Feeding and drinking habits of the black rhinoceros in Masai Mara Game Reserve

Feeding and drinking habits of the black rhinoceros (Diceros bicornis L.) population in Masai Mara Game Reserve, Kenya, were studied from May 1971 to August 1972. A total of 108 rhinoceros were recorded in the study area. Feeding rhinoceros were followed behind their feeding tracks until they stopped feeding (or changed to another activity) and the plants which they selected were identified. A technique was used which provided an indication of the relative importance of certain plants in the diet during May to September 1971 (wet-semi-dry), October 1971 to February 1972 (dry) and February to May 1972 (wet-semi-dry). A total of 240 h were spent actually watching feeding rhinoceros in thirteen distribution areas. During this period rhinoceros were observed eating seventy plant species from thirty botanical families. In all distribution areas rhinoceros were very selective for herbs and shrubs, and showed a marked preference for Solanum incanum, Dichrostachys cinerea and Acacia species. Rhinoceros were also observed to visit salt licks which contained sodium, magnesium, potassium and calcium. Two feeding peaks, one in morning and the other in the afternoon were recorded. Black rhinoceros drink water mainly at night. They spend most of the night time near the watering places for they were mostly located in the mornings walking to the feeding grounds.     

Urinary steroid evaluations to monitor ovarian function in exotic ungulates: V. Estrogen and pregnanediol-3-glucuronide excretion in the black rhinoceros (Diceros bicornis)

A study of female black rhinoceros (Diceros bicomis) urinary steroid and steroid metabolite excretion was performed to determine if techniques useful for monitoring reproductive events in the Indian rhinoceros (Rhinoceros unicornis) could be utilized to evaluate the black rhinoceros. Urine samples from 19 zoo-held black rhinoceros were analyzed for estrogen, estrone conjugates (EC), and pregnanediol-3-glucuronide (PDG) content by direct radioimmunoassays. Estrogen analysis revealed that >95% of the estrogens present in female black rhinoceros urine are conjugated, with estrone and estradiol accounting for virtually all of these estrogens. There is no observable difference in the amount of estrogen present in estrus; postestrus; and early-, mid-, and late-gestation urine samples. Analysis of serial urine samples for EC failed to reveal any discernible levels or patterns which reflected reproductive status. Neither nonpregnant nor early-gestational female black rhinoceros' urine samples contained detectable amounts of PDG. Urinary PDG concentrations became measurable in midgestation (9–12 months prior to parturition) and rose steadily throughout the remainder of gestation. PDG levels declined sharply and became nondetectable 1 day postpartum. Though a wide range in PDG levels was observed among individual pregnant animals, each female consistently excreted increasing amounts of PDG through latter pregnancy.     

FOOD PREFERENCES OF TWO BLACK RHINOCEROS POPULATIONS

Food preferences of two discrete black rhinoceros (Diceros bicornis L.) populations were studied in northern Tanzania from 1964–1966 Feeding rhinoceros were watched for a period of one hour, and the plants which they selected and rejected were identified, either as they were feeding or when they had moved on. A technique was used which provided an indication of the relative importance of certain plants in the diet. Observations were made in six different habitat types used by the rhinoceros during the wet and dry seasons. A total of 307 hours was spent actually watching feeding rhinoceros. During this period they were observed eating 191 plant species from 49 botanical families. In all habitat types rhinoceros consume a wide variety of the spectrum of plants available, but are highly selective for herbs and shrubs. At certain periods of the year stenophagous characteristics are apparent, and the species shows a marked preference for legumes. Grasses make up a small proportion of the diet.     

