Fat soluble vitamins in blood and tissues of free-ranging and captive rhinoceros

Several disease syndromes in captive rhinoceroses have been linked to low vitamin status. Blood samples from captive and free-ranging black (Diceros bicornis) and white rhinoceros (Ceratotherium simum) and tissue samples of captive individuals from four rhinoceros species were analysed for vitamins A and E. Circulating vitamin A levels measured as retinol for free-ranging versus captive black and white rhinoceros were 0.04 (+/- 0.03 SD) vs. 0.08 (+/- 0.08) and 0.07 (+/- 0.04) vs. 0.06 (+/- 0.02) microgram/ml, respectively. Circulating vitamin E levels measured as alpha-tocopherol were 0.58 (+/- 0.30) vs. 0.84 (+/- 0.96) and 0.62 (+/- 0.48) vs. 0.77 (+/- 0.32) microgram/ml, respectively. In contrast to earlier findings, there was no significant difference in vitamin E concentration between captive and free-ranging black rhinoceros. When the samples of captive black rhinoceros were grouped into those taken before 1990 and after 1990, however, those collected before 1990 had significantly lower (P < 0.001) vitamin E levels (0.46 +/- 0.83 microgram/ml) and those collected in 1990 or later significantly higher (P < 0.001) vitamin E levels (1.03 +/- 1.04 micrograms/ml) than the captive population as a whole. This is probably due to increased dietary supplementation. There were significant differences in circulating vitamin concentrations in black rhinoceroses from different regions in the wild. Serum 25-hydroxy (OH) vitamin D3 averaged 55.7 ng/ml in free-ranging rhinoceroses; no carotenoids were detected in any blood samples. Captive black and white rhinoceroses appear to be adequately supplemented in vitamin A and E. Captive Indian rhinoceroses (Rhinoceros unicornis) had significantly lower vitamin A concentrations in blood (P < 0.001) and higher vitamin A concentrations in liver tissue samples (P < 0.001) than other rhinoceros species. Equine requirements are not recommended as a model for rhinoceros vitamin requirements.     

Tannin-binding salivary proteins in three captive rhinoceros species

Tannin-binding salivary proteins (TBSP) are considered to be counter-defences acquired in the course of evolution by animals whose natural forage contains such tannins. As tannins mostly occur in browse material but not in grasses, it is assumed that grazers do not have a need for TBSP. Whereas it has been shown in several non-ungulate species that TBSP can be induced by dietary tannins, their presence or absence in ungulates has, so far, been shown to be a species-specific characteristic independent of dietary manipulations. We investigated saliva from three rhinoceros species from zoological gardens fed comparable, conventional zoo diets. As expected, saliva from white rhinoceroses (Ceratotherum simum, grazer) had lower tannin-binding capacities than that from black rhinoceroses (Diceros bicornis, browser). Surprisingly, however, Indian rhinoceroses (Rhinoceros unicornis), commonly regarded as grazers as well, displayed the highest tannin-binding capacities of the three species investigated. It is speculated that this discrepancy might be a result of an evolutionarily recent switch to a grass-dominated diet in Indian rhinoceroses, and that the black rhinoceros, which is closer related to the white rhinoceros than the Indian species, has evolved an inducible mechanism of TBSP production. In separate trials during which the tannin content of the diets of black rhinoceroses was increased by the addition of either tannic acid or quebracho, the tannin-binding capacity of black rhinoceros saliva was increased to levels within the same range as that of Indian rhinoceroses on the conventional diets. While induction trials in white and Indian rhinoceroses remain to be performed for a full understanding of salivary anti-tannin defence in rhinoceroses, these results are the first report of an induced salivary response to increased dietary tannin levels in an ungulate species.     

Characterization of microsatellite loci in the black rhinoceros (Diceros bicornis) and white rhinoceros (Ceratotherium simum): their use for cross-species amplification and differentiation between the two species

As the population sizes of the black and white rhinoceroses continues to decline, more efforts are needed in multiple areas to help with the conservation efforts. One area being explored is the use of genetic diversity information to aid conservation decisions. In this study, we designed 21 microsatellite primers for white and black rhinoceroses, 16 and 17 of which amplified bands in the white and black rhinoceros, respectively. Out of these primers all 16 were polymorphic in the white rhinoceros and 12 of the 17 were polymorphic in the black rhinoceros. The mean number of alleles was 3.31 and 2.12, the expected heterozygosities were 0.420 and 0.372, and the observed heterozygosities were 0.436 and 0.322 for the white and black rhinoceroses, respectively. Seven of the primers produced different allele sizes and variations that distinguished between black and white rhinoceroses. Further genetic analyses with larger wild population sample sizes and markers are recommended to obtain a better understanding of the genetic structure of the black and white rhinoceros populations in order to be useful in the conservation efforts of these critically endangered species. A. Kilbourn—In memoriam.     

