丹顶鹤在动物园繁殖成功的初步研究

丹顶鹤[Grus japonensis(Muller)]是我国特产的大型珍禽,被列为国家保护动物,自古以来即被饲养展览,闻名于世。由于它的分布区狭窄,数量又十分稀少,因此,研究在人工饲养条件下的繁殖生物学,不仅可以解决动物的来源问题,而且也为合理猎捕和自然保护提供资料,目前国内虽有些动物园能繁殖,但一直很少报道。     

人工饲养鲸类动物的繁殖

介绍多年来对鲸类动物在人工饲养条件下繁殖问题的研究成果,包括：雌雄性生殖器官的组织解剖,饲养和采精训练,人工饲养条件下的繁殖,孕豚护理,分娩和幼豚饲养。为推动我国鲸类动物的人工繁殖提供科学资料。     

人工饲养下白枕鹤繁殖生态的研究

人工饲养下白枕鹤繁殖生态的研究徐新杰,刘冰许郑州动物园４５０００２白枕鹤（ＯＩ,ｓ吻功）是国家二级保护动物,《国际濒危物种贸易公约》中列为１级濒危物种【‘］。研究在人工饲养条件下的繁殖生态,是移地保护的重要内容。我们近年进行了该项研究,报告如下。１亲...     

中国动物园动物种类与种群大小

2007～2008年,我们开展了中国动物园物种编目与易地保护抽样调查,抽样调查了68家动物园。抽样动物园饲养了789种[(包括虎(Panthera tigris)和金钱豹(P.pardus)的亚种]野生动物,比20世纪90年代初中国动物园饲养的600种野生动物,增加了180多种;抽样动物园饲养展出野生动物中有国外野生动物种类267种,比20世纪90年代初中国动物园饲养的100种国外野生动物,增加了160种。抽样动物园展出的中国哺乳类、鸟类、爬行类和两栖类种类数分别占中国哺乳类(607种)、鸟类(1332种)、爬行类(384种)和两栖类(302种)种类总数的25.0%、28.2%、22.7%、4.0%。这些抽样动物园饲养了234种国家重点保护野生动物和254种CITES附录物种,其中,饲养的国家Ⅰ级和Ⅱ级重点保护野生动物分别占国家Ⅰ级和Ⅱ级重点保护野生动物总数的70.57%和47.09%;饲养的列入CITES附录Ⅰ、附录Ⅱ及附录Ⅲ的中国动物分别占列入这些附录的中国动物总数的64.21%、60.86%和50%。中国动物园成功繁殖了大熊猫(Ailuiopodidae melanoleuca)、金丝猴(Rhinopithecus roxellanae)、雪豹(P.unicia)、华南虎(P.tigris amoyensis)和亚洲象(Elephas maximus)等濒危物种,也成功繁殖了从国外引入的猎豹(Acinonyx jubatus)、大猩猩(Gorilla gorilla)、美洲狮(Puma concolor)等动物。然而,调查发现,(1)抽样动物园仅饲养了四分之一左右的中国哺乳类、鸟类及爬行类动物种类,饲养的两栖类更少;(2)抽样动物园饲养种群小,多数物种没有形成可繁殖种群。抽样调查的动物园两栖类、爬行类、鸟类及哺乳类种群大小分别为5.09(±2.15)只、5.69(±4.28)只、15.00(±6.63)只和10.08(±2.91)只;(3)一些动物园,特别是小型动物园动物饲养空间小,一些动物表现出刻板行为;(4)中国动物园饲养繁殖的大熊猫、华南虎、鹤类已经建立了谱系,其他一些物种的谱系正在建立之中,然而,多数动物还没有谱系;(5)一些小型动物园存在笼舍不清洁,仅饲养了单只动物,展出动物名牌错误等问题。动物园是人类社会的重要组成部分。应当重视动物园的发展,加强国际交流与合作,为更多动物建立谱系,加大动物园的投入,增加动物种类,增大动物园面积,丰富圈养环境,发挥大型动物园的示范作用,以充分发挥动物园的动物展示、科学普及与物种资源保存功能。     

介绍一种新型的实验动物—高原鼠兔

鼠兔属动物的早期人工饲养开始于Dice对科罗拉多鼠兔(Ochotona priceps saratilis)的试养,室内繁殖未成功,直至1969年Puget从阿富汗喀布尔地区,捕获野生的阿富汗鼠兔(O. rufescens rufescens),并在人工饲养下繁殖成功。日本1974年引进作为基础对其进行实验动物化培育,供医学生物学研究用,目前已成为法、美和日本等国的实验动物。 高原鼠兔(O. curzoniac)的人工饲养始于60年代,由于鼠兔繁殖生物学因素的影响,     

