856 resultados para White-backed stilt
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Successful biodiversity conservation requires safeguarding viable populations of species. To work with this challenge Sweden has introduced a concept of Action Plans, which focus on the recovery of one or more species; while keeping in mind the philosophy of addressing ecosystems in a more comprehensive way, following the umbrella concept. In this paper we investigate the implementationprocess of the ActionPlanfor one umbrella species, the White-backed Woodpecker (WBW) Dendrocopos leucotos. We describe the plan's organisation and goals, and investigate its implementation and accomplishment of particular targets, based on interviewing and surveying the key actors. The achievement of the targets in 2005-2008 was on average much lower than planned, explained partially by the lack of knowledge/data, experienced workers, and administrative flexibility. Surprisingly, the perceived importance of particular conservation measures, the investment priority accorded to them, the money available and various practical obstacles all failed to kg? explain the target levels achieved. However qualitative data from both the interviews and the survey highlight possible implementation obstacles: competing interests with other conservation actions and the level of engagement of particular implementing actors. Therefore we suggest that for successful implementation of recovery plans, there is aneed for initial and inclusive scoping prior to embarking on the plan, where not only issues like ecological knowledge and practical resources are considered, but also possible conflicts and synergies with other conservation actions. An adaptive approach with regular review of the conservation process is essential, particularly in the case of such complex action plans as the one for the WBW.
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The foraging behavior of two White-backed stilts (Himantopus melanurus) was studied in a lake at the municipality of Santa Gertrudes, state of São Paulo, Brazil. The foraging strategies observed were classified in two categories: pluging (65.8% of total maneuvers) and pecking (34.3%). Only in 26.8% of the foraging maneuvers the individuals captured preys (72.9% by plunging and 27.1% by pecking). When comparing both strategies, plunging was successful 29.7% of the times, but pecking only 21.2%. At the study site, individuals foraged only up to 20 m away from the lake margin. The foraging area exploited by the White-backed stilts was estimated in about 720 m 2. Foraging activities lasted since before sunrise until after sunset. © 2006 Instituto de Ciências Biológicas - UFMG.
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This paper develops a dynamic model for cost-effective selection of sites for restoring biodiversity when habitat quality develops over time and is uncertain. A safety-first decision criterion is used for ensuring a minimum level of habitats, and this is formulated in a chance-constrained programming framework. The theoretical results show; (i) inclusion of quality growth reduces overall cost for achieving a future biodiversity target from relatively early establishment of habitats, but (ii) consideration of uncertainty in growth increases total cost and delays establishment, and (iii) cost-effective trading of habitat requires exchange rate between sites that varies over time. An empirical application to the red listed umbrella species - white-backed woodpecker - shows that the total cost of achieving habitat targets specified in the Swedish recovery plan is doubled if the target is to be achieved with high reliability, and that equilibrating price on a habitat trading market differs considerably between different quality growth combinations. © 2013 Elsevier GmbH.
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Veterinary use of the nonsteroidal anti-inflammatory (NSAID) drug diclofenac in South Asia has resulted in the collapse of populations of three vulture species of the genus Gyps to the most severe category of global extinction risk. Vultures are exposed to diclofenac when scavenging on livestock treated with the drug shortly before death. Diclofenac causes kidney damage, increased serum uric acid concentrations, visceral gout, and death. Concern about this issue led the Indian Government to announce its intention to ban the veterinary use of diclofenac by September 2005. Implementation of a ban is still in progress late in 2005, and to facilitate this we sought potential alternative NSAIDs by obtaining information from captive bird collections worldwide. We found that the NSAID meloxicam had been administered to 35 captive Gyps vultures with no apparent ill effects. We then undertook a phased programme of safety testing of meloxicam on the African white-backed vulture Gyps africanus, which we had previously established to be as susceptible to diclofenac poisoning as the endangered Asian Gyps vultures. We estimated the likely maximum level of exposure (MLE) of wild vultures and dosed birds by gavage (oral administration) with increasing quantities of the drug until the likely MLE was exceeded in a sample of 40 G. africanus. Subsequently, six G. africanus were fed tissues from cattle which had been treated with a higher than standard veterinary course of meloxicam prior to death. In the final phase, ten Asian vultures of two of the endangered species (Gyps bengalensis, Gyps indicus) were dosed with meloxicam by gavage; five of them at more than the likely MLE dosage. All meloxicam-treated birds survived all treatments, and none suffered any obvious clinical effects. Serum uric acid concentrations remained within the normal limits throughout, and were significantly lower than those from birds treated with diclofenac in other studies. We conclude that meloxicam is of low toxicity to Gyps vultures and that its use in place of diclofenac would reduce vulture mortality substantially in the Indian subcontinent. Meloxicam is already available for veterinary use in India.
