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1.
The hunting behaviour and habitat use of second-calendar-year males (subadult) and grey (adult) males of Montagu's harrier Circus pygargus were compared in south-east Poland. Subadult males performed cruising flights less frequently than did adult males. In contrast, subadult males more frequently soared thermals and were harassed more often by other birds. Overall, adult males were more frequently engaged in hunting activities than subadult males. Additionally, adult males were more successful in trapping prey than were subadult males. Only 7% (n=92) of trapping attempts by subadult males were successful, compared with 17% (n=126) by grey males. Both adult and subadult males tried to catch prey flushed by foxes Vulpes vulpes. Subadult males were seen begging and pirating from prey-carrying raptors. Communicated by M.E. dos Santos  相似文献   

2.
The behaviour of an individual affects the probability that it will find food or a mate, and whether it will avoid becoming food itself. Because the birth and death of individuals are the constituents of the birth and death rates of populations, it seems likely that population dynamics is affected by variation in the behaviour of individuals. While intuitively appealing, there are few data to support this contention. I suggest that this lack of support stems from the failure to make use of manipulative experiments to test the hypothesis. Manipulative experiments are not the only approach to testing these hypotheses, but this powerful tool has not been used as effectively as it might. The behaviour of an animal can be manipulated with information-carrying chemicals in its environment, and pharmacologically. Variation in behaviour among individuals that is genetically based can also provide experimental material to test hypotheses about the role of behaviour in population dynamics. Manipulative experiments have the advantages of increased statistical power, and the elimination of unmeasured covariates. They have the disadvantage that they can introduce artifacts into the study system. It seems unlikely, however, that different kinds of manipulations would produce the same kinds of artifacts.  相似文献   

3.
Farmed fishes are often selectively bred for desirable production traits, such as rapid growth, that brings with them behavioural differences. In addition, the striking differences in the environment experienced by wild and cultured fishes offers considerable scope both for unplanned, natural selection for different inherited behavioural phenotypes and for behavioural differences arising from differential experience. In this paper, the evidence that such processes have produced behavioural differences between wild and cultured fishes is reviewed in relation to feeding, antipredator responses, aggression and reproductive behaviour. The reported findings are discussed in relation to the concept of 'behavioural syndromes', or suites of co‐varying behavioural traits that adapt individuals of the same population to spatial and temporal variation in selection regimes. The implications of the behaviour of cultured fishes for their welfare in production cages, for the environmental impact of escapees on wild stocks and for the success of hatchery‐based restocking programmes are considered. The review inevitably concentrates on salmonids, in which such phenomena have been intensively researched.  相似文献   

4.
The aim of this study was to assess the grazing, social and comfort behaviour of the indigenous purebred Ankole cattle breed and crossbred (Holstein × Ankole) animals under typical management conditions in south western Uganda. Twelve focal animals in each of four groups (two groups per genotype) were observed regarding their grazing, social and comfort behaviour on pasture.No significant differences in grazing behaviour patterns (eating, walking, standing) were found between the genotypes. Resting occurred only very rarely in both genotypes. Walking distances of Ankole and Ankole × Holstein crosses were also similar. There was no difference in the occurrence of agonistic interactions between the two genotypes. However, Ankole cattle engaged in more non-agonistic social interactions than their crossbred counterparts. Individual distances were lower in Ankole heifers and more herd mates were found within a radius of 5 m around the Ankole animals. The most important comfort behaviour pattern in both genotypes was self-licking, which occurred to similar frequency in Ankole and crossbred heifer groups. Crossbred animals scratched themselves and rubbed on objects more often than Ankole heifers.Although Ankole cattle and their Holstein crosses did not differ in grazing, distances walked and agonistic behaviours, the significant differences between the two genotypes in herd cohesion and comfort behaviour may pose challenges on the management of crossbred animals under extensive open grazing conditions as present in south western Uganda. Thus, apart from (re)productive performance traits, behavioural traits of both genotypes may also be taken into account for breeding decisions and management under current production conditions.  相似文献   

