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Codron D.,University of Zurich | Codron D.,University of KwaZulu - Natal | Codron D.,University of Colorado at Boulder | Sponheimer M.,University of Colorado at Boulder | And 6 more authors.
European Journal of Wildlife Research

Faecal stable isotope compositions reflect wildlife diets, if digestive processes along the gastrointestinal tract (GIT) do not alter diet-faeces isotopic relationships in an unpredictable way. We investigated 13C and 15N compositions of digesta along the ruminant GIT, using Saanen dairy goats kept on pure grass hay or browse for >20 days. Isotopic changes occurred in the ventral rumen, and in the small intestine, where digesta had significantly higher δ 13C and δ 15N (associated with lower C or higher N content, respectively) values relative to other GIT sites. However, effects on isotope fractionation were small (~1.0‰ for δ 13C and ~2.0‰ for δ 15N), and were reversed in the hindgut such that faecal isotope compositions did not differ from the foregut. No other substantial isotopic changes occurred across GIT sites, despite the morphophysiological complexity of the ruminant GIT. We found similarly small differences across GIT components of rheem gazelles (Gazella leptoceros) fed a mixture of C 3 lucerne and C 4 grass, although in this case faeces were 15N-depleted relative to other GIT components. Along with differences in δ 15N between goats fed browse or grass, this result implies a systematic difference in diet-faeces δ 15N relationships, contingent on the botanical composition of ruminant diets. Thus, while our results support faecal δ 13C as a reliable proxy for wildlife diets, further work on factors influencing faecal 15N abundance is needed. Finally, we note high levels of isotopic variability between individuals fed the same diets, even accounting for the relatively short duration of the experiments, suggesting an important influence of stochasticity on isotope fractionation. © 2011 Springer-Verlag. Source

Ritz J.,University of Zurich | Hammer C.,Al Wabra Wildlife Preservation | Clauss M.,University of Zurich
Zoo Biology

The growth and weight development of Leopard tortoise hatchings (Geochelone pardalis) kept at the Al Wabra Wildlife Preservation (AWWP), Qatar, was observed for more than four years, and compared to data in literature for freeranging animals on body weight or carapace measurements. The results document a distinctively faster growth in the captive animals. Indications for the same phenomenon in other tortoise species (Galapagos giant tortoises, G. nigra; Spurthighed tortoises, Testudo graeca; Desert tortoises, Gopherus agassizi) were found in the literature. The cause of the high growth rate most likely is the constant provision with highly digestible food of low fiber content. Increased growth rates are suspected to have negative consequences such as obesity, high mortality, gastrointestinal illnesses, renal diseases, "pyramiding," fibrous osteodystrophy or metabolic bone disease. The apparently widespread occurrence of high growth rates in intensively managed tortoises underlines how easily ectothermic animals can be oversupplemented with nutrients. © 2009 Wiley-Liss, Inc. Source

Hammer C.,Al Wabra Wildlife Preservation
International Zoo Yearbook

Al Wabra Wildlife Preservation (AWWP), Qatar, is the only facility worldwide to keep the Beira antelope Dorcatragus megalotis, a small antelope from East Africa, listed as Vulnerable by The IUCN Red List of Threatened Species. Physical, behavioural and physiological characteristics of the species are described in detail, based on observations in captivity. At AWWP, the Beira antelope population increased from 2000 until 2006 when it declined dramatically as a result of an epidemic-like outbreak of a respiratory disease most likely owing to a Mycoplasma infection. Management at AWWP includes a diet based on natural forage, careful group composition, enclosure design adapted to the need of the species and close monitoring. Apart from their important conservation status, Beira antelope are highly attractive animals with a particular shape and coloration, and a docile nature. © 2011 The Authors. International Zoo Yearbook © 2011 The Zoological Society of London. Source

Hebel C.,University of Zurich | Ortmann S.,Leibniz Institute for Zoo and Wildlife Research | Hammer S.,Al Wabra Wildlife Preservation | Hammer C.,Al Wabra Wildlife Preservation | And 3 more authors.
Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology

