Publications

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distinguishing extant elephants ivory from mammoth ivory using a short sequence of cytochrome b gene.trade in ivory from extant elephant species namely asian elephant (elephas maximus), african savanna elephant (loxodonta africana) and african forest elephant (loxodonta cyclotis) is regulated internationally, while the trade in ivory from extinct species of elephantidae, including woolly mammoth, is unregulated. this distinction creates opportunity for laundering and trading elephant ivory as mammoth ivory. the existing morphological and molecular genetics methods do not reliably distinguish th ...201931827140
individual and environmental risk factors associated with fecal glucocorticoid metabolite concentrations in zoo-housed asian and african elephants.a recent large-scale welfare study in north america involving 106 asian (elephas maximus) and 131 african (loxodonta africana) elephants at 64 accredited facilities identified links (i.e., risk factors) between zoo environmental factors and a number of welfare outcomes (stereotypic behavior, ovarian acyclicity, hyperprolactinemia, walking and recumbence, body condition, health status, serum cortisol). for this population of elephants, we used the same epidemiological methods to examine associati ...201931483790
update on comparative biology of elephants: factors affecting reproduction, health and welfare.asian (elephas maximus) and african (loxodonta africana) elephants serve as important keystone, umbrella and flagship species. despite that, population numbers are declining, due mainly to poaching and habitat destruction. understanding reproductive mechanisms is vital to effective management, particularly insurance populations in captivity, and to that end, long-term biological databases are key to understanding how intrinsic and extrinsic factors affect reproductive function at individual and ...201931471800
elequant: a developmental framework and validation of forensic and conservation real-time pcr assays.a framework for the development and validation of a qpcr assay for species identification and dna quantification for conservation and forensic purposes is presented. elephants are commonly poached for their ivory tusks, which is the primary driving force behind their endangered status. in addition to poaching and trade, habitat loss due to logging and mining has also resulted in loss of elephants. crimes against animals can be deterred and/or further prosecution sought through testing with foren ...201930721419
fatal tuberculosis in a free-ranging african elephant and one health implications of human pathogens in wildlife.tuberculosis (tb) in humans is a global public health concern and the discovery of animal cases of mycobacterium tuberculosis (mtb) infection and disease, especially in multi-host settings, also has significant implications for public health, veterinary disease control, and conservation endeavors. this paper describes a fatal case of mtb disease in a free-ranging african elephant (loxodonta africana) in a high human tb burden region. necropsy revealed extensive granulomatous pneumonia, from whic ...201930788347
ixodid ticks (acari: ixodidae) collected from african savanna elephants (loxodonta africana) and african forest elephants (loxodonta cyclotis).eight ixodid tick species were collected from 173 african savanna elephants (loxodonta africana) in kenya, northern mozambique and zimbabwe, and two species were collected from six african forest elephants (loxodonta cyclotis) in the republic of congo. a new host record is reported for amblyomma eburneum. a list of ticks collected from elephants in various african countries, and stored in the united states national tick collection, is supplied as well as an annotated checklist of the 27 ixodid t ...201931714141
mammoth ivory was the most suitable osseous raw material for the production of late pleistocene big game projectile points.late pleistocene societies throughout the northern hemisphere used mammoth and mastodon ivory not only for art and adornment, but also for tools, in particular projectile points. a comparative analysis of the mechanical properties of tusk dentine from woolly mammoth (mammuthus primigenius) and african elephant (loxodonta africana) reveals similar longitudinal stiffness values that are comparable to those of cervid antler compacta. the longitudinal bending strength and work of fracture of probosc ...201930783179
researching immunocontraceptive vaccines with mares (equus caballus) as both a target and model for african elephant (loxodonta africana) cows: a review.a sequence of studies is reviewed that reported the domestic horse (equus caballus) mare as an appropriate and accessible research platform for recording clinical and laboratory data post-immunisation with anti- gnrh and -zona pellucida (zp) immunocontraceptive vaccines. experience with a native porcine zp (pzp) vaccine in african elephant (loxodonta africana) cows highlighted needs for improving vaccine formulations and more clearly defining associated ovarian effects and safety profiles. initi ...201931208844
