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

Abstract

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.Keywords Alien invasive birds Á Climatic matching Á GISS Á Environmental impact Á Socioeconomic impacts Á Impact assessment

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

“…Although the feeding ecology of Rose-ringed Parakeets has been reported in other countries (Ahmad et al 2012;Fraticelli 2014;Shiels et al 2018), relatively little has been documented in South Africa (Thabethe et al 2015;Ivanova and Symes 2019). Given the evidence of environmental and socio-economic impacts associated with Rose-ringed Parakeets (Shivambu et al 2020a), it is important to understand their feeding biology in South Africa.…”

“…To date, the wild populations of this species appear to be increasing and occurring in different urban areas in South Africa (Hart and Downs 2014;Symes 2014;SABAP2 2020;Shivambu et al 2020b). The potential impacts associated with Rose-ringed Parakeets feeding ecology in other countries is well documented (Ahmad et al 2012;Fraticelli 2014;Shiels et al 2018;Shivambu et al 2020a). Given this, we studied aspects of their feeding ecology to (1) determine the distribution of Rose-ringed Parakeets feeding sites and their associated land-use types, (2) determine types of food items consumed and patterns of association in Rose-ringed Parakeets diet across the seasons, (3) identify bird species that fed communally with the Rose-ringed Parakeets, and explored the associations of different tree species between them, and (4) determine daily feeding times of Rose-ringed Parakeets.…”

Assessing the potential impacts of non-native small mammals in the South African pet trade

“…Non-native pets have been associated with negative impacts on biodiversity, human health, the economy, and agriculture (Marbuah et al 2014;Su et al 2015;Shivambu et al 2020). In Brazil, the common marmoset C. jacchus has been reported to negatively affect the population of vulnerable buffy-tufted marmosets C. aurita through hybridisation (Nogueira et al 2011;Malukiewicz et al 2014).…”

“…10 of 2004) (NEMBA) requires that impact and risk assessments are undertaken by either the issuing authority or the importer before issuing permits for non-native species being imported, sold, kept in captivity or released into the wild (van Wilgen et al 2008). Impact and risk assessment protocols are considered to be cost-effective and reliable methods that can be used to identify potential invasion impacts, enable ranking of them and support decision-making (Jeschke et al 2014;da Rosa et al 2018;Shivambu et al 2020). Both impact and risk assessment protocols have been successfully used for fishes (van der Veer and Nentwig 2015), plants (Novoa et al 2016) and for species in the pet trade (Bomford et al 2005;Patoka et al 2014;da Rosa et al 2018;Weiperth et al 2018) to investigate the potential invasion risks and impacts.…”

Tarantulas (Araneae: Theraphosidae) in the pet trade in South Africa

“…Many species that escape, or are released, may be unable to survive and establish self-sustaining populations (Zenni and Nuñez 2013). However, those species that successfully establish and become invasive can have severe environmental and economic impacts (Nelufule et al 2020;Shivambu et al 2020aShivambu et al , 2020b. Some of the species damage ecosystems (Martin and Coetzee 2011), compete for resources with native species (Mori et al 2017;Nunes et al 2017) and carry pathogens that threaten public health (Travis et al 2011) and agriculture (Witmer andHall 2011;Gibson and Yong 2017), and cause biodiversity loss (Engeman et al 2007;Faulkes 2010).A recent review by Lockwood et al (2019) highlights the urgent necessity to understand better how the exotic pet trade contributes to invasions in order to devise strategies to limit its harmful impacts.…”