5.
The effect of ovariectomy on feeding, mating, Juvenile Hormone (JH) production, and maternal behaviour was assessed in female ring-legged earwigs, Euborellia annulipes (Lucas) (Dermaptera: Carcinophoridae), during the first 16 days of adult life (the first gonadotrophic cycle and early brooding). Ovariectomy of 2-day-old adults did not affect weight gain, nor did it alter mating behaviour on day 7. Similarly, ovariectomy did not prevent the increase in JH biosynthesis that accompanies vitellogenesis in this species, which suggests a cycle of JH production that is not dependent on the presence of the ovaries. Both ovariectomy and mating status affected feeding behaviour. Most introduced eggs were consumed (i.e. disappeared) within 24 h, and younger (7-day-old) females consumed more eggs than did older ones. However, 12-day-old intact virgins and 16-day-old ovariectomized, mated females consumed fewest eggs, and allowed some hatching. Thus, ovariectomy did not abolish changes in feeding behaviour that normally accompany reproduction but, instead, appeared to delay the reduction in feeding that normally accompanies the completion of the cycle of egg development. By contrast, mating enhanced the reduction in feeding late in the reproductive cycle. Mating significantly enhanced maternal behaviour in both ovariectomized and sham-operated females. Hatching success from egg clutches introduced to day 16 virgin or mated females that had been ovariectomized or sham-operated on day 2, was significantly greater in the mated groups.  相似文献   

6.
This review assesses factors affecting fouling in conventional pens for slaughter pigs. Fouling of the pen happens when pigs change their excretory behaviour from occurring in the designated dunging area to the lying area. This can result in a lower hygiene, bad air quality, extra work for the farmer, disturbance of the pigs’ resting behaviour and an increase in agonistic interactions. A systematic search was conducted and results narrowed down to 21 articles. Four factors were found to affect fouling directly: insufficient space allowance, the flooring design of the pen, the thermal climate and pigs’ earlier experience. Further, these primary factors are affected by secondary factors such as the shape of the pen, the weight of the pigs and especially the heat balance of the pigs, which is affected by several tertiary factors including, for example, temperature, humidity and draught. Results indicate that the most important factor to control when trying to prevent fouling of a pen is the pen climate. An appropriate climate may be accomplished through floor cooling in the designated lying area, sprinklers above the designated dunging area and by ensuring a more optimal ambient temperature curve that also fits the weight of the pigs in different stages of the production. All in all, fouling of the pen in conventional slaughter pigs is a multifactorial problem, but it is important to focus on increasing the comfortability, and especially the climate, of the designated lying area.  相似文献   

7.
Examining the characteristics of an animal’s lying behaviour, such as frequency and duration of lying bouts, has become increasingly relevant for animal welfare research. Triaxial accelerometers have the advantage of being able to continuously monitor an animal’s standing and lying behaviour without relying on live observations or video recordings. Multiple models of accelerometers have been validated for use in monitoring dairy cattle; however, no units have been validated for use in equines. This study tested Onset Pendant G data loggers attached to the hind limb of each of two mature Standardbred horses for a period of 5 days. Data loggers were set to record their position every 20 s. Horses were monitored via live observations during the day and by video recordings during the night to compare activity against accelerometer data. All lying events occurred overnight (three to five lying bouts per horse per night). Data collected from the loggers was converted and edited using a macro program to calculate the number of bouts and the length of time each animal spent lying down by hour and by day. A paired t-test showed no significant difference between the video observations and the output from the data loggers (P=0.301). The data loggers did not distinguish standing hipshot from standing square. Predictability, sensitivity, and specificity were all >99%. This study has validated the use of Onset Pendant G data loggers to determine the frequency and duration of standing and lying bouts in adult horses when set to sample and register readings at 20 s intervals.  相似文献   