23个实验小鼠和大鼠近交系的保种研究

从1985年开始,陆续从国外实验动物著名机构引进常用近交系小鼠共23个品系(亚系和亚群)。在多年来保种繁殖过程中,根据修饰平行线系统选择留种动物,同时对动物进行全兄妹近亲交配繁殖,保持完整的谱系记录,控制饲养环境条件,成功地保持了绝大多数品系。同时对多数品系的繁殖性能和体重增长进行了观察,为这些品系的实验应用提供基本参数。     

人工哺育华南虎的繁殖六例推断

华南虎(Panthere tigris amcyensis),是我国的珍贵动物之一。如今由于人类的经济活动,使华南虎的分布区域逐渐缩小,且野生数量已为数不多,鉴于野生华南虎的数量越来越少,人工哺育华南虎的繁殖更有其现实意义。 我园对华南虎的饲养与繁殖已有20余年历史,其中华南虎的繁殖也有几十胎的记录,但有关完全用人工哺育,从未吃过初乳长大的华南虎的繁殖资料尚未见报道。现将我园人工哺育华南虎的繁殖六例记录加以整理,为人工哺育华南虎的繁殖工作提供一些资料。     

几种近交品系小鼠的毛色基因

生物医学研究的不断发展,要求提供各种基因型的近交系动物,用作试验模型。近交系动物具有遗传背景清楚,特性明确,基因纯合性较高等特点。国际上应用广泛。1975年第三版《国际实验动物索引》公布的近交系小鼠有388个品系。但尽管近交系动物的遗传性状相对稳定,在长期饲养过程中仍可能发生变异;也可能因为饲养管理的不慎而造成基因污染。所以饲养繁殖近交系动物时,必须定期进行遗传质量的监测,以确保近交系动物主要遗传特性的延续,使科学工作者能获得可靠的研究成果。     

黄鼬的繁殖

动物的繁殖是研究种群数量变动和资源利用的基础。对于重要资源动物黄鼬的繁殖问题,更有探究的必要。现就1963年至1978年5月在上海市郊和崇明岛的调查,以及室内饲养观     

以维生素及微量元素添加剂代替青饲料饲养家兔试验观察

长期以来,实验家兔在生产繁殖中均以混合饲料、青饲料作为其主要饲料。随着科学技术的不断发展,实验动物饲养管理水平的提高,对于动物的饲料有了大量的研究。目前,国外已应用维生素和微量元素添加剂代替青饲料,饲养无特定病原动物(Speciul pathogen free animal,简称SPF动物)和普通动物。在学习和参阅国内外饲养家兔的经验基础上,我们进行了一年的家兔饲养试验,取得一定结果,介绍如下。     

Social interactions in captive female Florida manatees

The Florida manatee (Trichechus manatus latirostris) is considered a semi‐social species with strong bonds developed primarily between mother and offspring. Some field studies suggest sociality may be more developed and such social relationships may facilitate survival. Seven facilities in Florida house manatees, many of which were brought into captivity because of injury or illness sustained in the wild. Decisions to release such manatees consider individual history and health. We examined social interactions in adult female captive manatees to assess level of association and implications for manatee care and release. We investigated the degree of contact among 20 manatees in captivity at four facilities housing two to nine adult female manatees. We used all contact behavior occurrences sampling and continuous recording for 180 continuous minutes per day over 3 consecutive days at each facility. Virtually all contacts were non‐aggressive. The number of contacts between manatees increased as the number of manatees per unit volume of water increased. Contacts did not fit a Poisson distribution, however, and were not random. When more than two manatees were present, manatees only associated with a subset of individuals in the aquarium. Relationships maintained in captivity indicate the potentially social nature of manatees, and suggest that further research is needed to examine the benefit of these relationships to the health and rehabilitation of manatees in captivity and conservation in the wild. Zoo Biol 24:135–144, 2005. © 2005 Wiley‐Liss, Inc.     

