16 research outputs found

    The Welfare Implications of Using Exotic Tortoises as Ecological Replacements

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    <div><h3>Background</h3><p>Ecological replacement involves the introduction of non-native species to habitats beyond their historical range, a factor identified as increasing the risk of failure for translocations. Yet the effectiveness and success of ecological replacement rely in part on the ability of translocatees to adapt, survive and potentially reproduce in a novel environment. We discuss the welfare aspects of translocating captive-reared non-native tortoises, <em>Aldabrachelys gigantea</em> and <em>Astrochelys radiata</em>, to two offshore Mauritian islands, and the costs and success of the projects to date.</p> <h3>Methodology/Principal Findings</h3><p>Because tortoises are long-lived, late-maturing reptiles, we assessed the progress of the translocation by monitoring the survival, health, growth, and breeding by the founders. Between 2000 and 2011, a total of 26 <em>A. gigantea</em> were introduced to Ile aux Aigrettes, and in 2007 twelve sexually immature <em>A. gigantea</em> and twelve male <em>A. radiata</em> were introduced to Round Island, Mauritius. Annual mortality rates were low, with most animals either maintaining or gaining weight. A minimum of 529 hatchlings were produced on Ile aux Aigrettes in 11 years; there was no potential for breeding on Round Island. Project costs were low. We attribute the success of these introductions to the tortoises’ generalist diet, habitat requirements, and innate behaviour.</p> <h3>Conclusions/Significance</h3><p>Feasibility analyses for ecological replacement and assisted colonisation projects should consider the candidate species’ welfare during translocation and in its recipient environment. Our study provides a useful model for how this should be done. In addition to serving as ecological replacements for extinct Mauritian tortoises, we found that releasing small numbers of captive-reared <em>A. gigantea</em> and <em>A. radiata</em> is cost-effective and successful in the short term. The ability to release small numbers of animals is a particularly important attribute for ecological replacement projects since it reduces the potential risk and controversy associated with introducing non-native species.</p> </div

    Assessment of avian erythrocytes that exhibit variant nuclear morphology

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    Avian erythrocytes are predominately nucleated with a typically ovoid, central nucleus composed of dense chromatin. However, some erythrocytes exhibit a variant nuclear morphology. The current study assessed blood films from 70 birds that encompassed 50 species and 16 orders, to determine the presence of erythrocytes with variant nuclear morphology. Overall, erythrocytes with variant nuclear morphology were recognised in the blood from 35/70 (50 %) birds. The most commonly encountered morphological variant was erythrocytes with a symmetrical constricted nucleus, with lesser numbers of the other variants; indented, bi-lobed/bi-nucleated, asymmetrical constricted and micro-lobed/micro-nucleated cells recognised. In the birds that had erythrocytes with variant nuclear morphology present, the mean concentration was 10.87 × 109/l. The current study demonstrates that a small proportion of erythrocytes with variant nuclear morphology can be detected in a wide range of birds. © 2014 Springer-Verlag London

    Erythroplastidcytosis in a Major Mitchell’s cockatoo (Lophochroa leadbeateri)

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    Avian erythrocytes are typically nucleated. However, a small proportion of anucleated erythrocytes, termed erythroplastids, may be encountered in the peripheral blood of birds. We document the presence of a large proportion (up to 47.6 %) of erythroplastids in the blood of a Major Mitchell’s cockatoo (Lophochroa leadbeateri) and consider the pathophysiology of this finding
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