Survey of the reproductive cyclicity status of Asian and African elephants in North America

The Asian and African elephant populations in North America are not self‐sustaining, and reproductive rates remain low. One problem identified from routine progestagen analyses is that some elephant females do not exhibit normal ovarian cycles. To better understand the extent of this problem, the Elephant TAG/SSP conducted a survey to determine the reproductive status of the captive population based on hormone and ultrasound evaluations. The survey response rates for facilities with Asian and African elephants were 81% and 71%, respectively, for the studbook populations, and nearly 100% for the SSP facilities. Of the elephants surveyed, 49% of Asian and 62% of African elephant females were being monitored for ovarian cyclicity via serum or urinary progestagen analyses on a weekly basis. Of these, 14% of Asian and 29% of African elephants either were not cycling at all or exhibited irregular cycles. For both species, ovarian inactivity was more prevalent in the older age categories (>30 years); however, acyclicity was found in all age groups of African elephants. Fewer elephant females (～30%) had been examined by transrectal ultrasound to assess reproductive‐tract integrity, and corresponding hormonal data were available for about three‐quarters of these females. Within this subset, most (～75%) cycling females had normal reproductive‐tract morphologies, whereas at least 70% of noncycling females exhibited some type of ovarian or uterine pathology. In summary, the survey results suggest that ovarian inactivity is a significant reproductive problem for elephants held in zoos, especially African elephants. To increase the fecundity of captive elephants, females should be bred at a young age, before reproductive pathologies occur. However, a significant number of older Asian elephants are still not being reproductively monitored. More significantly, many prime reproductive‐age (10–30 years) African females are not being monitored. This lack of information makes it difficult to determine what factors affect the reproductive health of elephants, and to develop mitigating treatments to reinitiate reproductive cyclicity. Zoo Biol 23:309–321, 2004. © 2004 Wiley‐Liss, Inc.     

Variation in nature: its implications for zoo elephant management

Despite many advances in animal care and welfare over the past few decades, zoos have been criticized recently for the quality of their elephant management programs. More specifically, critics have argued that elephants live miserable lives in captivity and thus should not be kept in zoos. Poor health and reproductive success, they say, are the result of the combined impact of: a lack of exercise; exposure to cold temperatures and disease; and stress due to the use of “brutal” training techniques, chaining and inappropriate social environments. Everyone, including zoo professionals, seems to agree that improvements in zoo elephant management are necessary and appropriate. However, there is considerable disagreement on how to proceed and little information on which to base such decisions. One tactic that the critics have adopted in their efforts to promote change is their frequent reference to “nature” as a yardstick for gauging the adequacy of zoo animal management and care. An argument is made that direct zoo–wild comparisons are of questionable utility and may be invalid from a scientific perspective. Some critics talk about “nature” as if it represented a fixed set of rules by which captive managers must either abide by or risk diminishing the health and welfare of their charges. However, many aspects of elephant natural history vary greatly depending on prevailing environmental conditions and elephants may be much more flexible than many critics are giving them credit for. Thus, although zoo animal managers should look to nature for clues about how to best care for captive elephants, they should not feel constrained by them. This revelation is not intended as an excuse for poor elephant management or to support the status quo. On the contrary, a better approach is to develop realistic and biologically meaningful metrics that reflect the quality of elephant care and welfare and to use them to measure the success of evolving zoo elephant programs. Zoo Biol 25:161–171, 2006. © 2006 Wiley‐Liss, Inc.     

Why inter‐country loans will not help sumatra's elephants

Asian elephants (Elephas maximus) in western zoos are likely to become extinct unless elephants are regrouped into breeding units or additional elephants are imported from range States. There have been proposals for the export of elephants from elephant camps in Sumatra, Indonesia. In exchange, zoos would be expected to provide funds or support ‘in kind’ for the camps or for the conservation of wild elephants. Most of the elephants in the Sumatran camps were captured because of crop‐raiding problems around protected areas or because elephant habitat has been and continues to be lost to development schemes and illegal conversion of protected areas to agriculture. Capture‐related mortality rates are high and conditions in the camps are poor, with low standards of veterinary care and husbandry. This is partly due to over‐crowding and inadequate budgets. It might seem, therefore, that the loan of elephants to western zoos would improve the lot of these elephants and reduce the pressures on the camps. However, we show that both total and annual demand for Asian elephants, and particularly Sumatran elephants (E. m. sumatranus), by western zoos are low, and consequently the resources generated by any loan scheme would be limited. Elephant loan schemes are unlikely to have significant beneficial impact on either the conservation or welfare of elephants in Sumatra. More importantly, a credible loan scheme would require a permanent moratorium on the capture of wild elephants in Sumatra. Such a moratorium is needed to prevent illicit captures for sale or loan. At present, wild elephants are caught to replace those that die at the camps or are moved to other facilities. Without a moratorium, the loan of elephants to overseas zoos would contribute directly to reductions in wild elephant populations in Sumatra. However, a moratorium is likely to prove impossible to enforce, and this alone should call into question the desirability of any loan scheme. Zoo Biol 25:235–246, 2006. © 2006 Wiley‐Liss, Inc.     

