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1.
PLoS One ; 15(6): e0234826, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32542033

RESUMO

Feeding practice in herbivorous mammals can impact their dental wear, due to excessive or irregular abrasion. Previous studies indicated that browsing species display more wear when kept in zoos compared to natural habitats. Comparable analyses in tapirs do not exist, as their dental anatomy and chewing kinematics are assumed to prevent the use of macroscopic wear proxies such as mesowear. We aimed at describing tapir chewing, dental anatomy and wear, to develop a system allowing comparison of free-ranging and captive specimens even in the absence of known age. Video analyses suggest that in contrast to other perissodactyls, tapirs have an orthal (and no lateral) chewing movement. Analysing cheek teeth from 74 museum specimens, we quantified dental anatomy, determined the sequence of dental wear along the tooth row, and established several morphometric measures of wear. In doing so, we showcase that tapir maxillary teeth distinctively change their morphology during wear, developing a height differential between less worn buccal and more worn lingual cusps, and that quantitative wear corresponds to the eruption sequence. We demonstrate that mesowear scoring shows a stable signal during initial wear stages but results in a rather high mesowear score compared to other browsing herbivores. Zoo specimens had lesser or equal mesowear scores as specimens from the wild; additionally, for the same level of third molar wear, premolars and other molars of zoo specimens showed similar or less wear compared specimens from the wild. While this might be due to the traditional use of non-roughage diet items in zoo tapirs, these results indicate that in contrast to the situation in other browsers, excessive tooth wear appears to be no relevant concern in ex situ tapir management.


Assuntos
Mastigação , Perissodáctilos/anatomia & histologia , Perissodáctilos/fisiologia , Dente/anatomia & histologia , Dente/fisiologia , Animais , Fenômenos Biomecânicos
2.
Sci Rep ; 10(1): 4117, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-32139707

RESUMO

Malayan tapirs are listed as endangered and are bred in captivity under governmental management. The success of captive breeding programs varies and the underlying causes are unclear. Here, we investigate how tapir reproduction is affected by previous breeding experience, enclosure type/size and visitor numbers so that appropriate steps can be taken to achieve self-sustaining captive populations. Data on social and reproductive behaviors were collected from six tapirs (three males, three females), from different breeding centers in Peninsular Malaysia for 18 weeks. Results revealed that social and reproductive behavior of both sexes was significantly influenced by social and environmental conditions. Larger enclosure size tended to increase social and reproductive behaviors, whereas high number of visitors reduced initial interaction between males and females. No specific breeding month was confirmed; however, reproductive behaviors were highest in April. Overall, this study contributes to a better understanding of the relationships between social and reproductive behaviors, and captive environments on Malayan tapirs. In future, frequency of sexual interactions should be monitored regularly to identify animals exhibiting below-average frequency and who might, therefore, be prone to reproductive difficulties.


Assuntos
Perissodáctilos/fisiologia , Comportamento Sexual Animal , Comportamento Social , Criação de Animais Domésticos , Animais , Cruzamento , Feminino , Masculino
3.
Zoo Biol ; 39(2): 141-144, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31797432

RESUMO

All extant species in the Rhinocerotidae family are experiencing escalating threats in the wild, making self-sustaining captive populations essential genetic reservoirs for species survival. Assisted reproductive technologies (ARTs) will become increasingly important for achieving and maintaining ex situ population sustainability and genetic diversity. Previous reports have shown that a large proportion of captive southern white rhinoceros (SWR) females are irregularly cyclic or acyclic, and that cycling females display two different estrous cycle lengths of approximately 30 or 70 days. It has been suggested that the longer estrous cycle length is infertile or subfertile, as no term pregnancies have been observed following long cycles. Here we report the achievement of two pregnancies following long luteal phases, using ovulation induction and artificial insemination with either fresh or frozen-thawed semen. One female SWR conceived on the first insemination attempt and gave birth to a live offspring. A second female conceived twice in consecutive long cycles although the first embryo was resorbed by 33 days post-insemination. A pregnancy from this female's second insemination is ongoing with expected parturition in November 2019. Whether prolonged estrous cycles in SWR are subfertile or infertile in natural breeding situations remains unclear. However, our findings demonstrate that the application of ARTs following prolonged cycles can result the successful establishment of pregnancies in SWR. Therefore, with ARTs, female SWR otherwise considered nonreproductive due to long estrous cycles may still have the potential for representation and contribution to the ex situ population.