The existence value of the Antillean manatee in the unprotected Hondo River (Mexico) as a fundamental component for its conservation

The Hondo River is the natural border between Mexico and Belize, and it is part of the distribution area of the Endangered Antillean manatee Trichechus manatus manatus. Currently, the Hondo River does not have any special protection. Employing qualitative research methods, we documented the social perception and local knowledge from riverside communities to assess conservation status and trends of manatees in the area. Fifty semi-structured interviews were carried out to river users in 16 Mexican communities, distributed in six segments along the riverbed. The claims of the inhabitants agree with boat-based surveys: most of the current and historical manatee sightings were reported in segments of the main watercourses, but also in small tributaries, which are usually shallow and rich in aquatic vegetation. Additionally, the local perception about manatee conservation status can be helpful to understand population trends and threats: 48 % of the interviewees claimed that nowadays the number of sighted manatees is less than that observed 10 years ago. The responders identified water pollution due to cane cultivation practices, motorized vessels traffic, and presence of fishing nets as potential threats to manatees. This study provides evidence of relevant local knowledge about the manatee ecology and its habitat, critical in the construction of binational conservation strategies for the species. Therefore, local resources users may play an increasingly significant role in manatee management and monitoring. Although manatees are poached for their meat in several areas of their distribution, the most common value attributed to manatees in Hondo River was non-use existence values. Local people recognize the challenges to observe this cryptic species in this river, but also identified manatees as potential flag species, suggesting that it may represent a valuable resource for ecotourism. We suggest that the non-extractive use of manatees has the potential for promoting species conservation and local economic growth.     

OBSERVATIONS OF FLORIDA MANATEES(TRICHECHUS MANATUS LATIROSTRIS) AROUND SELECTED POWER PLANTS IN WINTER

Sixty-four aerial surveys were flown during cold, winter weather between December 1982 and February 1772 to provide an index of trends in abundance of the Florida manatee ( Trichechus manatus latirostris )around five Florida Power & Light Company (FPL) plants. The surveys documented high winter use of warm-water discharges at four of the plants (Canaveral, Riviera. Port Everglades, and Fort Myers). The total number of manatees sighted at the five primary plants surveyed during a single survey ranged from 6 to 765 manatees (= 330 ± 45 manatees per survey): thus, up to 41% of the total Florida manatee minimum population of 1.850 animals may be found on cold days at FPL plants. The number of calves sighted at the plants during winter has decreased; similarly, for three consecutive years (winter 1989–1970 through winter 1991–1992), the percentage of the manatees that are calves sighted at the plants has decreased. Although data from the surveys of FPL plants do not necessarily reflect what may be happening with manatees located elsewhere in Florida, a possible reduction in calf numbers, coupled with increasing numbers of dead calves being documented by scientists involved in manatee carcass salvage work, is cause for concern in this slow-reproducing, endangered species.     

New aerial survey and hierarchical model to estimate manatee abundance

Monitoring the response of endangered and protected species to hydrological restoration is a major component of the adaptive management framework of the Comprehensive Everglades Restoration Plan. The endangered Florida manatee (Trichechus manatus latirostris) lives at the marine-freshwater interface in southwest Florida and is likely to be affected by hydrologic restoration. To provide managers with prerestoration information on distribution and abundance for postrestoration comparison, we developed and implemented a new aerial survey design and hierarchical statistical model to estimate and map abundance of manatees as a function of patch-specific habitat characteristics, indicative of manatee requirements for offshore forage (seagrass), inland fresh drinking water, and warm-water winter refuge. We estimated the number of groups of manatees from dual-observer counts and estimated the number of individuals within groups by removal sampling. Our model is unique in that we jointly analyzed group and individual counts using assumptions that allow probabilities of group detection to depend on group size. Ours is the first analysis of manatee aerial surveys to model spatial and temporal abundance of manatees in association with habitat type while accounting for imperfect detection. We conducted the study in the Ten Thousand Islands area of southwestern Florida, USA, which was expected to be affected by the Picayune Strand Restoration Project to restore hydrology altered for a failed real-estate development. We conducted 11 surveys in 2006, spanning the cold, dry season and warm, wet season. To examine short-term and seasonal changes in distribution we flew paired surveys 1–2 days apart within a given month during the year. Manatees were sparsely distributed across the landscape in small groups. Probability of detection of a group increased with group size; the magnitude of the relationship between group size and detection probability varied among surveys. Probability of detection of individual manatees within a group also differed among surveys, ranging from a low of 0.27 on 11 January to a high of 0.73 on 8 August. During winter surveys, abundance was always higher inland at Port of the Islands (POI), a manatee warm-water aggregation site, than in the other habitat types. During warm-season surveys, highest abundances were estimated in offshore habitat where manatees forage on seagrass. Manatees continued to use POI in summer, but in lower numbers than in winter, possibly to drink freshwater. Abundance in other inland systems and inshore bays was low compared to POI in winter and summer, possibly because of low availability of freshwater. During cold weather, maps of patch abundance of paired surveys showed daily changes in manatee distribution associated with rapid changes in air and water temperature as manatees sought warm water with falling temperatures and seagrass areas with increasing temperatures. Within a habitat type, some patches had higher manatee abundance suggesting differences in quality, possibly due to freshwater flow. If hydrological restoration alters the location of quality habitat, postrestoration comparisons using our methods will document how manatees adjust to new resources, providing managers with information on spatial needs for further monitoring or management. Total abundance for the entire area was similar among survey dates. Credible intervals however were large on a few surveys, and may limit our ability to statistically detect trends in total abundance. Additional modeling of abundance with time- and patch-specific covariates of salinity, water temperature, and seagrass abundance will directly link manatee abundance with physical and biological changes due to restoration and should decrease uncertainty of estimates. © 2011 The Wildlife Society.     

