Working with mahouts to explore the diet of work elephants in Myanmar (Burma)

At an elephant camp in central Myanmar (Burma), we interviewed mahouts and veterinarians to describe the diet of Asian elephants (Elephas maximus) in a mixed-deciduous forest. Elephants showed a broad dietary breadth (103 plant species from 42 families); consumed mostly browse (94% of plant species); and were very selective about plant parts [e.g., many trees were eaten exclusively for their bark (22%) or fruits (14%)]. The fruits from 29 plant species were recorded to be eaten by elephants. Several of these were found as fruit remains, seeds, or seedlings in elephant dung, suggesting a role of Asian elephants in seed dispersal. Work elephants and their mahouts prove to be a rich source of information to understand wild elephant ecology.     

象科动物对当地森林生态系统的影响

现存的象科动物(Elephantidae)分为非洲草原象(Loxodonta africana)、非洲森林象(Loxodonta cyclotis)和亚洲象(Elephas maximus)3 种,作为森林生态系统的关键物种,它们对当地森林生态系统的影响非常复杂,在一定环境条件下,既可能是积极的作用,也可能是消极的作用。积极的作用包括:帮助植物传播种子;促进种子萌发;创造断层,维持群落多样性;为其他动物增加食物资源;为其他动物创造栖息地。消极的作用包括:使一些物种的种群数量减小;使森林变成灌木丛和草原等。而由于活动受限导致的种群密度过高是象科动物对森林生态系统产生消极作用的主要原因。当前象科动物的3 个物种均面临种群数量锐减和生存空间不断缩小的危机,为此迫切需要针对其对生物多样性和生态平衡的影响开展深入和全面的研究,并且应根据实际情况因地制宜地制定管理措施。     

Feeding patterns of elephants at the Atherstone Collaborative Nature Reserve

The African savannah elephant (Loxodonta africana Blumenbach) is a generalist herbivore that relies on widely distributed resources. Vegetation decline, aggravated by these elephants, can compromise local conservation efforts. Thus it imperative to understand the factors that drive them to consume specific plant species and plant parts. The objective of our study was to investigate the feeding patterns of African savannah elephants in the enclosed bushveld savannah at the Atherstone Collaborative Nature Reserve in South Africa. For 1 year, we examined elephant selection of woody versus herbaceous vegetation, and identified which plant species and parts were preferentially consumed. We accomplished this by directly observing feeding elephants, and by utilizing data collected on elephant footprints, dung piles, stripped bark and broken branches. We further conducted vegetation surveys to determine selection frequency relative to species abundance. Elephants showed a preference for different plant parts consumption in the feeding plots. In total, leaves, branches and bark contributed mostly to their diet. Seasonal selection patterns showed an increasing proportion of bark and branch consumption during the dry season.     

Diet and distribution of elephant in the Maputo Elephant Reserve, Mozambique

The distribution and diet of the elephants of the Maputo Elephant Reserve were studied using dung counts, satellite tracking and faecal analysis. The results were compared with earlier data from before the civil war in Mozambique. The elephant population decreased during the civil war, but 180 animals still remain. Earlier studies described the elephants as preferring the grass plains. Currently, the elephants prefer the dense forest patches over the high quality forage found in the grass plains. Water salinity affected distribution; elephant dung piles were found closer to fresh water in the dry season. A total of 95 different plant species were identified in the faeces. The percentage of grass was relatively low compared with other studies, increasing at the beginning of the rainy season. At the end of the dry season, elephants concentrated on the few available browse species with young leaves, but generally preferred grass species to browse species. Diet composition was mainly affected by season and less by habitat. The elephants have changed their habitat preference in reaction to poaching, and probably increased the contribution of browse species in the diet. The presence of forest patches has been vital for the survival of the elephants.     