Assuntos
Ciclo Estral/fisiologia , Fase Luteal/fisiologia , Perissodáctilos/fisiologia , Animais , Feminino , Inseminação Artificial/veterinária , Masculino , Indução da Ovulação/veterinária , Gravidez
4.
PLoS One ; 14(5): e0216595, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31141536

RESUMO

In vivo and ex vivo sensors have the potential to aid tracking and anti-poaching endeavours and provide new insights into rhinoceros physiology and environment. However, the propagation of electromagnetic signals in rhinoceros tissue is currently not known. We present simulation and agar models of the rhinoceros that allow the investigation of electromagnetic propagation by in vivo and ex vivo devices without the need for surgery. Since the dielectric properties of rhinoceros tissue have not been documented, the conductivity and permittivity of the skin, fat, muscle, blood and other organs are first approximated by means of a meta-analysis that includes animals with similar physical properties. Subsequently, we develop anatomical models that include dermal layers, internal organs and a skeleton. We also develop a flank model that serves as an approximation of the anatomical model in certain situations. These models are used to determine the viability of communication between an in vivo device and an ex vivo device attached to the hind leg of the animal. Two types of antenna (microstrip-fed planar elliptical monopole antenna and printed inverted-F antenna) and three feasible implant locations (back, neck and chest) are considered. In addition to the computer models, phantom recipes using salt, sugar and agar are developed to match the dielectric properties of each tissue type at the industrial, scientific and medical (ISM) frequencies of 403MHz, 910MHz and 2.4GHz. The average error between the measured and theoretically predicted dielectric values was 6.22% over all recipes and 4.49% for the 2.4 GHz recipe specifically. When considering the predicted efficiency of the transmitting and receiving antennas, an agreement of 67.38% was demonstrated between the computer simulations and laboratory measurements using the agar rhinoceros flank models. Computer simulations using the anatomical model of the rhinoceros indicate that the chest is the optimal implant location and that best signal propagation is achieved using the planar inverted-F antenna (PIFA). Using this configuration, the simulations indicate that communication between the implant and an ex vivo device attached to the hind leg is challenging but possible. Furthermore, we find that the inclusion of factors such as the density and temperature of the phantom materials were found to be critical to the achievement of good agreement between practice and simulation.


Assuntos
Simulação por Computador , Impedância Elétrica , Modelos Anatômicos , Perissodáctilos/anatomia & histologia , Perissodáctilos/fisiologia , Imagens de Fantasmas , Algoritmos , Animais
5.
Microbiome ; 7(1): 27, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30770764