Elephant importation from range countries: ethical and practical considerations for accredited zoos

Zoo elephant populations are in serious demographic peril. Advances in elephant management and care are expected to lead to improved reproductive success. The existing cohort of reproductively viable adult females is aging, however, and effective changes may not come fast enough to sustain the population over time. If so, importation of captive, semi‐domesticated, and wild elephants from range countries may be necessary for zoo programs to survive. Yet, due to the high profile elephants now have with animal rights activists, there may be increasing legal and political barriers to elephant importation. This makes it especially important that zoos become more proactive in addressing remaining weaknesses in elephant management and care and building the case for elephants in zoos. This article summarizes the key considerations for AZA‐accredited zoos that are contemplating future importations. These include ethical, legal, practical, public relations, and other considerations. The authors strongly recommend that zoos position themselves for possible future importations immediately instead of waiting until the last minute. It is equally critical that zoos recognize their existing vulnerabilities and attempt to address them proactively; only then, can they take control of their own fate and reduce the potential for later regret. Zoo Biol 25:219–233, 2006. © 2006 Wiley‐Liss, Inc.     

Seasonality of reproduction in Asian elephants Elephas maximus and African elephants Loxodonta africana: underlying photoperiodic cueing?

相似文献   

Reproduction and monogamy in captive flock of greater flamingos (Phoenicopterus Roseus)

Due to the great number of greater flamingos in captivity and their long life span, studying their behavior and welfare might be useful to improve the husbandry and breeding of this species in zoos. This study aimed to investigate factors affecting the breeding activity of captive greater flamingos (Phoenicopterus roseus) from 2012 to 2016. To estimate reproductive success, the number of pairs, eggs laid, and hatchlings were recorded. In addition, information on age, egg-laying history of the partners, and pair composition was collected. An increase in the number of pairs, eggs, and hatchlings was reported over the years. For each breeding season, there were pairs who laid more than once, especially in 2014 and 2015. Approximately 50% of pairs were monogamous between consecutive years; however, the percentage dropped gradually when comparing nonconsecutive years. Senescence and previous experience seemed to affect the reproductive success of the study flamingos. In conclusion, different factors can influence the reproduction of greater flamingos in zoos. All these factors are related to nonhuman animal welfare and need to be considered in developing and improving management practices.     

Seasonal effects on the endocrine pattern of semi-captive female Asian elephants (Elephas maximus): timing of the anovulatory luteinizing hormone surge determines the length of the estrous cycle

Better breeding strategies for captive Asian elephants in range countries are needed to increase populations; this requires a thorough understanding of their reproductive physiology and factors affecting ovarian activity. Weekly blood samples were collected for 3.9 years from 22 semi-captive female Asian elephants in Thai elephant camps to characterize LH and progestin patterns throughout the estrous cycle. The duration of the estrous cycle was 14.6+/-0.2 weeks (mean+/-S.E.M.; n=71), with follicular and luteal phases of 6.1+/-0.2 and 8.5+/-0.2 weeks, respectively. Season had no significant effect on the overall length of the estrous cycle. However, follicular and luteal phase lengths varied among seasons and were negatively correlated (r=-0.658; P<0.01). During the follicular phase, the interval between the decrease in progestin concentrations to baseline and the anovulatory LH (anLH) surge varied in duration (average 25.9+/-2.0 days, range 7-41, n=23), and was longer in the rainy season (33.4+/-1.8 days, n=10) than in both the winter (22.2+/-4.5 days, n=5; P<0.05) and summer (18.9+/-2.6 days, n=8; P<0.05). By contrast, the interval between the anLH and ovulatory LH (ovLH) surge was more consistent (19.0+/-0.1 days, range 18-20, n=14). Thus, seasonal variation in estrous cycle characteristics were mediated by endocrine events during the early follicular phase, specifically related to timing of the anLH surge. Overall reproductive hormone patterns in Thai camp elephants were not markedly different from those in western zoos. However, this study was the first to more closely examine how timing of the LH surges impacted estrous cycle length in Asian elephants. These findings, and the ability to monitor reproductive hormones in range countries (and potentially in the field), should improve breeding management of captive and semi-wild elephants.     