Allozyme variation and differentiation in African and Indian rhinoceroses

We studied variation at 25 to 31 allozymic loci in African and Asian rhinoceroses. Four taxa in three genera were examined: African Ceratotherium simum simum (northern white rhinoceros), C. s. cottoni (southern white rhinoceros), Diceros bicornis (black rhinoceros), and Rhinoceros unicornis (Indian rhinoceros). Extremely small amounts of intraspecific variation were observed in sample sizes of 2 to 10 presumably unrelated individuals per taxon: P = .00-.10, H = 0.00-0.02. We examined demographic bottlenecks and sampling errors as possible reasons for the low levels of detectable variation. The very small intraspecific genetic distance (D = 0.005) between the two living white rhinoceros subspecies is far less than the distance that has been reported for other mammal subspecies. The mean D value of 0.32 +/- 0.11 between the two African genera was also less than expected given the divergence time of greater than 7 million years suggested by the fossil record. Rhinoceroses may be evolving more slowly at the structural gene loci than are some other mammal groups. The estimate of D = 1.05 +/- 0.24 for the African-Indian split supports this idea, as the lineage diverged at least 26 million years ago. Our results contribute to the currently available scientific information on which management decisions aimed toward saving endangered rhinoceroses should be based.     

Tourists' Effects on Drivers of Working Asian Elephants

ABSTRACT

A growing wildlife tourist industry in Asia sometimes includes the use of elephants to transport tourists. Elephant drivers are responsible for the safe management of their elephants while loading, transporting, and unloading tourists for rides to view wildlife. This study sought to investigate the preferences and perceptions of elephant drivers regarding tourists when viewing rhinoceroses in the field. Drivers were interviewed with standardized questions with translator assistance and asked to show the distances from the rhinoceros at which both they and tourists preferred to view a rhinoceros. According to drivers, they preferred to be a longer distance from a rhinoceros than did tourists. Drivers described that some tourists wanted to get closer than was safe to rhinoceroses and other wildlife so as to take good photographs; some even wanted to be within touching distance. Drivers noted that tourists with long camera lenses did not seek or request to be as close to the rhinoceros as tourists with cameras with short lenses.     

Comparative analysis of gonadal and adrenal activity in the black and white rhinoceros in North America by noninvasive endocrine monitoring

Patterns of fecal reproductive steroid metabolites and adrenal corticoids were characterized for 12‐ to 24‐month periods in black (n = 10 male, 16 female) and white (n = 6 male, 13 female) rhinoceroses at 14 institutions. All black rhinoceros females exhibited at least some ovarian cyclicity on the basis of fecal progestogen analysis (range, 2–12 cycles/yr). However, cycles often were erratic, with many being shorter (<20 days; 18% of cycles) or longer (>32 days; 21%) than the average of 26.8 ± 0.5 days (n = 104 cycles). Five females exhibited periods of acyclicity of 2–10‐month duration that were unrelated to season. One complete and seven partial pregnancies were evaluated in the black rhinoceros. Fecal progestogens increased over luteal phase concentrations after 3 months of gestation. Females resumed cyclicity within 3 months postpartum, before calves were weaned (n = 5). Approximately half of white rhinoceros females (6 of 13) showed no evidence of ovarian cyclicity. Of the cycles observed, 5 were “short” (32.8 ± 1.2 days) and 24 were “long” (70.1 ± 1.6 days). Only two females cycled continuously throughout the study. One had both long (n = 9) and short (n = 2) cycles, whereas the other exhibited long cycles only (n = 5). Fecal estrogen excretion was variable, and profiles were not useful for characterizing follicular activity or diagnosing pregnancy in either species. Males of both species showed no evidence of seasonality on the basis of fecal androgen profiles. Androgen metabolite concentrations were higher (P < 0.05) in the black (27.6 ± 6.9 ng/g) than in the white (16.8 ± 3.1 ng/g) rhinoceros. An adrenocorticotropin hormone challenge in four black rhinoceros males demonstrated that the clearance rate of corticoid metabolites into feces was ～24 hours. Fecal corticoid concentrations did not differ between males and females, but overall means were higher in the black (41.8 ± 3.1 ng/g) than in the white (31.2 ± 1.7 ng/g) rhinoceros. In summary, fecal steroid analysis identified a number of differences in hormonal secretory dynamics between the black and white rhinoceros that may be related to differences in reproductive rates in captivity. Most black rhinoceros females exhibited some cyclic ovarian activity. In contrast, few white rhinoceroses demonstrated evidence of regular estrous cyclicity, and those females that were active had comparatively long cycles. Results also suggest that fecal corticoid concentrations reflect adrenal activity and may be species specific. Continued studies are needed to determine whether fecal corticoid measurements will be useful for understanding the cause of inconsistent gonadal activity in these two species. Because all but three (15.8%) of the white rhinoceroses evaluated in this study were less than 20 years of age compared to 73.1% (19 of 26) of the black rhinoceroses, the impact of age on reproductive and adrenal activity also needs to be evaluated further. Zoo Biol 20:463–486, 2001. © 2002 Wiley‐Liss, Inc.     