RESUMO

BACKGROUND: Host microbiomes play a role in hormone production and subsequent fertility in humans, but this is less well understood in non-model organisms. This is of particular relevance to species in zoo-based conservation breeding programmes, as relationships between host microbiome composition and reproductive output may allow for the development of microbial augmentation strategies to improve success. Here, we characterise faecal bacterial communities of breeding and non-breeding eastern black rhino (Diceros bicornis michaeli) using 16S rRNA gene amplicon sequencing and quantify progestagen and glucocorticoid metabolite concentrations through enzyme immunoassays to identify such relationships. RESULTS: We identified significant differences in black rhino gut microbiome composition according to ID, institution, breeding success and ovarian cycle phase. In particular, the gut microbiome during pregnancy and post-parturition was significantly altered. Around a third of bacterial genera showed more than ± 10% correlation with either progestagen and/or glucocorticoid concentration, and in general, microbial genera correlated with both hormones in the same direction. Through a combination of analyses, we identified four genera (Aerococcaceae, Atopostipes, Carnobacteriaceae and Solobacterium) that were significantly associated with breeding success, pregnancy and/or post-parturition, and higher faecal progestagen metabolite concentrations. These genera had a lower-than-average relative abundance in the gut microbiome. CONCLUSION: Our results indicate that many members of the gut microbiome of black rhino are associated with hormone production and breeding success, and some members of the rare microbiota appear to be particularly important. Although the directionality of the relationship is unclear, the variation in gut microbiome communities represents a potential biomarker of reproductive health. We identified four genera that were associated with multiple indicators of reproductive output; these could be candidate probiotics to improve the breeding success of black rhino in zoo-based conservation breeding programmes. Further work is required to understand the efficacy and feasibility of this, either directly through microbial augmentation (e.g. probiotics) or indirectly via dietary manipulation or prebiotics.


Assuntos
Bactérias/classificação , Microbioma Gastrointestinal , Perissodáctilos/fisiologia , Análise de Sequência de DNA/veterinária , Animais , Bactérias/genética , Cruzamento , DNA Ribossômico/genética , Fezes/microbiologia , Feminino , Glucocorticoides/metabolismo , Ciclo Menstrual , Perissodáctilos/metabolismo , Perissodáctilos/microbiologia , Gravidez , Progestinas/metabolismo , RNA Ribossômico 16S/genética
6.
Biosystems ; 177: 24-33, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30659865

RESUMO

A three-species population system under a facultative mutualistic relationship of one of the species is studied. The considered interactions are as follows: facultative between the first species and the second species, obligatory mutualism between the second species and the first one, and the third species is a predator of the first species. For this purpose, we extend the model proposed by Morozov et al., originally used to describe obligatory mutualism, to consider obligatory and facultative mutualism and prove that under adequately selected parameters this system produces a spatial patchy spread of populations or continuous wave fronts. Since the analytical treatment of a three-species model is often prohibitive, we first analyze the interaction between two mutualist species without diffusion and without the presence of the predator. Some parameters are fixed in the bistable regime of the mutualistic species to further consider the influence of the third species. The remaining parameters are then selected to produce patchy patterns under different mortality rates. Finally, the equations of the final three-species system are numerically solved to test the influence of different initial conditions in the formation of patchy populations. It is confirmed that the velocity and the profile of a traveling front are independent on the initial conditions. Our approach opens the way to study more general biological situations.


Assuntos
Equidae/fisiologia , Cadeia Alimentar , Modelos Biológicos , Perissodáctilos/fisiologia , Comportamento Predatório , Estorninhos/fisiologia , Simbiose , Animais , Ecossistema , Modelos Estatísticos , Dinâmica Populacional
7.
PLoS One ; 14(1): e0209678, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30650097

RESUMO

Unrelenting poaching to feed the illegal trafficking of rhinoceros (rhino) horn remains the principle threat to the persistence of south-central black and southern white rhino that live in the Kruger National Park (Kruger), South Africa. Other global environmental change drivers, such as unpredictable climatic conditions, impose additional uncertainties on the management and persistence of these species. The drought experienced in Kruger over the 2015/2016 rainy season may have affected rhino population growth and thus added an additional population pressure to the poaching pressure already occurring. Under drought conditions, reduced grass biomass predicts increased natural deaths and a subsequent decrease in birth rate for the grazing white rhino. Such variance in natural death and birth rates for the browsing black rhino are not expected under these conditions. We evaluated these predictions using rhino population survey data from 2013 to 2017. Comparisons of natural deaths and birth rates between pre- (2013/2014 and 2014/15), during- (2015/2016) and post-drought (2016/2017) periods in Kruger showed increased natural mortality and decreased births for white rhino, but no significant changes for black rhino, supporting our predictions. As a result, despite reduced poaching rates, the total mortality rate of white rhino remains significantly higher than the birth rate. Decreased poaching, decreased natural deaths and no apparent drought effects in black rhino resulted in a lower total mortality rate than the estimated birth rate in 2017. Active biological management and traditional anti-poaching initiatives together therefore represent the most likely way to buffer the impacts of decreased population growth through climate change and wildlife crime on the persistence of rhinos.