terrestrial mammalian wildlife responses to unmanned aerial systems approaches.unmanned aerial systems (uas) are increasingly being used recreationally, commercially and for wildlife research, but very few studies have quantified terrestrial mammalian reactions to uas approaches. we used two vertical take-off and landing (vtol) uas to approach seven herbivore species in the moremi game reserve, botswana, after securing the relevant permissions. we recorded responses to 103 vertical and 120 horizontal approaches, the latter from three altitudes above ground level (agl). we ...201930765800
evidence of a growing elephant poaching problem in botswana.botswana holds roughly one-third of africa's remaining savannah elephants (loxodonta africana) [1, 2] and will play a key role in the future conservation of this species. to date, botswana has been one of the safest countries for elephants, with little poaching reported [3]. here, we present evidence of a new outbreak of elephant poaching for ivory in northern botswana. comparing results from 2014 and 2018 aerial surveys, we found that elephant populations were stable, but numbers of elephant ca ...201931204160
conservation genetic assessment of savannah elephants (loxodonta africana) in the greater kruger biosphere, south africa.savannah elephant populations have been severely reduced and fragmented throughout its remaining range. in general, however, there is limited information regarding their genetic status, which is essential knowledge for conservation. we investigated patterns of genetic variation in savannah elephants from the greater kruger biosphere, with a focus on those in previously unstudied nature reserves adjacent to kruger national park, using dung samples from 294 individuals and 18 microsatellites. the ...201931590388
"keep your feet on the ground": simulated range of motion and hind foot posture of the middle jurassic sauropod rhoetosaurus brownei and its implications for sauropod biology.the biomechanics of the sauropod dinosaur pes is poorly understood, particularly among the earliest members of the group. to date, reasonably complete and articulated pedes in early middle jurassic sauropods are rare, limited to a handful of taxa. of these, rhoetosaurus brownei, from eastern australia, is currently the only one from the gondwanan middle jurassic that preserves an articulated pes. using rhoetosaurus brownei as a case exemplar, we assessed its paleobiomechanical capabilities and p ...201930964205
do topography and fruit presence influence occurrence and intensity of crop-raiding by forest elephants (loxodonta africana cyclotis)?crop damage by forest elephants (loxodonta africana cyclotis) and the resulting human-elephant conflict are issues of great concern for both the conservation of the species and the protection of rural livelihoods in central africa. addressing these problems requires identifying the factors that facilitate or impede crop-raiding by forest elephants. yet to date, the environmental or anthropogenic factors that influence the occurrence and intensity of crop-raiding by forest elephants are largely u ...201930901366
determinants of elephant foraging behaviour in a coupled human-natural system: is brown the new green?crop raiding by wildlife poses major threats to both wildlife conservation and human well-being in agroecosystems worldwide. these threats are particularly acute in many parts of africa, where crop raiders include globally threatened megafauna such as elephants, and where smallholder agriculture is a primary source of human livelihood. one framework for understanding herbivore feeding behaviour, the forage-maturation hypothesis, predicts that herbivores should align their movements with intermed ...201930825191
seroprevalence of mycobacterium tuberculosis complex in free-ranging african elephants (loxodonta africana) in kruger national park, south africa.tuberculosis (tb) is a pathogenic disease that affects a range of wildlife species, including african elephants (loxodonta africana). the recent discovery of fatal disease caused by infection with mycobacterium tuberculosis in a bull elephant in the kruger national park (knp), which is a bovine tb endemic area, emphasizes the importance this disease could have on both wild and captive elephant populations globally. elephants with culture-confirmed tb have previously been shown to produce strong ...201931166850
mining morphometrics and age from past survey photographs.researchers often document wildlife surveys using images. these images contain data that can be used to understand alterative research objectives, even years after they were originally captured. we have developed a method to measure age and morphology (body size measurements and tusk size) from survey image databases and future surveys, without the availability of a known subject distance or a scale in each image. african savanna elephants (loxodonta africana) serve as an ideal model species to ...201931114625