Black rhinoceros (Diceros bicornis) in U.S. zoos: II. behavior,breeding success,and mortality in relation to housing facilities

The captive population of black rhinoceros (Diceros bicornis) is not self‐sustaining. The reasons for suboptimal reproduction and high mortality need to be investigated. This can only be achieved by cross‐institutional analyses of environments, behavior, and performance. In this study, we collected data on 23 zoos with black rhinoceros to compare zoo environments with reproductive success, mortality, and behavior. Institutional variation was characterized by enclosure area, percentage of walls around enclosure perimeter, percentage of public access along enclosure perimeter, climate, noise level, number of years zoo has maintained black rhinoceros, frequency of chlorine use, and number of male and female black rhinoceros at a zoo simultaneously. Birth and death rates for each institution were calculated from studbook records. We found that the breeding success of a zoo since 1973 correlated positively with enclosure area, and zoos with two or more females had a lower reproductive rate than zoos with only one female. Females residing during their pre‐reproductive years at a zoo with another reproductive female gave birth for the first time on average 3 years later than sole females. Mortality since 1973 correlated positively with percentage of public access. In Part I, we developed behavior profiles of 29.31 individual black rhinoceros from keeper ratings. Scores for males on the behavior trait Fear also correlated positively to percentage of public access, and we suggest that this aspect of black rhinoceros exhibits is a stressor for this species, especially the males. We found that different aspects of captive environments are associated with male and female black rhinoceros behavior. Male scores on the behavior trait dominant were higher in smaller enclosures, and female scores for a group of behaviors suggesting agitation (chasing/stereotypy/mouthing) were positively correlated with percentage of walls in their enclosure. These two behavior traits were found in Part I to be negatively correlated with the breeding success of an individual male or female. We re‐surveyed the behavior and husbandry of 29 black rhinoceros pairs in zoos 2 years after the original data were collected. The re‐survey confirmed that compatible black rhinoceros pairs are those with assertive females and submissive males, and that enclosure area and a low percentage of concrete walls around the enclosure are positive predictors of a pair's reproductive success. We conclude that temperament traits of individuals and characteristics of their captive environments both have an impact on a pair's breeding success. Our study demonstrates that cross‐institutional comparisons of zoo facilities, when integrated with behavioral assessments of individual animals, are a valuable tool for investigating potential causes of poor reproduction and well‐being in zoo animals. Zoo Biol 18:35–52, 1999. © 1999 Wiley‐Liss, Inc.     

Will tree euphorbias (Euphorbia tetragona and Euphorbia triangularis) survive under the impact of black rhinoceros (Bicornis diceros minor) browsing in the Great Fish River Reserve,South Africa?

The impact of black rhinoceros (Bicornis diceros minor) on the tree euphorbias Euphorbia tetragona and Euphorbia triangularis was studied in the Great Fish River Reserve, South Africa. Black rhinoceros pushed over about 5–7% of the trees in a 2‐month period. There was a preference of rhinos for smaller trees, however this preference did not guarantee euphorbia survival in the larger size classes. This means that tree euphorbias could very well disappear from all areas accessible to rhinos. Rhino feeding choices were correlated with higher plant moisture content, higher nitrogen content, and a higher digestibility.     

Suppression of important pea diseases by bacterial antagonists

The potential for widespreadand severe infection makes ascochyta blight,seedling blight, and root rots major hindrancesto pea production in Alberta, Canada. Over 300bacterial strains were isolated from pea seedand soil samples taken from pea fields. Thesestrains were investigated for their biologicalcontrol potential against four fungal pathogens(Pythium ultimum, Rhizoctoniasolani, Fusarium avenaceum and Ascochyta pisi) of field pea in vitro. Selected bacterial strains were furtherevaluated in vivo. In an initial agarplate bioassay, 30 strains exhibitedantagonistic properties against the fourpathogens, with inhibition zones ranging from 5to 25 mm. Thirteen of these strains, allisolated from soil, inhibited only one or twoof the pathogens, while the remainingseventeen, including nine strains isolated frompea seeds, inhibited either three or all fourpathogens. In a more stringent bioassay, eightof the thirty strains failed to demonstrate theantagonistic features shown in the initialbioassay. Eight strains inhibited only onepathogen, six inhibited two, four inhibitedthree, and four strains inhibited all fourpathogens tested. Two strains ofPseudomonas fluorescens, five strains of Serratia spp. and two strains of Bacillus spp. were further evaluated ingreenhouse experiments. Five of the isolatesreduced the severity of diseases caused byPythium or Ascochyta, two isolatesreduced the severity of Rhizoctonia andone reduced the severity of Fusarium.     

