Diversity and evolutionary patterns of immune genes in free-ranging Namibian leopards (Panthera pardus pardus)

The genes of the major histocompatibility complex (MHC) are a key component of the mammalian immune system and have become important molecular markers for fitness-related genetic variation in wildlife populations. Currently, no information about the MHC sequence variation and constitution in African leopards exists. In this study, we isolated and characterized genetic variation at the adaptively most important region of MHC class I and MHC class II-DRB genes in 25 free-ranging African leopards from Namibia and investigated the mechanisms that generate and maintain MHC polymorphism in the species. Using single-stranded conformation polymorphism analysis and direct sequencing, we detected 6 MHC class I and 6 MHC class II-DRB sequences, which likely correspond to at least 3 MHC class I and 3 MHC class II-DRB loci. Amino acid sequence variation in both MHC classes was higher or similar in comparison to other reported felids. We found signatures of positive selection shaping the diversity of MHC class I and MHC class II-DRB loci during the evolutionary history of the species. A comparison of MHC class I and MHC class II-DRB sequences of the leopard to those of other felids revealed a trans-species mode of evolution. In addition, the evolutionary relationships of MHC class II-DRB sequences between African and Asian leopard subspecies are discussed.     

Spatial ecology of cheetahs on north-central Namibian farmlands

Knowledge of a species' ranging behaviour is both fundamental to understanding its behavioural ecology and a prerequisite to planning its management. Few data exist on the spatial ecology of cheetahs Acinonyx jubatus outside protected areas, but such areas are particularly important to their conservation. Cheetahs on Namibian farmlands occupied exceptionally large home ranges, averaging 1651 km² (±1594 km²), with no detectable effect of sex, social grouping or seasonality. Despite such large ranges, cheetahs tended to utilize intensively only a small fraction of that area: 50% of the fixes were located within an average of 13.9±5.3% of the home range. Ranges were not exclusive, overlapping on average by 15.8±17.0%, with male cheetahs showing more intra-sexual range overlap than did females. Coalitions of males appeared to select for a dense, prey-rich habitat, but this preference was not apparent for other social groupings. Conflict with humans is an important contributor to the species' decline, and these large, overlapping cheetah home ranges result in the movements of each individual cheetah encompassing many farms (21 based on the average home-range size). Consequently, many cheetahs may be exposed to a minority of farmers attempting to kill them, and also that many farmers may see the same cheetahs, thereby gaining an exaggerated impression of their abundance. Conservation priorities for cheetahs outside protected areas are the development of techniques for conflict resolution, as well as the maintenance and restoration of suitable habitat and promotion of land-management practices compatible with the continued existence of large carnivores.     

Genetic variation in Sri Lankan leopards

Electrophoretic variation of 50 gene-enzyme systems was typed in a population of 33 captive leopards (Panthera pardus) from the island of Sri Lanka. The captive leopard population was composed of several lineages: (1) wild-caught leopards of the island subspecies (P. p. kotiya), (2) captive-born animals of the same subspecies, (3) a melanistic lineage whose founders were obtained from Malaysia (P. p. delacouri), and (4) leopards of known mixed lineage and unknown status. Two loci, APRT and PGD, were polymorphic in all samples, whereas 48 loci were invariant. Percent polymorphism (P) and percent average heterozygosity (H) were calculated as 4% and 1.4%, respectively, for the wild-caught leopards; 4% and 1.2% for the captive-born kotiya leopards; and 4% and 2.0% for the melanistic lineage. The overall results revealed a detectable decrease in genetic variability compared with a previous study of captive leopards from mainland origins. The mainland leopards had three additional polymorphic loci, ADA, ESI, and HBB. Reexamination of the TF locus using a revised protocol resolved a new allele in the sample of mainland leopards but not in the Sri Lankan sample. With this new polymorphism, recalculated P and H values for the mainland sample are 10% and 3.1%, respectively. No significant differences in polymorphic loci were observed between the leopard subspecies examined.     

