Academic literature on the topic 'Native Australian waterfowl'

Abstract The invasive Australian swamp stonecrop, Crassula helmsii, is a perennial amphibious herb originating from Australia and New Zealand. In freshwater wetlands of North-western Europe, this alien plant species is invasive due to its efficient colonization of empty niches. The establishment of dense C. helmsii growth is threatening native biodiversity and functioning of freshwater ecosystems, especially oligotrophic wetlands with high disturbance and nutrient enrichments. As the effects of these potential drivers of ecosystem degradation are generally difficult to determine in the field, we tested the competitive strength of C. helmsii in a greenhouse experiment with two native competitor species of the same habitat type, Pilularia globulifera and Littorella uniflora. Sods dominated by either of the native species, as well as bare soils, were collected from the field and manually infested with propagules of C. helmsii. Settlement and growth of C. helmsii was assessed after five weeks. In addition, the effect of nutrient enrichment by water bird feces on competition was studied by adding waterfowl droppings. C. helmsii was able to settle successfully in all treatments, but P. globulifera and L. uniflora dominance reduced settlement success and growth of C. helmsii. On vegetated sods, the addition of waterfowl droppings had a low effect on the performance of C. helmsii, however, this treatment significantly increased biomass production on bare soils with low nutrient availability. We conclude that both absence of native competitors and eutrophication, including guanotrophication by waterfowl, explain the establishment success and invasiveness of C. helmsii. Given the fact that eradication of C. helmsii is very challenging, our results imply that management should focus on a combination of increasing local species densities and abating eutrophication. This will strongly limit the window of opportunity for invasion of C. helmsii and enhance resistance by native plant communities.

A review is provided of information on the biology of elodea (Elodea canadensis Michx.). This submersed aquatic develops dense beds that impede water traffic and restrict water-based recreation in the southern portions of Quebec, Ontario, in British Columbia and Alberta. In some regions the dense beds decrease the efficiency of irrigated agriculture. Native to North America, elodea has recently spread to other parts of the world including Europe, Asia, South Africa, Australia and New Zealand. Elodea is beneficial in providing food and cover for insects and other small aquatic organisms, and consequently it increases food availability for fish and ducks. It also has some potential as a source of food and forage because of its relatively high nutritional content. Elodea is most frequent in clear, nutrient-rich, alkaline water. Phosphorus levels in the plant have been utilized as an indication of trends in the nutrient enrichment of water bodies. Limiting nutrients include bicarbonate and iron. Although seed formation is rare, dispersal of overwintering dormant apices and stem fragments by water and by waterfowl can result in rapid spread. Mechanical controls, including boats equipped with cutters, are the preferred methods of managing elodea, but adequate harvesting of cut material is necessary because every fragment with an axillary or terminal bud may develop into a new plant. Biological control using nonreproductive plant-eating fish is a promising area of research.Key words: Elodea canadensis, weed biology, aquatic, Canada, distribution

American wild celery (Vallisneria americana Michx.) is a native submerged aquatic plant that differs from other ribbon-leaved aquatics in having leaves with a well-defined midvein and paler zones on either side of a central dark band. In southern Ontario and Québec the dense leaf growth, and in particular the floating plants dislodged from the sediment, impede water traffic and restrict water-based recreation. Mechanical harvesting may be the best method of control in most situations. American wild celery is beneficial as an important food source for waterfowl and other wildlife, as cover and spawning area for fish, and may also be used as fertilizer and to feed livestock. There is also potential for increased use in biomonitoring. Widespread in eastern North America, it reaches its northern limit in southeastern Canada. It is introduced in British Columbia and the northwestern United States, and has also recently been reported from the southwestern United States, Mexico, the Carribean islands, northern Central America, southeast Asia and Australia. American wild celery occurs in alkaline to slightly saline waters with pH > 6, at depths of 0.3–7 m, and in a variety of sediment types. Clonal growth is extensive. Parent rosettes can each produce 20 or more new shoots within a season. These develop from buds at the tip of stolons, some of which overwinter as turions. Pollination takes place on the surface of the water with free-floating male flowers tipping into the surface depression created by the larger, attached female flowers. Fruits mature under the water. Key words:Vallisneria americana, American wild celery, weed biology, aquatic macrophyte, Canada, distribution