Assuntos
Conservação dos Recursos Naturais/métodos , Perissodáctilos/fisiologia , Animais , Animais Selvagens/fisiologia , Coeficiente de Natalidade , Secas , Cornos , Mortalidade , Dinâmica Populacional/tendências , Crescimento Demográfico , África do Sul , Especificidade da Espécie
8.
J Zoo Wildl Med ; 49(4): 849-855, 2018 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-30592907

RESUMO

The effects of etorphine on the pulmonary vascular system of white rhinoceros ( Ceratotherium simum) have not been described and could play a role in the severe hypoxemia that develops after immobilization with etorphine-based drug combinations. Characterization of these effects requires measurement of pulmonary vascular pressures and cardiac output (CO). To refine a technique for pulmonary arterial catheterization, five boma-habituated white rhinoceros (three females and two males weighing 1,012-1,572 kg) were immobilized by remote injection with etorphine plus azaperone followed by butorphanol. This afforded the opportunity to perform a pilot study and acquire preliminary measurements of pulmonary arterial pressure (PAP) and CO before and after supplemental etorphine given intravenously. Ultrasonographic guidance was used to insert a sheath introducer into a linguofacial branch of a jugular vein. A 160-cm-long pulmonary artery catheter with a balloon and thermistor was then passed through the introducer and positioned with its tip in the pulmonary artery. It was not long enough to permit wedging for measurement of pulmonary artery occlusion pressure. Mean PAP was 35 mm Hg (minimum, maximum 32, 47 mm Hg) and increased ( P = 0.031) by 83% (28, 106%) after supplemental etorphine. Thermodilution CO was 120 L/min (92, 145 L/min) and increased 27% (3, 43%) ( P = 0.031). Heart rate was 100 (88, 112) beats/min and increased 20% (4, 45%) ( P = 0.031), whereas arterial partial pressure of oxygen was 35 mm Hg (30, 94 mm Hg) and decreased 47% (20, 72%) ( P = 0.031). The cardiovascular observations could result from etorphine-induced generalized sympathetic outflow, as has been reported in horses. Further studies of etorphine in isolation are needed to test this suggestion and to discern how the changes in pulmonary vascular pressures and blood flow might relate to hypoxemia in etorphine-immobilized white rhinoceros.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Débito Cardíaco/efeitos dos fármacos , Etorfina/administração & dosagem , Hipnóticos e Sedativos/administração & dosagem , Imobilização/veterinária , Perissodáctilos/fisiologia , Animais , Animais de Zoológico/fisiologia , Feminino , Masculino , Projetos Piloto , Artéria Pulmonar/fisiologia , África do Sul
9.
J Zoo Wildl Med ; 49(4): 1041-1046, 2018 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-30592926

RESUMO

This report describes weekly repeated anesthesia in a 7-yr-old, 1,030 kg, female Eastern black rhinoceros ( Diceros bicornis michaeli), that was immobilized six times using a combination of 2 mg etorphine (0.002 mg/kg), 5 mg medetomidine (0.005 mg/kg), 25 mg midazolam (0.024 mg/kg), and 300 mg ketamine (0.29 mg/kg) delivered intramuscularly (IM) via remote dart to facilitate long-term medical care of a bilateral, obstructive Actinomyces sp. rhinitis. The drug combination described in this study resulted in reliable, rapid recumbency of the animal within 2-8 min after initial administration via dart and produced deep anesthesia for 34-78 min without supplemental anesthetic administration. Antagonist drugs (100 mg naltrexone [0.1 mg/kg] and 25 mg atipamezole [0.024 mg/kg] IM) produced reliable and uneventful recoveries in all the procedures. During each anesthetic procedure, the animal was intubated and provided intermittent positive pressure ventilation with a megavertebrate demand ventilator. Tachycardia and hypoxia noted after induction resolved after positive pressure ventilation with oxygen. This report provides useful information on a novel anesthetic protocol used repeatedly for intensive medical management in a black rhinoceros.