Diet composition and foraging ecology of Asian elephants in Shangyong, Xishuangbanna, China

The composition of the diet and the foraging ecology of the Asian elephant in its natural habitat were studied from 1998 to 2000 in the Shangyong National Natural Reserve located at Xishuangbanna, China, using field observation and dung analysis. A total of 106 plant species were recorded as being eaten by Asian elephants, 83 of which were identified in the elephants' dung. The plant families that contributed to a major proportion of the elephants' diet in the study area were: Gramineae (8 spp., 10.0%), Moraceae (7 spp., 9.9%), Papilionaceae (4 spp., 8.4%), Araliaceae (3 spp., 6.6%), Vitaceae (3 spp., 5.7%), Apocynaceae (3 spp., 4.6%), Musaceae (1 spp., 4.2%), Zingiberaceae (3 spp., 3.7%), Myrsinaceae (3 spp., 3.6%), Rosaceae (3 spp., 3.6%), Euphorbiaceae (5 spp., 3.3%), Ulmaceae (2 spp., 3.0%) and Mimosaceae (4 spp., 2.9%). The most important plants in the elephants' diet were Ficus spp. (Moraceae, 9.0%), Dendrocalamus spp. (Gramineae, 4.5%), Musa acuminata (Musaceae, 4.2%), Microstegium ciliatum (Gramineae, 3.5%) and Amalocalyx yunnanensis (Apocynaceae, 3.1%). Asian elephants consumed a variety of plants in terms of life forms, including trees, vines, shrubs and herbs. Early successional plant species constitute a higher proportion of the diet than late successional plants (42 spp. taking 59% vs. 32 spp. taking 37%). Browsing species accounted for a larger proportion of the diet compared to grazing species (77 spp. taking 91% vs. 6 spp. taking 9%). The number of plant taxa (species, genus, family) in elephants' diet each month negatively correlated with monthly rainfall and mean temperature. The study may help to develop proper strategies for wildlife management especially with regard to the human-elephant conflict, which is now a serious issue in the conservation of Asian elephants in this area.     

A Meta-Analysis of the Impact of African Elephants on Savanna Vegetation

Abstract: Large herbivores such as elephants (Loxodonta africana) apparently have a negative impact on woody vegetation at moderate to high population densities. The confounding effects that fire, drought, and management history have may complicate assignment of such impacts to herbivory. We reviewed 238 studies published over 45 years and conducted a meta-analysis based on 21 studies that provided sufficient information on response of woody vegetation to elephants. We considered size and duration of studies, elephant densities, rainfall, fences, and study outcomes in our analysis. We detected a disproportionate citation of 20 published studies in our database, 15 of which concluded that woody vegetation responded negatively to elephants. Our analysis showed that high elephant densities had a negative effect on woody vegetation but that rainfall and presence of fences influenced these effects. In arid savannas, woody vegetation always responded negatively to elephants. In transitional savannas, an increase in elephant densities did not influence woody vegetation response. In mesic savannas, negative responses of woody vegetation increased when elephants occurred at higher densities, whereas elephants confined by fences also had more negative effects on woody plants than elephants that were not confined. Our analysis suggested that rainfall and fences influenced elephant density related impact and that research results were often site-specific. Local environmental conditions and site-specific objectives should be considered when developing management actions to curb elephant impacts on woody vegetation.     

Elephant herbivory of knob-thorn (Senegalia nigrescens) and ivory palm (Hyphaene petersiana) in Bwabwata National Park,Caprivi, Namibia: The role of ivory palm as a biotic refuge

African elephants have major impacts on vegetation, particularly at high densities. Knob-thorns (Senegalia nigrescens) are typically ring-barked by elephant, and high levels of mortality are common at high elephant densities. Our study aimed to test whether ivory palm clusters (Hyphaene petersiana) form a biotic refuge for knob-thorn against elephant herbivory. We measured the density, damage and mortality of knob-thorns in sites differing according to ivory palm presence and elephant density, and thus, the probability of knob-thorn encounter by elephants. The site with palms and low elephant density, had a high density of knob-thorns, but lower proportions of damaged and dead trees, than sites without palms but with similar or higher elephant density. In the former, knob-thorns were associated with palm clusters, particularly saplings and young adults. In this site, low proportions of damaged and dead knob-thorns were recorded in palm clusters, compared with outside clusters, and to those in the other sites. Our study also showed that juvenile palms which protected knob-thorns, suffered low mortality in contrast to subadult palms. We have no evidence but implicate elephants and suggest that in palm clusters, subadult palms are more accessible to elephants than knob-thorns because of the different methods of utilisation.     

