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1.
Radio-collared coyotes (Canis latrans) were relocated every 15 min during continuous 24-h sampling periods. The data were used to estimate patterns of home-range use by coyotes. Utilization of the the home range was found to vary spatially and behaviourally. Spatial use was determined by relative amounts of time coyotes spent and amounts of distance they travelled within each are of their home ranges. Behavioural use was based on identification of three types of movement patterns that werew postulated to represent three general kinds of behaviour: (1) resting behaviour, (2) hunting or investigative behavour, and (3) ranging or traveling behaviour. Spatial and behavioural uses of the home range area were found to be interrelated; core areas in which animals spent most of their time were also used primarily for resting or hunting. In areas in which animals spent little time, coyotes exhibited primarily ranging behaviour. Use patterns were postulated to be the result of coyotes' selection of areas due to unique vegetal, faunal, or physiogfaphic characteristics. Temporal variatrions in home-range use were found and were postulated to result from seasonal and diel changes in coyote behaviour due to the annual reproductive cycle, the seasonal and diel cycle of temperature, possible cycles in prey behaviour.  相似文献   

2.
The rheological characteristics of bovine amniotic fluid have been studied at different shear rates. The viscosity of bovine amniotic fluid at 20°C was found to increase with time at a constant low shear rate during the measurement. Additionally, the viscosity was observed to decrease with increasing shear rate, indicating that a shear thinning behaviour of the fluid was occurring. The log-log plot of shear stress versus shear rate yielded a straight line, consistent with non-Newtonian behaviour of the fluid and characteristic of pseudoplastic liquids. The data of shear stress versus shear rate could be represented by a power law model. The treatment of amniotic fluid with cetylpyridinium chloride (CPC) resulted in the precipitation of a mixture of components, including complex sulphated polysaccharides and extracellular proteoglycans, with the viscosity of the resulting liquid similar to that of water at 20°C. In addition, the viscosity of the CPC-pretreated fluid did not increase with time at constant shear rate and remained constant with the increase in shear rate. The apparent increase in viscosity with time and the shear thinning behaviour of the amniotic fluid can thus be attributed to pseudoplastic liquid behaviour associated with the presence of structurally complex polysaccharides and extracellular proteoglycans. The implications of this fluid viscosity behaviour are discussed in terms of their impact on the operation of packed or expanded (fluidized) chromatographic bed systems when amniotic fluid biofeed-stocks are used as a source of commercially important proteins.  相似文献   

3.
In this preliminary study defense behaviour patterns (fear responses) are described in two closely related, behaviourally different inbred labyrinth fish subspecies and in their F1 generation. The subspecies M. opercularis (characterized briefly by “active escape”) and M. opercularis concolor (characterized by “passive escape”) showed specific differences in the manifestation of certain defense behaviour patterns. In the F1 hybrid generation dominance and overdominance of M. opercularis was found in most defense behaviour patterns. Analysing the frequencies and sequences of movement patterns it could be shown that defensive behaviour is not a random or entirely “plastic” process but that there is sequential linkage between the patterns and they form characteristic clusters. Our results suggest that manifestations of different patterns are under genetic control and presumably, genetic determination of certain patterns is not very complex. Attempts were made to determine whole brain noradrenaline, serotonine and dopamine levels of the two subspecies and a significant difference was found in the noradrenaline content.  相似文献   

4.
5.
The dwarf mongoose (Helogale undulata rufula) has a play vocalization, a short pulse at the 2-kHz level which is repeated at a rate of 3 to 12 or more pulses/s during the entire play period. The repetition rate is indicative of motivation intensity. This motivational study on object play shows that: (1) play becomes fragmented prior to termination; (2) motivation changes during a session fall into three different patterns all terminating at a ‘set point’ or ‘sollwert’; (3) the behaviour patterns performed during play show little sequencing related to original context but are causally different from those of exploration and have ‘optimum intensities’; (4) more limbs employed in object manipulation indicate higher intensity irrespective of the original non-play context of the behaviour pattern concerned; and (5) high intensity is coupled with more behaviour patterns performed per time interval. Hand-reared isolates show a delay in the appearance of play in ontogeny in comparison with pair-raised animals and their play contains a higher frequency of patterns bringing the object into close bodily contact. Play is considered as being a behaviour pattern complex with its own motivation which, through its performance, may compensate for motivational deficits or surpluses, a set point or sollwert replacing a consummatory act. Behaviour patterns from other behavioural contexts are taken over and reordered with regard to different rules, hence the apparent lack of sequencing. A threshold of general excitation associated with stimulus input is postulated as regulating the time of appearance of play in ontogeny, not maturational factors, and it may be used to compensate for specific stimulatory deficits occurring during ontogeny.  相似文献   

