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1.
The feeding ecology of western lowland gorillas (Gorilla gorilla gorilla) living in the Nouabalé-Ndoki National Park, northern Congo, was surveyed for one full year. This is the first record to make clear the seasonal changes in the feeding habits of gorillas in a whole year, living in the primary lowland forest almost completely undisturbed. Fecal contents, feeding traces, and direct observation were analyzed with reference to a fruit availability survey. Although the gorillas fed largely on fruits in the forest, their basic diet was fibrous parts of plants, including shoots, young leaves, and bark. Terrestrial herbaceous vegetation, such as monocotyledons of the Marantaceae and aquatic herbs having much protein content and minerals, were frequently eaten even in the fruiting season. As these highly nutritious fibrous foods were superabundant all year, the major foods of the Ndoki gorillas seemed to be those plants. However, they selected fruits as their alternative food resources in the fruiting season. Gorillas foraged on many fruit species, while showing strong preferences for some particular species. The swamp forest, including marshy grasslands, was an important and regular habitat for the Ndoki gorillas.  相似文献   

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Because mating entails both costs and potential benefits to both sexes, males and females should be under selection to make optimal choices from among available potential mates. For example, in some cases, individuals may benefit by using information on potential mates' previous sexual histories to make mate choices. In such cases, the form and direction of these benefits may vary both between the sexes and based on the sexual history of the choosing individuals themselves. We investigated the effects of recent previous sexual history on the mate choice and mating behavior of both males and females of the crayfish Orconectes limosus. In one experiment, we found that opposite‐sex dyads comprising crayfish that had both mated 7–8 d previously with other conspecifics were significantly less likely to mate than dyads in which at least one crayfish was unmated. In a second experiment, we found that, when presented with a choice of tethered (but free to move) opposite‐sex conspecifics, only virgin females discriminated between males based on sexual history, showing a preference for virgin males over recently mated males. Mated females, mated males, and virgin males showed no preferences based on the sexual histories of potential mates. We discuss the implications of these inferences in the context of what was previously known about mating behavior and potential sperm limitation in crustaceans and other taxa.  相似文献   

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In this study we investigated the communicative abilities of 10 orangutans (Pongo pygmaeus) and seven western lowland gorillas (Gorilla gorilla gorilla), and particularly focused on their sensitivity to the attentional state of a human experimenter when choosing from a repertoire of both auditory and visual communication strategies. In experiment 1 a banana was placed in front of the subject's cage and a human experimenter was either present or absent. The subject's behavior was recorded for 60 sec. Both gorillas and orangutans gestured (t(16)=-3.58, P<.005) and vocalized (t(16)=-2.47, P<.05) more when the experimenter was present. In experiment 2 a human experimenter held a banana in front of the subject's cage and was oriented either toward or away from the subject. Again the subject's behavior was recorded for 60 sec. In this experiment both gorillas and orangutans gestured significantly more frequently (t(16)=3.40, P<.005) when the experimenter was oriented toward them. In addition, gorillas and orangutans used other forms of visual communication signals, such as lip pout (t(16)=3.66, P<.005), barter/trade (t(16)=2.31, P<.05), and body present (t(16)=2.31, P<.05) significantly more when an experimenter was facing them. The overall results indicate that both gorillas and orangutans are sensitive to the attentional state of a human experimenter and use appropriate communicative signals to gain that individual's attention. These results are also similar to previous findings on communicative behaviors in chimpanzees.  相似文献   

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This article compares the migration processes to, and the socio‐economic conditions of colonial Caribbean migrants in, the metropoles. Specifically, it discusses: 1) the formation of modern colonies in the Caribbean after World War II; 2) the differences between colonial Caribbean migrations and migrations from Caribbean nation‐states; 3) the different socio‐economic characteristics among Caribbean colonial migrants in the metropoles; and 4) the labour market incorporation and public policies affecting colonial Caribbean migrants in each metropolitan society. There are interesting differences among these Caribbean colonial migrants regarding the process of incorporation into the host society. This is related to the different development of the welfare state in each metropole and to the presence or absence of specific public policies addressing the peculiar socio‐economic conditions of these migrants.  相似文献   