Social and environmental impacts on sleep in captive Asian elephants (Elephas maximus)

Modern zoos strive to improve standards of animal management, husbandry and welfare of their animals as part of a continual evaluation process. Elephants (Elephantidae) have received particular attention in recent years due to the challenge of providing environments which promote natural behavior and opportunities for social interaction. A number of measures have been proposed to measure wellbeing, with sleep quality increasingly being used. Sleep is a vital aspect of life for cell replenishment as well as optimal development of young. Sleep deprivation can lead to immunosuppression and illness; therefore animal managers have a responsibility to ensure they reduce the potential for disturbance through noise, light, or other environmental factors. The social environment also plays an essential role in wellbeing, particularly for species that live in multi-generational family units. In this study the nocturnal behavior of a multi-generational captive herd was observed to determine impacts of husbandry changes on sleep duration and bout length (measured as recumbent rest). As expected, average total duration of sleep was higher in younger elephants and rates were comparable to those reported in other studies of Asian elephants. Overnight access to an outdoor paddock in warmer weather increased overall average bout length of sleep in the herd. Average total duration of sleep also increased for the herd following the movement of an unrelated adult female who had previously shown weak bonds with other herd members. This indicates that social compatibility is a vital component of elephant welfare, impacting not only behavioral interactions but sleep quality and duration.     

Elephants in Thailand: determinants of health and welfare in working populations

The Asian elephant (Elephas maximus) has played a prominent role in Thai history and society. However, in the face of modernization, elephant handlers have been struggling to justify their continued ownership. As a result, working elephants may still encounter situations in which their health and welfare are jeopardized. This study developed both a survey instrument and a visual assessment to describe and evaluate the health and living conditions of elephants encountered in a variety of work and living situations. These situations were found to be significantly associated with whether or not an elephant received proper husbandry or was in good body condition. These results may prove valuable in predicting the welfare of elephants according to work and living situations.     

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。     

The historical development of zoo elephant survivorship

In the discussion about zoo elephant husbandry, the report of Clubb et al. (2008, Science 322: 1649) that zoo elephants had a “compromised survivorship” compared to certain non-zoo populations is a grave argument, and was possibly one of the triggers of a large variety of investigations into zoo elephant welfare, and changes in zoo elephant management. A side observation of that report was that whereas survivorship in African elephants (Loxodonta africana) improved since 1960, this was not the case in Asian elephants (Elephas maximus). We used historical data (based on the Species360 database) to revisit this aspect, including recent developments since 2008. Assessing the North American and European populations from 1910 until today, there were significant improvements of adult (≥10 years) survivorship in both species. For the period from 1960 until today, survivorship improvement was significant for African elephants and close to a significant improvement in Asian elephants; Asian elephants generally had a higher survivorship than Africans. Juvenile (<10 years) survivorship did not change significantly since 1960 and was higher in African elephants, most likely due to the effect of elephant herpes virus on Asian elephants. Current zoo elephant survivorship is higher than some, and lower than some other non-zoo populations. We discuss that in our view, the shape of the survivorship curve, and its change over time, are more relevant than comparisons with specific populations. Zoo elephant survivorship should be monitored continuously, and the expectation of a continuous trend towards improvement should be met.     