6.
1. Patterns of sheltering and activity are of fundamental importance in the ecology of animals and in determining interactions among predators and prey. Balancing decreased mortality risk when sheltering with increased feeding rate when exposed is believed to be a key determinant of diel patterns of sheltering in many animals. 2. Despite lower foraging efficiency at night than during the day, Atlantic salmon Salmo salar parr are nocturnal during winter and at low summer temperatures. Nocturnal activity also occurs at warm water temperatures during summer, but little is known about the functional significance of this behaviour. 3. This study aimed to determine: (1) the preferred activity and shelter pattern of Atlantic salmon parr during warm summer months, and (2) their response to variations in food availability when balancing growth rate (G) and mortality risk (M), as expressed through time out of shelter. We differentiated among four potential responses to reduced food availability: (1) no response; (2) G decreases but M remains constant; (3) G remains constant but M increases; and (4) G decreases and M increases. 4. Time exposed from shelter was inversely related to food availability. Fish subject to high food availability were significantly less active during the day than those with restricted rations. However, food availability had no significant effect on the extent to which fish were active at night. There was no evidence of variation in growth rate with food availability. 5. Salmon were predominantly nocturnal at high ration levels, consistent with their previously reported behaviour during winter. Rather than switching to diurnal behaviour at high temperatures per se, as previously was supposed, it appears that the fish are diurnal only to the extent needed to sustain a growth rate, and this extent depends on food availability. 6. Atlantic salmon parr modulate the amount of time they are active rather than growth when responding to variations in food availability over an order of magnitude.  相似文献   

7.
We studied how human presence in three urban parks in Madrid (Spain) might affect Blackbird densities by changing feeding behaviour patterns. Our specific purposes were: (a) to ascertain the effect of park visitors on Blackbird feeding behaviour; (b) to analyse the influence of human disturbance on foraging success; and (c) to determine how humans affect Blackbird spatial and temporal patterns of habitat use. Pedestrians were the main source of flushing responses in all sampled parks, followed by Magpies Pica pica and dogs accompanying visitors. Blackbird responses to visitors entailed more time being vigilant and moving away from people and less time searching for food (decreasing food intake), a response that remained constant in the three parks. The number of pedestrians was positively correlated with Blackbird distance to pathways and negatively correlated with distance to protective cover. The number of active birds decreased with increase in the number of pedestrians during the day. Blackbird density was negatively related to the number of visitors per park. Our results confirmed that human disturbance negatively affects Blackbird feeding strategies in urban parks, ultimately modifying spatial and temporal patterns of habitat selection and abundance. Since such responses could also affect densities of other urban species by the same process, we propose some management measures to decrease the levels of disturbance as well as to enhance the recreational use of urban parks.  相似文献   

8.
Human psychophysical studies have provided evidence of a short duration time constant associated with perceptual tasks. This time constant is approximately 3 s in duration, and evidence suggests that it represents a central neural mechanism that functions to integrate “successive events into a Gestalt” in order to create a “subjective present.” Recent studies have found a 3 s time constant in human and chimpanzee movement patterns, suggesting that a similar mechanism subserves both human perceptual and primate motor skills. These studies have focused exclusively on humans and chimpanzees; therefore, it is unclear whether this time constant represents a characteristic derived in the primate order or an ancestral characteristic found in many different mammalian orders. The current study looked for evidence of a 3 s time constant associated with movement patterns in six mammalian species representing three non-primate orders. The results showed that all six species' movement pattern event durations averaged about 3 s, and that there were no significant differences in the mean event durations among the species. Thus, the 3 s time constant originally found in human perceptual and primate motor skills is common among many mammalian orders and probably represents the operation of an ancestral neural mechanism.  相似文献   

