首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The behaviour of the three mediterranean benthic fish Tripterygion tripteronotus, T. xanthosoma, and T. melanurus is described from observations in the field and observations on captive animals. The ♂♂ defend a territory only during the reproductive season; ♀♀ do not defend a territory. At the height of the breeding season, a male T. tripteronotus on average spawns with four ♀♀ Per day. The ♂ defends the territory against egg predators and cleans the eggs. ♀♀ spawn repeatedly during a spawning season. A spawning pair of T. tripteronotus frequently attracts conspecifics. The majority of these “satellites” are small, sexually mature ♂♂, which do not own a territory themselves. The reproductive strategies of the two types of ♂♂ (territorial ♂♂ and satellite ♂♂) and of the ♀♀ are discussed. On the basis of ethological, morphological, and palaegeographic data the evolution of the eastern-atlantic and mediterranean Tripterygiidae is reconstructed. A bibliography of the literature on eastern-atlantic and mediterranean Tripterygiidae is given. As in their morphology and anatomy, benthic fish show convergent adaptations in their behaviour. Some of these are pointed out and discussed.  相似文献   

2.
The cues used by ♂♂ and ♀♀ of the checkered white butterfly, Pieris protodice, were explored using an assay that involved timing the responses of free-flying butterflies to tethered animals (“angling”). The models included ones that were made from the wings of ♂♂ and ♀♀ that had been extracted in a dilute ammonia solution. This procedure removes an ultraviolet-absorbing pigment from the wings and renders them more ultraviolet reflectant than normal without altering any other aspect of their coloration. The results show that both sexes make sexual discriminations using the sexual dimorphism in ultraviolet reflectance found in this species rather than using differences in the melanic markings on the wings, movement patterns, or chemical signals.  相似文献   

3.
Changing the Stimulus ♀ induced in ♂♂ of the poeciliid fish Poecilia sphenops a strong increase of copulation attempts, nipping and gonopodial swinging (“Coolidge effect”). There was a similar increase of sexual activities after social isolation of 23 hours and reintroducing the same ♀ like before. But in experiments it could be demonstrated that the effect of social deprivation can only partly be deduced from the Coolidge effect and seems to be also the result of sexual inactivity during the isolation period.  相似文献   

4.
Calling assemblies of Hypsignathus monstrosus were studied for 17 months in the field to determine if they were “leks” or mating arenas. Direct observations, netting of animals at the assembly sites, and radio-tracking of both ♂♂ and ♀♀ at the assembly sites, foraging grounds, and day roosts were all utilized to make this determination. Captive animals were maintained to establish growth rates. It is concluded that Hypsignathus exhibit lek behavior even by the most conservative definition and share many features with other avian and mammalian lek species.  相似文献   

5.
Sternopygus macrurus, eine der dreizehn im Rupununi Distrikt von Guyana beheimateten Messeraal-Arten benutzt elektrische Signale im Fortpflanzungsverhalten. Sternopygus leben in steinigen und sandigen Bächen und kommen nachts aus ihren Verstecken. Ihre Laichzeit beginnt vor Eintritt der Regenzeit Ende April. Sternopygus hat langdauernde Entladungen mit kurzen Pausen, die im Lautsprecher einen summenden Ton ergeben (im Unterschied zu Arten mit kurzen Entladungen und langen Pausen, die “knattern”). Von den vier summenden Fischarten hat S. macrurus eine eigene Tonlage und Tonstärke. Ausgewachsene ♂♂ und ♀♀ erzeugen verschiedene Ruhe-Entladungen. In der Laichzeit reagieren ♂♂ auf Annäherung eines ♀ mit veränderten Entladungen. Diese scheinen ♀♀ anzulocken. Auch ♀♀ können ihre Entladungen variieren. Künstlich über Elektroden ins Wasser gespielte Sinus-Schwingungen mit ♀-Frequenz wurden von ♂♂ richtig beantwortet; auf ♂-Frequenz oder Frequenzen anderer Arten gab es keine Reaktion. Beobachtungen an zwei Sternopygus-Paaren ergaben, daß die Individuen typische Entladungs-Frequenzen haben. Paarpartner können Frequenzen annehmen, die genau eine Oktave auseinander liegen.  相似文献   

6.
Observations were made on the behaviour of male Philanthus bicinctus (Mickel) which defend territories around the nesting burrows of ♀♀. ♂♂ were individually identified with small number tags and focal-animal samples were taken of the behaviour of these ♂♂. Intense interactions were observed between territorial ♂♂ and 1) conspecifics and 2) intruding insects which resembled conspecifics. Evidence is presented which suggests that ♂♂ scent mark their territories.  相似文献   