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Disease is a major concern for the conservation of great apes, and one that is likely to become increasingly relevant as deforestation and the rise of ecotourism bring humans and apes into ever closer proximity. Consequently, it is imperative that preventative measures are explored to ensure that future epidemics do not wipe out the remaining populations of these animals. In this paper, social network analysis was used to investigate vulnerability to disease in a population of wild orang-utans and a community of wild chimpanzees. Potential ‘superspreaders’ of disease - individuals with disproportionately central positions in the community or population - were identified, and the efficacy of vaccinating these individuals assessed using simulations. Three resident female orang-utans were identified as potential superspreaders, and females and unflanged males were predicted to be more influential in disease spread than flanged males. By contrast, no superspreaders were identified in the chimpanzee network, although males were significantly more central than females. In both species, simulating the vaccination of the most central individuals in the network caused a greater reduction in potential disease pathways than removing random individuals, but this effect was considerably more pronounced for orang-utans. This suggests that targeted vaccinations would have a greater impact on reducing disease spread among orang-utans than chimpanzees. Overall, these results have important implications for orang-utan and chimpanzee conservation and highlight the role that certain individuals may play in the spread of disease and its prevention by vaccination.  相似文献   

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S. T. Parker 《Human Evolution》1991,6(5-6):435-449
In this paper I present an hypothesis to explain the presence of mirror self-recognition (MSR) in great apes and human infants, and the absence of MSR in monkeys. This hypothesis is based on the following elements: 1) review of Gallupian studies of MSR in monkeys and apes; 2) review of Lewis & Brooks-Gunn's study for self-recognition in human infants; 3) application of the human model to comparative data on MSR in nonhuman primates; 4) discussion of cognitive correlates of MSR in human infants; 5) analysis of the cognitive correlates of MSR absence in monkeys, and MSR presence in apes; 6) comparative analysis of the modalities of occurrence of imitation and understanding of causality in monkeys and apes; and 7) a cladistic reconstruction of the evolution of MSR.  相似文献   

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Primates, especially apes, are popular with the public, often attracting large crowds. These crowds could cause behavioral change in captive primates, whether positive, neutral, or negative. We examined the impact of visitors on the behavior of six western lowland gorillas (Gorilla gorilla gorilla), observing the troop over 6 weeks during high season (4.5 hr/day, 35 days, May–July 2016). We used focal scan sampling to determine activity budget and enclosure usage, and focal continuous sampling to identify bouts of anxiety-related behavior (visitor-directed vigilance, self-scratching, and aggression). Both daily zoo-entry numbers (VGATE) and instantaneous crowds at the exhibit (VDENSITY) were measured. Overall, VGATE had little effect across behaviors. However, consistent with the more acute time frame of measurement, VDENSITY was a better predictor of behavior; at high crowd volumes, we observed significant group-level changes in activity budget (increased inactivity, increased locomotion, and decreased environment-related behaviors), increase in some anxiety-related behaviors, and decreased enclosure usage. Although contributing similar effects, it could not be determined if crowd numbers, composition, or noise most affected the troop, nor any chronic effects of exposure to large crowds. Nevertheless, our findings suggest that measures to minimize the impacts of large crowds at the exhibit would be beneficial. Furthermore, we highlight potential discrepancies between common methods for measuring visitor numbers: VGATE is less sensitive to detecting visitor effects on behavioral indices than VDENSITY. Future studies should appropriately match the biological time frame of welfare indicators and visitor measures used to ensure the reliability of findings.  相似文献   

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From the moment of its inception, human choice about how to treat the environment is a key part of ecological restoration. Because many, if not most, restoration projects require continual management once established, human choice remains a vital component of restoration projects for their entire life. But ecological restorationists often downplay the role of choice in restoration, partly because we see the choice to restore as obvious and inherently good and partly because we feel the restoration of more natural conditions for a habitat will lessen the impact of human choice over time. Some critics feel the role of human choice in restoration degrades the value of restoration. However, another response to human choice in restoration is to embrace choice, even with the problems it brings, and use choice as a way to more fully engage humans with the environment. If such choices are approached carefully, with recognition of the potential for poor choices, then restorationists can arrive at restorations that are better for both the environment and us.  相似文献   