Morphological characteristics of the forestomach, as well as reports of a natural diet that mostly excludes monocots, suggest that dikdiks (Madoqua spp.), among smallest extant ruminants, should have a 'moose-type' forestomach physiology characterised by a low degree of selective particle retention. We tested this assumption in a series of feeding experiments with 12 adult Phillip's dikdiks (Madoqua saltiana phillipsi) on three different intake levels per animal, using cobalt-EDTA as a solute marker and a 'conventional' chromium-mordanted fibre (< 2. mm; mean particle size 0.63. mm) marker for the particle phase. Body mass had no influence on retention measurements, whereas food intake level clearly had. Drinking water intake was not related to the retention of the solute marker. In contrast to our expectations, the particle marker was retained distinctively longer than the solute marker. Comparisons with results in larger ruminants and with faecal particle sizes measured in dikdiks suggested that in these small animals, the chosen particle marker was above the critical size threshold, above which particle delay in the forestomach is not only due to selective particle retention (as compared to fluids), but additionally due to the ruminal particle sorting mechanism that retains particles above this threshold longer than particles below this threshold. A second study with a similar marker of a lower mean particle size (0.17. mm, which is below the faecal particle size reported for dikdiks) resulted in particle and fluid retention patterns similar to those documented in other 'moose-type' ruminants. Nevertheless, even this smaller particle marker yielded retention times that were longer than those predicted by allometric equations based on quarter-power scaling, providing further support for observations that small ruminants generally achieve longer retention times and higher digestive efficiencies than expected based on their body size. © 2011 Elsevier Inc. Source

Hassanin A.,CNRS Systematics, Biodiversity and Evolution Institute | Delsuc F.,French National Center for Scientific Research | Ropiquet A.,University of the Western Cape | Hammer C.,Al Wabra Wildlife Preservation | And 8 more authors.
Comptes Rendus - Biologies

The order Cetartiodactyla includes cetaceans (whales, dolphins and porpoises) that are found in all oceans and seas, as well as in some rivers, and artiodactyls (ruminants, pigs, peccaries, hippos, camels and llamas) that are present on all continents, except Antarctica and until recent invasions, Australia. There are currently 332 recognized cetartiodactyl species, which are classified into 132 genera and 22 families. Most phylogenetic studies have focused on deep relationships, and no comprehensive time-calibrated tree for the group has been published yet. In this study, 128 new complete mitochondrial genomes of Cetartiodactyla were sequenced and aligned with those extracted from nucleotide databases. Our alignment includes 14,902 unambiguously aligned nucleotide characters for 210 taxa, representing 183 species, 107 genera, and all cetartiodactyl families. Our mtDNA data produced a statistically robust tree, which is largely consistent with previous classifications. However, a few taxa were found to be para- or polyphyletic, including the family Balaenopteridae, as well as several genera and species. Accordingly, we propose several taxonomic changes in order to render the classification compatible with our molecular phylogeny. In some cases, the results can be interpreted as possible taxonomic misidentification or evidence for mtDNA introgression. The existence of three new cryptic species of Ruminantia should therefore be confirmed by further analyses using nuclear data. We estimate divergence times using Bayesian relaxed molecular clock models. The deepest nodes appeared very sensitive to prior assumptions leading to unreliable estimates, primarily because of the misleading effects of rate heterogeneity, saturation and divergent outgroups. In addition, we detected that Whippomorpha contains slow-evolving taxa, such as large whales and hippos, as well as fast-evolving taxa, such as river dolphins. Our results nevertheless indicate that the evolutionary history of cetartiodactyls was punctuated by four main phases of rapid radiation during the Cenozoic era: the sudden occurrence of the three extant lineages within Cetartiodactyla (Cetruminantia, Suina and Tylopoda); the basal diversification of Cetacea during the Early Oligocene; and two radiations that involve Cetacea and Pecora, one at the Oligocene/Miocene boundary and the other in the Middle Miocene. In addition, we show that the high species diversity now observed in the families Bovidae and Cervidae accumulated mainly during the Late Miocene and Plio-Pleistocene. © 2011 Académie des sciences. Source

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