The species diversity, distributionand conservation of Namibian mammals

Namibia's extant mammal fauna of 250 species represents about 75% of the southern African region's species richness, 83% of generic richness and 98% of familial richness. Fourteen species are presently recognized as endemic (75% or more of the global population occurring within Namibian borders). These endemics occur in the Namib Desert, pro-Namib transition zone and adjoining escarpment, and are primarily rupicolous. The Namibian endemic mammal fauna is characterized by the monotypic Petromuridae, and the rodent genera Gerbillurus and Petromyscus. The distribution of smaller species has probably not changed significantly over the past 200 years, but species such as lion and plain zebra have undergone range reductions of 95% or more, and five species are listed as recently extinct. Approximately 50% of all Namibian mammal species are provisionally listed as 'secure'. However, due to patchy data, 94 species (38%) are classified as under possible or probable threat. Nineteen species (8%) are classified as under definite threat. Over 13% of Namibia is set aside by the state for conservation purposes. Ninety-five percent of mammal species occur in at least one park, over 80% occur in three or more parks, and 59 species (28%) occur in ten or more parks, although for most species nothing is known of their population viability there. Major threats to mammals in Namibia are invasive aliens, including the risk of genetic pollution, and habitat alteration, especially wetland degradation.     

Hunting behaviour in West African forest leopards

The leopard (Panthera pardus) is a major predator of mammals within the rainforest ecosystem of West Africa. Most of the available information on leopard hunting behaviour comes from studies conducted in open savannah habitats, while little is known about forest leopards. Our radio‐tracking data and scat analysis show that forest leopards differ in various ways from the savannah populations. Forest leopards are diurnal and crepuscular hunters who follow the activity pattern of their prey species. They exhibit seasonal differences in activity patterns, and they develop highly individualized prey preferences. These findings challenge the widespread notion of leopards as opportunistic nocturnal predators.     

Molecular evidence for species-level distinctions in clouded leopards

Among the 37 living species of Felidae, the clouded leopard (Neofelis nebulosa) is generally classified as a monotypic genus basal to the Panthera lineage of great cats. This secretive, mid-sized (16-23 kg) carnivore, now severely endangered, is traditionally subdivided into four southeast Asian subspecies (Figure 1A). We used molecular genetic methods to re-evaluate subspecies partitions and to quantify patterns of population genetic variation among 109 clouded leopards of known geographic origin (Figure 1A, Tables S1 ans S2 in the Supplemental Data available online). We found strong phylogeographic monophyly and large genetic distances between N. n. nebulosa (mainland) and N. n. diardi (Borneo; n = 3 individuals) with mtDNA (771 bp), nuclear DNA (3100 bp), and 51 microsatellite loci. Thirty-six fixed mitochondrial and nuclear nucleotide differences and 20 microsatellite loci with nonoverlapping allele-size ranges distinguished N. n. nebulosa from N. n. diardi. Along with fixed subspecies-specific chromosomal differences, this degree of differentiation is equivalent to, or greater than, comparable measures among five recognized Panthera species (lion, tiger, leopard, jaguar, and snow leopard). These distinctions increase the urgency of clouded leopard conservation efforts, and if affirmed by morphological analysis and wider sampling of N. n. diardi in Borneo and Sumatra, would support reclassification of N. n. diardi as a new species (Neofelis diardi).     

Field age determination of leopards by tooth wear

Age determination is an important tool in wildlife studies. Estimating the age of animals in the field using tooth wear criteria may be subject to error as a result of variations between individuals, habitats and populations. Data on age estimation of leopards and tooth wear characteristics are lacking. Nineteen leopards in Namibia were assessed for tooth eruption and wear. Between 1991 and 1995 leopards (including 13 individuals of known age) were monitored at one year intervals ('28 leopard years') to record age and tooth wear. At the age of two years leopards had fully developed dentition. Wear started with the incisors and canines, and spread to the premolars and molars. A chronology of tooth eruption and wear in relation to age is presented. Above the age of three years, male leopards showed higher frequencies of enamel flaking and canine fractures than females.     

