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1.
An estimate of how long marine mammals need to acclimate to captivity would permit more precise comparisons of husbandry practices, yet no quantitative analysis of acclimation has been performed. Therefore, we estimated the duration of acclimation to captivity for bottlenose dolphins (BD) and California sea lions (CSL) by comparing 5-d survival rates during the first 90 d of captivity with a survival rate based on days 91-365 in captivity. Wild-born BD (n = 1,270) and CSL (n = 1,650) acclimate to captivity in approximately 35 and 40 d, respectively, whereas captive born BD (n = 332) and CSL (n = 992) acclimate in approximately 50 and 40 d, respectively. When transferred between two institutions, BD (n = 911) acclimated in the same amount of time (45 d) as when first transferred from the wild, whereas transferred CSL (n = 336) acclimated more rapidly (15 VJ. 40 d) than when first transferred from the wild. Based on results from these two species, a 60-d acclimation period is recognized as a distinct interval of relatively high mortality that should be treated separately from long-term survival estimates when evaluating husbandry practices of ocean-aria and zoos. 相似文献
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Body mass (BM) was recorded regularly during pregnancy in four female Indian Ocean bottlenose dolphins (Tursiops truncatus). Daily food intakes were recorded for each animal before and after parturition. BM increase occurred variably between 2 and 5 months of gestation, and at parturition mass increases averaged 41.2% of initial prepregnancy mass. Changes in mass can thus be used as an early indicator of pregnancy. During the 12 months of pregnancy, no significant changes occurred in the amount of food ingested compared with previous years. Daily food intake during lactation (X = 13.2 kg, 8% of BM) proved significantly higher (P < 0.001) than during pregnancy (X = 8.7 kg, 5.2% of BM). 相似文献
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Two litters of rattlesnakes (Crotalus enyo; n = 6 per litter) were raised in large cages and small plastic boxes, respectively. No significant differences in exploration of a novel environment were observed between the litters, or between either of them and a group of wild-caught C. enyo, suggesting that the common practice of rearing baby snakes in small cages has no debilitating consequences on these measures. In the absence of differences between the litters, the two samples were pooled and additional analyses revealed the existence of reliable individual variation. Experiment 2 compared the two litters and the wild-caught snakes on measures of prey-directed behavior. The two captive-reared litters did not differ, but both exhibited lower levels of strike-induced chemosensory searching than did wild-caught snakes. 相似文献
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A quantitative evaluation was made of a food puzzle designed to be a behavioral enrichment device for captive chimpanzees. Subjects were two social groups of chimpanzees housed in semifree-ranging conditions at the University of Texas Science Park in Bastrop. Subjects used the device for a mean of 91.6 minutes after it was filled with peanuts. Group levels of agonistic interactions, displays, coprophagy, regurgitation, excessive grooming, and consumption of wood were not significantly altered by the use of the peanut box. However, the data indicate that some of these categories of behavior were significantly increased or decreased in individual animals. Although the food puzzle box appears to be a promising behavioral enrichment tool, the necessity of recognizing individual differences in response to environmental manipulations must be emphasized. 相似文献
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This is the first assessment of Manis javanica behavior in captivity. The aim of the investigation was to assess behavior in order to suggest ways of improving captive care and management of the species. This was undertaken by constructing time-budgets and activity patterns and identifying any abnormal repetitive behavior (ARB) exhibited. Scan and focal animal sampling were implemented in observations of seven subjects. Analyses detailed idiosyncrasies in how subjects partitioned their active time. Peak activity occurred between 18:00 and 21:00 hr. Two ARBs, clawing and pacing, were identified and the cessation of clawing in one subject was possible by modifying its enclosure. Stress-related behavior, understood to be related to several factors, means maintaining this species in captivity remains problematic. Recommendations are made pertaining to husbandry, captive management, and future research. 相似文献
6.
