◽  
Author(s):  
Andrea Hill ◽  
Sylvia Poss
Keyword(s):  
South Africa ◽  
South African ◽  
Couple Therapy ◽  
South African Society ◽  
Depressive Position ◽  
Central Hypothesis ◽  
Transference And Countertransference ◽  
Constructive Engagement ◽  
The Impact ◽  
Therapy Intervention

The paper addresses the question of reparation in post-apartheid South Africa. The central hypothesis of the paper is that in South Africa current traumas or losses, such as the 2008 xenophobic attacks, may activate a ‘shared unconscious phantasy’ of irreparable damage inflicted by apartheid on the collective psyche of the South African nation which could block constructive engagement and healing. A brief couple therapy intervention by a white therapist with a black couple is used as a ‘microcosm’ to explore this question. The impact of an extreme current loss, when earlier losses have been sustained, is explored. Additionally, the impact of racial difference on the transference and countertransference between the therapist and the couple is explored to illustrate factors complicating the productive grieving and working through of the depressive position towards reparation.

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