The ecology of

Dactylanthus taylorii, a root parasite in the family Balanophoraceae, is New Zealand's only fully parasitic flowering plant. It grows attached to the roots of a wide range of hardwood trees and shrubs, often in fire-induced secondary forest on the margin of podocarp-hardwood forest. It is inconstantly dioecious with a skewed sex ratio of approximately 5:1 male to female inflorescences. The inflorescences, especially the males, contain a large quantity of nectar, up to 1.6 mi, and can produce 0.5 mi per day for 10 days. The morphology of the inflorescences, the quantity and chemistry of the nectar, time-lapse video monitoring and other evidence suggest that the Dactylanthus flowers are adapted for pollination by short-tailed bats. Ship rats are also effective pollinators but occasionally destroy the inflorescences. Kiore completely destroyed all the inflorescences observed on Little Barrier Island in 1992 and 1993, although some seed was found there in 1991. Dactylanthus plants have been successfully cultivated by sowing seeds close to the roots of broadleaf plants. Germination was very slow with the highest rates occurring nearly five years after the seed was sown. Further research is needed to clarify the role of fungal hyphae found inside the cells of a young plant and that of the sheath processes which may assist vegetative reproduction. Video monitoring provided evidence that the introduced possum, by browsing the inflorescences, threatens the survival of Dactylanthus at most North Island sites. Where possums were present, and the plants unprotected, almost all the inflorescences were browsed. Adult plants at the main study site had a half-life of only 8.5 years. Conservation management to ensure the survival of Dactylanthus will require protection of the plants from possums, rats and humans and adequate areas of secondary forest containing abundant host plants.     

Nitrite oxidation in the Namibian oxygen minimum zone

Nitrite oxidation is the second step of nitrification. It is the primary source of oceanic nitrate, the predominant form of bioavailable nitrogen in the ocean. Despite its obvious importance, nitrite oxidation has rarely been investigated in marine settings. We determined nitrite oxidation rates directly in ¹⁵N-incubation experiments and compared the rates with those of nitrate reduction to nitrite, ammonia oxidation, anammox, denitrification, as well as dissimilatory nitrate/nitrite reduction to ammonium in the Namibian oxygen minimum zone (OMZ). Nitrite oxidation (⩽372 nM NO₂⁻ d⁻¹) was detected throughout the OMZ even when in situ oxygen concentrations were low to non-detectable. Nitrite oxidation rates often exceeded ammonia oxidation rates, whereas nitrate reduction served as an alternative and significant source of nitrite. Nitrite oxidation and anammox co-occurred in these oxygen-deficient waters, suggesting that nitrite-oxidizing bacteria (NOB) likely compete with anammox bacteria for nitrite when substrate availability became low. Among all of the known NOB genera targeted via catalyzed reporter deposition fluorescence in situ hybridization, only Nitrospina and Nitrococcus were detectable in the Namibian OMZ samples investigated. These NOB were abundant throughout the OMZ and contributed up to ∼9% of total microbial community. Our combined results reveal that a considerable fraction of the recently recycled nitrogen or reduced NO₃⁻ was re-oxidized back to NO₃⁻ via nitrite oxidation, instead of being lost from the system through the anammox or denitrification pathways.     

Personality assessment in snow leopards (Uncia uncia)

Knowledge of individual personality is a useful tool in animal husbandry and can be used effectively to improve welfare. This study assessed personality in snow leopards (Uncia uncia) by examining their reactions to six novel objects and comparing them to personality assessments based on a survey completed by zookeepers. The objectives were to determine whether these methods could detect differences in personality, including age and sex differences, and to assess whether the two methods yielded comparable results. Both keeper assessments and novel object tests identified age, sex, and individual differences in snow leopards. Five dimensions of personality were found based on keepers' ratings: Active/Vigilant, Curious/Playful, Calm/Self-Assured, Timid/Anxious, and Friendly to Humans. The dimension Active/Vigilant was significantly positively correlated with the number of visits to the object, time spent locomoting, and time spent in exploratory behaviors. Curious/Playful was significantly positively correlated with the number of visits to the object, time spent locomoting, and time spent in exploratory behaviors. However, other dimensions (Calm/Self-Assured, Friendly to Humans, and Timid/Anxious) did not correlate with novel-object test variables and possible explanations for this are discussed. Thus, some of the traits and behaviors were correlated between assessment methods, showing the novel-object test to be useful in assessing an animal's personality should a keeper be unable to, or to support a keeper's assessment.     