8.
Cooperative breeding has been described for several cichlids from the genus Julidochromis (Perciformes: Cichlidae) under laboratory conditions, but field evidence is scarce. Here we describe the breeding system of the cichlid Julidochromis ornatus (Boulenger) in Lake Tanganyika (Zambia). Groups defended a breeding shelter under a large flat stone. Smaller group members stayed and fed under or close to the stone, actively guarded by the larger group members. Six out of 28 groups were newly established by breeders, joined by subordinates from a large pool of independent fish (comprising 50–70% of the total population), and four groups were seen to dissolve during a total of 77 observation days. Breeding groups consisted of a large breeding male and female with zero to five smaller subordinates (average 2). Larger breeders and subordinates were found in larger groups. All group members participated in territory defence and -maintenance, but the breeders were only present at the shelter 48% of the time, in contrast to the subordinates which guarded the breeding shelter 94% of the time. Smaller group members showed submissive behaviours to larger group members. We conclude subordinates in J. ornatus are helpers, but we did not find evidence that helpers increased the group’s current reproductive success. Personal observations combined with a literature review revealed at least 19 species of Lake Tanganyika cichlids show evidence of cooperative breeding, entirely confined to the substrate breeding tribe of the Lamprologini (24% of 80 species in total): 2 Chalinochromis spp., 5 Julidochromis spp., 12 Neolamprologus spp. More effort should be put into detecting cooperative breeding in American and Asian substrate breeding cichlid species.  相似文献   

9.
10.
ABSTRACT. In an ambient temperature ( T a) range of 18–28°C, thoracic temperatures ( T th) of individual male Lymantria dispar (L.), caught at flight in the field, ranged from 21 to 36.5°C, with a correlation coefficient of 0.63 between T th and ambient temperature ( T a). Ambient temperature (and insolation) altered the insect's body temperature and the probabilities, latencies, and durations of preflight responses to pheromone. In a wind tunnel at 16 and 20°C, quiescent males exposed to pheromone raised their T th by sustained wing fanning from 17 and 21°C, respectively, to c. 24°C before takeoff. At 24 and 28°C ambient, T th rose by takeoff to 28 and 31°C, respectively. The latencies of male wing fanning in response to pheromone decreased from 1.44 min at 16°C ambient, to 0.58 min at 20°C, to 0.26 min at 24°C, and to 0.16min at 28°C. The components of behaviour (antennal twitch, body jerk, step and wing tremor) that occurred between quiescence and wing fanning were more frequent at ambients of 16 and 20°C than at 24 and 28°C.  相似文献   

11.
Synopsis Characteristics of nest sites and reproductive behaviour of territorial male demoiselles Chromis dispilus were examined at sites of low, medium and high population density in northeastern New Zealand, by use of SCUBA diving and a remote underwater video system. Nest territories were closer together at high density (relative to areas of low population density) and this was accompanied by an increase in the frequency of spawning sequences and territorial defence against conspecifics. Territorial males were more aggressive during periods of display and spawning than during egg guarding. Fish from areas of low density spent more time on courtship display (signal jumps) and territorial defence against fish of other species, than demoiselles from areas of high population density. Territories and nest sizes tended to be largest in areas of medium population density. As in other damselfishes, population density is a major determinant of the frequency and intensity of reproductive behaviours.  相似文献   

12.
The movements of seabream (Sparus aurata L) were recorded in two earthen ponds (250 m2 and 400 m2) by tracking fish tagged with miniature acoustic transmitters. Five seabreams, 500 g in weight, were tracked for periods of four or five days. Fish positions were recorded continuously using an acoustic telemetry system. Each of the five tagged seabreams were tracked individually. Two fishes were released schooled with numerous other individuals, two others were released in isolation and one was grouped with three other individuals.The schooled seabreams were more active in general and, in the large school they were diurnal; isolated fishes however, were more active at night. Temperature influences significantly and progressively the fish activity. Activity decreases at night and increases during daylight. Oxygen saturation also influences swimming activity with a general positive relationship.The horizontal distribution of this species was not uniform. Its resting area was generally located around some particular landmarks such as inlet or outlet pipes in the ponds. No feverish feeding competition was observed between individuals of the same school. The feeding area was cleaned rapidly, in less than 10 minutes, without subsequent returns from the resting area to the feeding area.
Résumé Les déplacements de la daurade (Sparus aurata L.) ont été enregistrés dans deux bassins en terre (250 m2 et 400 m2) en suivant des poissons marqués avec des émetteurs acoustiques miniaturisés. Cinq daurades d'un poids individuel de 500 g furent suivies durant des périodes de 4 ou 5 jours. Les positions des poissons ont été enregistrées en continu avec un systéme de télémétrie acoustique. Chacun des cinq poissons marqués fut suivi individuellement. Deux poissons furent regroupés avec de nombreux autres individus, deux autres furent laissés seuls et le dernier fut mis avec trois autres individus.Les daurades groupées étaient en général plus actives et, en grand banc, étaient diurnes; les poissons isolés étaient toutefois plus actifs durant la nuit. La température influence significativement et progressivement l'activité des poissons. L'activité décroît durant la nuit et augmente pendant le jour. Le pourcentage de saturation en oxygéne agit aussi, de façon positive, sur l'activité de nage.La distribution horizontale de cette espéce n'est pas uniforme. Son aire de repos est généralement localisée dans quelques zones particuliéres comme les arrivées et les sorties d'eau. Aucune compétition alimentaire fébrile n'a été observée entre les individus d'un même banc. L'aire de nourrissage est rapidement nettoyée, en moins de 10 minutes, sans retours ultérieurs depuis la zone de repos jusqu' à la zone de nourrissage.
  相似文献   