Molecular phylogeny of the domesticated silkworm,Bombyx mori, based on the sequences of mitochondrialcytochrome b genes

Pupae from the Chinese wild mulberry silkworm,Bombyx mandarina, and 11 representative strains of the domesticated silkworm,Bombyx mori were selected for preparation of mitochondrial DNA. The 5′-end fragments ofcytochrome b genes (Cytb) were generated by polymerase chain reaction products and sequenced directly. The homologous sequences of the JapaneseB. mandarina and three strains ofB. mori were from the GenBank database. The sequences of the 16 silkworm strains were analysed with DNASTAR software and a phylogenic tree was constructed using PHYLIP software. The result showed that: (i) The sequence divergence between the strains ofB. mori and the JapaneseB. mandarina was larger (5.4% ≈ 5.8%) compared with that between strains ofB. mori and the ChineseB. mandarina (0.8% ≈ 1.9%). Analysis of clustering also showed that the sequences ofB. mori strains and ChineseB. mandarina clustered into group (B group), while that of JapaneseB. mandarina (A group) was outside this cluster. This may be evidence for the hypothesis thatB. mori originated from ChineseB. mandarina. (ii) Among 14 strains ofB. mori, sequence divergence was small and the most divergence was seen between strains Yanhe-1 and Chuxiong, whose sequences branched off from those of the otherB. mori strains on the phylogenetic tree. From this and from historical records, we infer that the strains Yanhe-1 and Chuxiong originated independently from southwest China.     

Diverse<Emphasis Type="Italic"> Mesorhizobium plurifarium</Emphasis> populations native to Mexican soils

Forty-six Mesorhizobium strains associated with the leguminous plants Leucaena leucocephala and Sesbania herbacea in an uncultivated Mexican field were characterized using a polyphasic approach. The strains were identified as Mesorhizobium plurifarium based upon the close relationships with the reference strains for this species in PCR-based restriction fragment length polymorphism analyses, sequencing of 16S rRNA genes, multilocus enzyme electrophoresis, and DNA-DNA hybridization. Although the strains isolated from both plants formed the same group in multilocus enzyme electrophoresis and cross-nodulations were observed in the laboratory, different electrophoretic types were obtained from the two plants grown in natural soils, indicating the existence of a preferable association between the plants and the rhizobia. The M. plurifarium strains from Mexico and the reference strains from Africa and Brazil formed different phenotypic clusters in a numerical taxonomy. The Mexican strains did not grow at 37 °C and were sensitive to salty-alkaline conditions, while the reference strains from Africa and Brazil grew at 42 °C and were more resistant to salty-alkaline conditions. These results demonstrate that both the plants and environmental factors affected the evolution of rhizobia and that the Mexican strains had adapted to the neutral soils and the cool climate where they were isolated.     

The Serological Heterogeneity of Pseudomonas syringae pv. atrofaciens Strains and Their Ecological Niches

The paper deals with a comparative analysis of the serological and ecological properties of Pseudomonas syringae pv. atrofaciens strains from the collections of microbial cultures at the Malkov Institute for Plant Genetic Resources and Zabolotny Institute of Microbiology and Virology. All of the strains from the Bulgarian collection, except for one, fall into five serogroups (II through VI) of the classification system of Pastushenko and Simonovich. The P. syringae pv. atrofaciens strains isolated from Bulgarian and Ukrainian wheats belong mainly to serogroups II and IV, respectively. The strains that were isolated from rye plants belong to serogroup I. The strains isolated from sorghum and Sudan grass belong to serogroups II, IV, and VI. Serogroup III includes the P. syringae pv. atrofaciens strains that were isolated from cereals in the United Kingdom but not in Ukraine.     