african savanna elephants (loxodonta africana) as an example of a herbivore making movement choices based on nutritional needs.the increasing human population and global intensification of agriculture have had a major impact on the world's natural ecosystems and caused devastating effects on populations of mega-herbivores such as the african savanna elephants, through habitat reduction and fragmentation and increased human-animal conflict. animals with vast home ranges are forced into increasingly smaller geographical areas, often restricted by fencing or encroaching anthropogenic activities, resulting in huge pressures ...201930723615
african elephant genetics: enigmas and anomalies.during the last two decades, our understanding of the genetics of african elephant populations has greatly increased. strong evidence, both morphological and genetic, supports recognition of two african elephant species: the savanna elephant (loxodonta africana) and the forest elephant (l. cyclotis). among elephantids, phylogeographic patterns for mitochondrial dna are highly incongruent with those detected using nuclear dna markers, and this incongruence is almost certainly due to strongly male ...201931544772
bilateral phacoemulsification in an african elephant (loxodonta africana).a 37-year-old bull african elephant (loxodonta africana) at the north carolina zoo (ncz) was diagnosed with bilateral cataracts leading to behavioral changes and significant weight loss secondary to functional blindness. on initial examination, a weight loss of 234 kg, a mature cataract in the right eye, and a focal cataract in the left eye were diagnosed. ultrasound and electroretinography (erg) indicated normal retinal attachment and both eyes were viable candidates for surgery. after careful ...201931380140
leveraging multidimensional heterogeneity in resource selection to define movement tactics of animals.increasing interest in the complexity, variation and drivers of movement-related behaviours promise new insight into fundamental components of ecology. resolving the multidimensionality of spatially explicit behaviour remains a challenge for investigating tactics and their relation to niche construction, but high-resolution movement data are providing unprecedented understanding of the diversity of spatially explicit behaviours. we introduce a framework for investigating individual variation in ...201931240840
war-induced collapse and asymmetric recovery of large-mammal populations in gorongosa national park, mozambique.how do large-mammal communities reassemble after being pushed to the brink of extinction? few data are available to answer this question, as it is rarely possible to document both the decline and recovery of wildlife populations. here we present the first in-depth quantitative account of war-induced collapse and postwar recovery in a diverse assemblage of large herbivores. in mozambique's gorongosa national park, we assembled data from 15 aerial wildlife counts conducted before (1968-1972) and a ...201930865663
hyperprolactinemic african elephant (loxodonta africana) females exhibit elevated dopamine, oxytocin and serotonin concentrations compared to normal cycling and noncycling, low prolactin elephants†.many zoo elephants do not cycle normally, and for african elephants, it is often associated with hyperprolactinemia. dopamine agonists successfully treat hyperprolactinemia-induced ovarian dysfunction in women, but not elephants. the objective of this study was to determine how longitudinal dopamine, serotonin, and oxytocin patterns in african elephants are related to ovarian cycle function. we hypothesized that dopamine concentrations are decreased, while oxytocin and serotonin are increased in ...201930848798
survey of antituberculosis drug administration and adverse effects in elephants in north america.tuberculosis, caused by mycobacterium tuberculosis, is a disease causing morbidity and mortality in captive elephants (elephas maximus and loxodonta africana) as well as free-ranging individuals. elephants in north america diagnosed with tuberculosis are often treated with antituberculosis drugs, unlike livestock species, which has necessitated the development of treatment guidelines adapted from recommendations for humans. there are few published reports describing empirical treatment, which ma ...201931120659
molecular characterization of encephalomyocarditis virus strains isolated from an african elephant and rats in a french zoo.in november 2013, a fatal encephalomyocarditis virus (emcv) case in a captive african elephant (loxodonta africana) occurred at the réserve africaine de sigean, a zoo in the south of france. here we report the molecular characterization of the emcv strains isolated from samples collected from the dead elephant and from 3 rats (rattus rattus) captured in the zoo at the same time. the emcv infection was confirmed by reverse-transcription real-time pcr (rt-rtpcr) and genome sequencing. complete gen ...202033292091