SEAGRASSES are a group of some 72 species of marine flowering plants found in the world’s shallow coastal oceans (Green and Short 2003, Short et al. 2011). There is now scientific consensus that they create an important marine habitat not only by themselves, but also as a component of more complex ecosystems within marine coastal zones. Seagrasses contribute to the health of coral reefs and mangroves, salt marshes and oyster reefs (Dorenbosch et al. 2004; Duke et al. 2007; Heck et al. 2008; Unsworth et al. 2008). Seagrasses have high primary productivity and are a basis of many marine food webs through direct herbivory and the through a detrital cycle (Hemminga and Duarte, 2000). They have enormous value in providing nutrients (N and P) and organic carbon to other parts of the oceans, including the deep sea, and they contribute significantly to carbon sequestration (Suchanek et al. 1985; Duarte et al. 2005). Armed with this knowledge today it is interesting to remember that it is only just over a hundred years since scientists first began speculating on the roles and values of seagrass in the marine environment, with the first focus occurring in Europe on eelgrass (Zostera marina). Many at the time discounted seagrass as an important primary producer (den Hartog 1980). It was not until after the 1930s, when vast areas of Zostera marina were lost in the northern hemisphere from a wasting disease that scientists and governments started to understand and investigate the value of seagrass to coastal ecosystems (Milne and Milne 1951). The loss of Zostera marina led to obvious declines in migratory waterfowl, crustaceans, finfish and shellfish populations (Thayer et al. 1984) In response to those concerns about ongoing losses of Zostera marina and other seagrass species, a meeting of scientists in Fairbanks, Alaska in early 1973 decided to coordinate seagrass research globally. This led to the first International Seagrass Workshop being organized and held in Leiden, The Netherlands, later that year. The report of that conference (McRoy and Helfferich 1977) makes interesting reading, looking back from the perspective of the 21st century. There is only one contribution from the southern hemisphere (Larkum 1977) with Australia referred to as a “little known region”. What we now know as the centre of seagrass biodiversity, Insular Southeast Asia and the broader Indo Pacific region, receives no mention at all. A significant and long-lasting outcome of the Leiden meeting was the birth of the journal “Aquatic Botany”.

One of the crucial issues of our decades is how to stop the loss of biodiversity. Policy–makers need reliable data to base their decisions on. Managing wildlife populations requires, first of all, science–based knowledge of their abundance, dynamics, ecology, behaviour and dispersal capacities based on reliable qualitative data. The importance of dialogue and communication with the local actors should be stressed (Sennerby Forsse, 2010) as bag statistics and other monitoring data in wildlife management could be more precise if local actors, notably hunters, were better informed and aware of their importance, especially in supporting existing and emerging policies at national and international levels. Another essential issue in wildlife management is the conflicts generated by humans and their activities when they interact with wildlife (Heredia & Bass, 2011). A sociologic approach is required to take into account those human groups whose interests are divergent, facilitating communication and collaborative learning among these users of the same ecosytem. Obstacles should be addressed and solutions devised to protect and encourage a sustainable use of this ecosystem in, as much as possible, a win–win relationship. Policy objectives and mana-gement strategies should be discussed and debated among the stakeholders involved, then formulated. Policies can be translated into different types of instruments, economic and legislative, but also informative and educa-tive. As awareness of the actors is a key factor of successful regulation, the regulations should be sufficiently explained and stakeholders should be involved in the implementation of these regulations as much as possible. Finally, the effectiveness of the regulations should be evaluated in light of their objectives, and where necessary, the regulations should be strengthened or adapted to improve their performance (Van Gossum et al., 2010).The various aspects of the processes