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1.
P. Leimgruber B. Senior Uga Myint Aung M. A. Songer T. Mueller C. Wemmer & J. D. Ballou 《Animal Conservation》2008,11(3):198-205
Captive Asian elephants Elephas maximus , used as work animals, constitute up to 22–30% of remaining Asian elephants. Myanmar has the largest captive population worldwide (∼6000), maintained at this level for over a century. We used published demographic data to assess the viability of this captive population. We tested how this population can be self-sustained, how many elephants must be supplemented from the wild to maintain it, and what consequences live capture may have for Myanmar's wild population. Our results demonstrate that the current captive population is not self-sustaining because mortality is too high and birth rates are too low. Our models also suggest ∼100 elephants year−1 have been captured in the wild to supplement the captive population. Such supplementation cannot be supported by a wild population of fewer than 4000 elephants. Given the most recent expert estimate of ∼2000 wild elephants remaining in Myanmar, a harvest of 100 elephants year−1 could result in extinction of the wild population in 31 years. Continued live capture threatens the survival of wild and captive populations and must stop. In addition, captive breeding should be increased. These measures are essential to slow the decline and extinction of all of Myanmar's elephants. 相似文献
2.
Joseph Saragusty Robert Hermes Frank Gritz Dennis L. Schmitt Thomas B. Hildebrandt 《Animal reproduction science》2009,115(1-4):247-254
Sex allocation theories predict equal offspring number of both sexes unless differential investment is required or some competition exists. Left undisturbed, elephants reproduce well and in approximately even numbers in the wild. We report an excess of males are born and substantial juvenile mortality occurs, perinatally, in captivity. Studbook data on captive births (CB, n = 487) and premature deaths (PD, <5 years of age; n = 164) in Asian and African elephants in Europe and North America were compared with data on Myanmar timber (Asian) elephants (CB, n = 3070; PD, n = 738). Growth in CB was found in three of the captive populations. A significant excess of male births occurred in European Asian elephants (ratio: 0.61, P = 0.044) and in births following artificial insemination (0.83, P = 0.003), and a numerical inclination in North American African elephants (0.6). While juvenile mortality in European African and Myanmar populations was 21–23%, it was almost double (40–45%) in all other captive populations. In zoo populations, 68–91% of PD were within 1 month of birth with stillbirth and infanticide being major causes. In Myanmar, 62% of juvenile deaths were at >6 months with maternal insufficient milk production, natural hazards and accidents being the main causes. European Asian and Myanmar elephants PD was biased towards males (0.71, P = 0.024 and 0.56, P < 0.001, respectively). The skewed birth sex ratio and high juvenile mortality hinder efforts to help captive populations become self-sustaining. Efforts should be invested to identify the mechanism behind these trends and seek solutions for them. 相似文献
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4.
Most of the fossil mammal sites on Cyprus, as well as on other Mediterranean islands, consist of large quantities of bones
found in caves. Of 32 sites with Phanourios minutus and 21 with Elephas cypriotes on Cyprus, 19 were located in caves, two in rock-shelters, and 11 at open-air sites. Fifteen of them were littoral, four
coastal, and 13 inland. The purpose of this paper is to examine possible reasons why Phanourios and Elephas remains accumulated mainly in littoral and coastal caves. Based on an analysis of the behavior exhibited by living hippopotami
and elephants, we assume that the extinct large mammals of Cyprus entered these caves in search of fresh water and to protect
themselves from the heat in the cool and moist cave environment. A further reason may have been that these mammals entered
the caves seeking mineral licks to rectify possible mineral deficiencies, to bind secondary plant compounds such as tannins,
or to counteract acidosis. By entering caves, or even passing along narrow paths through cliffs, they were at risk of becoming
trapped in natural traps, such as caves with their openings facing upwards, sinkholes, and mire traps. There is no evidence
that Phanourios and Elephas remains were accumulated by natural predators because on the island there were no predators large enough to carry such large
mammals. The only exception are the remains in the Akrotiri Aetokremnos rock shelter on the Akrotiri peninsula, where there is evidence that the 218,459 Phanourios and 330 Elephas remains were accumulated by the first human settlers of Cyprus, about 10,000 years BP. 相似文献
5.
Juichi Yamagiwa Ndunda Mwanza Takakazu Yumoto Tamaki Maruhashi 《Primates; journal of primatology》1994,35(1):1-14
Details are presented of the composition of the diet of eastern lowland gorillas, derived mainly from a study of their fresh
trails and fecal analysis, during the course of an entire year in the tropical lowland forests of the Itebero region, Zaire.
