The distribution and spread of the invasive alien common myna, Acridotheres tristis L. (Aves: Sturnidae), in southern Africa.
South African Journal of Science 103(11-12):465-473.
The common myna is an Asian starling that has become established in many parts of the world outside of its native range due to accidental or deliberate introductions by humans. The South African population of this species originated from captive birds that escaped in Durban in 1902. A century later, the common myna has become abundant throughout much of South Africa and is considered to pose a serious threat to indigenous biodiversity. Preliminary observations suggest that the common myna's distribution is closely tied to that of humans, but empirical evidence for this hypothesis is lacking. We have investigated the relationships between common myna distribution, human population size and land-transformation values at a quarter-degree resolution in South Africa. Common mynas were found more frequently than expected by chance in areas with greater human population numbers and land-transformation values. We also investigated the spatial relationship between the bird's range and the locations of South Africa's protected areas at the quarter-degree scale. These results indicate that, although there is some overlap, the common myna distribution is not closely tied to the spatial arrangement of protected areas. We discuss the original introduction, establishment and rate of spread of the common myna in South Africa and neighbouring countries and contrast the current distribution with that presented in The Atlas of Southern African Birds. We also discuss the factors that affect the common myna's success and the consequences that invasion by this species is likely to have, specifically in protected areas.
Paddlefish (Polyodon spathula) in Europe: An aquaculture species and a potential invader.
Journal of Applied Ichthyology 35 (1): 267-274. https://doi.org/10.1111/jai.13672
The paddlefish (Polyodon spathula) was first introduced to Europe in 1974, mainly due to its potential for rearing in natural polyculture ponds and large temperate reservoirs. The information on the history of paddlefish aquaculture efforts in Europe is scarce, as well as data on current paddlefish aquaculture status and trends. In addition, there is a lack of data on its presence and potential establishment in the wild, while its invasive potential and associated risks and impacts are largely unknown. In order to evaluate its current status in Europe, we conducted a survey among scientists, aquaculture producers and other stakeholders, and reviewed literature and data on the Internet. Based on the results obtained, we discuss the potential and the challenges in European paddlefish aquaculture development, and analyze paddlefish invasive potential and risks associated with its naturalization. Paddlefish aquaculture is well established only regionally in Europe, but offers relatively high potential for further development in pond farms. Nevertheless, future development will require careful planning, especially regarding market development and improved marketing strategies. While paddlefish likely represents a low‐risk invader, improved control and reporting on trade and intentional and unintentional releases will be required. Given the lack of knowledge on potential impacts following its introduction, due caution seems highly advisable.
The status and impact of the Rainbow lorikeet (Trichoglossus haematodus moluccanus) in south-west Western Australia.
Department of Agriculture and Food, Western Australia, Perth. Report 04/2005.
Rainbow lorikeets Trichoglossus haematodus moluccanus were first recorded in Perth in 1968 and the population was thought to have originated from fewer than 10 birds that were either deliberately released or had escaped from aviaries. Since the early 1960s, the population has increased exponentially and spread rapidly over 174 km2 of the metropolitan area. The population now numbers an estimated 8,400 birds and is expanding in range at a rate of 0.7 km per year. Rainbow lorikeets are highly mobile, have generalised feeding and breeding requirements and can quickly adapt to exploit new feeding and breeding resources. They have taken advantage of the year-round supply of native and exotic food plants available in Australia’s major cities and are expanding in number and distribution in Brisbane, Sydney, Melbourne, Canberra, Adelaide and Perth. The rainbow lorikeet is regarded as either a pest of agriculture or an unwanted organism in New Zealand, the Northern Territory, Queensland, the Australian Capital Territory, Victoria, Tasmania and South Australia. It is also a major pest of agriculture in the Northern Territory, Queensland and the fruit growing regions of the Adelaide Hills in South Australia. Analyses conducted in this study show that the feral rainbow lorikeet population in Perth poses an extreme risk to the State’s social, environmental and agricultural values. Rainbow lorikeets cause a nuisance in the form of noise, damage to backyard fruit crops and fouling of outdoor areas and vehicles with droppings. The large roosting flock of over 1000 birds near Perth domestic airport may also pose a risk of bird-strike to aircraft.
The lorikeets also exclude native birds from feeding resources and nesting sites, kill the nestlings of other bird species and carry Psittacine beak and feather disease in the liver (once infected), which they can spread to native lorikeets and parrots. Lorikeets are a serious pest of cherries, apples, pears and stone fruit and a very serious pest of grapes in Australia and this study showed that the potential for rainbow lorikeets to spread outside the Perth metropolitan area is high. Thus, the lorikeets pose an extreme threat to Western Australia’s $245 million fruit, nut and grape growing industry. An integrated pest management program must be developed to: restrict the population to the Perth metropolitan area, and reduce the number of birds in the population from an estimated 8400 in 2004 to an estimated 5000 by 2020. The management program should include the following objectives:
- Investigate sources and obtain the funding required to manage the population.
