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Many terrestrial mammalian migrations are disappearing before they are documented. The Boma-Jonglei ecosystem in South Sudan, one of the world's poorest and most conflicted countries, contains some of the largest, longest, and least studied ungulate migrations. A rapidly increasing human population, ongoing armed conflict, and looming oil development, however, threatens the migration of 800,000 white-eared kob ( Kobus kob leucotis) and 160,000 tiang ( Damaliscus lunatus tiang) in this system. To document these migrations and identify potential conflicts, we examined the movements of ungulates in the Boma-Jonglei ecosystem using data from 14 collared individuals (12 kob, 2 tiang). We identified two separate dry season ranges of kob; from each, kob initiated migration with the onset of the rainy season, and migrated to a shared rainy season range also shared by the tiang. The maximum straight-line distance between telemetry locations of kob (399 km) and tiang (298 km) on their dry and rainy season ranges indicated these migrations were among the longest in Africa. The kob range was 68,805 km, 29% of which was within national parks and 72% within leased oil concessions (54-83% of parks overlap with potential oil concessions). The range of the tiang (35,992 km) occurred almost entirely (> 99%) within land leased to oil companies. Because disruption or elimination of these migrations will inevitably lead to significant population reductions, maintenance of the migration routes we identified through additional protection measures are essential to conserve one of the largest ungulate aggregations in the world. [ABSTRACT FROM AUTHOR]

[Objective] The paper was to provide scientific basis for popularization and application of 70% Thiamethoxam ZF. [Method] 70% Thiamethoxam ZF was selected and applied in the soil for controlling Ceratovacuna lanigera Zehntner and Baliathrips serratus Kobus. [Result] 70% Thiamethoxam ZF had good control effect against C. lanigera and B. serratus. The optimum dosage of 70% Thiamethoxam ZF was 450 g/hm²(effective ingredients 315 g). 70% Thiamethoxam ZF (dosage per hm²) mixed with the regular fertilizer (dosage per hm²) should be applied together in sugarcane planting and management from February to June. The control effects against C. lanigera and B. serratus were above 98.4% and 82.9% respectively. The actual yield and sugar content were increased by more than 34 290 kg/hm² and 6.8% respectively compared to blank control. [Conclusion] 70% Thiamethoxam ZF was a new ideal pesticide with characteristics of sustainedrelease, long-lasting and low-toxic for controlling C. lanigera and B. serratus, and should be applied widely in the sugarcane planting area. [ABSTRACT FROM AUTHOR]

New antelope material from the Tatrot type locality of the Tatrot Formation, Upper Siwaliks, northern Pakistan, allows us to recognize four antelopes, i.e., Antilope intermedia sp. nov. Khan and Akhtar, Antilope subtorta Pilgrim, 1937, Antilope cervicapra (Linnaeus, 1758), and Kobus porrecticornis (Lydekker, 1878). Comparisons with A. cervicapra and A. subtorta suggest that A. intermedia sp. nov. is closely related to the black buck A. cervicapra. The new material from Tatrot confirms the idea that antelopes in the Upper Pliocene Tatrot Formation were rather diverse. [ABSTRACT FROM AUTHOR]

The synthesis and post-synthesis separation of nanoparticles that are polydispersed in size and shape is important due to their variety of applications. In the present study, it is demonstrated that the Magnolia kobus plant extract produces a diverse mixture of extracellular gold and silver nanocrystals with a majority of polydispersed spheres; however, there are a significant number of homogeneously sized triangles, pentagons, and hexagons. The gold and silver nanoparticles synthesized using the M. kobus plant extract can be separated using density gradient centrifugation in the size range of 52 ∼ 117 nm and 38 ∼ 61 nm, respectively. The average particle sizes increase with increases in the sucrose concentration of each layer. Relatively larger but long, thin plates of gold nanoparticles appear in the higher density sediments, whereas a larger proportion of smaller spheres featured in the lower density gradients. Similarly, silver nanospheres of different sizes are separated at different density gradients with smaller proportions of plates. [ABSTRACT FROM AUTHOR]

In group-forming prey species, theory assumes that individuals within groups should scan independently of one another, with vigilance sequences being relatively unpredictable, making interscan durations highly variable. We attempted to detect any divergence from randomness in the scanning process in three mammalian prey species phylogenetically and geographically separated and exposed to different levels of predation: waterbuck, Kobus ellipsiprymnus defassa, under a high observed predation risk, eastern grey kangaroo, Macropus giganteus, still experiencing occasional predation and European roe deer, Capreolus capreolus, under a very low natural predation risk. Our results revealed that the focal interscan duration increased when the duration of the preceding interscan increased, whatever the studied species and the predation risk that its individuals experienced, and decreased with the preceding scan duration in two species under, respectively, occasional and low predation risks. The exponential distribution was the tested model that fitted the observed distributions of interscan durations least well. We discuss what can trigger non-randomness in scanning, through a non-homogenous Poisson process, at both intra-individual and inter-individual levels, particularly with regard to previous studies that have demonstrated synchronisation of vigilance in such mammals. Our results suggest the need to reconsider any assumption of randomness in scanning in the basic model predicting form and frequency of scanning behaviour by prey species. [ABSTRACT FROM AUTHOR]