Gamete rescue in the African black rhinoceros (Diceros bicornis)

Mortality rates are high among captive African black rhinoceroses (Diceros bicornis), due to increased susceptibility to disease. The ability to rescue genetic material from individuals that die unexpectedly represents a practical approach to assist ex situ conservation efforts. The objectives of the present study were to attempt postmortem oocyte recovery from ovaries of African black rhinoceroses (N = 6) and to test the efficacy of equine protocols for rhinoceros oocyte IVM and IVF using cryopreserved rhinoceros sperm. The interval from ovary removal to oocyte recovery was 25.3 ± 13.9 h (mean ± SD). Ovaries were transported at 4 °C or 22 °C and effects of temperature on postmortem oocyte competence was evaluated. Numbers of oocytes collected per female averaged 15.8 ± 6.9. In total, 95 oocytes were recovered. Of these, 85 were inseminated using homologous sperm and 10 were inseminated using heterologous sperm. Overall, substantial numbers of viable oocytes were retrieved from African black rhinoceros ovaries 1 to 2 days postmortem from ovaries stored at ambient temperature. A proportion of these oocytes matured and underwent penetration and fertilization by heterologous or homologous frozen-thawed rhinoceros sperm. The reproductive competence of postmortem oocytes was further demonstrated by development of a single two-cell embryo. Despite the need for further refinements, gamete rescue in the rhinoceros has promise for producing rhinoceros embryos, as well as testing sperm functions in vitro.     

One Small Step for Rhinos,One Giant Leap for Wildlife Management- Imaging Diagnosis of Bone Pathology in Distal Limb

Chronic foot disease poses a threat to the general health, represents a tremendous clinical challenge, and often is a reason for euthanasia in captive megaherbivores, among them the elephant and rhinoceros. Nevertheless, apart from the elephant, foot pathology is handled as being confined only to soft tissues whereas bone pathology is often overlooked. As a case in point, the authors selected the second largest mammal on land, the rhinoceros. We performed a computed tomographic (CT) study using the highest resolution available in veterinary world, followed by digital radiography of eight distal limbs from two white and one Indian rhinoceroses. Our study demonstrated that bone pathology in rhinoceroses’ foot is present and in large numbers, yet none of these were diagnosed ante mortem. Even when the animals were euthanized due to foot problems, the decision was based on soft tissue pathology rather than orthopedic reasons. Even more worrying is the fact that the largest number of osteopathologies was present in one of the white rhinoceroses that showed no discernable related clinical signs. This study describes for the first time the existence of bone pathology in white rhinoceros foot, in addition to the two previously described rhinoceros species - Indian and black rhinoceroses. Furthermore, the chronic foot disease reported for the Indian rhinoceros in our study was not restricted to soft tissue structures as was presumed ante mortem but included severe bone pathology. New evidence suggesting that osteopathology in rhinoceroses’ distal limb is more widespread than it was thought before could force us to rethink of radiographic diagnosis in captive megaherbivores as routine examination incorporated into their health management. The anticipated improvements in radiologic examinations in megaherbivores will increase the effectiveness of their management and husbandry and open the way for improved animal welfare and better wildlife conservation.     

Ovarian superstimulation, transrectal ultrasound-guided oocyte recovery, and IVF in rhinoceros