13.
We monitored the behaviour of farmed silver foxes housed in family units in enlarged cage systems from weaning until late October. Activity of family members, use of space available, and aggressive acts were recorded. Aggressiveness between family members increased from July until October, leading to a more scattered use of the available space. Furthermore, the mean activity level of family members increased, and the synchrony of activity decreased. We conclude that social tension in the fox families increased gradually during the autumn, leading to dispersion of the family members. Received in revised form: 22 October 2001 Electronic Publication  相似文献   

14.
Sexual cannibalism in scorpions: fact or fiction?   总被引:2,自引:0,他引:2  
Females of several scorpion species are currently deemed to be sexual cannibals, but this reputation is, however, largely built on anecdotal evidence from the older literature. Theoretical models predict that given the low rates of female-male encounter, males should allow themselves to be cannibalized after sperm transfer. The present paper examines the information available for a number of species to determine (a) whether sexual cannibalism is as widespread as previously suggested, and (b) whether it is likely to involve male self-sacrifice. Information on three scorpions currently regarded as sexual cannibals is presented: the bothriurids Bothriurus bonariensis (C.L. Koch) and Urophonius jheringii Pocock, and the buthid Leiurus quinquestriatus (Hemprich & Ehrenberg). No post-mating cannibalism was ever observed in these species, nor in another 19 representatives of four families. In L. quinquestriatus only two cases of cannibalism of the male by the female occurred, both in the beginning of courtship and after long periods of food deprivation. We suggest that if sexual cannibalism occurs in scorpions, it is most likely to be of an 'economic' type, where females perceive males as prey rather than mates, and not a 'self-sacrificial', post-mating cannibalism enhancing the fitness of the offspring of the male.  相似文献   

15.
Maintaining a territory and being able to hunt are imperative for the success of African lion Panthera leo prides. We aimed to determine whether captive‐origin prides display similar territorial and hunting behaviour to wild lions. Behaviours and locations of two captive‐origin prides and one wild pride were collected through direct observation. All prides established territories, and core areas corresponded to resource requirements. There was no evidence that pride origin affected territorial or hunting behaviour. Captive‐origin prides exhibited behaviours that lead us to be optimistic about each pride's ability to establish and defend a territory successfully, and to hunt, following reintroduction.  相似文献   

16.
The immune system can influence social motivation with potentially dire consequences for group-housed production animals, such as pigs. The aim of this study was to test the effect of a controlled immune activation in group-housed pigs, through an injection with lipopolysaccharide (LPS) and an intervention with ketoprofen on centrality parameters at the individual level. In addition, we wanted to test the effect of time relative to the injection on general network parameters in order to get a better understanding of changes in social network structures at the group level. 52 female pigs (11–12 weeks) were allocated to four treatments, comprising two injections: ketoprofen-LPS (KL), ketoprofen-saline (KS), saline-LPS (SL) and saline-saline (SS). Social behaviour with a focus on damaging behaviour was observed continuously in 10 × 15 min bouts between 0800 am and 1700 pm 1 day before (baseline) and two subsequent days after injection. Activity was scan-sampled every 5 min for 6 h after the last injection in the pen. Saliva samples were taken for cortisol analysis at baseline and at 4, 24, 48, 72 h after the injections. A controlled immune activation affected centrality parameters for ear manipulation networks at the individual level. Lipopolysaccharide-injected pigs had a lower in-degree centrality, thus, received less interactions, 2 days after the challenge. Treatment effects on tail manipulation and fighting networks were not observed at the individual level. For networks of manipulation of other body parts, in-degree centrality was positively correlated with cortisol response at 4 h and lying behaviour in the first 6 h after the challenge in LPS-injected pigs. Thus, the stronger the pigs reacted to the LPS, the more interactions they received in the subsequent days. The time in relation to injection affected general network parameters for ear manipulation and fighting networks at the group level. For ear manipulation networks, in-degree centralisation was higher on the days following injection, thus, certain individuals in the pen received more interactions than the rest of the group compared to baseline. For fighting networks, betweenness decreased on the first day after injection compared to baseline, indicating that network connectivity increased after the challenge. Networks of tail manipulation and manipulation of other body parts did not change on the days after injection at the group level. Social network analysis is a method that can potentially provide important insights into the effects of sickness on social behaviour in group-housed pigs.  相似文献   