Reproductive effort should negatively correlate with reproductive value, yielding a pattern of increased effort with age. According to the terminal investment hypothesis, females near the end of their reproductive life span should devote more resources to reproduction than those near the start of their reproductive careers. We tested predictions of the terminal investment hypothesis by evaluating 38 years of reproductive life-history data collected from Nile lechwe (Kobus megaceros), an ungulate species living at San Diego Zoo's Wild Animal Park. The maximum reproductive success of Nile lechwe matched predictions of models of lifetime reproductive effort, with the relative mass of newborn calves providing an accurate indicator of the costs of reproduction. Newborn mass was significantly correlated with maternal age, and neonatal males tended to be heavier than neonatal females. Older dams were more likely to produce sons than daughters, dams that produced sons were more likely to die than were dams that produced daughters, and male calves were less likely to survive than were female calves. We conclude that young females endure a fertility cost while breeding, whereas older females encounter a survivorship cost, associated with progeny production. Our findings support the terminal investment hypothesis, and we suggest that secondary sex ratio bias among older female Nile lechwe reflects the evolution of a flexible life-history strategy promoting production of costly male calves when reproductive value is declining. [ABSTRACT FROM AUTHOR]

The article offers information on the research conducted on the intra-tooth enamel stable isotopes of waterbuck Kobus ellipsiprymnus at the Queen Elizabeth National Park (QENP) in Uganda. Researchers found that waterbuck Kobus ellipsiprymnus (K. e.), comprise two genetically distinct subspecies K. e. ellipsiprymnus and K. e. defassa, which are known to be predominantly grazers, which browse in their diet, especially during the dry season when grasses become higher in structural components and lower in protein. Carbon isotope ratio data confirm that defassa waterbuck in the QENP consume mainly C4 grass but include some C3 browse in its diets.

Mitochondrial DNA control region sequences and seven microsatellites were used to estimate the genetic structuring, evolutionary history and historic migration patterns of the kob antelope ( Kobus kob). Ten populations were analysed, representing the three recognized K. kob subspecies: K. k. kob in west Africa, K. k. thomasi in Uganda and K. k. leucotis in Sudan and Ethiopia. Despite being classified as K. k. thomasi and being phenotypically identical to the kob in Queen Elizabeth National Park (NP), the Murchison Falls population in Uganda showed high genetic similarity with the phenotypically distinct K. k. leucotis populations in Sudan and Ethiopia. This was regardless of marker type. Pairwise comparisons and genetic distances between populations grouped Murchison with K. k. leucotis, as did the Bayesian analysis, which failed to find any genetic structuring within the group. We propose that the divergent phenotype and life-history adaptations of K. k. leucotis reflect the isolation of kob populations in refugia in west and east Africa during the Pleistocene. Subsequent dispersal has led to secondary contact and hybridization in northern Uganda between lineages, which was supported by high levels of genetic diversity in Murchison. The reduced variability observed in Queen Elizabeth NP reflects a small founder population from west Africa and in part the decimation of Uganda's wildlife during the country's political turmoil in the 1970s. Due to similarities in phenotype and ecology, and the joint evolutionary history of their mtDNA sequences, the taxonomic status of K. k. kob and K. k. thomasi as separate subspecies is called into question. [ABSTRACT FROM AUTHOR]

Focuses on populations of puku antelope Kobus vardoni scattered throughout eastern and central Africa. Percentage of the total population that is restricted to the Kilombero Valley, Tanzania; View that the Kilombero Valley is an area rich in agricultural potential and natural resources; How wildlife populations are high and the inner valley is a game controlled area, although this only provides limited protection; Results of aerial surveys during the 1989, 1994 and 1998 dry seasons regarding puku population; Where signs of human activity were highest, indicating intense pressure on `boundary-zone? habitats at the floodplain-woodland interface; How puku use `boundary-zone? habitats during the wet season when large areas of grassland are flooded; Potential threats to the puku population; Impact of licensed trophy hunting on puku; How illegal hunting represents a serious threat near human settlements during the wet season and in accessible parts of the floodplain during the dry season.