Beavers (Castor spp.) tend not to be a commonly held species and little published material exists relating to their captive care. We review published material and discuss husbandry issues taking into account the requirements of wild beavers. As social mammals with complex chemical communication systems and with such an ability to modify their environments, studies of wild counterparts suggest the captive requirements of beavers may actually be more sophisticated than generally perceived. Common field techniques may have practical application in the captive setting. Their widespread utilisation in conservation, including reintroductions, translocations and habitat management, also requires components of captive care. As welfare science advances there is increasing pressure on captive collections to improve standards and justify the keeping of animals. Conservation science is increasingly challenged to address individual welfare standards. Further research focusing on the captive care of beavers is required. Zoo Biol. 34:101–109, 2015. © 2015 The Authors. Zoo Biology published by Wiley Periodicals, Inc. 相似文献
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Alexander Gillespie 《Ocean Development & International Law》2013,44(2):135-158
Abstract The purpose of this article is to set out the essential requirements for a successful regional agreement for Sirenians in the South Pacific. To achieve this, the current Dugong Action Plan, which is being formed under the auspice of the South Pacific Regional Environmental Program, will be juxtaposed against the “best practice” in this area, as evinced by current development in international environmental law and policy relating to Sirenians. 相似文献
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海洋哺乳动物主要包括生活在水里的鲸类、基本生活在水里的海牛类以及水陆两栖的鳍足类,均为珍稀的国家二级及以上保护动物。微生物在哺乳动物体内起到营养吸收、辅助消化过程以及增强免疫功能的作用,是宿主体内不可或缺的一部分,而作为适应海洋环境的特殊哺乳动物类群,海洋哺乳动物的生存环境和食性的特殊性导致其体内微生物群落与陆生哺乳动物有显著差异。正是这种差异性导致我们对研究较多的陆地哺乳动物微生物的很多认识无法简单地套入海洋哺乳动物中。因此,深入了解海洋哺乳动物的微生物群落结构和功能对于了解海洋哺乳动物与环境的互作关系以及提高其保育工作的水平至关重要。本文对近年来海洋哺乳动物微生物组研究的进展进行了总结,并探讨了相关技术方法以及未来研究中值得关注的科学问题。 相似文献
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Impact of population bottlenecks on genetic variation and the importance of life-history; a case study of the northern elephant seal 总被引:5,自引:0,他引:5
A. RUS HOELZEL 《Biological journal of the Linnean Society. Linnean Society of London》1999,68(1-2):23-39
This paper reviews some of the important factors related to the impact of population bottlenecks, using the northern elephant seal (Mirounga angustirostrus) as a case study for illustration. The northern elephant seal was hunted extensively in the 19th century and forced through a bottleneck of approximately 10–20 seals. All measures of molecular genetic variation show current levels for the northern elephant seal to be low. Levels of genetic variation were compared with expectations based on a simulation model that recapitulates demographic growth, based on age-specific data on reproduction and mortality. Predictions from the simulation model are then presented to illustrate the importance of differences in life-history strategy and skewed reproductive success. Either high reproductive skew (e.g. polygyny) or a low growth rate in a population can increase the impact of a bottleneck on molecular variation. Severe population bottlenecks can also disrupt aspects of developmental stability and thereby increase the fluctuating asymmetry and variability of quantitative traits. A comparison of skulls collected before and after the bottleneck showed this to have occurred for some elephant seal quantitative characters. 相似文献
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SURVIVORSHIP PATTERNS IN THREE SPECIES OF CAPTIVE CETACEANS 总被引:1,自引:0,他引:1
Survival rates for three species of captive cetaceans are reported, based on records of dates of capture, birth, and death of individual animals. The annual survival rate was 0.93 for bottlenose dolphins and killer whales and 0.94 for white whales. Confidence limits of these estimates are discussed. Differences in survival rates between institutions were significant for bottlenose dolphins only. Calf survival for bottlenose dolphins was lower than non-calf survival. Survivorship of male killer whales was significantly less than survivorship of female killer whales; sex-specific survival rates were similar for the other two species. Estimates of average or maximum longevity alone were not useful in comparing rates of survival. Because survival in the first year of captivity may be lower than subsequent years, estimates of the expected lifespan, based on data from the first few years of captivity, may be biased. 相似文献
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Some aspects of captive marine mammal research have become matters of controversy, largely due to a misunderstanding of the value of such studies and of their importance to effective management and conservation of these species. Understanding of the physiological mechanisms underlying the special adaptations for aquatic life that marine mammals demonstrate provides essential information relating to their health and survival. The need for such information is increasing as disturbance of the world's marine environments steadily escalates. While studies of these animals in their natural habitats contribute much to our comprehension of their biology, a more complete understanding of the physiological basis of their behavior depends upon experimental laboratory investigations. Some of the new knowledge thus gained has potentially important implications for human medicine. 相似文献
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Lara Scherer Laurie Bingaman Lackey Marcus Clauss Katrin Gries David Hagan Arne Lawrenz Dennis W. H. Müller Marco Roller Christian Schiffmann Ann-Kathrin Oerke 《Zoo biology》2023,42(2):328-338
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. 相似文献
15.
- Sperm whales Physeter macrocephalus emit impulsive sound signals in short series of rhythmic clicks (codas) for communication, and in long series of single acoustic events (usual clicks) for echolocation. Both click types are generated pneumatically within the hypertrophied nasal complex, at the ‘monkey lips’ at the rostral end of the right nasal passage. Each individual click comprises repetitive pulses decaying in intensity. However, the decay rate is distinctly higher in usual clicks than in coda clicks.
- The mechanism of decay rate control in the clicks is still unclear, and it is unclear why the right nasal passage crosses the nasal acoustic pathway between two hypertrophied acoustic fat bodies (spermaceti organ, junk), so that it resembles a ‘bent acoustic horn’.