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Three Gyps vulture species are on the brink of extinction in South Asia owing to the veterinary non-steroidal anti-inflammatory drug (NSAID) diclofenac. Carcasses of domesticated ungulates are the main food source for Asia's vultures and birds die from kidney failure after consuming diclofenac-contaminated tissues. Here, we report on the safety testing of the NSAID ketoprofen, which was not reported to cause mortality in clinical treatment of scavenging birds and is rapidly eliminated from livestock tissues. Safety testing was undertaken using captive non-releasable Cape griffon vultures (Gyps coprotheres) and wild-caught African white-backed vultures (G. africanus), both previously identified as susceptible to diclofenac and suitable surrogates. Ketoprofen doses ranged from 0.5 to 5 mg kg(-1) vulture body weight, based upon recommended veterinary guidelines and maximum levels of exposure for wild vultures (estimated as 1.54 mg kg(-1)). Doses were administered by oral gavage or through feeding tissues from cattle dosed with ketoprofen at 6 mg kg(-1) cattle body weight, before slaughter. Mortalities occurred at dose levels of 1.5 and 5 mg kg(-1) vulture body weight (within the range recommended for clinical treatment) with the same clinical signs as observed for diclofenac. Surveys of livestock carcasses in India indicate that toxic levels of residual ketoprofen are already present in vulture food supplies. Consequently, we strongly recommend that ketoprofen is not used for veterinary treatment of livestock in Asia and in other regions of the world where vultures access livestock carcasses. The only alternative to diclofenac that should be promoted as safe for vultures is the NSAID meloxicam.
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Die vorliegende Untersuchung analysiert die Eignung der "Spechtgemeinschaft" als ökologische Indikatorengruppe und formuliert vor dem Hintergrund der Ergebnisse Forderungen und Empfehlungen für einen "spechtgerechten" Umgang mit Wäldern. Die Habitatnutzung von sieben Spechtarten beim Nahrungserwerb wurde über einen Zeitraum von zwei Jahren in urwaldartigen und forstlich genutzten Beständen verschiedener Waldgesellschaften systematisch beobachtet. Das Untersuchungsgebiet ist der Bialowieza-Wald im äußersten Osten Polens, wo in enger räumlicher Nachbarschaft Natur- und Wirtschaftswaldflächen bearbeitet werden konnten. Die Beobachtungen erfolgten zwischen Anfang März 1999 und Ende Februar 2001 und wurden zu allen Jahreszeiten durchgeführt. Vier der insgesamt sechs Probeflächen repräsentieren die wichtigste Laubwaldgesellschaft des Gebietes, das Tilio-Carpinetum, die übrigen zwei die wichtigste Nadelwaldgesellschaft, das Peucedano-Pinetum. Die Hälfte der zwischen 42 und 54 ha großen Probeflächen lag im streng geschützten Urwaldreservat des Bialowieza-Nationalparkes, die übrigen in forstlich genutzten Waldbeständen. Zusätzlich wurde ein 2,5 km langes Transekt durch bewirtschafteten Erlen-Eschen-Auenwald und sehr naturnahen Erlenbruch bearbeitet. Die Probeflächen wurden in ein Raster aus 50x50m großen Quadranten unterteilt. Zur Beobachtung der Spechte beim Nahrungserwerb erfolgten 21 Begehungen je Probefläche bzw. Transekt. Die Probeflächen wurden dazu auf parallelen Linien mit Abständen von je 100m begangen, Startpunkt und Startrichtung wurden variiert. Zur Charakterisierung der Vegetation und Bestandesstruktur erfolgten Erhebungen zur Baumartenzusammensetzung, Größenklassenverteilung der Bäume, Totholzanteil und Krautvegetation. 