movement reveals reproductive tactics in male elephants.long-term bio-logging has the potential to reveal how movements, and hence life-history trade-offs, vary over a lifetime. reproductive tactics in particular may vary as individuals' trade-off current investment versus lifetime fitness. male african savanna elephants (loxodona africana) provide a telling example of balancing body growth with reproductive fitness due to the combination of indeterminate growth and strongly delineated periods of sexual activity (musth), which results in reproductive ...202031236936
effects of diet, habitat, and phylogeny on the fecal microbiome of wild african savanna (loxodonta africana) and forest elephants (l. cyclotis).the gut microbiome, or the community of microorganisms inhabiting the digestive tract, is often unique to its symbiont and, in many animal taxa, is highly influenced by host phylogeny and diet. in this study, we characterized the gut microbiome of the african savanna elephant (loxodonta africana) and the african forest elephant (loxodonta cyclotis), sister taxa separated by 2.6-5.6 million years of independent evolution. we examined the effect of host phylogeny on microbiome composition. additio ...202032607180
spatial geochemistry influences the home range of elephants.the unique geochemistry surrounding the palabora mining company (pmc) land may act as a micronutrient hotspot, attracting elephants to the area. the pmc produces refined copper and extracts phosphates and other minerals. understanding the spatial influence of geochemistry on the home range size of african elephants is important for elephant population management and conservation. the home ranges of collared elephants surrounding the pmc were significantly smaller (p = 0.001) than conspecifics in ...202032388134
the vetmax™ m. tuberculosis complex pcr kit detects mtbc dna in antemortem and postmortem samples from white rhinoceros (ceratotherium simum), african elephants (loxodonta africana) and african buffaloes (syncerus caffer).bovine tuberculosis and tuberculosis are chronic infectious diseases caused by the mycobacterium tuberculosis complex members, mycobacterium bovis and mycobacterium tuberculosis, respectively. infection with m. bovis and m. tuberculosis have significant implications for wildlife species management, public health, veterinary disease control, and conservation endeavours.202032600471
characterizing the landscape of movement to identify critical wildlife habitat and corridors.landscape planning that ensures the ecological integrity of ecosystems is critical in the face of rapid human-driven habitat conversion and development pressure. wildlife tracking data provide unique and valuable information on animal distribution and location-specific behaviors that can serve to increase the efficacy of such planning. given the spatiotemporal complexity inherent to animal movements, the interaction between movement behavior and a location is often oversimplified in commonly app ...202032323365
understanding the drivers of mortality in african savannah elephants.populations of african savannah elephants (loxodonta africana) have been declining due to poaching, human-elephant conflict, and habitat loss. understanding the causes of these declines could aid in stabilizing elephant populations. we used data from the great elephant census, a 19-country aerial survey of savannah elephants conducted in 2014 and 2015, to examine effects of a suite of variables on elephant mortality. independent variables included spatially explicit measures of natural processes ...202032297403
analyses of african elephant (loxodonta africana) diet with various browse and pellet inclusion levels.to more closely simulate the diet of free-ranging elephants, the diet of six (2.4) african elephants (loxodonta africana) was altered to include more browse and less pelleted complete feed (5% total diet). dietary proximate compounds, minerals, vitamins a (and carotenoids), d and e, and fatty acids were analyzed on pelleted diet items and forages including hay, grass, and browse. a total of 42 browse species were offered over 1 year with an average total diet inclusion of 5.2% (dry matter basis) ...202031710122
understanding prolactin regulation and determining the efficacy of cabergoline and domperidone to mitigate prolactin-associated ovarian cycle problems in zoo african elephants (loxodonta africana ).perturbations in serum prolactin secretion, both over- and underproduction, are observed in zoo african elephants (loxodonta africana) that exhibit abnormal ovarian cycles. similar prolactin problems are associated with infertility in other species. pituitary prolactin is held under constant inhibition by a hypothalamic-derived neurotransmitter, dopamine; thus, regulation by exogenous treatment with agonists or antagonists may be capable of reinitiating normal ovarian cycles. this study tested t ...202032212542