Assuntos
Actinomicose/veterinária , Obstrução das Vias Respiratórias/veterinária , Anestesia/veterinária , Anestésicos/administração & dosagem , Perissodáctilos/fisiologia , Rinite/veterinária , Actinomyces/fisiologia , Actinomicose/terapia , Obstrução das Vias Respiratórias/terapia , Anestesia/métodos , Animais , Animais de Zoológico/fisiologia , Etorfina/administração & dosagem , Feminino , Injeções Intramusculares/veterinária , Ketamina/administração & dosagem , Medetomidina/administração & dosagem , Midazolam/administração & dosagem , Rinite/terapia
10.
Proc Biol Sci ; 285(1890)2018 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-30404873

RESUMO

The white rhinoceros (Ceratotherium simum) has a discontinuous African distribution, which is limited by the extent of sub-Saharan grasslands. The southern population (SWR) declined to its lowest number around the turn of the nineteenth century, but recovered to become the world's most numerous rhinoceros. In contrast, the northern population (NWR) was common during much of the twentieth century, declining rapidly since the 1970s, and now only two post-reproductive individuals remain. Despite this species's conservation status, it lacks a genetic assessment of its demographic history. We therefore sampled 232 individuals from extant and museum sources and analysed ten microsatellite loci and the mtDNA control region. Both marker types reliably partitioned the species into SWR and NWR, with moderate nuclear genetic diversity and only three mtDNA haplotypes for the species, including historical samples. We detected ancient interglacial demographic declines in both populations. Both populations may also have been affected by recent declines associated with the colonial expansion for the SWR, and with the much earlier Bantu migrations for the NWR. Finally, we detected post-divergence secondary contact between NWR and SWR, possibly occurring as recently as the last glacial maximum. These results suggest the species was subjected to regular periods of fragmentation and low genetic diversity, which may have been replenished upon secondary contact during glacial periods. The species's current situation thus reflects prehistoric declines that were exacerbated by anthropogenic pressure associated with the rise of late Holocene technological advancement in Africa. Importantly, secondary contact suggests a potentially positive outcome for a hybrid rescue conservation strategy, although further genome-wide data are desirable to corroborate these results.


Assuntos
Evolução Biológica , Variação Genética , Perissodáctilos/fisiologia , África , Distribuição Animal , Animais , Perissodáctilos/genética , Dinâmica Populacional , Especificidade da Espécie
12.
Electrophoresis ; 39(24): 3185-3190, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30192403

RESUMO

In the present study, a quantitative proteomic approach was used to analyze and compare the proteome in horns from endangered species (rhinoceros, Saiga antelope, and Tibetan antelope) and common species (yak, water buffalo, and goat) based on the isobaric tag for relative and absolute quantification techniques. In total, 591 proteins were identified, and 321 were quantified and categorized based on molecular function, cellular component, and biological process. Principal component analysis and hierarchical clustering analysis results based on differences in the amount of protein identified three major clusters, and proteins including transglutaminase, desmocollin, and elongation factors were selected as trait components from proteomic patterns of horn samples from different species. Quantitative proteomic analysis based strategies can therefore provide further evidence for sustainable alternatives to replace animal horn from threatened species.