Sex and size related differences in the dry season feeding patterns of elephants in Chobe National Park, Botswana

Differences in feeding patterns of the African elephant were examined by sex and age during the dry season in a dystrophic savanna-woodland ecosystem in northern Botswana. Adult males had the least diverse diet in terms of woody plant species, but they consumed more plant parts than family units. The diameter of stems of food plants broken or bitten off was also greater for adult males than for females and subadult males. Adult males spent more time foraging on each woody plant than did females. The number of woody plant species and individuals present were higher at feeding sites of family units than at feeding sites of adult males, indicating that family units positioned themselves at feeding sites with higher species diversity than those of males. We argue that the most likely explanation for these differences is related to the pronounced sexual size dimorphism exhibited by elephants, resulting in sex differences in browsing patterns due to the allometric relationships that govern the tolerance of herbivores for variation in diet quality. From our results this Body Size Hypothesis is accepted rather than the alternative Scramble Competition Hypothesis, which predicts that adult male elephants consume lower quality browse because they are displaced from preferred browse as an outcome of scramble competition with adult females and their offspring. If the feeding patterns of adult male elephants were affected by intersexual scramble competition, we would expect adult males to browse at a higher level in the canopy than the smaller-bodied females and their offspring. No evidence was found for this, although adult females were found to browse at a higher level in the canopy when feeding in close proximity to subadults and juveniles than when feeding alone. Sex differences in elephant browsing patterns are, we propose, of relevance to understanding and managing elephant impacts on African woodlands.     

Elephant Genomes Reveal Accelerated Evolution in Mechanisms Underlying Disease Defenses

Disease susceptibility and resistance are important factors for the conservation of endangered species, including elephants. We analyzed pathology data from 26 zoos and report that Asian elephants have increased neoplasia and malignancy prevalence compared with African bush elephants. This is consistent with observed higher susceptibility to tuberculosis and elephant endotheliotropic herpesvirus (EEHV) in Asian elephants. To investigate genetic mechanisms underlying disease resistance, including differential responses between species, among other elephant traits, we sequenced multiple elephant genomes. We report a draft assembly for an Asian elephant, and defined 862 and 1,017 conserved potential regulatory elements in Asian and African bush elephants, respectively. In the genomes of both elephant species, conserved elements were significantly enriched with genes differentially expressed between the species. In Asian elephants, these putative regulatory regions were involved in immunity pathways including tumor-necrosis factor, which plays an important role in EEHV response. Genomic sequences of African bush, forest, and Asian elephant genomes revealed extensive sequence conservation at TP53 retrogene loci across three species, which may be related to TP53 functionality in elephant cancer resistance. Positive selection scans revealed outlier genes related to additional elephant traits. Our study suggests that gene regulation plays an important role in the differential inflammatory response of Asian and African elephants, leading to increased infectious disease and cancer susceptibility in Asian elephants. These genomic discoveries can inform future functional and translational studies aimed at identifying effective treatment approaches for ill elephants, which may improve conservation.     

Patterns of elephant impact on woody plants in the Hluhluwe-Imfolozi park, Kwazulu-Natal, South Africa

This study identifies patterns of elephant Loxodonta africana africana impacts upon tree species and woody plant communities in Hluhluwe-Imfolozi Park, a South African savannahs/woodlands area. Elephants were reintroduced there from 1981, following more than 80 years of absence. Data were collected in 2003 on elephant impact on woodland in the Park. Different vegetation types were susceptible to different types and levels of damage by elephants, suggesting that elephants will not homogenize the vegetation. Elephants targeted larger stems for all types of damage, with a strong preference for some of the less abundant species such as Albizia versicolor (breaking and toppling) and Cordia caffra and Schotia brachypetala (debarking). Elephant impacts tended to be distributed evenly across the park landscape, irrespective of stem density or proximity to permanent water. Overall, elephants have little impact on slowing or reversing the spread of undesirable woody species, but are having a marked impact on certain less common tree species and larger tree size-classes in the Hluhluwe-Imfolozi Park.     