african elephants interpret a trunk gesture as a clue to direction of interest.orienting to gaze-direction is widespread among animal species, but evidence for spontaneous use of gesture for direction is limited [1]. remarkably, african elephants (loxodonta africana) have been found able to follow human pointing, including subtle actions in which the contralateral hand is used, and in which the body silhouette is not broken [2,3]. the natural origin of this ability is puzzling, as the species is not reported to use trunk- or limb-gesture for showing directions [4]. one nat ...202032810448
circulating nutrients and hematological parameters in managed african elephants (loxodonta africana) over a 1-year period.african elephants (loxodonta africana) are currently considered a vulnerable species. one key to improving methods of species management is to better monitor and understand elephant nutrition. analyzing circulating nutrients is one of the best and least invasive methods of monitoring managed elephant nutrition, but limited reference values are available. this study examined the circulating basic hematology concentrations, minerals, vitamins a, d, and e, and fatty acids of six african elephants ( ...202032633838
international high-risk clone of multidrug-resistant ctx-m-8-producing escherichia coli c-st410 infecting an elephant (loxodonta africana) in a zoo. 202032622999
diurnal variation of salivary cortisol in captive african elephants (loxodonta africana) under routine management conditions and in relation to a translocation event.the present study assessed the diurnal variation in salivary cortisol in captive african elephants during routine management (baseline) and in relation to a potential stressor (translocation) to evaluate to what extent acute stress may affect diurnal cortisol patterns. under baseline conditions, we collected morning and afternoon saliva samples of 10 animals (three zoos) on different days in two study periods (n = 3-10 per animal, daytime and period). under stress conditions, we sampled the tran ...202032134143
mapping and assessing the impact of small-scale ephemeral water sources on wildlife in an african seasonal savannah.in many savannah regions of africa, pronounced seasonal variability in rainfall results in wildlife being restricted to floodplains and other habitats adjacent to permanent surface water in the dry season. during the wet season, rainfall fills small-scale, ephemeral water sources that allow wildlife to exploit forage and other resources far from permanent surface water. these water sources remain difficult to quantify, however, due to their small and ephemeral nature, and as a result are rarely ...202032598524
a multispecies assessment of wildlife impacts on local community livelihoods.conflicts between the interests of agriculture and wildlife conservation are a major threat to biodiversity and human well-being globally. addressing such conflicts requires a thorough understanding of the impacts associated with living alongside protected wildlife. despite this, most studies reporting on human-wildlife impacts and the strategies used to mitigate them focus on a single species, thus oversimplifying often complex systems of human-wildlife interactions. we sought to characterize t ...202032496643
noninvasive sampling for detection of elephant endotheliotropic herpesvirus and genomic dna in asian (elephas maximus) and african (loxodonta africana) elephants.elephant endotheliotropic herpesvirus (eehv) hemorrhagic disease (eehv-hd) threatens asian elephant (elephas maximus) population sustainability in north america. clusters of cases have also been reported in african elephants (loxodonta africana). risk to range country elephant populations is unknown. currently, eehv detection depends upon sampling elephants trained for invasive blood and trunk wash collection. to evaluate noninvasive sample collection options, paired invasively collected (blood, ...202032549575
strongylid infection varies with age, sex, movement and social factors in wild african elephants.comparing parasitic infection among individuals of wildlife populations can provide insight into factors that influence wildlife disease ecology. strongylids are parasitic worms that infect the intestinal tract of vertebrates, and infection with strongylids can be approximated by counting strongylid eggs in dung samples. here we tested for correlations between strongylid egg counts and 18 different individual characteristics, environmental and social factors in individually known wild african el ...202031840634
can an herbivore affect where a top predator kills its prey by modifying woody vegetation structure?in large mammal communities, little is known about modification of interspecific interactions through habitat structure changes. we assessed the effects of african elephants (loxodonta africana) on features of woody habitat structure that can affect predator-prey interactions. we then explored how this can influence where african lions (panthera leo) kill their prey. indeed, lions are stalk-and-ambush predators and habitat structure and concealment opportunities are assumed to influence their hu ...202032060732