Gorillas ate 194 plant foods from 121 species and 45 families. They consumed 48 species of fruits; and 89% of fecal samples
contained fruit seeds, but fruits were a relatively small part (25%) of the total number of food items. The composition of
their diet changed seasonally. When consumption of fruit decreased in the long rainy and the long dry seasons, the gorillas
ate, in addition to Zingiberaceae and Marantaceae, many kinds of leaf and bark, which may be an important buffer against the
shortage of fruits. Gorillas also fed regularly on ants (Ponerinae), and the frequency of consumption showed small seasonal
variations. From a comparison of diet composition, eastern lowland gorillas appeared to be intermediate between the other
two subspecies. The choice of food showed differences in preference of fruits and insects between subspecies and may reflect
high similarities within subspecies in lowland and montane forests. 相似文献
6.
2021年4月,我国15头野生亚洲象(Elephas maximus)从西双版纳一路北迁至昆明市受到了全世界的关注,分析我国野生亚洲象分布区土地利用变化、生态系统服务供需关系如何影响野生亚洲象分布,对保护亚洲象与提高当地人类福祉具有重要的意义。利用生态系统服务价值当量因子法和生态系统服务需求模型计算中国野生亚洲象分布区1990、2005、2015年生态系统服务供给价值与需求指数,通过空间标准化匹配出四种生态系统服务供需模式,探究我国野生亚洲象偏好分布的供需模式。结果表明,林地、草地和耕地是最主要的土地利用类型,1990—2015年,林地、草地和耕地的面积变化率分别为1.09%、-4.82%、-4.86%。1990、2005、2015年生态系统供给总价值分别为6108.55亿元、7434.41亿元、13973.37亿元;生态系统服务需求不断提高,整体呈现中间高,四周低的分布格局。在研究的25年内,亚洲象分布于高供给-高需求与高供给-低需求区域,且有向高供给-高需求区域迁徙的趋势。 相似文献
7.
Summary Stable carbon isotope ratios in bone collagen have been used in a variety of dietary studies in modern and fossil animals, including humans. Inherent in the stable isotope technique is the assumption that the isotopic signature is a reflection of the diet and is persistent in collagen because this is a relatively inert protein. Carbon isotope analyses of bones from a southern Indian population of Asian elephant (Elephas maximus), a long-lived mammal that alternates seasonally between a predominantly C3 (browse) and C4 (grass) plant diet, showed two patterns that have important implications for dietary interpretation based on isotopic studies. Relative to the quantity of the two plant types consumed on average, the δ13C signal in collagen indicated that more carbon was incorporated from C3 plants, possibly due to their higher protein contribution. There was a much greater variance in δ13C values of collagen in sub-adult (range -10.5‰ to-22.7‰, variance=14.51) compared to adult animals (range -16.0‰ to -20.3‰, variance=1.85) pointing to high collagen turnover rates and non-persistent isotopic signatures in younger, growing animals. It thus seems important to correct for any significant relative differences in nutritive value of food types and also consider the age of an animal before drawing definite conclusions about its diet from isotope ratios. 相似文献
8.
Swen C. Renner Pamela C. Rasmussen John H. Rappole Thein Aung Myint Aung 《Journal of Ornithology》2009,150(3):671-683
The little-known taxon Cyornis [banyumas] magnirostris has long been treated as a race of the widespread Hill Blue Flycatcher C. banyumas, with which it was thought to be allopatric during the breeding season. On the basis of morphology, magnirostris has lately been considered a full species, endemic as a breeder to northeastern India. Our recent field work during migration
and the breeding season (September 2005 and June–July 2006) has, however, resulted in the first records of magnirostris from northern Burma/Myanmar, establishing that its breeding range broadly overlaps the range of C. banyumas
whitei. We demonstrate how historical factors, sources of error, including fraud, errors of omission and commission, and inferences
based on lack of data have all negatively affected assessment of species limits and conservation status in this speciose group
of flycatchers. We also provide evidence that the taxon C. [banyumas] lemprieri is highly distinct and should be treated as a full species. 相似文献
9.
Historically, the Asian elephant has never bred well in captivity. We have carried out demographic analyses of elephants captured in the wild or born in captivity and kept in forest timber camps in southern India during the past century. The average fecundity during this period was 0.095/adult female/year. During 1969–89, however, the fecundity was higher at 0.155/adult female/year, which compares favorably with wild populations. There was seasonality in births with a peak in January. The sex ratio of 129 male to 109 female calves at birth is not significantly different from equality, although the excess of male calves born mainly to mothers 20–40 years old may have biological significance. Mortality rates were higher in females than in males up to age 10, but much lower in females than in males above age 10 years. The population growth rate, based on the lower secundity over the century, was 0.5% per year, and based on the higher secundity during 1969–89, was 1.8% per year. The analyses thus showed that timber camp elephants in southern India could potentially maintain a stationary or increasing population without resorting to captures from the wild. Breeding efforts for elephants in zoos can thus profitably learn from the experience of traditional management systems in part of Asia. Zoo Biol 16:263–272, 1997. © 1997 Wiley-Liss, Inc. 相似文献
10.