SKIN DENSITY AND ITS INFLUENCE ON BUOYANCY IN THE MANATEE (TRICHECHUS MANATUS LATIROSTRIS), HARBOR PORPOISE (PHOCOENA PHOCOENA), AND BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS)

This study investigated how skin contributes to buoyancy control in the Florida manatee ( Trichechus manatus latirostris ), harbor porpoise ( Phocoena phocoena ), and bottlenose dolphin ( Tursiops truncatus ). Manatees are shallow divers and control their position in the water column hydrostatically. The two cetaceans are relatively deep divers that control their buoyancy hydrodynamically. Although the cetacean skin had been hypothesized to lower total body density ( e. g. , Dearolf et al. 2000, Nowacek et al. 2001), its buoyant force had not been calculated. The density of manatee skin, and its contribution to buoyancy, was unknown. Skin densities of 27 manatees, five harbor porpoises, and five bottlenose dolphins were measured volumetrically. Skin mass and density were used to calculate buoyant force. Harbor porpoise (952 kg/m³) and bottlenose dolphin (969 kg/m³) skins were less dense than seawater, and added 9 and 25 N of positive buoyant force, respectively, to total body buoyancy. By contrast, manatee skin (1,121 kg/m³) contributed 56 N of negative buoyant force, which equaled 70% of the negative buoyant force of their dense, pachyosteosclerotic ribs. Calculation of buoyant forces of the skeleton, skin and lungs demonstrates that the manatee is positively buoyant at the surface and negatively buoyant at depths of less than 10 m.     

PREHENSILE USE OF PERIORAL BRISTLES DURING FEEDING AND ASSOCIATED BEHAVIORS OF THE FLORIDA MANATEE (TRICHECHUS MANATUS LATIROSTRIS)

The use of perioral bristles (modified vibrissae) by 17 captive Florida manatees and approximately 20 wild manatees was analyzed. Captive manatees were fed six species of aquatic vegetation normally eaten in the wild (four freshwater species and two seagrasses). Inanimate objects were placed in the holding tanks with manatees at Lowry Park Zoological Gardens (Tampa, FL) to determine the degree to which perioral bristles were used in exploration and to define the range of manipulative behavior. In addition, behavioral observations were made on the use of perioral bristles during social interactions with conspecifics. Observations were recorded using a Hi8-format video camera. Florida manatees possess an unusually large degree of fine motor control of the snout and perioral bristles. The large and robust perioral bristle fields of the upper lip were used in a prehensile manner during feeding. Bristle use by manatees feeding on submerged vegetation differed from that seen during feeding on floating vegetation. Other behavioral use of the perioral bristles shows variation depending upon the situation encountered. The degree of plasticity of perioral bristle use supports our hypothesis that the vibrissal-muscular complex of the Florida manatee has evolved to increase the efficiency of grazing and browsing on aquatic vegetation and to fully maximize the potential of the manatee as a generalist feeder. The manipulative and sensitive nature of the manatee snout is likely a manifestation of a complex sensory and motor system which has evolved for marine mammal aquatic herbivores living in shallow turbid habitats.     