- Estimate the number of birds in the Perth population, establish its distribution and locate major roost sites.
- Alter the status of the rainbow lorikeet in south-west Western Australia so that it is a declared pest in the metropolitan area (alter to A2; ‘subject to eradication in the wild’ south of the 20th parallel of latitude, and A5; ‘numbers to be reduced/controlled’ in the Perth metropolitan area).
- Investigate methods of population reduction in the metropolitan area and document their effectiveness.
- Educate the public on the impacts of rainbow lorikeets and the need for control.
- Eradicate rainbow lorikeets that are sighted outside the metropolitan area.
- Investigate and document the effectiveness of methods for the mitigation of agricultural damage.
- Conduct a cost/benefit analysis of the damage caused by rainbow lorikeets and lorikeet control.
- Develop a molecular approach to population control and management.
- Review standards for the import and keeping of rainbow lorikeets to reduce the risk of aviary escapes.
Range expansion of an exotic ungulate (Ammotragus lervia) in southern Spain: ecological and conservation concerns.
Biodiversity and Conservation 13: 851. https://doi.org/10.1023/B:BIOC.0000014461.69034.78
Evidence of aoudad Ammotragus lervia expansion in the southeastern quarter of the Iberian Peninsula is provided based on recent field surveys. Aoudad has become common in a limited region of the southeast of Spain since its introduction as a game species in Sierra Espuña Natural Park in 1970. Its adaptability enabled it to colonise nearby areas in a short period. Apart from this source of expansion, the increasing number of aoudads in Spanish private game reserves provided other centres of dispersion. In addition, aoudads were introduced on La Palma Island (Canary Islands), becoming a serious threat to endemic flora. Of great conservation concern is the species' potential as a competitor against native ungulates inhabiting the peninsula. Surveys conducted in southern Spain documented rapid colonization of new areas and established viable populations, consisting of adult males and females and the unequivocal presence of nursery groups, in the provinces of Alicante, Almería, Granada and Murcia. Also, aoudads have spread throughout the north and centre of La Palma. There are two main conservational concerns: the necessity of conducting detailed and reliable surveys in all potential regions where the species might expand, and the urgent need of changing current game policies in order to establish reliable controls on big game reserves to prevent animals from escaping.
The control of dingoes in New South Wales in the period 1883-1930 and its likely impact on their distribution andabundance.
Australian Zoologist 31 (3): 432-442
The sheep grazing industry has been an economic mainstay of New South Wales from the early period of European settlement. The dingo quickly established itself as a predator of sheep and a pest of the pastoral industry. In the latter decades of the nineteenth century, a system was established under which bounties were paid on a wide range of species, but bounties paid for dingoes were far in excess of those paid for other species. In addition,an exclusion fence was built, spanning 5'614 km and three States, to prevent dingoes from reinvading south-eastern Australia. This level of control effortreflects the importance of the dingo as a pest of the sheep industry. In the period between 1883 and 1930, over 280,000 bounties were paid for dingoes in New South Wales. At the beginning of this period. dingoes appeared to be distributed throughout New South Wales. By 1930, dingoes were scarce in all but the north-eastern corner of the State. The highest numbers of sheep were grazed in the areas that showed the most rapid decline in dingo numbers, while relatively low numbers were grazed in the areas where dingoes remained common.
No relationship was observed between the value of bounties offered and the number of scalps submitted. The main incentive for the destruction of dingoes by humans is likely to have been the protection of stock, rather thanthe monetary reward of the bounty payments.
Die invasiven gebietsfremden Arten der Unionsliste der Verordnung (EU) Nr.1143/2014 – Erste Fortschreibung 2017.
Hrsg. Bundesamt für Naturschutz, Bonn. BfN-Skripten 471. 164 Seiten
Unter den behandelten Arten befinden sich die folgenden Wirbeltierarten, die gegenwärtig in europäischen Zoos gehalten werden:
- *Nilgans (Alopochen aegyptiaca )
- Pallas-Schönhörnchen (Callosciurus erythraeus)
- Nordamerikanischer Ochsenfrosch (Lithobates catesbeianus)
- Chinesischer Muntjak (Muntiacus reevesi)
- Nutria (Myocastor coypus)
- Marderhund (Nyctereutes procyonoides)
- *Bisam (Ondatra zibethicus)
- Schwarzkopf-Ruderente (Oxyura jamaicensis)
- Amurgrundel (Perccottus glenii)
- Waschbär (Procyon lotor)
- Blaubandbärbling (Pseudorasbora parva)
- Grauhörnchen (Sciurus carolinensis)
- Fuchshörnchen (Sciurus niger)
- Sibirisches Streifenhörnchen (Tamias sibiricus)
- Heiliger Ibis (Threskiornis aethiopicus)
- Buchstaben-Schmuckschildkröte (Trachemys scripta)
Einwanderung von Fischarten in die Schweiz - Rheineinzugsgebiet.