9.
Energy regulation by traplining hummingbirds   总被引:2,自引:0,他引:2  
1. A published model of constant diurnal energy accumulation by territorial hummingbirds does not accurately reflect the temporal distribution of feeding behaviour of traplining hummingbirds, Phaethornis longirostris (Long-Tailed Hermit Hummingbirds).
2. In an enclosure study, gross nectar intake by P . longirostris decreased through the day, mirroring nectar production rates in its natural food-flowers and mimicking its natural foraging patterns.
3. Using a simulation model, the energetic consequences of constant and decreasing net energy intake rates for traplining hummingbirds are compared.
4. Given natural patterns of nectar production, model birds with decreasing diurnal net intake rates met their energetic needs with fewer flowers than those with constant net intake, and spent less time foraging.
5. It is concluded that P . longirostris do not satisfy the physiological assumptions of the published model, and that in this way they are different from the territorial species on which the model has previously been tested.  相似文献   

10.
Stereotypies are repetitive, unvarying and goalless behaviour patterns that are often considered indicative of poor welfare in captive animals. Quantifying stereotypies can be difficult, particularly during the early stages of their development when behaviour is still flexible. We compared two methods for objectively quantifying the development of route-tracing stereotypies in caged starlings. We used Markov chains and T-pattern analysis (implemented by the software package, Theme) to identify patterns in the sequence of locations a bird occupied within its cage. Pattern metrics produced by both methods correlated with the frequency of established measures of stereotypic behaviour and abnormal behaviour patterns counted from video recordings, suggesting that both methods could be useful for identifying stereotypic individuals and quantifying stereotypic behaviour. We discuss the relative benefits and disadvantages of the two approaches.  相似文献   

11.
Seventeen litters of German Shepherd dogs were observed for 5–7 days per week between 3 and 8 weeks post-partum. Social behaviour patterns, aggressive signals towards the puppies and nursing were quantified. Mothers were found to differ in the frequency of both social and aggressive behaviour. Nursing declined during the period, while both agonistic and grooming behaviour towards puppies increased until the 7th week. During Week 7, agonistic behaviour patterns were found to be significantly correlated to grooming behaviour patterns. Some of these behaviour traits were significantly correlated to the puppies performance on a puppy test given at the age of 8 weeks. It is suggested that the interaction between mother and offspring may facilitate the appearance of submission, and the effects on later trainability are discussed.  相似文献   

12.
The behaviour of insects between making contact with a potential oviposition site and the act of oviposition itself determines the conditions in which their progeny begin development and, in many cases, whether a crop or commodity is damaged. In this paper the behaviour of female cowpea seed beetles, Callosobruchus maculatus (Fabricius) (Coleoptera: Bruchidae), during this period has been examined. The duration of discrete behaviour patterns within this period and the transitional frequencies between them have been used to compare the behaviour of beetles on two different hosts. In a 30-min period, beetles laid more eggs on mung than adzuki beans and rejected mung as an oviposition site much less frequently. A log-linear contingency table analysis of the transitional frequencies indicated a highly significant interaction between successive behaviours and between the second of the two behaviours and the host seed, indicating that the sequence of behaviours is partially determined by the host seed. Grooming, departure from the seed and loops in behavioural sequences occur more often on adzuki than mung and are indicative of a less acceptable host. Discriminant analysis showed that the total time spent exhibiting different behaviour patterns was significantly different on the two hosts. Mann–Whitney tests revealed small but significant differences in the mean durations of only three behaviour patterns on the two seed types. Measurement of the duration of each behavioural pattern confirms what can be deduced about host acceptability by observing the simple occurrence of different behavioural patterns and the determination of the frequency of transitions between them. Differences in acceptability were predominantly reflected in the frequency of certain behaviour patterns and of particular transitions from one pattern to another, not in the mean duration of each exhibition of a defined behaviour pattern. It is argued that the utility of measuring the duration of behavioural elements could only be demonstrated because behavioural patterns or categories were precisely defined.  相似文献   