described above were highlighted in the plenary talk and the five oral communications presented during the session on wildlife law and policy. In his plenary talk, Dr Borja Heredia, Head of the Scientific Unit of the Secretariat of the CMS/UNEP in Bonn, pointed out different sources of human–wildlife conflicts, such as the logging activities in subtropical forests that induce overexploitation and poaching for bushmeat consumption; the problem of predators on livestock and the poisoning of lions in the Masaï Reserve; animals invading the human territory; and game species as a vector of diseases in humans and livestock (Heredia & Bass, 2011). Heredia stressed the importance for wildlife managers to deal with the human dimension; he stressed the importance of successful conflict management based on principles such as a non–adversial framework, an analytical approach, a problem–solving orientation, the direct participation of the conflicting parties, dialogue as a basis for mutual understanding and facilitation by a trained third party. Heredia explained how the Convention on Migratory Species of Wild Animals (UNEP/CMS) contributes to confict resolution and in this way increases the chance of survival of these species. The CMS (see CMS website) works for the con-servation of a wide array of endangered migratory animals worldwide through the negotiation and implementation of agreements and action plans. Migratory species threatened with extinction are listed in Appendix I of the Con-vention. CMS parties strive towards strictly protecting these animals, conserving or restoring the places where they live, mitigating obstacles to migration and controlling other factors that might endanger them. Besides establishing obligations for each State joining the CMS, CMS promotes concerted action among the Range States of many of these species. Migratory species that need, or would significantly benefit from, international co–operation are listed in Appendix II of the Convention. For this reason, the Convention encourages the Range states to reach global or regional agreements. The Convention acts, in this res-pect as a framework convention. The Agreements may range from legally binding treaties (called agreements, there are seven) to less formal instruments, such as Memoranda of Understanding, or actions plans (there are 20), and they can be adapted to the requirements of particular regions. The development of models tailored according to the conservation needs throughout the migratory range is a unique capacity to CMS. Heredia detailed inter alia the Agreement on the Conservation of Albatrosses and Petrels, the Great Apes Survival Part-nership, the Agreement on the Conservation of Gorillas and their Habitats, the MoU on the Saïga Antelope, and the Programme for the Conservation and sustainable use of the wild saker falcon (Falco cherrug) in Mongolia.The talk of Sarah Wilks, research fellow at the School of Law, University of Western Sydney, illus-trated the importance of adequate transparency and public consultation in environmental and conservation law and decision making. Wilks (2012) examined the Australian legislation concerning animal welfare and the export of Australian wildlife products and, as a case study, explored the Tasmanian State Government’s recent decision to promote the com-mercial harvest and export of brushtail possums She pointed out that although the Enviromment Protection and Biodiversity Conservation 1999 (EPBC) process intended to be open and co–operative, it is not, in prac-tice, co–operative, public and transparent. The export of possum products requires Australian Government approval under the Department of Primary Industries, Parks, Water and Environment (EPBC). Wilks (2012) assessed the Tasmanian Wildlife Trade Management Plan for Common Brushtail Possums developed by the EPBC, the public submissions to the Austra-lian Government, and the Australian Government’s response against the provisions of the EPBC. As a result, she deplored that welfare outcomes, like that of back or pouch juveniles whose mother had been trapped or killed have not been adequately considered either at Tasmanian State or at Australian Govenment level. She concluded by deploring that submissions on ethical grounds could not yet be considered by the Australian Government because the decision to harvest or not to harvest is made at State level, and yet the Tasmanian State legislation is deficient in mandating public consultation.Data on hunting and game resources provide quan-titative and qualitative information on game species, but moreover, game monitoring has shown to be efficient in identifying threats to biodiversity, such as biodiversity problems in agriculture and forest ecosystems, and also to be an early warning in assessing threats from invasive alien species (Sennerby Forsse, 2010). They are an essential tool for game managers, scientists and