西双版纳尚勇亚洲象的食物组成与取食生态

于1998—2000在西双版纳国家级自然保护区尚勇子保护区的自然生境中,通过对亚洲象取食植物调查和粪便分析,了解亚洲象的食物组成与取食习性。结果显示,野外跟踪调查共记录有106种植物被亚洲象所取食。其中有83种出现在象的粪便中,这些种类分别属于：禾本科8种（10．0％）、桑科7种（9．9％）、蝶形花科4种（8．4％）、五加科3种（6．6％）、葡萄科3种（5．7％）、夹竹桃科3种（4．6％）、芭蕉科1种（4．2％）、姜科3种（3．7％）、紫金牛科3种（3．6％）、蔷薇科3种（3．6％）、大戟科5种（3．3％）、榆科2种（3．O％）、含羞草科4种（2．9％）13个植物科。根据食物中所占的比率,桑科的榕属（Ficus）、禾本科的竹类（Bambusoideae）、小果野芭蕉（Musa acuminate）和莠竹（Microstegium ciliatum）是亚洲象的主要食物资源。在觅食过程中,亚洲象取食包括乔木、藤本灌木和草本等各种生活型的植物,其中先锋种所占比率（59％）高于后续种;选择性啃食枝条的植物种类（77种）高于牧草式取食的种类（6种）。亚洲象取食植物种类的月变化与月平均温度和月降雨量成负相关,旱季取食植物种类高于雨季。本研究对制定保护区野生动物管理策略,以及解决保护区周边日趋恶化的人象矛盾,具有一定的参考价值。     

The influence of tree canopies and elephants on sub-canopy vegetation in a savannah

The apparent influence of elephants on the structure of savannahs in Africa may be enhanced by management activities, fire and other herbivores. We separated the effect elephants have on grasses, woody seedlings (<0.5 m) and saplings (0.5–2 m) from the effect of tree canopies (canopy effect), and herbivory (park effect). We defined the canopy effect as the differences between plant abundances and diversity indices under tree canopies and 20 m away from these. Our testing of the park effect relied on the differences in the sub-canopy plant indices inside and outside a protected area that supported a range of herbivores. We based our assessment of the elephant effect on sub-canopy vegetation indices associated with elephant induced reductions in tree canopies. The park and canopy effects were more pronounced than the elephant effect. The park effect suppressed the development of woody seedlings into saplings. Conditions associated with tree canopies benefited woody plants, but not the grasses, as their indices were lower under trees. Elephants reducing canopies facilitated grass species tolerant of direct solar radiation. We concluded that management should consider other agents operating in the system when deciding on reducing the impact that elephants may have on vegetation.     

中国亚洲象取食植物种类统计与分析

2016年1月至2017年12月,分别采用样线法和跟踪调查法对中国境内分布的野生亚洲象和云南西双版纳亚洲象种源繁育与救助中心的10头圈养亚洲象放养时取食植物进行调查,经分类鉴定,共收集到亚洲象取食植物111种,分属29目、42科、77属,其中新增亚洲象取食植物57种,分属于21目、32科、44属。与文献中记载的中国亚洲象植物性食物进行了汇总,统计得到新的中国亚洲象植物性食物名录,共计32目、62科、162属、240种。多样性分析结果显示,G-F多样性指数为0.84,表明中国野生及圈养亚洲象取食的植物具有较高的多样性,这些植物涉及蕨类植物门、裸子植物门和被子植物门。其中,圈养亚洲象采食植物种类共84种,西双版纳境内圈养亚洲象以禾本科(Gramineae)的甘蔗(Saccharum spp.)、玉米(Zea mays)、马唐(Digitaria spp.)、象草(Pennisetum purpureum)、粽叶芦(Thysanolaena latifolia)等为主要食物,而国内其它地方(北京动物园、广州动物园和昆明动物园)圈养的亚洲象主要饲喂高粱属(Sorghum)的高粱(S.bicolor)或苏丹草(S.sudanense)等。因此,在将来开展野生亚洲象栖息地保护、恢复及食物源基地项目规划与建设时应规避农作物和经济作物,优选亚洲象喜食、速生、生物量大的土著物种,如野芭蕉、棕叶芦、董棕、构树、重阳木、中平树、马唐属及竹类等植物,按照不同季节进行套种,为亚洲象提供更多可口食物。对于圈养亚洲象,需要设计足够面积的食物源基地供放养,补充食物种类,增加运动量,增强体质,提高其生活质量。     

Evidence for rapid evolutionary change in an invasive plant in response to biological control