13.
The present study investigated whether pairing with a conspecific female would restore rhythmicity in the singing behaviour of arrhythmic male songbirds. We recorded the singing and, as the circadian response indicator, monitored the activity–rest pattern in male zebra finches (Taeniopygia guttata) housed without or with a conspecific female under 12 h light: 12 h darkness (12L:12D) or constant bright light (LLbright). Both unpaired and paired birds exhibited a significant daily rhythm in the singing and activity behaviour, but paired birds, under 12L:12D, showed a ~2 h extension in the evening. Exposure to LLbright decayed rhythmicity, but the female presence restored rhythmic patterns without affecting the 24 h song output. In the acoustic features, we found a significant difference in the motif duration between unpaired and paired male songs. Overall, these results demonstrated for the first time the role of the female in restoring the circadian phenotype of singing behaviour in male songbirds with disrupted circadian functions, although how interaction between sexes affects the circadian timing of male singing is not understood yet. It is suggested that social cues rendered by a conspecific female could improve the circadian performance by restoring rhythmicity in the biological functions of the cohabiting arrhythmic male partner.  相似文献   

14.
Abstract. 1. The lifecycle, mating and larval behaviour of Clunaris are described. Adults appeared in the autumn and nested in the following spring. The female beetle remained in the nest with the brood and could nest again the following year.
2. Nesting was initiated when virgin females were mated in the spring. Brood balls were formed by techniques sirnilar to those used by Scarabaeini. The female beetle left the nest soon after the first imagos broke out of the brood balls.
3. Nesting behaviour was readily modified by external conditions. Many parts of the sequence could be repeated or omitted. The female beetle left the nest if the brood was removed, but she remained for longer than usual if younger brood was substituted near the end of the normal nesting period.
4. Certain experimental conditions released behaviour patterns typical of other species. These were formation of superficial nests or of two-chambered nests, oviposition before completing the brood ball, and coating of the brood balls with soil (all found in other Coprina), as well as ball rolling and ball burial (found in Scarabaeini). The results are discussed in relation to the evolution of Copris nesting behaviour.  相似文献   

15.
Down syndrome is a common disorder associated with intellectual disability in humans. Among a variety of severe health problems, patients with Down syndrome exhibit disrupted sleep and abnormal 24‐h rest/activity patterns. The transchromosomic mouse model of Down syndrome, Tc1, is a trans‐species mouse model for Down syndrome, carrying most of human chromosome 21 in addition to the normal complement of mouse chromosomes and expresses many of the phenotypes characteristic of Down syndrome. To date, however, sleep and circadian rhythms have not been characterized in Tc1 mice. Using both circadian wheel‐running analysis and video‐based sleep scoring, we showed that these mice exhibited fragmented patterns of sleep‐like behaviour during the light phase of a 12:12‐h light/dark (LD) cycle with an extended period of continuous wakefulness at the beginning of the dark phase. Moreover, an acute light pulse during night‐time was less effective in inducing sleep‐like behaviour in Tc1 animals than in wild‐type controls. In wheel‐running analysis, free running in constant light (LL) or constant darkness (DD) showed no changes in the circadian period of Tc1 animals although they did express subtle behavioural differences including a reduction in total distance travelled on the wheel and differences in the acrophase of activity in LD and in DD. Our data confirm that Tc1 mice express sleep‐related phenotypes that are comparable with those seen in Down syndrome patients with moderate disruptions in rest/activity patterns and hyperactive episodes, while circadian period under constant lighting conditions is essentially unaffected.  相似文献   

16.
Animals can exhibit complex movement patterns that may be the result of interactions with their environment or may be directly the mechanism by which their behaviour is governed. In order to understand the drivers of these patterns we examine the movement behaviour of individual desert locusts in a homogenous experimental arena with minimal external cues. Locust motion is intermittent and we reveal that as pauses become longer, the probability that a locust changes direction from its previous direction of travel increases. Long pauses (of greater than 100 s) can be considered reorientation bouts, while shorter pauses (of less than 6 s) appear to act as periods of resting between displacements. We observe power-law behaviour in the distribution of move and pause lengths of over 1.5 orders of magnitude. While Lévy features do exist, locusts' movement patterns are more fully described by considering moves, pauses and turns in combination. Further analysis reveals that these combinations give rise to two behavioural modes that are organized in time: local search behaviour (long exploratory pauses with short moves) and relocation behaviour (long displacement moves with shorter resting pauses). These findings offer a new perspective on how complex animal movement patterns emerge in nature.  相似文献   