Formation of biogenic amines as criteria for the selection of wine yeasts

This work deals with biogenic amine production by yeast strains isolated from grapes and wines. A total of 50 strains were tested for their capacity to produce biogenic amines in wine. In general, all the species produced very low or non-detectable amounts of histamine, whereas methylamine and agmatine were formed by all the species considered. The highest concentration of total biogenic amines was formed by Brettanomyces bruxellensis, with an average value of 15 mg/l, followed by Saccharomyces cerevisiae with an average of 12.14 mg/l. The other species formed less than 10 mg of total biogenic amines per litre. Wines fermented with the most fermentative strains of S. cerevisiae species had the highest contents of ethanolamine, from 2.3 to 16 mg/l, and of agmatine, from 3.1 to 7.5 mg/l. The strains of the other species, which exhibited a low fermentative ability, Kloeckera apiculata, B. bruxellensis and Metschnikowia pulcherrima, varied in the production of agmatine and phenylethylamine. A significant variability in the production of cadaverine was characteristic of Candida stellata strains, which varied also in ethanolamine production. Our results emphasize the importance of using selected strains of S. cerevisiae, not only for the expression of desirable technological traits, but also to avoid potentially negative effects on human health. Therefore, the characterization of strains of S. cerevisiae for the 'production of biogenic amines' becomes of applicative interest.     

Ornibactin production and transport properties in strains of Burkholderia vietnamiensis and Burkholderia cepacia (formerly Pseudomonas cepacia)

Several strains of Burkholderia vietnamiensis, isolated from the rhizosphere of rice plants, and four strains formerly known as Pseudomonas cepacia including two collection strains and two clinical isolates were compared for siderophore production and iron uptake. The B. vietnamiensis (TVV strains) as well as the B. cepacia strains (ATCC 25416 and ATCC 17759) and the clinical isolates K132 and LMG 6999 were all found to produce ornibactins under iron starvation. The two ATCC strains of B. cepacia additionally produced the previously described siderophores, pyochelin and cepabactin. Analysis of the ratio of isolated ornibactins (C4, C6 and C8) by HPLC revealed nearly identical profiles. Supplementation of the production medium with ornithine (20 mm) resulted in a 2.5-fold increase in ornibactin synthesis. Ornibactin-mediated iron uptake was independent of the length of the acyl side chain and was observed with all strains of B. vietnamiensis and B. cepacia, but was absent with strains of Pseudomonas aeruginosa, Pseudomonas fluorescens and Pseudomonas stutzeri, known to produce pyoverdines or desferriferrioxamines as siderophores. These results suggest that ornibactin production is a common feature of all Burkholderia strains and that these strains develop an ornibactin-specific iron transport system which is distinct from the pyoverdine-specific transport in Pseudomonas strains.     

Selection of Portuguese Rhizobium leguminosarum bv. trifolii strains for production of legume inoculants

From several native clover species, growing in six different soil types, 170 Rhizobium leguminosarum biovar trifolii strains were isolated, covering the central and southern regions of Portugal. The effectiveness of the strains varied from ineffective to highly effective on T. subterraneum cv. Clare and on T. fragiferum cv. Palestine, with a predominance of medium and high effectiveness on both host plants. The effectiveness was not influenced by provenence (soil or plant), except for the strains from the rankers soils and for the strains isolated from T. pratense, that were ineffective or medium effective on T. subterraneum.Selected strains were evaluated for effectiveness on T. subterraneum cv. Clare, using the commercial strain TA1 as reference. Several of the isolated strains were more effective than TA1, indicating that local strains may be used to produce better inoculants.     

Sexual forms of yeasts in clinical samples

The sexual or teleomorphic state of yeasts has only been described in a few clinically involved species, mainly those of the Saccharomycetaceae family. With the aim of gathering information on their incidence in human pathology, a study has been made of a total of 2,135 strains isolated from clinical samples and cultivated in McClary agar. From these, 8 strains in teleomorphic state were identified: Kluyveromyces marxianus [1], Pichia anomala [2], Pichia farinosa [1], Pichia membranaefaciens [1] and Saccharomyces cerevisiae [3]. The two strains of P. anomala were responsible for fungemia; K. marxianus and the two strains of S. cerevisiae produced vaginitis; the other strains were oral cavity colonizers.     

