House crow (Corvus splendens) eradication measures from eThekwini Municipality, KwaZulu-Natal, South Africa

Within the Province of KwaZulu-Natal, in South Africa, eThekwini Municipality intends to implement a Project aimed at eradicating the House Crow (Corvus splendens) from its jurisdiction. In terms of the National Environmental Management: Biodiversity Act (NEMBA), Act 10 of 2004, the species is listed as a Category 1a under the Invasive Alien Species (IAS) Regulations gazetted in July 2014 and as such requires immediate eradication efforts. The species belongs to a cosmopolitan family Corvidae, which has well over 120 species including oscine passerine birds such as crows, ravens, magpies, rooks, treepies etc. In line with legislation, eThekwini Municipality has implemented a number of large-scale programmes and projects aimed at controlling invasive alien species. In achieving this, the municipality has a strong belief in forming partnerships with relevant stakeholders, including academic institutions, neighboring municipalities, conservation authorities, conservancies, non-profit organizations, the private sector, provincial and national government departments etc

Non-native small mammal species in the South African pet trade

Non-native small mammals are amongst the most popular species traded as pets around the world. Some of these mammals have become invasive through various pet trade releases and escapees in most countries. In South Africa, several nonnative small mammals have been introduced for pet trade purposes. We assessed the sale of non-native small mammals in South Africa from September 2018 to 2019 to determine their abundance and degree of trade online and in pet shops. A total of seven websites were recorded selling 2,681 individuals representing 24 species belonging to seven taxonomic orders. For physical pet shops, 19,391 individuals representing 16 species and seven orders were recorded from 122 pet shops. Rodents and primates were the most dominant groups in both online and pet shops. The most common small mammal species traded were the Norwegian rat Rattus norvegicus, the guinea pig Cavia porcellus, the European rabbit Oryctolagus cuniculus and the house mouse Mus musculus. Prices ranged from ZAR9.00 to ZAR12,000.00, with rodents offered at relatively low prices. The most abundant species traded were relatively cheap when compared with the least abundant species and CITES species were more expensive than non-CITES species. Species with high abundances traded at low prices and have a history of invasion through pet trade releases and escapes pose an invasion risk in South Africa. Therefore, their trade should be strictly regulated

Aspects of the feeding ecology of introduced Rose-ringed Parakeets Psittacula krameri in the urban landscape mosaic of Durban, KwaZulu-Natal Province, South Africa

The Rose-ringed Parakeet Psittacula krameri is one of the world’s commonest invasive bird species and has established in the South African urban landscapes. However, relatively little is known about the feeding biology of parakeets here. We surveyed areas in eThekwini Municipality, Durban, South Africa, to determine their feeding sites and the related land-use types. Patterns of the association were explored using Correspondence Analysis to determine parakeets’ diet across seasons and interaction between different tree species fed on by parakeets and other bird species. Dietary items were determined visually using binoculars. We identified a total of 63 feeding sites with many in the urban built land-use cover type. The parakeets’ diet differed significantly across the seasons with spring accounting for 33% of annual food items. We identified 31 fruiting/flowering tree species fed on by the parakeets, with fleshy fruits and flowers accounting for 58% and 19%, respectively. Native tree species (63%) were mostly relied on when compared with non-native (27%). They also fed on carpenter ants Camponotus cinctellus which contributed 3% of their diet. The forest fever-berry Croton sylvaticus (fleshy fruits) and African star-chestnut Sterculia africana (flowers) were the most preferred tree species in autumn and summer. The observed number of bird species that communally fed with parakeets were significantly different across the sampled seasons. The diets for the Common Myna Acridotheres tristis and the Speckled Mousebird Colius striatus overlapped with parakeets for most tree species. Parakeets were observed actively feeding in the early mornings and late afternoons before roosting. Our study supports that parakeets are generalist-opportunistic feeders. The assessment of Rose-ringed Parakeets feeding ecology may help understand their potential impact on native tree and bird species within an urban landscape

Population estimates of non-native rose-ringed parakeets Psittacula krameri (Scopoli, 1769) in the Durban Metropole, KwaZulu-Natal Province, South Africa

Rose-ringed parakeetsPsittacula krameriare one of the most widely distributed urban avian invader species present in similar to 35 countries with population sizes increasing. These parakeets were introduced to South Africa as part of the pet trade, and feral populations have established in several urban areas since and are of concern. We, therefore, conducted monthly surveys between August 2018 - December 2019 in the greater Durban Metropole, KwaZulu-Natal Province, to determine their population size and roosting sites. In addition, we recorded bird species that communally roosted with rose-ringed parakeets, and tree species characteristics that they used for roosting. We identified five main roost site areas with an overall mean (+/- SD) monthly population size of 1 783.3 +/- 505.2 rose-ringed parakeets. There was an increase in rose-ringed parakeet numbers, particularly in August and December after their breeding. Most rose-ringed parakeets were recorded in the north, with fewer in the south of the metropole; and many were located around shopping centres and parks. A total of seven bird species communally shared roost sites with rose-ringed parakeets, with the non-native common mynaAcridotheres tristisbeing the species that frequently shared roosts with parakeets. Three tree species were used as roosts, with the Natal mahoganyTrichilia emeticaand the giant palmRaphia australis, so being the preferred roost tree species. The results showed variations in the measured tree traits and the number of individual parakeets roosting per tree species. The population size of non-native rose-ringed parakeets showed persistent growth, and it is, therefore, suggested that control measures for this species are introduced before its population expands further