1332 Beobachtungen von Spechten beim Nahrungserwerb konnten ausgewertet werden. Der Buntspecht wurde in allen Flächen am häufigsten gesehen. Mittel-, Weißrücken- und Kleinspecht wurden überwiegend in den Tilio-Carpineten beobachtet, in den Naturwäldern häufiger als in den bewirtschafteten Beständen. Der Dreizehenspecht wurde im Nadelwald und stärker mit Fichten durchmischtem Laubwald angetroffen. Bei Schwarz- und Grauspecht konnte keine klare Vorliebe für bestimmte Waldgesellschaften ermittelt werden. Der Buntspecht ernährte sich vor allem im Herbst und Winter überwiegend von fetthaltigen Samen und wurde dann meist beim Bearbeiten von Fichten- oder Kiefernzapfen in Schmieden beobachtet. Der Mittelspecht suchte als "Sammelspecht" seine Nahrung vor allem an den Oberflächen der Stämme und Äste. Klein-, Weißrücken-, Dreizehen- und Schwarzspecht traten als Hackspechte in Erscheinung. Die wenigen Daten zum Grauspecht reichen nicht zur Ermittlung der bevorzugten Nahrungserwerbstechnik aus. Bei Bunt-, Mittel- und Weißrückenspecht konnte eine deutliche Vorliebe für die Stieleiche als Nahrungsbaum nachgewiesen werden. Der Dreizehenspecht ist jedoch die einzige der beobachteten Arten mit einer weitgehenden Spezialisierung auf eine bestimmte Baumart, er nutzte in allen Waldgesellschaften meist die Fichte. Insgesamt bevorzugten die Spechte Bäume mit großen Stammdurchmessern, beim Kleinspecht ist diese Vorliebe allerdings nur schwach ausgeprägt. Totholz wurde von Weißrücken-, Dreizehen- und Kleinspecht bei der Nahrungssuche bevorzugt, vom Mittelspecht jedoch nur gelegentlich genutzt. Beim Buntspecht zeigte der Totholz-Nutzungsanteil erhebliche Unterschiede zwischen verschiedenen Baumarten. Liegendes Totholz spielte in den Tilio-Carpineten im Vergleich zu stehendem Totholz und toten Teilen lebender Bäume nur eine geringe Rolle für Nahrung suchende Spechte.
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This paper represents my attempt to turn the gaze and demonstrate how Indigenous Studies is controlled in some Australian universities in ways that witness Indigenous peoples being further marginalised, denigrated and exploited. I have endeavoured to do this through sharing an experience as a case study. I have opted to write about it as a way of exposing the problematic nature of racism, systemic marginalisation, white race privilege and radicalised subjectivity played out within an Australian higher education institution and because I am dissatisfied with the on-going status quo. In bringing forth analysis to this case study, I reveal the relationships between oppression, white race privilege and institutional privilege and the epistemology that maintains them. In moving from the position of being silent on this experience to speaking about it, I am able to move from the position of object to subject and to gain a form of liberated voice (hooks 1989:9). Furthermore, I am hopeful that it will encourage others to examine their own practices within universities and to challenge the domination that continues to subjugate Indigenous peoples.
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Objects have consequences, seemingly. They move, atomic, formlessly – when static they are seen. That they vibrate constantly, that they are NOW present, is something we will have to trust the physicists on. They only seem here. Now is their moment of form, but later, who knows? Things SEEM when we recognise our own transience and temporary-ness. We call upon a bevy of senses that forever frustrate us with their limitation, despite our little understanding of what we actually have – is this here? So some forms seem to be telling us to trust our senses – that this world IS as it seems. Their form constantly refines and is refined and refined until in its essentialness it cannot be doubted – it absolutely IS. Is this our eyes? Can we only see it? But light is also a particle, if I remember correctly, so there is some weight to seeing. So to SEEM is also to FEEL,as this light imposes its visual weight upon our skins – we see with every pore of our body.