Social organization of the Asian elephant (Elephas maximus) is not well understood in the absence of long-term studies of identified individuals. Adult Asian elephant females and their young offspring of both sexes form matriarchal groups, with pubertal males dispersing from natal groups, but whether these social groups represent families and whether males show locational or social dispersal were unknown. Using nuclear microsatellite loci amplified from dung-extracted DNA of free-ranging elephants in a large southern Indian population, we demonstrate that female-led herds comprise closely related individuals that are indeed families, and that males exhibit non-random locational dispersal. 相似文献
11.
Summary Vanda longitepala, a new species of orchid from northern Burma is described and discussed. 相似文献
12.
J. Green 《Hydrobiologia》2007,593(1):5-12
Keratella cochlearis was present in 27 of 35 water bodies sampled in Myanmar, and was the most abundant rotifer in 10. Measurements of lorica length and posterior spine length from 20 localities showed that posterior spine length varied both with lorica length and with the composition of the crustacean zooplankton. Long spines were associated with dominance by Heliodiaptomus. The shortest spines were found in samples dominated by cladocerans or cyclopoid copepods. Posterior spine length was positively correlated with the number of diaptomid copepods. Forms without posterior spines were found in 17 localities. The lorica lengths of these spineless forms were generally similar to those of co-occurring spined forms (r = 0.68), but in a few samples the loricas of the spineless forms were significantly larger. These larger forms are similar to the ‘aspina’ forms recently recognised in the River Thames in England. These samples were dominated by cladocerans or cyclopoid copepods. In one locality spineless forms were found without spined forms. The crustacean zooplankton in this locality was also dominated by cladocerans. Guest editors: S. S. S. Sarma, R. D. Gulati, R. L. Wallace, S. Nandini, H. J. Dumont & R. Rico-Martínez Advances in Rotifer Research 相似文献
13.
A fossil scorpion belonging to a new family, genus and species, Chaerilobuthus complexus gen. n., sp. n., is described from Cretaceous amber of Myanmar (Burma). This is the third species and the fourth scorpion specimen to have been found and described from Burmese amber. The new family seems quite distinct from the family Archaeobuthidae Lourenço, 2001 described from Cretaceous amber of Lebanon. 相似文献
14.
Prachya Musikasinthorn 《Ichthyological Research》1998,45(4):355-362
Channa panaw sp. nov. (Channidae) is described from 32 specimens collected from the Irrawaddy and Sittang River basins, Myanmar. It is
distinguishable from all known congeners by the combination of the following characters: 32–35 dorsal fin rays, 23–24 anal
fin rays, 17–20 pectoral fin rays, 39–41 lateral line scales, 39–41 total vertebrae, one large scale on each side of the lower
jaw (rarely 2 on one side), pelvic fin length always more than 50% of pectoral fin length, and 7–12 irregular black blotches
on the upper half of the body. 相似文献
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16.
Toshifumi Saeki Yoichi Sakai Hiroaki Hashimoto Kenji Gushima 《Ichthyological Research》2005,52(3):302-305
The feeding habits of two small gobies, Trimma caudomaculata and T. caesiura, were surveyed on coral reefs in Okinawa, Japan. Both species actively exhibited foraging attempts beneath overhanging reef structures during the daytime, and fed on small animals, mainly copepods. Trimma caudomaculata formed feeding schools in water columns to swallow mainly Calanoida and Harpacticoida. Trimma caesiura stayed by themselves on the reef substratum and captured mainly Harpacticoida by taking short jumps into the water column. Diet compositions of these congeneric gobies may reflect differences in their foraging behaviors and use of microhabitats. 相似文献
17.
Dr. Ioan Davies 《Cell and tissue research》1977,184(4):529-538
Summary The ultrastructure of mid-gut cells of female Nasonia fed on a diet of 10% sterile sucrose is described. There are extensive alterations in cell organelles, particularly the mitochondria, rough endoplasmic reticulum (R.E.R.) and lipid inclusions, when compared to similar insects fed a normal diet of dipteran pupae. A proportion of the mitochondria found in the apical cell region are enlarged in size and contain electron-dense granules. The remaining mitochondria are smaller, but also contain electron-dense granules. Cytochrome-c oxidase activity appears to be absent from the enlarged mitochondria. The R.E.R. appears reduced in many cells of the 1 day old, sugar-fed insects, however, this component fluctuates throughout the remaining life span. The lipid inclusions prominent in the 1 day old, pupae-fed insects are not present in sucrose-fed females of the same age, but lipid deposition was recorded later in the life span. There are many large residual bodies and cytolysosomes present in the old, sugar-fed insects. These changes in ultrastructure are discussed in relation to diet and longevity. 相似文献
18.