We present evidence that populations of an invasive plant species that have become re‐associated with a specialist herbivore in the exotic range through biological control have rapidly evolved increased antiherbivore defences compared to populations not exposed to biocontrol. We grew half‐sib families of the invasive plant Lythrum salicaria sourced from 17 populations near Ottawa, Canada, that differed in their history of exposure to a biocontrol agent, the specialist beetle Neogalerucella calmariensis. In a glasshouse experiment, we manipulated larval and adult herbivory to examine whether a population's history of biocontrol influenced plant defence and growth. Plants sourced from populations with a history of biocontrol suffered lower defoliation than naïve, previously unexposed populations, strongly suggesting they had evolved higher resistance. Plants from biocontrol‐exposed populations were also larger and produced more branches in response to herbivory, regrew faster even in the absence of herbivory and were better at compensating for the impacts of herbivory on growth (i.e. they exhibited increased tolerance). Furthermore, resistance and tolerance were positively correlated among genotypes with a history of biocontrol but not among naïve genotypes. Our findings suggest that biocontrol can rapidly select for increased defences in an invasive plant and may favour a mixed defence strategy of resistance and tolerance without an obvious cost to plant vigour. Although rarely studied, such evolutionary responses in the target species have important implications for the long‐term efficacy of biocontrol programmes.     

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) per day. Dietary Na and Se were low while Fe and Mn were high compared to published intake levels for elephants. Analyzed nutrients within browse varied widely among seasons and species. Ingredient analyses were used to create predicted elephant nutrient intake for (a) the current diet, (b) a diet excluding pellets, and (c) a diet excluding pellets and providing browse at doubled levels. Formulated diets excluding pellets had lower mineral levels than the current diet and doubled browse did not alter mineral inclusions of concern. This study provides seasonal data on the nutrient levels of Southeastern browse species important for various pachyderm and herbivorous species. Predicted nutrient intake with new diet scenarios does not support the exclusion of pellets in the diets of African elephants without greater browse quantity availability, strict diet management, or additional supplements.     

The savanna ecology of Kidepo Valley National Park

(1) Food habits of elephant and giraffe were recorded in short sample periods over several years using the feeding minutes technique. (2) Twelve species of common plants were collected on these occasions, separated into their main parts and analysed chemically. (3) Damage to trees was also recorded at intervals. (4) Fifty-nine species of plant were eaten by elephant. During wet months their diet was predominantly grass but during dry months woody vegetation became more important. Giraffe were observed eating from thirty-nine species of plant which were almost entirely browse throughout the year. At least eighteen of these species were also eaten by elephant. (5) Three of the browse species most important to giraffe were also important to elephant in dry seasons. In the driest month the species eaten by giraffe formed more than two-thirds of the observed diet of elephants. (6) Chemical analyses of plants show that browse leaves had a higher level of protein, fat and minerals than most other plants. (7) The trunk of an elephant and the tongue of a giraffe are highly sensitive organs which permit food selection. Elephant in particular appeared to alter their food habits seasonally and it is suggested that this may be an attempt to obtain a balanced intake of nutrients. (8) Due to the effect of elephant and other agencies there is an accelerating decline in Acacia gerrardii woodlands. Browsing and fire are independently preventing their regeneration. (9) The extensive overlap of food requirements on preferred but diminishing browse resources implies potential if not already existing competition between elephant and giraffe. (See Part III.)     

Comparative and functional analyses of fecal microbiome in Asian elephants

Asian elephant is large herbivorous animal with elongated hindgut. To explore fecal microbial community composition with various ages, sex and diets, and their role in plant biomass degrading and nutrition conversation. We generated 119 Gb by metagenome sequencing from 10 different individual feces and identified 5.3 million non-redundant genes. The comprehensive analysis established that the Bacteroidetes, Firmicutes and Proteobacteria constituted the most dominant phyla in overall fecal samples. In different individuals, the alpha diversity of the fecal microbiota in female was lower than male, and the alpha diversity of the fecal microbiota in older was higher than younger, and the fecal microbial diversity was the most complex in wild elephant. But the predominant population compositions were similar to each other. Moreover, the newborn infant elephant feces assembled and maintained a diverse but host-specific fecal microbial population. The discovery speculated that Asian elephant maybe have start to building microbial populations before birth. Meanwhile, these results illustrated that host phylogeny, diets, ages and sex are significant factors for fecal microbial community composition. Therefore, we put forward the process of Asian elephant fecal microbial community composition that the dominant populations were built first under the guidance of phylogeny, and then shaped gradually a unique and flexible gut microbial community structure under the influences of diet, age and sex. This study found also that the Bacteroidetes were presumably the main drivers of plant fiber-degradation. A large of secondary metabolite biosynthetic gene clusters, and genes related to enediyne biosynthesis were found and showed that the Asian elephant fecal microbiome harbored a diverse and abundant genetic resource. A picture of antibiotic resistance genes (ARGs) reservoirs of fecal microbiota in Asian elephants was provided. Surprisingly, there was such wide range of ARGs in newborn infant elephant. Further strengthening our speculation that the fetus of Asian elephant has colonized prototypical fecal microbiota before birth. However, it is necessary to point out that the data give a first inside into the gut microbiota of Asian elephants but too few individuals were studied to draw general conclusions for differences among wild and captured elephants, female and male or different ages. Further studies are required. Additionally, the cultured actinomycetes from Asian elephant feces also were investigated, which the feces of Asian elephants could be an important source of actinomycetes.