Rates and consequences of relaying in Cassin's auklets Ptychoramphus aleuticus and rhinoceros auklets Cerorhinca monocerata breeding in a seasonal environment

We removed first eggs from early‐laying females to measure rates and consequences of relaying in Cassin's auklets Ptychoramphus aleuticus and rhinoceros auklets Cerorhinca monocerata at Triangle Island, British Columbia, Canada. Based on egg size and composition, the investment that Cassin's auklets made in first eggs was very close to that predicted from adult body mass, whereas rhinoceros auklets invested more. In both species, a high percentage of females relaid (90% of Cassin's and 87% of rhinoceros auklets). Breeding success declined weakly with later laying among control Cassin's auklet pairs, but pairs that we induced to relay bred more successfully than naturally late pairs, and similar to values predicted from laying dates of their first eggs. Their chicks also fledged heavier and younger than late control chicks, and similar to values in early control chicks, but followed the population‐wide seasonal decline in wing length at fledging. Nestling diets were dominated by Neocalanus copepods until late in the season, a sign that feeding conditions remained favourable until late. In contrast, rhinoceros auklet pairs induced to relay followed the population‐wide seasonal decline in breeding success, which was driven by a decline in hatching success. Pacific sandlance Ammodytes hexapterus, thought to be a preferred prey species, virtually disappeared from nestling diets in mid‐to‐late season, yet there was no seasonal decline in fledging mass. However, chicks from replacement eggs followed the declines among control chicks in both age and wing length at fledging. Despite the female having produced a replacement egg, and despite delayed breeding, there appeared to be little immediate consequence associated with relaying for Cassin's auklets, except for a tendency for their chicks to fledge with short wings. Consequences were more marked in rhinoceros auklets (greatly reduced hatching success, and having their chicks fledge with short wings), and this may have been due to the large investment made in eggs, and/or to delayed breeding. Results of this study show that attributes of Cassin's and rhinoceros auklets that lay at different times in the season can be important in driving seasonal declines in breeding performance, as found in studies on other Alcidae. They also show how decisions taken during the egg stage can have variable yet potentially important implications for fitness, even in relatively long‐lived species that lay single‐egg clutches.     

Grouping of phenol hydroxylase and catechol 2,3-dioxygenase genes among phenol- and p-cresol-degrading Pseudomonas species and biotypes

Phenol- and p-cresol-degrading pseudomonads isolated from phenol-polluted water were analysed by the sequences of a large subunit of multicomponent phenol hydroxylase (LmPH) and catechol 2,3-dioxygenase (C23O), as well as according to the structure of the plasmid-borne pheBA operon encoding catechol 1,2-dioxygenase and single component phenol hydoxylase. Comparison of the carA gene sequences (encodes the small subunit of carbamoylphosphate synthase) between the strains showed species- and biotype-specific phylogenetic grouping. LmPHs and C23Os clustered similarly in P. fluorescens biotype B, whereas in P. mendocina strains strong genetic heterogeneity became evident. P. fluorescens strains from biotypes C and F were shown to possess the pheBA operon, which was also detected in the majority of P. putida biotype B strains which use the ortho pathway for phenol degradation. Six strains forming a separate LmPH cluster were described as the first pseudomonads possessing the Mop type LmPHs. Two strains of this cluster possessed the genes for both single and multicomponent PHs, and two had genetic rearrangements in the pheBA operon leading to the deletion of the pheA gene. Our data suggest that few central routes for the degradation of phenolic compounds may emerge in bacteria as a result of the combination of genetically diverse catabolic genes.     

Evaluation of habitat use and ecological carrying capacity for the reintroduced Eastern black rhinoceros (Diceros bicornis michaeli) in Ruma National Park,Kenya

We carried out a postrelease evaluation to determine predictors of habitat use and carrying capacity for the black rhinoceros (Diceros bicornis michaeli), which are critical for monitoring how the Ruma National Park sub-population may contribute to Kenya's meta-population strategy. We determined whether level of elevation, rockiness, shade, distance to fence, roads, and human settlements predict habitat use, differences in habitat and diet preference between female and male black rhinoceros, and the ecological carrying capacity (CC) of black rhinoceros in the park. We used standard ecological methods to collect data on predictors of habitat use, habitat preference and to estimate CC. Results show, first, that none of the environmental and anthropogenic factors evaluated predicted habitat use by black rhinoceros in the park. Second, although there was no significant difference in habitat preference between the sexes (U = 16.50, p = 0.306), there was a 60% difference in Jaccard's dissimilarity in diet selection between the sexes. Third, the park can support 65 black rhinoceros. Altogether, the findings suggest that the park has potential to support other sub-populations in Kenya. We recommend that future similar studies should incorporate population viability analysis and a community-based approach to forecast the species health and extinction risk.     