The genetic differentiation among kob populations (Kobus kob) representing two recognized subspecies was examined using mitochondrial control region sequences. Two distinct lineages (estimated sequence divergence of 9.8%) exhibited different geographical distributions and do not coincide with previously recognized ranges of subspecies. The presence of the two lineages was further supported with sequences of mitochondrial cytochrome b gene. One lineage was predominant in the west and southern ranges of the populations studied and the other was commonly found in a more northern distribution (Murchison populations) in Uganda. Murchison and the geographically intermediate Toro populations (Uganda) represented the area of overlap. The existence of the two lineages in the area of overlap is hypothesized to have resulted from a range expansion and secondary contact of the two lineages of kob that evolved in allopatry. The existence of the kob during the Pleistocene offers a plausible explanation for the observed biogeographic pattern. Our mitochondrial data reveal two examples of discordance between a gene tree and presumed species tree as: (i) the two lineages co-occur in the kob subspecies, Kobus kob thomasi (Uganda kob); and (ii) the puku, which was included in the analysis because of its controversial taxonomic status (currently recognized as a distinct species from the kob), is paraphyletic with respect to the kob. Significant degrees of heterogeneity were detected between populations. Relatively high genetic variation was observed in the populations, however, the inclusion of distinct lineages influences the population structure and nucleotide diversity of the kob populations. [ABSTRACT FROM AUTHOR]

G- and C-banded karyotypes of four species of the genus Kobus were compared using the standard karyotype of Bos taurus . Chromosomal complements were 2n = 50–54 in K. ellipsiprymnus , 2n = 50 in K. kob , 2n = 48 in K. leche , and 2n = 52 in K. megaceros . The number of autosomal arms in all karyotypes was 58. Fifteen autosomal pairs were conserved among these four species, including the 1;19 and 2;25 centric fusions, and autosomal differences involved eight centric fusion rearrangements. Five centric fusions were each unique to a particular taxon: 3;10 (K. leche ), 3;11 and 6;29 (K. kob ), and 5;17 and 7;11 (K. ellipsiprymnus ). The 4;7 fusion occurred in K. leche and K. megaceros , whereas the 5;13 fusion occurred in K. kob and K. leche ; the 6;18 fusion was found in three species but was absent in K. kob . Differences between the X chromosomes of the four Kobus species were attributed to heterochromatic additions or deletions, and Y-chromosome differences may have been the result of pericentric inversion. G-banded karyotypes of putative K. l. leche and K. l. kafuensis appeared identical, as did C-banded karyotypes of the two subspecies. Karyotypes of K. e. ellipsiprymnus and K. e. defassa differed as a result of the 6;18 centric fusion, which was polymorphic in K. e. defassa , and the 7;11 centric fusion, which was polymorphic in K. e. ellipsiprymnus but absent in K. e. defassa . Several centric fusions were related by monobrachial chain-IV complexes; however, records of hybridization indicate that reproductive isolation between at least certain species of Kobus is incomplete. Karyotypic differences between K. ellipsiprymnus (including K. e. ellipsiprymnus and K. e. defassa ), K. kob , K. leche , and K. megaceros support the validity of these taxa, as well as the need to manage them as separate populations. Copyright © 2001 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Although it is commonly presumed that many populations of large-herbivores are limited by food availability, supporting evidence is scarce. This hypothesis was investigated in a population of over 800,000 white-eared kob in the Boma National Park region of the southern Sudan. Food availability, body condition, and mortality rates of adults and calves were measured during the dry seasons of 1982 and 1983. Sampled age distributions from both the live population and carcasses were used to calculate age-specific rates of mortality. In 1982, food supplies during the dry season were augmented by substantial rainfall, which produced regrowth of grass in areas that ordinarily had little green forage. As a result, fat reserves declined little, and rates of adult mortality showed no increasing trend. Total adult mortality was 5%. In 1983, there was no rainfall during the dry season and food intake was insufficient to meet the estimated energy requirements of kob. As a result, fat reserves declined and adult mortality rates increased fourfold. Total adult mortality was 10% (equivalent to the recruitment rate of yearling into the population). Calf mortality during the dry season was similar in both years (50%), based on field estimates of mortality rates and calf/female ratios. Lactation throughout the dry season possibly provided a buffer for calves against variations in food availability. The age structure of the live population in 1983 suggests that a drought in 1980 reduced kob numbers by 40%. These results suggest that adult survival is influenced strongly by the availability of food during the dry season. However, the duration of the dry season also plays an important role. During the dry season, declining fat reserves make an increasing proportion of the population vulnerable to mortality. As a result, even moderate droughts may lead to substantial changes in population numbers. [ABSTRACT FROM AUTHOR]

In Lake Nakuru National Park, Kenya, some territorial male waterbuck tolerate an additional adult male on the territory, which shares in the defence of the territory and has a higher chance than an outsider to become a territory owner. [ABSTRACT FROM AUTHOR]

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