Assuntos
Espécies em Perigo de Extinção , Cornos/química , Proteoma/análise , Proteômica/métodos , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Análise por Conglomerados , Espectrometria de Massas , Perissodáctilos/fisiologia , Análise de Componente Principal , Ruminantes/fisiologia
13.
J Zoo Wildl Med ; 49(3): 704-714, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30212337

RESUMO

The objective of this study was to determine the major nutrient composition of Indian rhinoceros milk ( Rhinoceros unicornis) over the first 13 mo of an 18-mo lactation period and to compare the results to those of previous studies on rhinoceros, African elephant ( Loxodonta africana), and horse milk ( Equus ferus caballus). The following parameters were measured: dry matter (DM), crude ash (ASH), crude protein (CP), ether extract (EE), nitrogen-free extract (NFE; calculated), lactose, calcium (Ca), phosphorus (P), magnesium (Mg), fatty acids (FAs), and gross energy (GE). DM, ASH, CP, and EE were determined with a proximate analysis, lactose with infrared spectroscopy and an enzymatic method, minerals with an autoanalyzer, FA with gas chromatography, and GE with bomb calorimetry. Milk samples were collected from two Indian rhinoceros cows from Zoo Basel. Rhino A gave birth to her third calf on 10 September 2012; three samples were collected and analyzed (colostrum, milk 1 wk and 2 wk postpartum). Rhino B gave birth to her eighth calf on 05 October 2013; samples were collected and 15 were chosen for the analyses (from colostrum to 13 mo postpartum). The composition of rhino B's colostrum was 13.8% DM (wet-weight basis), 4.8% ASH, 61.8% CP, 0.7% EE, 32.6% NFE, 26.7% lactose, 0.59% Ca, 0.54% P, 0.2% Mg (DM basis), and 20.3 MJ GE/kg DM. Rhino B's sample collected 13 mo postpartum averaged 8.0% DM (wet-weight basis), 3.6% ASH, 16.3% CP, 1.8% EE, 78.3% NFE, 84.7% lactose, 0.54% Ca, 0.48% P, 0.09% Mg (on DM basis), and 17.43 MJ GE/kg DM. The main FAs in rhino B's and rhino A's samples were C10 : 0, C12 : 0, C16 : 0, C18 : 1n9c, and C18 : 2n6c. Milk of the Indian rhinoceros is low in fat and protein but high in lactose, which is comparable to the milk composition of other rhinoceros species and horses, but not African elephants.


Assuntos
Lactação/fisiologia , Leite/química , Perissodáctilos/fisiologia , Animais , Animais de Zoológico , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Feminino
14.
J Chem Ecol ; 44(10): 875-885, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30009329

RESUMO

Many mammals enhance their olfactory signals visually by depositing them in conspicuous locations such as well-travelled paths. It is also possible to enhance the odour itself through behaviours aimed at modifying odour emission rates. White rhinos defecate in communal middens. While defecating, territorial males kick sharply with their back feet which disperses their dung. Despite being a ubiquitous trait of territorial male white rhinos, the reason behind this behaviour is unclear. We hypothesised that the purpose of dung kicking was for olfactory signal amplification (OSA) in terms of an increased emission of volatile compounds (i.e. increased signal strength). Using dung collected from non-territorial adult males (because it is not possible to collect whole dung from territorial males), we show that the dispersal of male white rhino dung causes OSA by increasing the emission of hydrocarbon acids. The dung odour of territorial and non-territorial males differs only quantitatively, hence it is likely that the same emission patterns occur for territorial male dung odours following dung dispersal. The volatile compound indicating age of intact dung was toluene, but for dispersed dung it was acetophenone (similar to territorial male dung). Despite the benefits of OSA, dung dispersal carried a cost of decreased odour longevity. Thus, signal detectability is temporally reduced. However, territorial males likely counteract this by defecating in middens both before and during peak visitation times by other individuals (15:00-23:00). As a result, we suggest that dung kicking by territorial males amplifies signal strength, such that their dung odours are the most prominent and easily detectable by individuals visiting the middens. This would then better signal territorial ownership to both potential rivals and potential mates.