块菌(松露)宿主可培养内生菌群落结构与多样性研究

探究四川凉山彝族自治州块菌主产区华山松内生菌群的结构及多样性。在会东县选取4个点(新田乡、新云乡、淌塘镇、雪山乡)的块菌宿主华山松的根、茎、叶为实验材料,通过不同培养基分离样品根、茎、叶的内生细菌、真菌、放线菌,DNA分子鉴定分离菌株的种属,最终分离得到细菌46株,其中欧文氏菌属(Erwinia)5株,沙门氏菌属(Salmonell)1株,杆菌属(Bacillus)22株,葡萄球菌属(Staphylococcus)2株,假单胞菌属(Pseudomonas)2株,类芽胞杆菌属(Paenibacillus)2株,布丘氏菌属(Buttiauxella)2株,肠杆菌属(Enterobacte)3株,爱文氏菌属(Ewingella)1株,泛菌属(Rahnella)1株,拉恩氏菌属(Rahnella Izard)2株,其他属3株;真菌19株,均为子囊菌门(Ascomycota),其中青霉属(Penicillium)4株,疱霉属(Phoma)1株,子囊菌门未知菌1株,篮状菌属(Cladosporium)1株,分枝孢子菌属(Sydowia)1株,曲霉属(Aspergillus)1株,其他属10株;放线菌33株,为链霉菌属(Streptomyces)22株,短小杆菌属(Curtobacterium)2株,短杆菌属(Brevibacterium)1株,其他属8株。研究结果表明,来自不同地点、不同植株部位、不同培养基分离得到的块菌宿主华山松内生菌有差异,证实微生物在土壤、块菌、宿主植物之间有着复杂的相互作用,为块菌的人工栽培提供参考。     

Host plant growth response to inoculation withFrankia

Optimum growth conditions and inoculation regimes were determined for severalFrankia strains isolated from both Alnus and Casuarina host plants. Growth conditions were estabilished that allowed a reduction in generation time to less than 15 hours for certain Alnus derivedFrankia. Differences in plant growth response were observed with differing inoculum levels and soil mixtures. Elite strains of Alnus derivedFrankia were isolated that elicited similar growth reponses in allAlnus species tested; however, differences were observed betweenFrankia strains and plant growth response of variousCasuarina species tested.     

Identification of an arsenic resistance mechanism in rhizobial strains

Arsenic (As) is a very toxic metalloid to a great number of organisms. It is one of the most important global environmental pollutants. To resist the arsenate invasion, some microorganisms have developed or acquired genes that permit the cell to neutralize the toxic effects of arsenic through the exclusion of arsenic from the cells. In this work, two arsenic resistance genes, arsA and arsC, were identified in three strains of Rhizobium isolated from nodules of legumes that grew in contaminated soils with effluents from the chemical and fertilizer industry containing heavy-metals, in the industrial area of Estarreja, Portugal. The arsC gene was identified in strains of Sinorhizobium loti [DQ398936], Rhizobium leguminosarum [DQ398938] and Mesorhizobium loti [DQ398939]. This is the first time that arsenic resistance genes, namely arsC, have been identified in Rhizobium leguminosarum strains. The search for the arsA gene revealed that not all the strains with the arsenate reductase gene had a positive result for ArsA, the ATPase for the arsenite-translocating system. Only in Mesorhizobium loti was the arsA gene amplified [DQ398940]. The presence of an arsenate reductase in these strains and the identification of the arsA gene in Mesorhizobium loti, confirm the presence of an ars operon and consequently arsenate resistance.