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Ring‐tailed lemurs reside in many animal collections worldwide. Lemur welfare may be a cause of concern due to some captive individuals exhibiting stereotypic behavior. Despite these concerns, there has been little exploration of methods of environmental enrichment for ring‐tailed lemurs. Olfactory stimulation can enhance captive animal welfare by encouraging species‐typical behaviors, enhancing behavioral diversity, and decreasing stereotypic behaviors. We aimed to investigate the effects of olfactory stimulation via lavender, peppermint, coconut, and prey odor upon the behavior of eight captive ring‐tailed lemurs. We exposed the lemurs to six individual odor conditions (odor control, novel object control, lavender, peppermint, coconut, and Morio worms) and observed them for 4 hr a day for 3 days with an intervening period of 4 days between conditions. We recorded the lemurs’ behavior under each condition using instantaneous scan sampling. We found significant effects of olfactory stimulation on the ring‐tailed lemurs’ behavior in the initial analysis but these did not survive correction for multiple testing. Overall, while our findings are suggestive of a general effect of olfactory stimulation on the captive ring‐tailed lemurs they did not indicate a marked influence of olfactory condition. However, further investigation with a larger sample size and more biologically relevant odors may be beneficial to fully examine potential effects of olfactory stimulation in captive lemurs.  相似文献   

11.
Theoretical analyses of selection on mutations affecting female responsiveness to male traits suggested that sexually antagonistic selection and traditional female choice are not exclusive alternatives. They can act simultaneously on the same female traits, and can either reinforce or act against each other. These analyses do not yield theoretical predictions regarding the relative frequency and importance of the two types of selection on female responsiveness, as the balance between them is affected by complex factors, including the frequency distribution of male traits, and the mechanisms of male action. Male–female interactions differ from many other evolutionary interactions involving potential evolutionary conflict, in that male and female genomes are irretrievably mixed in their offspring, thus increasing the possibility of indirect payoffs to one participant from the traits of its partner.  相似文献   

12.
During the breeding season, the reproductive condition of female mammals changes. Females may or may not be sexually receptive. We conducted a series of experiments to determine whether reproductive condition of female meadow voles affects their scent marking behavior as well as the scent marking behavior of male conspecifics. In expt 1, females in postpartum estrus (PPE females) deposited more scent marks than females that were neither pregnant nor lactating (REF females) or ovariectomized females (OVX females). In expt 2, male voles scent marked more and deposited more over‐marks in areas marked by PPE females than by REF and OVX females. In expt 3, PPE females deposited more scent marks and over‐marks in areas marked by males than did females in the other reproductive states. The results of these experiments showed that male and female voles may vary in the number, type and location of scent marks they deposit in areas scented by particular conspecifics.  相似文献   

13.
Since the adoption of the WTO‐TRIPS Agreement in 1994, there has been significant controversy over the impact of pharmaceutical patent protection on the access to medicines in the developing world. In addition to the market exclusivity provided by patents, the pharmaceutical industry has also sought to further extend their monopolies by advocating the need for additional ‘regulatory’ protection for new medicines, known as data exclusivity. Data exclusivity limits the use of clinical trial data that need to be submitted to the regulatory authorities before a new drug can enter the market. For a specified period, generic competitors cannot apply for regulatory approval for equivalent drugs relying on the originator's data. As a consequence, data exclusivity lengthens the monopoly for the original drug, impairing the availability of generic drugs. This article illustrates how the pharmaceutical industry has convinced the US and the EU to impose data exclusivity on their trade partners, many of them developing countries. The key arguments formulated by the pharmaceutical industry in favor of adopting data exclusivity and their underlying ethical assumptions are described in this article, analyzed, and found to be unconvincing. Contrary to industry's arguments, it is unlikely that data exclusivity will promote innovation, especially in developing countries. Moreover, the industry's appeal to a property rights claim over clinical test data and the idea that data exclusivity can prevent the generic competitors from ‘free‐riding’ encounters some important problems: Neither legitimize excluding all others.  相似文献   

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Pigs used in research are often housed in barren environments. The effects of ice as a simple enrichment tool for newly weaned pigs were investigated. Four replicates of 120 pigs were separated into 3 groups. One group was given free access to blocks of ice (ice group), another group had access to Classic Kong toys (Kong group), and a 3rd group did not receive any enrichment (control group). The behavior of each group was observed every 5 min from 08:00 hr to 12:00 hr during 4 consecutive days. Pigs were motivated to explore the ice blocks (4.85% ± 1.34) over the Classic Kong toys (2.03% ± 0.59). No differences in other behaviors were found between treatments. Ice is an effective and easy-to-replace enrichment device. Blocks of ice can be used as enrichment devices for pigs housed in research facilities.  相似文献   