17.
The leucocyte common antigen (LCA or CD45) consists of various isoforms generated by alternative splicing of variable exons 4, 5 and 6 (or A, B and C). To follow splicing behaviour in different cell types we developed a human CD45 mini-gene and analysed its expression in transfected cell lines and transgenic mouse tissues. In Cos-1, HeLa and 3T3 cells we found distinct expression patterns which could only be modulated slightly by protein synthesis inhibitors but not by variation in culture conditions like pH, serum concentration and cell density, or by stimulation with phorbol ester (TPA). In all non-lymphoid transgenic tissues the default splicing pattern (CD45R0) was found, while the expression profile in lymphoid cells, where all eight isoforms are present, mimics that of the endogenous mouse LCA gene products. Next, to examine the factors involved in alternative exon use we analysed the expression pattern of members of the family of SR proteins, well known splicing regulators with arginine/serine-rich (R/S) domains. Cell lines expressed variable levels of SRp75, SRp30 and SRp20 and constant amounts of SRp40. Mouse tissues expressed large amounts of SRp75, SRp55 and SRp40, additional expression of SRp30s and SRp20 was restricted to lymphoid tissues. Therefore, SRp30 and SRp20 may contribute to forming the appropriate cellular conditions for alternative use of CD45 exons 4-6 in the haematopoietic compartment.  相似文献   

18.
The oral behaviour of adult Brown Leghorn hens was recorded in response to oral stimulation with water, 2 M sodium chloride, 2 M acetic acid and 0.1 M quinine hydrochloride before and after surgical ablation of either the anterior telencephalon or the entire telencephalon and/or the diencephalon. It was found that beak wiping behaviour could be abolished by the removal of the anterior telencephalon. Head shaking behaviour was abolished only by the complete removal of the forebrain (telencephalon and diencephalon) whereas beak and tongue movements persisted after forebrain removal. Although these three behaviour patterns occur together in response to the stimulus, they appear to be controlled in different areas of the brain. The results are discussed in relation to the current work on the control of oral behaviour in mammals.  相似文献   

19.
Adaptation of asexual populations is driven by beneficial mutations and therefore the dynamics of this process, besides other factors, depends on the distribution of beneficial fitness effects. It is known that on uncorrelated fitness landscapes, this distribution can only be of three types: truncated, exponential and power law. We performed extensive stochastic simulations to study the adaptation dynamics on rugged fitness landscapes, and identified two quantities that can be used to distinguish the underlying distribution of beneficial fitness effects. The first quantity studied here is the fitness difference between successive mutations that spread in the population, which is found to decrease in the case of truncated distributions, remains nearly a constant for exponentially decaying distributions and increases when the fitness distribution decays as a power law. The second quantity of interest, namely, the rate of change of fitness with time also shows quantitatively different behaviour for different beneficial fitness distributions. The patterns displayed by the two aforementioned quantities are found to hold good for both low and high mutation rates. We discuss how these patterns can be exploited to determine the distribution of beneficial fitness effects in microbial experiments.  相似文献   

20.
The dynamic state of post-translational acetylation of eukaryotic histones is maintained by histone acetyltransferases (HATs) and histone deacetylases (HDACs). HATs and HDACs have been shown to be components of various regulatory protein complexes in the cell. Their enzymatic activities, intracellular localization and substrate specificities are regulated in a complex, cell cycle related manner. In the myxomycete Physarum polycephalum multiple HATs and HDACs can be distinguished in biochemical terms and they exhibit dynamic activity patterns depending on the cell cycle stage. Here we report on the cloning of the first P. polycephalum HDAC (PpHDAC1) related to the S. cerevisiae Rpd3 protein. The expression pattern of PpHDAC1 mRNA was analysed at different time points of the cell cycle and found to be largely constant. Treatment of macroplasmodia with the HDAC inhibitor trichostatin A at several cell cycle stages resulted in a significant delay in entry into mitosis of treated versus untreated plasmodia. No effect of TSA treatment could be observed on PpHDAC1 expression itself.  相似文献   

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