Body mass and food intake in captive,breeding bottlenose dolphins,Tursiops truncatus

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).     

Behavior of captive-raised rattlesnakes (Crotalus enyo) as a function of rearing conditions

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.     

Objective evaluation of a behavioral enrichment device for captive chimpanzees (Pan troglodytes)

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.     

The Dugong Action Plan for the South Pacific: An Evaluation Based on the Need for International and Regional Conservation of Sirenians

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.     

海洋哺乳动物微生物组研究进展

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。     

Impact of population bottlenecks on genetic variation and the importance of life-history; a case study of the northern elephant seal

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.     

SURVIVORSHIP PATTERNS IN THREE SPECIES OF CAPTIVE CETACEANS

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.     

IMPLICATIONS FROM PHYSIOLOGICAL STUDIES OF MARINE MAMMALS1

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.     

Microbiological characterization of three Atlantic whiteside dolphins (Lagenorhynchus acutus) from stranding through captivity with subsequent rehabilitation and release of one animal

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.     

THERMOREGULATORY ADAPTATIONS IN MARINE MAMMALS: INTERACTING EFFECTS OF EXERCISE AND BODY MASS. A REVIEW1

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.