Mitteilungen zur Fischerei 72: 1-89.
Herausgeber: Bundesamt für Umwelt, Wald und Landschaft (BUWAL)
Die Fischartengemeinschaft der Schweiz war durch das Aussterben und die Neu- oder Wiedereinwanderung seit jeher Veränderungen unterworfen. Neben natürlichen Ursachen wie z. B. Klimaschwankungen ist seit einigen hundert Jahren der Mensch zunehmend verantwortlich für Verschiebungen im Artengefüge. Seit Ende des 19. Jahrhunderts ist die Beeinflussung durch den Menschen derart gross, dass in der Schweiz 8 Fischarten als Folge der Gewässerverschmutzung, der Überfischung, vor allem aber der Flussverbauungen ausgestorben sind.
Gleichzeitig mit dem Verschwinden dieser Arten wurde eine beträchtliche Anzahl nicht einheimischer (allochthoner) Fischarten (Fisch-Neozoen) vorwiegend aus fischereilichen Überlegungen in unsere Gewässer eingesetzt. Heute umfasst die Fischfauna der Schweiz mindestens 16 fremde Fischarten, die zumeist etablierte Bestände bilden konnten. 13 Arten gelangten durch gezielten Besatz oder das Einschleppen via Besatzmaterial, 2 Arten über die Zierfischhaltung und 1 Art aus unbekannten Gründen in die Gewässer. Heute ist das Einsetzen allochthoner Fischarten in der Schweiz auf gesetzlicher Ebene befriedigend geregelt.
Allochthone Fischarten können in vielerlei Hinsicht negative ökologische Auswirkungen haben. So sind beispielsweise ein Konkurrenz- oder Prädationsdruck auf einheimische (autochthone) Arten möglich. Auch eine Hybridisierung mit nah verwandten Vertretern der lokalen Fauna oder das Einschleppen von Krankheiten und Parasiten kann zu Beeinträchtigungen führen. Neozoen müssen aber nicht immer Probleme verursachen. Sie können sich auch unauffällig in die lokale Artengemeinschaft einfügen.
Das Wissen über die Rolle, die die allochthonen Fischarten innerhalb der autochthonen Artengemeinschaft spielen, weist fast durchwegs grosse Lücken auf. Unerwünschte Interaktionen mit den einheimischen Arten können daher unbemerkt ablaufen. Bei unerklärlichen Bestandesrückgängen autochthoner Fischarten sollte daher auch der Einfluss von Neozoen in Betracht gezogen werden. Dieser könnte in den nächsten Jahren an Bedeutung gewinnen, da eine ganze Anzahl neuer Fischarten quasi vor der Tür
in die Schweiz steht. Nachdem der Rapfen (Aspius aspius) und der Blaubandbärbling (Pseudorasbora parva) in den letzten Jahren via Hochrhein den Weg in die Schweiz gefunden haben, ist zu erwarten, dass kurzfristig 6, mittel- und langfristig 9 zusätzliche allochthone Fischarten auf diesem Weg in die Schweizer Gewässer gelangen könnten. Bei 6 dieser potenziellen Neozoen ist mit beträchtlichen negativen Auswirkungen auf die autochthone Fischgemeinschaft (Konkurrenz, Prädation) zu rechnen; es handelt sich um die Dickkopf-Elritze (Pimephales promelas), die Amurgrundel (Perccottus glehni), die Flussgrundel (Neogobius fluviatilis), die Nackthals-Grundel (N. gymnotrachelus), die Kessler-Grundel (N. kessleri) und die Schwarzmund-Grundel (N. melanostomus).
Neben einer Einwanderung allochthoner ist auch die Immigration ausgestorbener, autochthoner Fischarten in den nächsten Jahren zu erwarten. Dies gilt vor allem für das Flussneunauge (Lampetra fluviatilis), den Lachs (Salmo salar) und die Meerforelle (Salmo trutta).
Der vorliegende Bericht liefert eine Übersicht über die Neozoen der Schweizer Fischfauna. Neben den bereits vorkommenden Arten befasst er sich mit möglichen Neueinwanderern, aber auch mit den heute ausgestorbenen, dereinst hoffentlich wieder einwandernden Arten. Die Situation im Einzugsgebiet des Rheins steht dabei im Zentrum der Betrachtung. 37 Arten (bzw. Taxa) werden im Detail beschrieben.
Discovery of South American suckermouth armored catfishes (Loricariidae, Pterygoplichthys spp.) in the Santa Fe River drainage, Suwannee River basin, USA.