Numerous reports on reproductive pathology in all rhinoceros species illustrate the abundance of female infertility in captive populations. In infertile rhinoceroses, oocyte collection and embryo production could represent the best remaining option for these animals to reproduce and to contribute to the genetic pool. We report here on superstimulation, repeated oocyte recovery, and attempted in vitro fertilization (IVF) in white and black rhinoceroses. Four anestrous rhinoceroses (two white, two black) with unknown follicular status were treated with gonadotropin-releasing hormone analogue, deslorelin acetate, for 6 to 7 d. Number and size of follicles in superstimulated females was significantly higher and larger compared with those in nonstimulated anestrous females (n = 9). Ovum pick-up was achieved by transrectal ultrasound-guided follicle aspiration. Up to 15 follicles were aspirated per ovary. During six ovum pick-ups, a total of 29 cumulus-oocyte complexes (COCs) were harvested with a range of 2 to 9 COCs per collection. No postsurgical complications were noted on the rhinoceros ovaries using this minimally invasive approach. Various in vitro maturation (IVM) and IVF protocols were tested on the collected COCs. Despite the low total number of COCs available for IVM and IVF in this study, we can report the first rhinoceros embryo ever produced in vitro. The production of a 4-cell embryo demonstrated the potential of transrectal ultrasound-guided oocyte recovery as a valuable tool for in vitro production of rhinoceros embryos from otherwise infertile females.     

Ciliated intestinal protozoa of black (Diceros bicornis michaeli) and white rhinoceroses (Ceratotherium simum simum) in Kenya

The aim of this study was to survey ciliated intestinal protozoa of the black rhinoceros ( Diceros bicornis michaeli ) and white rhinoceros ( Ceratotherium simum simum ) in Kenyan National Parks. Faecal samples from 28 rhinoceroses that were chemically immobilized for translocation were opportunistically collected. Presence of ciliates was assessed using faecal floatation and sedimentation techniques. The ciliates were identified using cellular morphological features. Ophryoscoleciidae, Cycloposthiidae and Blepharocrythiidae were the three ciliate families represented. Ophryoscoleciidae had nine genera, Cycloposthiidae six genera and Blepharocorythiidae 1 genus. The dominant ciliate genus in all the rhinoceroses that were sampled was entodinium . It was found that the nutrient composition of the diet influences the diversity and numbers of intestinal ciliates, which in turn regulates the nutrient available to the animal. This interplay of nutrient composition of diet, ciliate diversity and nutritional benefits to the host has been used as an index to assess the nutritional state of ruminants. Because of the occurrence of rumenal ciliates in the hindgut fermentative chamber of the rhinoceros, such an index can be used to guide the formulation of feed mixtures for rhinoceros in captivity and remote nutritional assessments of rhinoceros both in free-range and in captivity.     

Cage restraints for rhinoceroses

Captive breeding programs for the rhinoceros can be enhanced by studying their reproductive physiology. To do so requires repetitive manipulations under physically controlled circumstances. To facilitate these procedures, zoos throughout the world have constructed restraint devices, or chutes. Chute designs are usually determined by the space in which they are to be situated and the budget available for their construction. In this study, eight chute designs at seven institutions were compared for efficiency in controlling rhinoceroses during ultrasonography, semen collection, and blood sampling. Procedures were conducted on 16 rhinoceroses of four species: the white rhinoceros (Ceratotherium simum simum), the black (Diceros bicornis), the greater one-horned Asian (Rhinoceros unicornis), and the Sumatran (Dicerorhinus sumatrensis). Chutes were evaluated for dimensions, fabricating materials, procedures to be attempted, and structural features such as shoulder restraints. Permanent, indoor, side-adjustable, pass-through chutes were determined to be the most efficient and convenient type because they saved time and reduced stress on the animals. Zoo Biol 17:343–359, 1998. © 1998 Wiley-Liss, Inc.     

THE FATE OF BLACK RHINOCEROSES RELEASED IN NAIROBI NATIONAL PARK

Information on the black rhinoceros population of Nairobi National Park has been obtained from two-month surveys in 1967 and 1968 backed by data collected at random over the past few years. It proved impossible to identify some of the rhinoceroses whose presence was indicated by spoor and unidentified sightings, and an estimate of the total number present at the end of 1968 must vary between 27 and 33 animals. Twenty-two rhinoceroses have been brought into the Park by the Game Department Capture Unit since November 1966. The fate of these animals has been: two dead, two not seen and 18 identified in the Park 3–33 months after release. The newcomers have produced only one serious conflict with a resident rhinoceros and two collisions with motor vehicles. Despite the small size of the Park, the inadequacy of its boundaries and the legendary intolerance of the species, it would appear that the translocation operations have been a success.     

Observations on rhinoceros tongue morphology

The rhinoceros tongue is distinguished among perissodactyl organs by its sagittally divided intermolar eminence crowned by a dextral and a sinistral cluster of circumvallate papillae. These structures were originally noted in the Indian rhinoceros by Owen (1852) but have since remained unmentioned for this, or for any other rhinoceros form. They are here described for specimens of the Indian, African White and African Black rhinoceroses. The structural and functional nature of the intermolar eminence is established and this entity is distinguished from an hitherto unrecognized topographical component of the tongue, designated the pars elliptica linguae. The lingual morphology of the three rhinoceros forms is summarised and certain intergeneric differences are noted.     