Applicability of age-based hunting regulations for African leopards

In species in which juvenile survival depends strongly on male tenure, excessive trophy hunting can artificially elevate male turnover and increase infanticide, potentially to unsustainable levels. Simulation models show that the likelihood of safe harvests can be improved by restricting offtakes to males old enough to have reared their first cohort of offspring to independence; in the case of African leopards, males were ≥7 years old. Here, we explore the applicability of an age-based approach for regulating trophy hunting of leopards. We conducted a structured survey comprising photographs of known-age leopards to assess the ability of wildlife practitioners to sex and age leopards. We also evaluated the utility of four phenotypic traits for use by trophy hunters to age male leopards in the field. Our logistic regression models showed that male leopard age affected the likelihood of survey respondents identifying the correct sex; notably, males <2 years were typically misidentified as females, while mature males (≥4 years) were sexed correctly. Mature male leopards were also more likely to be aged correctly, as were portrait photographs. Aging proficiency was also influenced by the profession of respondents, with hunters recording the lowest scores. A discriminant model including dewlap size, the condition of the ears, and the extent of facial scarring accurately discriminated among male leopard age classes. Model classification rates were considerably higher than the respective scores attained by survey respondents, implying that the aging ability of hunters could theoretically improve with appropriate training. Dewlap size was a particularly reliable indicator of males ≥7 years and a review of online trophy galleries suggested its wider utility as an aging criterion. Our study demonstrated that an age-based hunting approach is practically applicable for leopards. However, implementation would require major reform within the regulatory framework and the hunting industry.     

亚洲同域分布虎和豹竞争与共存关系概述

虎(Panthera tigris)和豹(P. pardus)作为食物链的顶级捕食者对维持生态系统结构与功能稳定性起到重要作用。强烈的人为干扰已导致亚洲虎和豹种群(以下简称虎豹)分布呈现破碎化状态, 探究二者之间的相互作用对缓解人类威胁和濒危物种保护具有重要意义。尽管虎豹竞争和共存研究已持续几十年, 但多局限于区域性种群, 缺乏系统性研究。本研究梳理了1976-2021年间36篇涉及虎豹竞争性相互作用研究的文献, 涵盖中国、俄罗斯、泰国、马来西亚、印度、尼泊尔、不丹共7个国家26个区域, 系统阐述了虎豹目前在亚洲的主要分布以及它们之间的干涉型和资源利用型竞争的主要表现形式, 并分析了猎物与干扰因素对虎豹竞争与共存的影响。本研究提出了5个可能影响种间作用的猎物构成情况, 强调了不同大小有蹄类猎物的丰富度和多度以及人为干扰的空间分布对虎豹区域竞争和共存的调控作用。现有研究显示虎豹的空间利用取决于本地的生境、猎物和干扰等因素。豹相对于虎具有更强的行为可塑性, 虎豹之间在空间、时间和营养生态位等维度权衡生态机会(如容易捕获的猎物)与冲突风险(人或竞争者带来的风险)来促进共存。目前虎豹相互作用研究存在严重的亚种和区域不平衡性, 未来研究重点应关注各种生物和非生物类因素对虎豹种间竞争类型和作用强度的调控方式以及调控的生态阈值效应。     

The role of Namibian inselbergs in contributing to local and regional plant species richness

This study investigated four inselberg landscapes in Namibia's aridNama Karoo. Inselbergs of different size and geology were investigated (a) todetermine environmental variables influencing the number of inselberg restrictedplant species and (b) to investigate seed dispersal spectra as one parameterdescribing functional properties of inselberg specialists. With regard to therole of inselbergs in contributing to local and regional species richness, manyspecies restricted to inselberg habitats occurred (up to 79 species recorded inthis survey) and so contribute to local and regional species richness. As nospecies endemic to an inselberg were recorded in this study, inselbergspecialists may provide an indicator for conservation value of these mountains.Elevation rather than surface area provided a measure for predicting the numberof inselberg specialists. Besides elevation, underlying geology, and resultinglandforms and edaphic conditions, as well as distance to potential mainland alsoinfluenced the number of inselberg specialists. Functional relationships betweeninselbergs based on seed dispersal spectra of inselberg specialists were notconclusive.     

Impact of leopards on a working ranch in Laikipia,Kenya

This study of leopard predation on livestock was carried out on the Lolldaiga Hills ranch (200 km²) in the Laikipia District in Kenya between September 1989 and August 1995. The aims of the study were to find out whether leopards depend on livestock as a food resource on the ranch, and to quantify the economic impact of leopards on the livestock production systems. The density of leopards was estimated in three ways, and the biomass density of potential prey for leopards, both wild and domestic. Diet analysis of leopards revealed that leopards are not relying on livestock as an important food resource. To quantify the effects of leopards, an approach used in the economic assessment of agricultural development schemes was adopted ( Gittinger, 1982 ) and models were derived by following those criteria. It was found that leopards, not being persecuted, live at a relatively high density on the ranch but have less of an adverse impact on livestock than might be expected. Wildlife as a food resource for leopards and a buffer against the killing of livestock could be of benefit on a working ranch to reduce the economic impact of predators on the production system.