BioInvasions Records (2012) Volume 1, Issue 3: 179–200
We report on the occurrence of South American suckermouth armored catfishes (Loricariidae) in the Suwannee River basin, southeastern USA. Over the past few years (2009-2012), loricariid catfishes have been observed at various sites in the Santa Fe River drainage, a major tributary of the Suwannee in the state of Florida. Similar to other introduced populations of Pterygoplichthys, there is high likelihood of hybridization. To date, we have captured nine specimens (270-585 mm, standard length) in the Santa Fe River drainage. One specimen taken from Poe Spring best agrees with Pterygoplichthys gibbiceps (Kner, 1854) or may be a hybrid with either P. pardalis or P. disjunctivus. The other specimens were taken from several sites in the drainage and include seven that best agree with Pterygoplichthys disjunctivus (Weber, 1991); and one a possible P. disjunctivus × P. pardalis hybrid. We observed additional individuals, either these or similar appearing loricariids, in Hornsby and Poe springs and at various sites upstream and downstream of the long (> 4 km) subterranean portion of the Santa Fe River. These specimens represent the first confirmed records of Pterygoplichthys in the Suwannee River basin. The P. gibbiceps specimen represents the first documented record of an adult or near adult of this species in open waters of North America. Pterygoplichthys disjunctivus or its hybrids (perhaps hybrid swarms) are already abundant and widespread in other parts of peninsular Florida, but the Santa Fe River represents a northern extension of the catfish in the state. Pterygoplichthys are still relatively uncommon in the Santa Fe drainage and successful reproduction not yet documented. However, in May 2012 we captured five adult catfish (two mature or maturing males and three gravid females) from a single riverine swallet pool. One male was stationed at a nest burrow (no eggs present). To survive the occasional harsh Florida winters, these South American catfish apparently use artesian springs as thermal refugia. In the Santa Fe River, eradication might be possible during cold periods when catfish congregate in spring habitats. However, should Pterygoplichthys increase in number and disperse more widely, the opportunity to eliminate them from the drainage will pass.
Discovery of South American suckermouth armored catfishes (Loricariidae, Pterygoplichthys spp.) in the Santa Fe River drainage, Suwannee River basin, USA (PDF Download Available). Available from: https://www.researchgate.net/publication/264375985_Discovery_of_South_American_suckermouth_armored_catfishes_Loricariidae_Pterygoplichthys_spp_in_the_Santa_Fe_River_drainage_Suwannee_River_basin_USA [accessed Feb 28 2018].
Introduced Birds and Mammals in New Zealand and Their Effect on the Environment.
Tuatara 27 (2): 77-104 (December 1984).
Thirty three species of introduced birds and thirty two species of introduced mammals are now widely accepted as a part of New Zealand fauna. The history of the introduction of these vertebrates into New Zealand is documented, and consideration is given to their effect on the native vegetation and fauna. The status of introduced mammals in the late 1940's (Wodzicki 1950) is compared with the present, and the success of control is discussed. Improved technology and the high export value of quality animal products led to a population decline of certain mammals as farming became commercially viable. While the distribution of many introduced mammals has expanded, population numbers have generally decreased since the first survey. A notable exception is the possum.
Conservation of the Sunda gharial Tomistoma schlegelii in Lake Mesangat, Indonesia.
International Zoo Yearbook 49: 137–149. ISSN 0074-9644.DOI: 10.1111/izy.12068.
Although featured in many international zoo collections for decades, little was known about the natural history of Sunda gharial Tomistoma schlegelii until recently. Zoos rarely keep large individuals and breeding success has been low. As late as 1998, even though most conservationists regarded the conservation status of the species as Endangered, the reality was that over most of the range the actual status of the Sunda gharial was Data Deficient. Beginning with surveys of the species by international and local scientists in Indonesian Sumatra and, later, in Kalimantan, Indonesian Borneo, supported by the International Union for Conservation of Nature/Species Survival Commission Crocodile Specialist Group, more details on the broad distribution of this crocodilian came to light. Ironically, rediscovery of a large and healthy population of T. schlegelii in East Kalimantan arose from an oil-palm company accessing the area to develop a site called Danau Mesangat. Subsequently through a cooperation agreement with the oil-palm company's conservation department and a local foundation, a group of dedicated zoos in Europe and America, and the Tomistoma Task Force set up by the Crocodile Specialist Group, provided funding for three consecutive years of field studies by a research group. These studies investigated the ecology of T. schlegelii and of a sympatric population of the Critically Endangered Siamese crocodile Crocodylus siamensis. The role of the zoos, including their role in the development of the research programme, is described. Accounts are given of the characteristics of the Mesangat habitat, some new details about the distribution and abundance of Sunda gharial and Siamese crocodiles in the habitat, and information about reproduction in T. schlegelii. In summary, an overview of threats and suggestions for conservation actions needed at the Mesangat site are provided.