a comparative perspective on the evolution of mammalian reactions to dead conspecifics.in a variety of mammalian species, mothers and others care for and/or carry deceased newborns, and sometimes other conspecifics. the rationale for such behavior remains elusive. based upon field observations of olive baboon (papio anubis), african elephant (loxodonta africana), and thornicroft's giraffe (giraffa camelopardalis) responses to recently dead conspecifics, combined with reports in the literature, a hypothesis is proposed to account for this activity. among female mammals, lifetime re ...202030895413
accurate sex identification of ancient elephant and other animal remains using low-coverage dna shotgun sequencing data.sex identification of ancient animal biological remains can benefit our understanding of historical population structure, demography and social behavior. traditional methods for sex identification (e.g., osteological and morphometric comparisons) may be ineffective when animal remains are not well preserved, when sex distinguishing characteristics have not yet developed, or where organisms do not exhibit sex-associated phenotypic dimorphisms. here we adapt a method developed for human sex determ ...202032107273
the xpert mtb/rif ultra assay detects mycobacterium tuberculosis complex dna in white rhinoceros (ceratotherium simum) and african elephants (loxodonta africana).the study describes the novel use of the xpert mtb/rif ultra assay for detection of mycobacterium tuberculosis complex (mtbc) dna in samples from white rhinoceros (ceratotherium simum) and african elephants (loxodonta africana). culture negative respiratory sample matrices were spiked to determine if the ultra could detect mtbc dna in rhinoceros and elephant samples. rhinoceros bronchial alveolar lavage fluid (balf) was found to have an inhibitory effect on the ultra. in this study, the limit of ...202032879401
ovarian cyclicity and prolactin status of african elephants (loxodonta africana) in north american zoos may be influenced by life experience and individual temperament.hyperprolactinemia is an endocrine disorder associated with infertility in many species, including elephants. in a recent survey of zoos accredited by the association of zoos and aquariums (aza), over half of african elephant females (n = 101) were not cycling normally, 30% of which exhibited hyperprolactinemia. we examined whether life experience and temperament predict ovarian cyclicity and circulating prolactin status in individual african elephant females. we hypothesized that, similar to hu ...202032531397
contagious yawning in african elephants (loxodonta africana): responses to other elephants and familiar humans.while spontaneous yawning is common across all vertebrate classes, contagious yawning is less common and has been observed only in a few species of social animals. interspecific contagious yawning in response to yawning by humans has been observed only by chimpanzees and dogs. after confirming additional occurrences of intraspecific contagious yawning in a group of captive african elephants previously studied, we further investigated the potential for the same group of elephants to engage in int ...202032457923
wildlife impacts and vulnerable livelihoods in a transfrontier conservation landscape.interactions between humans and wildlife resulting in negative impacts are among the most pressing conservation challenges globally. in regions of smallholder livestock and crop production, interactions with wildlife can compromise human well-being and motivate negative sentiment and retaliation toward wildlife, undermining conservation goals. although impacts may be unavoidable when human and wildlife land use overlap, scant large-scale human data exist quantifying the direct costs of wildlife ...202032406981
exploring movement decisions: can bayesian movement-state models explain crop consumption behaviour in elephants (loxodonta africana)?animal movements towards goals or targets are based upon either maximization of resource acquisition or risk avoidance, and the way animals move can reveal information about their motivation. we use hidden markov models (hmms) fitted in a bayesian framework and hourly global positioning system fixes to distinguish animal movements into distinct states and analyse the influence of environmental variables on being in, and switching to, a particular state. specifically, we apply our models to under ...202031960413
non-invasive assessment of body condition and stress-related fecal glucocorticoid metabolite concentrations in african elephants (loxodonta africana) roaming in fynbos vegetation.fynbos is a unique endemic vegetation type belonging to the cape floral kingdom in the western cape province of south africa, representing the smallest of the six floral kingdoms in the world. nowadays, only a few game reserves in this region support populations of african elephants (loxodonta africana), and thus, little information exists regarding the suitability of the nutritionally poor fynbos vegetation for these megaherbivores. using already established non-invasive methods, the monitoring ...202032397066