17.
18.
This article introduces recent advances in the machine analysis of facial expressions. It describes the problem space, surveys the problem domain and examines the state of the art. Two recent research topics are discussed with particular attention: analysis of facial dynamics and analysis of naturalistic (spontaneously displayed) facial behaviour. Scientific and engineering challenges in the field in general, and in these specific subproblem areas in particular, are discussed and recommendations for accomplishing a better facial expression measurement technology are outlined.  相似文献   

19.
Group living is widespread in animals, and many fishes form shoals. Examining within-group interactions in fishes may contribute to the general understanding of dynamic social structures in animals. The sex ratio of a group has been shown to influence grouping decisions of fishes and can be expected to affect behaviour at group level. Behavioural experiments usually involve relatively short acclimatisation times, although the establishment of environmental habituation in fishes is understudied. This study tests whether the sex ratio and long-term habituation to experimental conditions influence general shoal performance (activity parameters, density) and responses of shoals to an acoustic-mechanical disturbance cue in juveniles of the cichlid fish Pelvicachromis taeniatus via individual tracking. The disturbance consisted of a defined hit against the experimental tank, which caused sudden noise and water movement. We found that a higher proportion of females increases shoal activity (swimming speed and distance covered), suggesting that female P. taeniatus are more active than males. Furthermore, shoal activity declined when shoals habituated to the experimental settings and with the time that the shoals were grouped together, which may reflect intensified group member familiarity. Moreover, behavioural changes after disturbance were weaker when individuals were kept with their group longer and more familiar to the experimental conditions. For prey species, lower activity might be beneficial under natural conditions due to lower conspicuousness of the group. We did not find any significant effects of the investigated factors on shoal density (mean interindividual distance) and speed synchronisation. The results indicate that sexual composition, familiarity between shoal members and habituation to the experimental environment affect shoal performance in a cichlid fish.  相似文献   

20.
Despite essential progress towards understanding the evolution of cooperative behaviour, we still lack detailed knowledge about its underlying molecular mechanisms, genetic basis, evolutionary dynamics and ontogeny. An international workshop “Genetics and Development of Cooperation,” organized by the University of Bern (Switzerland), aimed at discussing the current progress in this research field and suggesting avenues for future research. This review uses the major themes of the meeting as a springboard to synthesize the concepts of genetic and nongenetic inheritance of cooperation, and to review a quantitative genetic framework that allows for the inclusion of indirect genetic effects. Furthermore, we argue that including nongenetic inheritance, such as transgenerational epigenetic effects, parental effects, ecological and cultural inheritance, provides a more nuanced view of the evolution of cooperation. We summarize those genes and molecular pathways in a range of species that seem promising candidates for mechanisms underlying cooperative behaviours. Concerning the neurobiological substrate of cooperation, we suggest three cognitive skills necessary for the ability to cooperate: (i) event memory, (ii) synchrony with others and (iii) responsiveness to others. Taking a closer look at the developmental trajectories that lead to the expression of cooperative behaviours, we discuss the dichotomy between early morphological specialization in social insects and more flexible behavioural specialization in cooperatively breeding vertebrates. Finally, we provide recommendations for which biological systems and species may be particularly suitable, which specific traits and parameters should be measured, what type of approaches should be followed, and which methods should be employed in studies of cooperation to better understand how cooperation evolves and manifests in nature.  相似文献   

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