Uemura Y Asakuma S Yon L Saito T Fukuda K Arai I Urashima T 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2006,145(4):468-478
Milk of an Asian elephant (Elephas maximus), collected at 11 days post partum, contained 91 g/L of hexose and 3 g/L of sialic acid. The dominant saccharide in this milk sample was lactose, but it also contained isoglobotriose (Glc(alpha1-3)Gal(beta1-4)Glc) as well as a variety of sialyl oligosaccharides. The sialyl oligosaccharides were separated from neutral saccharides by anion exchange chromatography on DEAE-Sephadex A-50 and successive gel chromatography on Bio Gel P-2. They were purified by high performance liquid chromatography (HPLC) using an Amide-80 column and characterized by 1H-NMR spectroscopy. Their structures were determined to be those of 3'-sialyllactose, 6'-sialyllactose, monofucosyl monosialyl lactose (Neu5Ac(alpha2-3)Gal(beta1-4)[Fuc(alpha1-3)]Glc), sialyl lacto-N-neotetraose c (LST c), galactosyl monosialyl lacto-N-neohexaose, galactosyl monofucosyl monosialyl lacto-N-neohexaose and three novel oligosaccharides as follows: Neu5Ac(alpha2-3)Gal(beta1-4)[Fuc(alpha1-3)]GlcNAc(beta1-3)Gal(beta1-4)Glc, Neu5Ac(alpha2-6)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc, and Neu5Ac(alpha2-3)Gal(beta1-4)[Fuc(alpha1-3)]GlcNAc(beta1-3)Gal(beta1-4)[Fuc(alpha1-3)]GlcNAc(beta1-3)Gal(beta1-4)Glc. The higher oligosaccharides contained only the type II chain (Gal(beta1-4)GlcNAc); this finding differed from previously published data on Asian elephant milk oligosaccharides. 相似文献
19.
Remis MJ 《Primates; journal of primatology》2006,47(1):56-64
Ripe fruit eating shapes the behavior of most of the apes. Gorillas (Gorilla gorilla) and chimpanzees (Pan troglodytes) are very different sizes and, consequently, have been traditionally viewed as ecologically distinct, but few studies have explored the behavioral and physiological foundations of their diets. Debate continues on the extent that large-bodied gorillas may be less selective and more opportunistic fruit eaters than chimpanzees. Taste responses have been predicted to relate to body size and digestive strategies. This study employs laboratory research on taste perception and discrimination among captive zoo-housed chimpanzees and relates it to previous work on gorillas to better characterize diets and niche separation among these apes. During the captive trials, differences were recorded in consumption patterns of water and varying concentrations of dilute aqueous fructose (sweet) and tannic acid solutions (astringent), compounds commonly found in wild foods. The chimpanzees exhibited similar preference thresholds for fructose (50 mM) to other primates studied. They exhibited slightly lower inhibition thresholds for tannic acid solutions than gorillas, but higher than smaller primates studied to date. These preliminary findings suggest that tannin tolerance may well be mediated by body size, though possible species differences in salivary proteins or other sensory differences remain to be explored. This research furthers our efforts to understand the roles of body size and physiological adaptations in shaping diet and niche separation of chimpanzees and gorillas. 相似文献
20.
The relationship of changes of body and mouth shape with diet during ontogeny in the Chinese hook snout carp Opsariichthys bidens was examined. Shape changes were analyzed using geometric morphometrics. Body shape changed from a shallow body to a deep body as size increased. Similarly, the head of O. bidens changed from an upward-pointing direction to a downward-pointing directing as size increased. The position of the eye also changed during ontogeny, with large individuals having an eye situated higher on the head than small individuals. The conspicuous symphyseal knob on the lower jaw of O. bidens results in a typical zigzag pattern of the jaw. The zigzag pattern became more pronounced as fish grew larger. No difference in body shape or jaw shape was found between males and females. The shape changes were associated with changes in diet, suggesting that diet choice over the course of ontogeny has a strong impact on body shape. Benthic macroinvertebrates and zooplankton dominated the diet of small individuals, medium-size individuals specialized in benthic macroinvertebrates, and fish dominated the diet of large individuals. 相似文献