hypermucoviscous/hypervirulent and extensively drug-resistant qnrb2-, qnrs1-, and ctx-m-3-coproducing klebsiella pneumoniae st2121 isolated from an infected elephant (loxodonta africana).the rapid dissemination of extended-spectrum β-lactamases (esbls)-producing enterobacterales from different spheres worldwide over recent years has become a serious problem in both human and veterinary medicine. ctx-m-3-type esbl has only been reported on few occasions, and in brazil the blactx-m-3 gene has been identified only once in clinical strains. in this study, we aimed to molecularly characterize a hypermucoviscous (hm), hypervirulent (hv), and extensively drug-resistant (xdr) klebsiella ...202033176213
genetic connectivity and population structure of african savanna elephants (loxodonta africana) in tanzania.increasing human population growth, exurban development, and associated habitat fragmentation is accelerating the isolation of many natural areas and wildlife populations across the planet. in tanzania, rapid and ongoing habitat conversion to agriculture has severed many of the country's former wildlife corridors between protected areas. to identify historically linked protected areas, we investigated the genetic structure and gene flow of african savanna elephants in tanzania using microsatelli ...202033144949
'remote' behavioural ecology: do megaherbivores consume vegetation in proportion to its presence in the landscape?examination of the feeding habits of mammalian species such as the african elephant (loxodonta africana) that range over large seasonally dynamic areas is exceptionally challenging using field-based methods alone. although much is known of their feeding preferences from field studies, conclusions, especially in relation to differing habits in wet and dry seasons, are often contradictory. here, two remote approaches, stable carbon isotope analysis and remote sensing, were combined to investigate ...202032117638
unilateral phacoemulsification in a captive african elephant (loxodonta africana).the following case reports describe the clinical presentation, surgical protocol, post-operative care, and long-term follow-up of an african elephant (loxodonta africana) presenting with a unilateral cataract.202032042648
normalized difference vegetation index, temperature and age affect faecal thyroid hormone concentrations in free-ranging african elephants.conservation biologists can use hormone measurements to assess animals' welfare, reproductive state, susceptibility to stressors, as well as energy expenditure. quantifying hormone concentrations from faecal samples is particularly advantageous as samples can be collected without disturbing animals' behaviour. in order for an endocrine marker to be useful for wildlife managers, we need to understand how extrinsic and intrinsic factors affect hormone concentrations in free-ranging animal populati ...202032577285
sperm motility, kinematics, morphometry and morphology over two seasons in free-ranging african elephants (loxodonta africana).this study aimed to address the lack of information on quantitative semen and sperm characteristics of free-ranging african elephants. nineteen ejaculates were collected from 12 elephant bulls by means of electroejaculation in spring (season 1, end of dry season, n=7) and in autumn (season 2, end of rainy season, n=12). while most elephant cows are in oestrus in the rainy season, it is not evident whether sperm quality also improves during this period. semen samples were assessed using computer- ...202031972123
soft and persistent-the influence of sand-flooring and calves on the resting behavior of a zoo-kept african elephant (loxodonta africana) group.caring for all aspects of zoo elephants' well-being is considered a major challenge. providing an appropriate flooring substrate to facilitate lying rest presents a meaningful part of a holistic management concept. investigating the impact of a new sand flooring on the nocturnal resting behavior of a breeding group of seven african elephants living at one zoo revealed more total lying rest, longer bouts of lying rest and a reduced side preference in the adult females. with an average total daily ...202031663179
elephant behavior toward the dead: a review and insights from field observations.many nonhuman animals have been documented to take an interest in their dead. a few socially complex and cognitively advanced taxa-primates, cetaceans, and proboscideans-stand out for the range and duration of behaviors that they display at conspecific carcasses. here, we review the literature on field observations of elephants at carcasses to identify patterns in behaviors exhibited. we add to this literature by describing elephant responses to dead elephants in the samburu national reserve, no ...202031713106