Assuntos
Fezes/química , Perissodáctilos/fisiologia , Olfato , Animais , Comportamento Animal , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Territorialidade , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química
16.
PLoS One ; 13(3): e0192166, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29513670

RESUMO

Describing vocal repertoires represents an essential step towards gaining an overview about the complexity of acoustic communication in a given species. The analysis of infant vocalisations is essential for understanding the development and usage of species-specific vocalisations, but is often underrepresented, especially in species with long inter-birth intervals such as the white rhinoceros. Thus, this study aimed for the first time to characterise the infant and juvenile vocal repertoire of the Southern white rhinoceros and to relate these findings to the adult vocal repertoire. The behaviour of seven mother-reared white rhinoceros calves (two males, five females) and one hand-reared calf (male), ranging from one month to four years, was simultaneously audio and video-taped at three zoos. Normally reared infants and juveniles uttered four discriminable call types (Whine, Snort, Threat, and Pant) that were produced in different behavioural contexts. All call types were also uttered by the hand-reared calf. Call rates of Whines, but not of the other call types, decreased with age. These findings provide the first evidence that infant and juvenile rhinoceros utter specific call types in distinct contexts, even if they grow up with limited social interaction with conspecifics. By comparing our findings with the current literature on vocalisations of adult white rhinoceros and other solitary rhinoceros species, we discuss to which extent differences in the social lifestyle across species affect acoustic communication in mammals.


Assuntos
Comunicação Animal , Perissodáctilos/fisiologia , Vocalização Animal/fisiologia , Acústica , Fatores Etários , Animais , Animais de Zoológico , Feminino , Masculino , Perissodáctilos/crescimento & desenvolvimento , Comportamento Social , Espectrografia do Som , Gravação em Vídeo
17.
J Morphol ; 279(1): 50-61, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28948643

RESUMO

Extant rhinoceroses share the characteristic nasal horn, although the number and size of horns varies among the five species. Although all species are herbivores, their dietary preferences, occipital shapes, and common head postures vary. Traditionally, to predict the "usual" head posture (the most used head posture of animals during normal unstressed activities, i.e., standing) of rhinos, the occipital shape was used. While a backward inclined occiput implies a downward hanging head (often found in grazers), a forward inclined occiput is related to the horizontal head posture in browsing rhinos. In this study, the lateral semicircular canal (LSC) of the bony labyrinth was virtually reconstructed from µCT-images in order to investigate a possible link between LSC orientation and head posture in extant rhinoceroses. The usual head posture was formerly reconstructed for several non-rhinoceros taxa with the assumption that the LSC of the inner ear is held horizontal (parallel to the ground) during normal activity of the living animal. The current analysis of the LSC orientation resulted in a downward inclined usual head posture for the grazing white rhinoceros and a nearly horizontal head posture in the browsing Javan rhinoceros. The other three browsing or mixed feeding species show subhorizontal (closer to horizontal than a downgrade inclination) head postures. The results show that anatomical and behavioral aspects, like occipital shape, presence and size of horns/tusk-like lower incisors, as well as feeding and feeding height preferences influence the usual head posture. Because quantitative behavioral data are lacking for the usual head postures of the extant rhinos, the here described relationship between the LSC orientation and the resulting head posture linked to feeding preferences gives new insights. The results show, that the inner ear provides additional information to interpret usual head postures linked to feeding preferences that can easily be adapted to fossil rhinoceroses.


Assuntos
Comportamento Alimentar , Perissodáctilos/anatomia & histologia , Perissodáctilos/fisiologia , Postura , Canais Semicirculares/anatomia & histologia , Animais , Fósseis , Cabeça , Modelos Anatômicos
18.
J Hum Evol ; 120: 203-214, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-28870375