Positive Reinforcement Training for a Trunk Wash in Nepal's Working Elephants: Demonstrating Alternatives to Traditional Elephant Training Techniques

Many trainers of animals in the zoo now rely on positive reinforcement training to teach animals to voluntarily participate in husbandry and veterinary procedures in an effort to improve behavioral reliability, captive management, and welfare. However, captive elephant handlers in Nepal still rely heavily on punishment- and aversion-based methods. The aim of this project was to determine the effectiveness of secondary positive reinforcement (SPR) in training free-contact elephants in Nepal to voluntarily participate in a trunk wash for the purpose of tuberculosis testing. Five female elephants, 4 juveniles and 1 adult, were enrolled in the project. Data were collected in the form of minutes of training, number of offers made for each training task, and success rate for each task in performance tests. Four out of 5 elephants, all juveniles, successfully learned the trunk wash in 35 sessions or fewer, with each session lasting a mean duration of 12 min. The elephants' performance improved from a mean success rate of 39.0% to 89.3% during the course of the training. This study proves that it is feasible to efficiently train juvenile, free-contact, traditionally trained elephants in Nepal to voluntarily and reliably participate in a trunk wash using only SPR techniques.     

Causes and correlates of calf mortality in captive Asian elephants (Elephas maximus)

Juvenile mortality is a key factor influencing population growth rate in density-independent, predation-free, well-managed captive populations. Currently at least a quarter of all Asian elephants live in captivity, but both the wild and captive populations are unsustainable with the present fertility and calf mortality rates. Despite the need for detailed data on calf mortality to manage effectively populations and to minimize the need for capture from the wild, very little is known of the causes and correlates of calf mortality in Asian elephants. Here we use the world''s largest multigenerational demographic dataset on a semi-captive population of Asian elephants compiled from timber camps in Myanmar to investigate the survival of calves (n = 1020) to age five born to captive-born mothers (n = 391) between 1960 and 1999. Mortality risk varied significantly across different ages and was higher for males at any age. Maternal reproductive history was associated with large differences in both stillbirth and liveborn mortality risk: first-time mothers had a higher risk of calf loss as did mothers producing another calf soon (<3.7 years) after a previous birth, and when giving birth at older age. Stillbirth (4%) and pre-weaning mortality (25.6%) were considerably lower than those reported for zoo elephants and used in published population viability analyses. A large proportion of deaths were caused by accidents and lack of maternal milk/calf weakness which both might be partly preventable by supplementary feeding of mothers and calves and work reduction of high-risk mothers. Our results on Myanmar timber elephants with an extensive keeping system provide an important comparison to compromised survivorship reported in zoo elephants. They have implications for improving captive working elephant management systems in range countries and for refining population viability analyses with realistic parameter values in order to predict future population size of the Asian elephant.     

Public Attitudes in India and Australia toward Elephants in Zoos

ABSTRACT

We surveyed the attitudes of people toward captive elephants in australia, where importation into zoos has been controversial recently, compared with India, where elephants are indigenous. Both australian (AR, n = 101) and Indian (IR, n = 101) respondents rated conservation as the most important reason for the role of zoos and sanctuaries. Australian respondents were more concerned about the husbandry conditions for keeping wild animals in zoos and sanctuaries than Indian respondents (p = 0.02). This concern for captive animals increased with the higher educational level of the respondents. Female australian respondents were more concerned about the practice of keeping elephants in captivity than australian men. More australian respondents were prepared to pay extra to visit a zoo with elephants (AR 42.6%, IR 7.9%, p < 0.001). Indian respondents believed more than their australian counterparts that it was important for any zoo to display elephants, and wanted to interact with elephants by feeding, touching, and riding on them. While australian respondents? perceptions of captive elephants acknowledged their scientific value, Indian respondents viewed elephants primarily of religious, cultural, and historical significance. We conclude that australians and Indians have different requirements for keeping elephants in zoos, which should inform zoo directors about the best way to present them to the public.     

Circadian Rhythm of Salivary Cortisol in Asian Elephants (Elephas maximus): A Factor to Consider During Welfare Assessment

Elevated glucocorticoid levels during an extended time period might be a stress indicator in nonhuman animals. Therefore, knowledge of the circadian pattern of cortisol secretion is very important to correctly interpret data obtained for welfare assessment of animals in captivity through salivary cortisol. In order to define the circadian rhythm of salivary cortisol secretion in the Asian elephant (Elephas maximus), morning and evening saliva samples of 3 Asian elephants were collected and analyzed by radioimmunoassay. Significantly higher salivary cortisol concentrations were found in the morning than in the evening in all individuals. These results show that salivary cortisol of Asian elephants follows a diurnal pattern of secretion, which could be taken into account when using this methodology to assess welfare in captive Asian elephants.     