     

Heterogeneity in African savanna elephant distributions and their impacts on trees in Kruger National Park,South Africa

1. Though elephants are a major cause of savanna tree mortality and threaten vulnerable tree species, managing their impact remains difficult, in part because relatively little is known about how elephant impacts are distributed throughout space.
2. This is exacerbated by uncertainty about what determines the distribution of elephants themselves, as well as whether the distribution of elephants is even informative for understanding the distribution of their impacts.
3. To better understand the factors that underlie elephant impacts, we modeled elephant distributions and their damage to trees with respect to soil properties, water availability, and vegetation in Kruger National Park, South Africa, using structural equation modeling.
4. We found that bull elephants and mixed herds differed markedly in their distributions, with bull elephants concentrating in sparsely treed basaltic sites close to artificial waterholes and mixed herds aggregating around permanent rivers, particularly in areas with little grass.
5. Surprisingly, we also found that the distribution of elephant impacts, while highly heterogeneous, was largely unrelated to the distribution of elephants themselves, with damage concentrated instead in densely treed areas and particularly on basaltic soils.
6. Results underscore the importance of surface water for elephants but suggest that elephant water dependence operates together with other landscape factors, particularly vegetation community composition and historical management interventions, to influence elephant distributions.

     

Assessing the effects of elephant foraging on the structure and diversity of an Afrotropical forest

African forest elephants (Loxodonta cyclotis) are ecosystem engineers that browse and damage large quantities of vegetation during their foraging and movement. Though elephant trail networks and clearings are conspicuous features of many African forests, the consequences of elephant foraging for forest structure and diversity are poorly documented. In this study in northeastern Gabon, we compare stem size, stem density, proportional damage, species diversity, and species relative abundance of seedlings and saplings in the vicinity of seven tree species that produce elephant-preferred fruits (“elephant trees”) relative to control trees that do not. Across 34 survey trees, with a combined census area of 2.04 ha, we recorded data on 26,128 woody stems in three sizes classes. Compared with control trees, the area around elephant trees had the following: (a) a significantly greater proportion of damaged seedlings and a marginally greater proportion of damaged saplings (with 82% and 24% greater odds of damage, respectively); (b) no significant difference in stem density or species diversity; and (c) a significantly greater relative abundance of seedlings of elephant tree species. Increasing distance away from focal elephant trees was associated with significantly reduced sapling stem damage, significantly increased sapling stem density, and significantly increased sapling species diversity. Considered in sum, our results suggest that elephants can affect the structure and diversity of Afrotropical forests through their foraging activities, with some variation based on location and plant size class. Developing a more complete understanding of elephants’ ecological effects will require continued research, ideally with manipulative experiments.     

Observations on the length of the intestinal tract of African <Emphasis Type="Italic">Loxodonta africana</Emphasis> (Blumenbach 1797) and Asian elephants <Emphasis Type="Italic">Elephas maximus</Emphasis> (Linné 1735)

The digestive tract of elephants is surprisingly short compared to other herbivorous mammals. However, measurements relating the length of the intestine to the body mass of the respective individual are rare. In this study, we report such data for an African elephant and an Asian elephant. Our data support the hypothesis that Asian elephants have a longer intestinal tract than their African counterparts. These findings are in accord with the observation of longer retention times and higher digestion coefficients in Asian as compared to African elephants. This difference between the species could be the reflection of slightly different ecological niches, with Asian elephants adapted to a natural diet with a higher proportion of grass.