RESUMO

The Oldowan site HWK EE (Olduvai Gorge, Tanzania) has yielded a large fossil and stone tool assemblage at the transition from Lower to Middle Bed II, ∼1.7 Ma. Integrated tooth wear and stable isotope analyses were performed on the three most abundant ungulate taxa from HWK EE, namely Alcelaphini, cf. Antidorcas recki (Antilopini) and Equus oldowayensis (Equini), to infer dietary traits in each taxon. Some paleodietary changes were observed for cf. A. recki and E. oldowayensis based on tooth wear at the transition from the Lemuta to the Lower Augitic Sandstone (LAS) interval within the HWK EE sequence. Stable carbon and oxygen isotope data show no significant changes in bulk diet or hydroclimate between the Lemuta and LAS intervals. The combined tooth wear and stable isotope data suggest similar paleoecological conditions across the two HWK EE intervals, but that differences in vegetation consumed among ungulates may have resulted in changes in dietary niches. Integrating tooth wear and stable isotope analyses permits the characterization of ungulate diets and habitats at HWK EE where C4 dominated and minor mixed C3 and C4 habitats were present. Our results provide a better understanding of the paleoenvironmental conditions of the Lemuta and LAS intervals. The LAS assemblage was mostly accumulated during relatively dry periods at Olduvai Gorge when grasses were not as readily available and grazing animals may have been more nutritionally-stressed than during the formation of the Lemuta assemblage. This helps to contextualize variations in hominin and carnivore feeding behavior observed from the faunal assemblages produced during the two main occupations of the site.


Assuntos
Artiodáctilos/fisiologia , Dieta , Perissodáctilos/fisiologia , Mamífero Proboscídeo/fisiologia , Dente/anatomia & histologia , Dente/química , Animais , Arqueologia , Artiodáctilos/anatomia & histologia , Isótopos de Carbono/análise , Comportamento Alimentar , Isótopos de Oxigênio/análise , Paleontologia , Perissodáctilos/anatomia & histologia , Mamífero Proboscídeo/anatomia & histologia , Tanzânia
19.
Environ Res ; 160: 514-517, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29103585

RESUMO

Videos recorded with infrared camera traps placed in petroleum contaminated areas of the Peruvian Amazon have shown that four wildlife species, the most important for indigenous peoples' diet (lowland tapir, paca, red-brocket deer and collared peccary), consume oil-contaminated soils and water. Further research is needed to clarify whether Amazonian wildlife's geophagy can be a route of exposure to petrogenic contamination for populations living in the vicinity of oil extraction areas and relying on subsistence hunting.


Assuntos
Artiodáctilos/fisiologia , Cuniculidae/fisiologia , Exposição Ambiental , Comportamento Alimentar , Perissodáctilos/fisiologia , Poluição por Petróleo/análise , Poluentes do Solo/análise , Animais , Contaminação de Alimentos , Humanos , Peru , Solo/química
20.
Theriogenology ; 109: 48-57, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29249327

RESUMO

Despite their size and potentially dangerous demeanor, the rhinoceros has been a preferred subject of wildlife reproductive scientists. Several factors contribute to this taxon's popularity including the ability to utilize insightful tools like non-invasive hormone metabolite monitoring and transrectal ultrasonography, the necessity for mate introductions to coincide with the female's estrus when breeding certain species or individuals, and the desire to develop assisted reproductive technologies to facilitate the genetic management and ultimate sustainability of small, managed populations in human care. The resulting profusion of rhinoceros reproductive studies has revealed significant species-specific characteristics and exposed the prevalence of aberrant reproductive activity within this taxon. Of equal importance, it has guided necessary intervention and enhanced our success in overcoming challenges associated with breeding rhinoceroses.


Assuntos
Animais Selvagens/fisiologia , Ovário/fisiologia , Perissodáctilos/fisiologia , Reprodução/fisiologia , Aborto Animal/prevenção & controle , Animais , Cruzamento/métodos , Estrogênios/análise , Ciclo Estral/fisiologia , Feminino , Monitorização Fisiológica/métodos , Monitorização Fisiológica/veterinária , Indução da Ovulação/métodos , Indução da Ovulação/veterinária , Técnicas de Reprodução Assistida/veterinária , Especificidade da Espécie , Ultrassonografia/métodos , Ultrassonografia/veterinária
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