frenemy at the gate: invasion by pheidole megacephala facilitates a competitively subordinate plant ant in kenya.biological invasions can lead to the reassembly of communities, and understanding and predicting the impacts of exotic species on community structure and functioning is a key challenge in ecology. we investigated the impact of a predatory species of invasive ant, pheidole megacephala, on the structure and function of a foundational mutualism between acacia drepanolobium and its associated acacia-ant community in an east african savanna. invasion by p. megacephala was associated with the extirpat ...202033098658
increasing browse and social complexity can improve zoo elephant welfare.while recent work has assessed how environmental and managerial changes influence elephant welfare across multiple zoos, few studies have addressed the effects of management changes within a single institution. in this paper, we examine how management changes related to social structure and diet affect the behavior of a group of zoo elephants over a 23-month period while also considering underlying factors, such as time of day, hormonal cycle, and individual differences. we recorded individual b ...202033043537
weigh and see-body mass recordings versus body condition scoring in european zoo elephants (loxodonta africana and elephas maximus).regular body mass (bm) monitoring plays a key role in preventative health care of zoo animals. in some species, including african (loxodonta africana) and asian elephants (elephas maximus), the process of weighing can be challenging, and alternative methods such as visual body condition scoring (bcs) have been developed. we investigated the temporal development of both parameters regarding correlation patterns between them, and their suitability as monitoring measures in dependence of an elephan ...202031737945
development of a multiplex, pcr-based genotyping assay for african and asian elephants for forensic purposes.wildlife crimes and the threats they present to elephant populations raise the need to develop and implement dna-based methodology as an aid for wildlife forensic investigations and conservation efforts. this study describes the development of a tetra-nucleotide repeat str multiplex, genotyping assay that will identify asian elephant (elephas maximus) and african elephant (loxodonta africana) dna. the assay targets six tetra-nucleotide strs and two sex-typing markers simultaneously in both gener ...202031190288
importance of old bulls: leaders and followers in collective movements of all-male groups in african savannah elephants (loxodonta africana).in long-lived social species, older individuals can provide fitness benefits to their groupmates through the imparting of ecological knowledge. research in this area has largely focused on females in matrilineal societies where, for example, older female african savannah elephants (loxodonta africana) are most effective at making decisions crucial to herd survival, and old post-reproductive female resident killer whales (orcinus orca) lead collective movements in hunting grounds. in contrast, li ...202032883968
behavioural variability among captive african elephants in the use of the trunk while feeding.the proboscideans, an order of mammals including elephants, are the largest of the earth lands animals. one probable consequence of the rapid increase of their body size is the development of the trunk, a multitask highly sensitive organ used in a large repertoire of behaviours. the absence of bones in the trunk allows a substantial degree of freedom for movement in all directions, and this ability could underlie individual-level strategies. we hypothesised a stronger behavioural variability in ...202032874780
serum health biomarkers in african and asian elephants: value ranges and clinical values indicative of the immune response.serum biomarkers indicative of inflammation and disease can provide useful information regarding host immune processes, responses to treatment and prognosis. the aims of this study were to assess the use of commercially available anti-equine reagents for the quantification of cytokines (tumor necrosis factor-alpha (tnf-α), interferon-gamma (ifn-γ), interleukins (il) 2, 6, and 10) in african (loxodonta africana, n = 125) and asian (elephas maximus, n = 104) elephants, and alongside previously val ...202032992555
structural analysis of covid-19 spike protein in recognizing the ace2 receptor of different mammalian species and its susceptibility to viral infection.the pandemic covid-19 was caused by a novel coronavirus-2 (sars-cov-2) that infects humans through the binding of glycosylated sars-cov-2 spike 2 protein to the glycosylated ace2 receptor. the spike 2 protein recognizes the n-terminal helices of the glycosylated metalloprotease domain in the human ace2 receptor. to understand the susceptibility of animals for infection and transmission, we did sequence and structure-based molecular interaction analysis of 16 ace2 receptors from different mammali ...202133552834
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