16.
Current ecological surveys for great crested newts are time‐consuming and expensive and can only be carried out within a short survey window. Additional survey methods which would facilitate the detection of rare or protected species such as the great crested newt (Triturus cristatus) would be extremely advantageous. Environmental DNA (eDNA) analysis has been utilized for the detection of great crested newts in Denmark. Here, the same methodology has been applied to water samples taken from UK ponds concurrently with conventional field surveying techniques. Our eDNA analysis exhibited an 84% success rate with a kappa coefficient of agreement between field and eDNA surveys of 0.86. One pond determined to be negative for great crested newt by field survey was positive by eDNA analysis, revealing the potential for improved detection rates using this methodology. Analysis of water samples collected in late summer indicates that eDNA analysis could be used to detect great crested newt after the optimal survey window for current field techniques had passed. Consequently, eDNA analysis could augment currently stipulated techniques for great crested newt surveying as a relatively quick and inexpensive tool for collecting great crested newt presence and distribution data within the UK instead of or prior to full field surveys.  相似文献   

17.
Oviposition behavior may be affected by the presence of potential future competitors, mates, or predators of offspring. We examined patch choice, oviposition site preference and egg production in the predaceous mites Phytoseiulus persimilis and Neoseiulus californicus (Acari: Phytoseiidae) when given a choice between paired spider mite patches with and without conspecific eggs, with and without heterospecific eggs, and with conspecific or heterospecific eggs. Neoseiulus californicus females had no patch preference and distributed their eggs randomly in all choice situations. This was also the case with P. persimilis females given a choice between patches with and without conspecific eggs and between patches with either con- or heterospecific eggs. Phytoseiulus persimilis females confronted with patches with and without heterospecific eggs preferentially stayed and oviposited in the predator free patches. We discuss the oviposition strategies of P. persimilis and N. californicus with respect to food competition, cannibalism and intraguild predation.  相似文献   

18.
Abstract

Access to marine genetic resources (MGRs) in areas beyond national jurisdiction (ABNJ) and the sharing of benefits arising out of the utilization of these resources are among the most contentious at the UN Intergovernmental Conference on Marine Biodiversity of Areas Beyond National Jurisdiction. This article examines the applicability of the marine scientific research (MSR) regime of the UN Convention on the Law of the Sea (UNCLOS) to the access and benefit-sharing issues. It concludes that the MSR regime of UNCLOS provides the legal basis for setting up nonmonetary-benefit sharing obligations, including the dissemination of information, data, and research results concerning MGRs at the UN negotiations on marine biodiversity in the ABNJ.  相似文献   

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The neurotransmitter gamma-aminobutyric acid (GABA) is depolarizing in the developing vertebrate brain, but in older animals switches to hyperpolarizing and becomes the major inhibitory neurotransmitter in adults. We discovered a similar developmental switch in GABA response in Caenorhabditis elegans and have genetically analyzed its mechanism and function in a well-defined circuit. Worm GABA neurons innervate body wall muscles to control locomotion. Activation of GABAA receptors with their agonist muscimol in newly hatched first larval (L1) stage animals excites muscle contraction and thus is depolarizing. At the mid-L1 stage, as the GABAergic neurons rewire onto their mature muscle targets, muscimol shifts to relaxing muscles and thus has switched to hyperpolarizing. This muscimol response switch depends on chloride transporters in the muscles analogous to those that control GABA response in mammalian neurons: the chloride accumulator sodium-potassium-chloride-cotransporter-1 (NKCC-1) is required for the early depolarizing muscimol response, while the two chloride extruders potassium-chloride-cotransporter-2 (KCC-2) and anion-bicarbonate-transporter-1 (ABTS-1) are required for the later hyperpolarizing response. Using mutations that disrupt GABA signaling, we found that neural circuit development still proceeds to completion but with an ∼6-hr delay. Using optogenetic activation of GABAergic neurons, we found that endogenous GABAA signaling in early L1 animals, although presumably depolarizing, does not cause an excitatory response. Thus a developmental depolarizing-to-hyperpolarizing shift is an ancient conserved feature of GABA signaling, but existing theories for why this shift occurs appear inadequate to explain its function upon rigorous genetic analysis of a well-defined neural circuit.  相似文献   

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