Exotic gastropods for sale: an assessment of land and aquatic snails in the South African pet trade

Gastropods are amongst the most popular of the Mollusca in the pet trade, with globalisation being the main contributing factor facilitating their establishment globally. Although it is known that gastropods are kept as pets in South Africa, relatively little has been documented on the trade for this group. Physical pet stores selling gastropod species were surveyed seasonally in South Africa, aiming to determine 1) the types of species sold, including their trade popularity, trade volume, and the biogeographic realms they originated from, and 2) seasonal variations in gastropod species traded. Six gastropod species were recorded in the South African pet stores with three known invasives (Achatina fulica, A. immaculata, and Pomacea canaliculata). Of these species, the African giant snail A. fulica and the channeled golden apple snail P. canaliculata were the species with higher trade popularity throughout the year. The trade of the other species fluctuated with seasons among pet stores and provinces. Gastropod species sampled in this study originated from four biogeographic realms, with two species from the Afrotropical and Neotropical realms, and one each from the Indomalayan and the Palaearctic. The number of gastropod individuals observed in this study was relatively large; as a result, they may pose a potential risk of invasion should they be released or escape captivity. The pet trade industry at a national level needs to be regularly monitored and the policies on selling invasive non-native species should be implemented to avoid the introduction and establishment of potential invaders

Impact assessment of seven alien invasive bird species already introduced to South Africa

Globally, various avian species have been introduced accidentally and deliberately by humans through different pathways. Some of these species were able to establish, multiply, and become invasive. In this study, we identified areas that are climatically suitable for seven introduced invasive bird species and assessed the environmental and socio-economic impacts associated with the selected bird species in South Africa. We used present distribution records to predict potential climatic suitability distributions and used the Generic Impact Scoring Scheme to assess the impacts associated with seven invasive bird species in South Africa. We found that all the seven species were climatically suitable to South Africa and Passer domesticus, Sturnus vulgaris, and Anas platyrhynchos each had relatively large climatic suitability distributions. The climatic suitability for all the species was within their occurrence ranges in and outside South Africa. For impact assessments, we found that all seven selected species had impacts, with A. platyrhynchos, Acridotheres tristis, Columba livia, and Psittacula krameri having the highest overall impacts respectively. The socio-economic impact ranked higher than environmental impact for all species. The socio-economic impacts were frequently through agricultural production and human infrastructure, while the environmental impact was mostly through impacts of birds on other animals and competition. These need to be incorporated in decision-making and eradication plans for these alien invasive birds in South Africa

Numbers of invasive House Sparrows Passer domesticusin a rural landscape of Limpopo province, South Africa

The House SparrowPasser domesticusis recognised as one of the commonest avian invasive species globally, with its occurrence associated with human existence. However, relatively little on population sizes of this species in rural landscapes has been documented. The study on House Sparrows was conducted in three areas in a rural landscape of Limpopo province, South Africa where it is an invasive, to 1) determine population numbers of the House Sparrow between the years 2014 and 2016, and 2) investigate the interaction between the number of House Sparrows and the number of their active nests. The House Sparrow population numbers showed no significant differences between 2014, 2015 and 2016. The House Sparrow numbers were influenced by the number of active nests in 2014 and 2016. The current study showed that the presence of House Sparrows was not affected by the house type they roosted in, and the number of active nests was not influenced by the house types available in each area. The results also showed that the House Sparrow occurs across a rural landscape with variation in numbers across seasons. The evidence reported provides significant insight into how invasive House Sparrows are well established in rural landscapes around human habitation, and it is recommended that this should be incorporated into the management of such alien invasive birds

Genetic identification of freely traded synanthropic invasive murid rodents in pet shops in Gauteng Province, South Africa

Although synanthropic invasive murid rodents are freely traded in pet shops in South Africa, their taxonomic identities, however, remain largely unknown. Twenty-four murid rodents were sampled from pet shops in four of the five municipalities in Gauteng Province, South Africa for genetic identification using mitochondrial cytochrome b (mtDNA) sequence data. Distance-based Neighbour-Joining (NJ), character-based maximum likelihood (ML) and model-based Bayesian inference (BI) were used to infer the relationship between the pet murid rodents. Brown rats (Rattus norvegicus) and house mice (Mus musculus) were the most dominant species in the pet shops. The results demonstrated that pet shop owners lacked the taxonomic expertise to identify murid rodent species they trade in. For example, the juveniles of brown rats were misidentified as adults of the house mouse. The murid rodents sampled in the current study were genetically affiliated to both wild and laboratory strains of R. norvegicus and M. musculus. The results of the BI showed that the pet murid rodents were in the terminal clades as those of conspecifics in NCBI GenBank reference sequences. The molecular data used in the current study may be useful for developing national policies and regulations for synanthropic invasive murid rodents in the pet trade industry in South Africa