- We present a new concept to explain how the flat right nasal passage can serve as a variable acoustic valve, and how the amount and distribution of its air filling can be controlled by muscle action. This mechanism allows the whale to determine the pulse decay rate and thus switch between the two modes of click production. Coda clicks are generated by reverberations within the spermaceti organ (partial trapping of sound) and by the release of sound energy in fractions through the air‐filled right nasal passage. In contrast, echolocation clicks as single events are released during the partial collapse of the right nasal passage between the spermaceti organ and the junk.
- This interpretation of the right nasal passage as an adaptive acoustic valve elucidates why the spermaceti organ and the junk are separated from each other by an air‐filled space of variable volume crossing the sound path of the ‘bent acoustic horn’ in the posterior part of the nasal complex.
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Three live Atlantic whiteside dolphins (Lagenorhynchus acutus) were found beach-stranded on Cape Cod in Massachusetts and were shipped to Mystic Marinelife Aquarium in Connecticut and held in captivity. Swab samples were collected routinely from the anus and blowhole of live animals and from internal organs at necropsy for microbial culture. Despite antibiotic therapy, one animal died on day 9 of captivity, and one died after 110 days. The survivor was released after 126 days of captivity. Klebsiella pneumoniae septicemia and staphylococcal pneumonia were likely responsible for the two deaths. A total of 26 different organisms (or groups of organisms) were recovered from the three dolphins, including several (e.g., Pseudomonas spp, Streptococcus faecalis Candida albicans, Proteus-Morganella spp, Vibrio spp) that, in addition to the above organisms, could be potentially pathogenic for debilitated animals. Newly rescued marine mammals should be segregated from healthy animals if possible. 相似文献
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Mónica Y. Rodríguez‐Pérez David Aurioles‐Gamboa Laura Sánchez‐Velásco Seth D. Newsome 《Marine Mammal Science》2018,34(3):790-805
The vaquita (Phocoena sinus) is the world's most endangered cetacean and has experienced a 60% reduction in the size of its population in the past decade. Knowledge of its basic ecology is essential for developing successful management plans to protect and conserve this species. In this study, we identified vaquita foraging areas by creating an isoscape of the Upper Gulf of California (UGC) based on sediment and zooplankton carbon (δ13C) and nitrogen (δ15N) isotope values. Our results confirm that this species is confined to the western region of the UGC, which is characterized by relatively high δ15N values (sediments: 10.2‰ ± 2.0‰, zooplankton: 15.8‰ ± 1.3‰), higher sea surface temperatures (~16°C–25°C), higher concentrations of silt in sediments, and the highest turbidity. In contrast, the eastern region of the UGC had relatively low sediment (7.7‰ ± 2.4‰) and zooplankton (14.6‰ ± 1.0‰) δ15N values, and the highest concentrations of sand in sediments. Our approach is an effective use of marine isoscapes over a small spatial scale (<200 km) to identify the environmental characteristics that define the critical habitat for an extremely endangered marine mammal. 相似文献
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G. C. Whittow 《Marine Mammal Science》1987,3(3):220-241
A review of thermoregulation in marine mammals led to the following conclusions: very little is known about thermoregulation in large cetaceans. The only measured value for the metabolic rate of a whale, albeit a young one, was substantially higher than the predicted value for a terrestrial mammal of similar size. Very small and newborn marine mammals rely on a high metabolic heat production to sustain their body temperature during exposure to cold or in the water. The considerable insulation of some adult marine mammals may absolve them from the need for a high level of heat production. One marine mammal in tropical or subtropical waters is hypometabolic. There is evidence for a powerful control of thermoregulatory mechanisms by the anterior hypothalamic/preoptic region of the brain in two species. Thermoregulation in marine mammals during exercise remains paradoxical. 相似文献
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Victoria Eugenia Holguin-Medina John Fontenele-Araujo Víctor Manuel Alcaraz-Romero Jose Francisco Cortes Jairo Muñoz-Delgado 《Biological Rhythm Research》2015,46(5):631-645
In this study, we show temporal organization of activity patterns in larger temporal series recording. The objective of this study was to determine the temporal pattern of the rest-activity rhythm in manatee (Trichechus manatus manatus) in captivity. Activity recordings were programmed from August 2010 to September 2011 with actimetry devices, and behavior recordings were conducted in dry and rainy seasons. We showed that the marine manatee presents a complex temporal organization, in which the rest-activity rhythm comprises several frequencies with a predominant circadian component and multiple ultradian components. Our results indicate that the animals were more active during the day with respect to the night. The temporal organization of this cycle entails multiple frequencies that include ultradian rhythms, which may be expressions generated by physiological needs, such as food availability and thermoregulatory requirements. These patterns should be taken into consideration for future studies of biological rhythms in manatee. 相似文献