African manatee (Trichechus senegalensis) habitat suitability at Lake Ossa,Cameroon, using trophic state models and predictions of submerged aquatic vegetation

The present study aims at investigating the past and current trophic status of Lake Ossa and evaluating its potential impact on African manatee health. Lake Ossa is known as a refuge for the threatened African manatees in Cameroon. Little information exists on the water quality and health of the ecosystem as reflected by its chemical and biological characteristics. Aquatic biotic and abiotic parameters including water clarity, nitrogen, phosphorous, and chlorophyll concentrations were measured monthly during four months at each of 18 water sampling stations evenly distributed across the lake. These parameters were then compared with historical values obtained from the literature to examine the dynamic trophic state of Lake Ossa. Results indicate that Lake Ossa''s trophic state parameters doubled in only three decades (from 1985 to 2016), moving from a mesotrophic to a eutrophic state. The decreasing nutrient gradient moving from the mouth of the lake (in the south) to the north indicates that the flow of the adjacent Sanaga River is the primary source of nutrient input. Further analysis suggests that the poor transparency of the lake is not associated with chlorophyll concentrations but rather with the suspended sediments brought‐in by the Sanaga River. Consequently, our model demonstrated that despite nutrient enrichment, less than 5% of the lake bottom surface sustained submerged aquatic vegetation. Thus, shoreline emergent vegetation is the primary food available for the local manatee population. During the dry season, water recedes drastically and disconnects from the dominant shoreline emergent vegetation, decreasing accessibility for manatees. The current study revealed major environmental concerns (eutrophication and sedimentation) that may negatively impact habitat quality for manatees. The information from the results will be key for the development of the management plan of the lake and its manatee population. Efficient land use and water management across the entire watershed may be necessary to mitigate such issues.     

Digesta passage rates in the Florida manatee (Trichechus manatus latirostris)

The Florida manatee, Trichechus manatus latirostris (Sirenia: Trichechidae), is an herbivorous marine mammal found within coastal areas throughout the state of Florida, which feeds on both fresh and salt water sea grasses. Manatees, like other Sirenians, are a tropical species with little tolerance for water temperatures below 20°C, rely on a relatively poor nutritional food source, and have a low metabolic rate. Although manatees are hindgut fermenting herbivores, they are very efficient at extracting nutrients from the plants on which they feed. Slow passage rates of digesta have been suggested to be a factor in this increased efficiency. Two studies monitored the digesta passage times and mixing of particulate digesta within the manatee digestive tract using MicroGrits colored corncob grit as a fecal marker. Fecal samples were collected subsequently from four manatees in Study 1 and 3 manatees in Study 2, grit pieces removed, counted, and measured. The digesta passage times ranged from 6 and 10 days in Study 1, and 4.3 and 8.3 days in Study 2, supporting data presented in previous studies. When two different colored markers were administered on sequential days, minimal to no mixing was seen in recovered feces, suggesting that the digesta from a given day traveled through the tract as a bolus. Less than 1% of the marker fed was recovered and we hypothesize that perpendicular folds of the large intestine may be the major contributing factor, with pieces being retained and eventually digested. Zoo Biol 26:503–515, 2007. © 2007 Wiley‐Liss, Inc.     

INFLUENCE OF POWER PLANTS AND OTHER WARM-WATER REFUGES ON FLORIDA MANATEES

Because of limited tolerance to cold, most Florida manatees survive cold winter periods by aggregating at warm‐water discharges from power plants and natural springs in central and northern Florida. Many power plants used by manatees may soon be retired. When this occurs, some people assume manatees will move to warmer areas in southern Florida; others fear they will stay near retired plants and sustain high levels of cold‐related deaths causing a decline in abundance. To assess these possibilities, we examine warm‐water habitats, population structure and movement, cold‐related deaths, and information on possible historical manatee distribution. Winter water temperatures even in southernmost Florida periodically fall below manatee tolerance levels. To survive such periods, manatees use two types of warm‐water refuges: warm‐water discharges, and passive thermal basins that cool slowly, thereby temporarily retaining warm temperatures. During the coldest periods, perhaps 60% of all manatees use 10 power plants and 15% use four natural springs; most others use thermal basins in southern Florida. Site fidelity to these refuges appears to be the principal factor segregating manatees into at least four subpopulations. Since 1986, rates of cold‐related deaths in southernmost Florida (10.0%) have exceeded those in areas with natural springs in central and northern Florida (8.8%). Our findings suggest that warm‐water springs in northern Florida offer better winter habitat than thermal basins in southern Florida and are better able to support large numbers of manatees. Although evidence is scant, we suggest that manatees historically overwintered principally at northern springs, but that Pre‐Columbian and European hunting restricted their winter range to southernmost Florida by the early 1900s. We also suggest that southernmost Florida may not be able to sustain a large influx of displaced of manatees in the absence of power plants, and that warm‐water springs in northern Florida should be considered the most important source of natural warm‐water habitat.