Fluid and particle retention times in the black rhinocerosDiceros bicornis, a large hindgut-fermenting browser

The mean retention time (MRT) of ingesta in the gastrointestinal tract is one of the major determinants of herbivore digestive physiology. We examined MRTs of fluids and particles in the gastrointestinal tract of six adult captive black rhinocerosesDiceros bicornis on conventional zoo diets. Fluid MRT ranged from 25–45 h and averaged 31 h. Particle MRT ranged from 28–59 h and averaged 38 h. In the six animals, both fluid and particle MRT declined as relative dry matter intake (g/kg metabolic body mass) increased. Black rhinoceroses, which are large hindgut-fermenting browsers, retained ingesta for a shorter period relative to their body size than grazing equids or grazing rhinoceros species. Our findings support the hypothesis that browsing hindgut fermenters have relatively shorter MRTs than grazing hindgut fermenters.     

A potential link between lateral semicircular canal orientation,head posture,and dietary habits in extant rhinos (Perissodactyla,Rhinocerotidae)

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.     

Serum alpha-tocopherol, all-trans retinol, total lipids and cholesterol in the black rhinoceros (Diceros bicornis)

1. Mean concentration of serum alpha-tocopherol (Vitamin E) in 28 free-living black rhinoceroses sedated during translocation in Zimbabwe was 1.92 (SD, 0.43) mg/l. 2. Alpha-tocopherol was not detectable (less than 0.15 mg/l) in five captive black rhinoceroses held at London Zoo. 3. Circulating levels of all-trans retinol (Vitamin A) were not different between the two groups. 4. The low level of alpha-tocopherol in captive rhinoceroses suggests a risk of acute haemolytic anaemia.     

Some specific morphological and ecological features of the fossil woolly rhinoceros (Coelodonta antiquitatis Blumenbach 1799)

The results of anatomical and morphological studies of new corpse remains of the fossil woolly rhinoceros found in 2007 in the lower reaches of the Kolyma River are described. These new data provide additional details of the specific features of the structures and sizes of individual body parts of the fossil rhinoceros and allow for several inferences on the specific adaptations of this species to the cold climate of the Ice Age. Palynological data for the stomach contents of the woolly rhinoceroses that lived during the Karginian interglacial period of the Late Pleistocene are given. It is been shown that herbs (cereals and forbs) account for the major part of the woolly rhinoceros diet.     

Chemical and pathological oxidative influences on band 3 protein anion-exchanger.

BACKGROUND/AIMS: The erythrocyte is a cell exposed to a high level of oxygen pressure and to oxidative chemical agents. This stress involves SH-groups oxidation, cell shrinkage by activation of K-Cl co-transport (KCC) and elevation of the band 3 tyrosine phosphorylation level. The aim of our study was to test whether oxidative stress could influence band 3-mediated anion transport in human red blood cells. METHODS: To evaluate this hypothesis, normal and pathological (glucose 6 phosphate dehydrogenase (G6PDH) defficient) erythrocytes were treated with known sulphydryl-blocking or thiol-oxidizing agents, such as N-ethylmaleimide (NEM), azodicarboxylic acid bis[dimethylamide] (diamide), orthovanadate, Mg2+ and tested for sulphate (SO4-) uptake, K+ efflux, G6PDH activity and glutathione (GSH) concentration. RESULTS: In normal red blood cells, the rate constants of SO4- uptake decreased by about 28 % when cells were incubated with NEM, diamide and orthovanadate. In G6PDH-deficient red blood cells, in which oxidative stress occurs naturally, the rate constant of sulphate uptake was decreased by about 40% that of normal red cells. Addition of oxidizing and phosphatase inhibitor agents to pathological erythrocytes further decreased anion transport. In contrast, G6PDH activity was increased under oxidative stress in normal as well as in pathological cells and was lower in the presence of exogenous Mg2+ in parallel to a significant increase in sulphate transport. In both cells, the oxidizing agents increased K+ efflux with depletion of GSH. CONCLUSION: The data are discussed in light of the possible opposite effects exerted by oxidative agents and Mg2+ on KCC and on the protein tyrosine kinase (PTK)-protein tyrosine phosphatase (PTP) equilibrium. The decreased sulphate uptake observed in the experimental and pathological conditions could be due to band 3 SH-groups oxidation or to oxidative stress-induced K-Cl symport-mediated cell shrinkage with concomitant band 3 tyrosine phosphorylation.