policy–makers, and hunters and hunter organisations are key resources in the collection of this information.The ARTEMIS data bank was initiated by the Federation of Asssociations of Hunting and Conservation of the Euro-pean Union FACE (see ARTEMIS website) to improve information about game in support of existing and emer-ging European policies. The objective of ARTEMIS is to centralise and analyse, in a coordinated and coherent Animal Biodiversity and Conservation 35.2 (2012)161extending the ban to all waterfowl hunting and not only that undertaken in protected wetlands.The presentation of K. E. Skordas, from the Hunting Federation of Macedonia and Thrace, Research Divi-sion, Greece, illustrated the contribution of the Hellenic Hunters Confederation (HHC) to law enforcement for wildlife protection. It showed how stakeholders, hun-ters, set up heir own Game Warden Service in 1999, through their Hunting Associations, in order to assume responsibility for the control of illegal hunting and wil-dlife protection, in collaboration with the local Forest Service. These game wardens carry out repressive and preventive controls and prosecutions. Besides this initiative, information campaigns are organised by the HHC to improve hunters’ awareness (see website of the Hellenic Hunters Confederation, HHC). Skordas & Papaspyropoulos (2011) analysed the relation between law enforcement, hunter awareness and infringement categories, classed in degree of influencing wildlife protection. They observed a strong reduction in the number of infringements; particularly, they found that hunting out of season and hunting without a license decreased from 23.4% to 7.31% and from 30.12% to 11.8%, respectively.All the talks presented in this session stressed the importance of dialogue in wildlife management as a basis for mutual understanding. Communication and involvement of the local actors/stakeholders are key factors at different stages of wildlife management: when collecting reliable data on which policy–makers may draw up their decisions, when debating policy objectives and strategies, and when implementing regulations and administrative acts

A consensus classification for the waterfowl (order Anseriformes) has never been reached. There have been many revisions of the relationships within the order including those of the monotypic Australian genera. The Southern Hemisphere anseriforms comprise a large number of monotypic, endemic genera which have traditionally been linked to the established genera and tribes of the Northern Hemisphere. More recently, however, with the recognition of endemic Australian radiations of marsupial mammals (Main and Bakker 1981) and passerine birds (Cracraft 1976; Sibley and Ahlquist 1985; Christidis et al. 1988; Christidis and Schodde 1991), the affinities of the six monotypic Australian genera of anseriforms have been questioned (Delacour 1954; Frith 1955, 1964a, b, 1982; Johnsgard 196la, b, 1966; Davies and Frith 1964; Fullager 1990). In particular, whether they are more closely related to one another, or whether some or all of these monotypic genera have closer affinities with the Northern Hemisphere genera. Classification of the taxonomic relationships of the aberrant Australian endemic species may also corroborate or refute the recently advanced hypothesis of a Southern Hemisphere origin for the Anseriformes (Cracraft 1976, 1980; Livezey 1986; Olson 1988). A 307bp fragment of the mitochondrial cytochrome b gene of the 19 native Australian anseriforms and four Northern Hemisphere species was enzymatically amplified by PCR and manually sequenced. The Chicken (Gallus gallus) and Muscovy Duck (Cairinia moschatd) cytochrome b sequences were obtained from Genbank. The patterns of evolutionary dynamics within the cytochrome b gene of Anseriformes appear to conform to those reported in studies of avian and other vertebrate mtDNA. A new phylogenetic classification for the Anseriformes is proposed. The phylogenetic trees generated in this study indicate that the monotypic Australian genera, the pygmygeese and the swans and geese are members of the subfamily Anserinae which appears to represent a Southern Hemisphere radiation. Within the Anserinae, the Cape Barren Goose and Freckled Duck link most closely with each other, the Pink-eared Duck appears to be closely related to the true geese, the Musk Duck is a sister taxon to the Pink-eared Duck and may be less closely related to the Oxyura than previously thought and the Magpie Goose is the most divergent member of the Anseriformes included in this study. The Maned Duck and the remaining native Australian anseriforms are members of the established European genera and tribes of waterfowl. These species probably represent a secondary radiation of recent Northern Hemisphere invaders of Australia. Finally, the data provides some support for the theory of a Southern origin for the Anseriformes.