The Sizes of Elephant Groups in Zoos: Implications for Elephant Welfare

This study examined the distribution of 495 Asian elephants (Elephas maximus) and 336 African elephants (Loxodonta africana) in 194 zoos, most of which were located in Europe (49.1%) and North America (32.6%). Cows outnumbered bulls 4 to 1 (Loxodonta) and 3 to 1 (Elephas). Groups contained 7 or fewer: mean, 4.28 (σ = 5.73). One fifth of elephants lived alone or with one conspecific. Forty-six elephants (5.5%) had no conspecific. Many zoos ignore minimum group sizes of regional zoo association guidelines. The American Zoo and Aquarium Association recommends that breeding facilities keep herds of 6 to 12 elephants. The British and Irish Association of Zoos and Aquariums recommends keeping together at least 4 cows over 2 years old. Over 69% Asian and 80% African cow groups—including those under 2 years—consisted of fewer than 4 individuals. Recently, Europe and North America have made progress with some zoos no longer keeping elephants and with others investing in improved facilities and forming larger herds. The welfare of individual elephants should outweigh all other considerations; zoos should urgently seek to integrate small groups into larger herds.     

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.     

Genomic DNA sequences from mastodon and woolly mammoth reveal deep speciation of forest and savanna elephants

To elucidate the history of living and extinct elephantids, we generated 39,763 bp of aligned nuclear DNA sequence across 375 loci for African savanna elephant, African forest elephant, Asian elephant, the extinct American mastodon, and the woolly mammoth. Our data establish that the Asian elephant is the closest living relative of the extinct mammoth in the nuclear genome, extending previous findings from mitochondrial DNA analyses. We also find that savanna and forest elephants, which some have argued are the same species, are as or more divergent in the nuclear genome as mammoths and Asian elephants, which are considered to be distinct genera, thus resolving a long-standing debate about the appropriate taxonomic classification of the African elephants. Finally, we document a much larger effective population size in forest elephants compared with the other elephantid taxa, likely reflecting species differences in ancient geographic structure and range and differences in life history traits such as variance in male reproductive success.     

Dung as a potential medium for inter-sexual chemical signaling in Asian elephants (Elephas maximus)

Chemical signaling is a prominent mode of male-female communication among elephants, especially during their sexually active periods. Studies on the Asian elephant in zoos have shown the significance of a urinary pheromone (Z7-12:Ac) in conveying the reproductive status of a female toward the opposite sex. We investigated the additional possibility of an inter-sexual chemical signal being conveyed through dung. Sixteen semi-captive adult male elephants were presented with dung samples of three female elephants in different reproductive phases. Each male was tested in 3 separate trials, within an interval of 1-3 days. The trials followed a double-blind pattern as the male and female elephants used in the trials were strangers, and the observer was not aware of the reproductive status of females during the period of bioassays. Males responded preferentially (P<0.005), in terms of higher frequency of sniff, check and place behavior toward the dung of females close to pre-ovulatory period (follicular-phase) as compared to those in post-ovulatory period (luteal-phase). The response toward the follicular phase samples declined over repeated trials though was still significantly higher than the corresponding response toward the non-ovulatory phase in each of the trials performed. This is the first study to show that male Asian elephants were able to distinguish the reproductive phase of the female by possibly detecting a pre-ovulatory pheromone released in dung.     

The assessment of reproductive potential in Micronesian kingfisher pairs

The Micronesian kingfisher Halcyon cinnamomina cinnamomina is now extinct in the wild and survives only in U.S. zoos. Although pairs have reproduced in captivity, the captive breeding program has been plagued with inconsistencies in reproductive success. One problem has been determining whether birds housed as reproductive pairs have really established pairbonds. The behavior of newly paired birds may provide information that could be used to predict future reproductive success. Observations conducted for 90 min immediately after introduction of five new pairs at three institutions suggest that the specific behavioral combination of high nest activity and low aggression may indicate reproductive compatibility. Pairs that ultimately produced surviving offspring were less aggressive and engaged in more nest activity than pairs that were not productive. Observations conducted on four of these pairs for an additional month after introduction failed to provide additional information relevant to the assessment of pair status. Although long-term behavioral observations are also desirable, quick assessments such as these may be useful for determining the reproductive potential of more pairs than would be possible using traditional methods. The identification of sexually compatible pairs is a critical step toward the ultimate goal of re-establishing this species in the wild. Zoo Biol 17:425–432, 1998. © 1998 Wiley-Liss, Inc.