7.
There has been much recent research interest in the existence of a major axis of life‐history variation along a fast–slow continuum within almost all major taxonomic groups. Eco‐evolutionary models of density‐dependent selection provide a general explanation for such observations of interspecific variation in the "pace of life." One issue, however, is that some large‐bodied long‐lived “slow” species (e.g., trees and large fish) often show an explosive “fast” type of reproduction with many small offspring, and species with “fast” adult life stages can have comparatively “slow” offspring life stages (e.g., mayflies). We attempt to explain such life‐history evolution using the same eco‐evolutionary modeling approach but with two life stages, separating adult reproductive strategies from offspring survival strategies. When the population dynamics in the two life stages are closely linked and affect each other, density‐dependent selection occurs in parallel on both reproduction and survival, producing the usual one‐dimensional fast–slow continuum (e.g., houseflies to blue whales). However, strong density dependence at either the adult reproduction or offspring survival life stage creates quasi‐independent population dynamics, allowing fast‐type reproduction alongside slow‐type survival (e.g., trees and large fish), or the perhaps rarer slow‐type reproduction alongside fast‐type survival (e.g., mayflies—short‐lived adults producing few long‐lived offspring). Therefore, most types of species life histories in nature can potentially be explained via the eco‐evolutionary consequences of density‐dependent selection given the possible separation of demographic effects at different life stages.  相似文献   

8.
Junge Thryomanes bewickii wurden im William L. Finley National Wildlife Refuge by Corvallis, Oregon, USA, untersucht. Sie werden nach etwa 35 Tagen von ihren Eltern unabhängig. Elf ♂♂ waren auf eine durchschnittliche Entfernung von 1,2 km verstreut (im Bereich von 0,1 bis 3,2 km). Vier ♂♂ (60, 80, 110 und 135 Tage alt) äußerten Jugendgesang (subsong) in Revieren, die sie lebenslang besetzt hielten. 60 Tage ist höchstwahrscheinlich das durchschnittliche Alter für Reviergründung und Beginn des Jugendgesangs. Das durchschnittliche Lied-Repertoire von 31 ausgewachsenen ♂♂ bestand aus 16 Liedtypen. Jeder Liedtyp bestand aus einer stabilen und mehrmals wiederholten Sequenz, die 2—5 melodische Themen hat (Anhäufungen von Noten oder Trillern). Der Jugendgesang des 60 Tage alten ♂ enthielt etwa 95 % der Themen des Repertoires eines Erwachsenen; bei einem zweiten Vogel waren alle Typen von Themen und Sequenzen im Alter von 115 Tagen vollständig ausgebildet. Ein Thema oder höchstens ein ganzer Liedtyp, der sich bei einem jungen ♂ entwickelt, muß — wie Ähnlichkeitsvergleiche zeigen — auf Erfahrungen beruhen, die das Tier vor Gründung seines Reviers gemacht hat. Die meisten Liedtypen im Repertoire sind jedoch vergleichbar mit den Liedern der ♂♂, die unmittelbare Nachbarn des neu gegründeten Reviers sind. Folglich ist die Bereitschaft zum Lernen von Themen und Sequenzen am größten, einige Zeit nachdem sie von ihren Eltern unabhängig werden (35 Tage), jedoch vor dem Beginn des Jugendgesangs (60 Tage). Während der Gesangs-Entwicklung lernen junge ♂♂ die Lieder Erwachsener, mit denen sie häufigen und engen Kontakt haben. Da die Reviere, die während der Entwicklung des Liedes gegründet wurden, dauerhaft sind und während des übrigen Jahres verteidigt werden, sind die Repertoires der Nachbar-♂♂ beinahe identisch. Einige Junge überqueren geringe Populations-Barrieren, die dann den akustischen Kontakt mit ♂♂ der anderen Seite verringern. Lernen neuer Lieder kommt deshalb beschränkt vor. Die Variationen kommen zustande durch mangelhaftes Nachahmen eines Liedes, vielleicht auch durch Improvisation oder “Drift”. Darum fehlen viele Lieder, die an einer Stelle häufig sind, anderswo, auch ganz in der Nähe, vollkommen.  相似文献   

9.
Das Verhalten zwischen je zwei C. centrarchus-♂♂ wurde daraufhin untersucht, ob Laute auftraten und ob solche Laute der Verständigung zwischen den Tieren dienen. Die Laute, die produziert wurden, waren gleichartiges tiefes Knurren; es gab individuelle Unterschiede in der Dauer und im zeitlichen Muster des Knurrens. Diese Laute sind nicht zufallsverteilt, sondern stark mit aggressivem Verhalten korreliert. Diese Korrelation besteht auch zum Verhalten, das auf den Laut folgt; Angriffe folgen viel öfter auf Verhalten mit als auf solches ohne Lautproduktion, auch ist die Reaktion anderer Tiere darauf unterschiedlich. Auf lautlose Verhaltensweisen reagieren sie meist “nachahmend”, auf Laute meist “vermeidend”, selten “drohend”. Informationstheoretische Analyse bewies, daß die übermittelte Informationsmenge anders war, wenn die Tiere einander hören und sehen konnten, als wenn sie einander nur sehen konnten. Es scheint, daß Laute aggressives Verhalten im Empfänger hemmen. Im natürlichen Lebensraum benützt C. centrarchus wahrscheinlich Laute, um Artgenossen vom Eindringen in ihr Revier, Rivalisieren um Nahrung oder Stören der Brut abzuschrecken. Vielleicht dient akustische Verständigung zwischen verschiedenen Arten denselben Zwecken.  相似文献   

10.
Behavioral interactions among color-marked individual Vidua chalybeata that shared common song dialects were observed for 5 years in two populations at Lochinvar National Park, Zambia. Social interactions involved ♂♂ visiting and competing for mating sites and ♀♀ visiting ♂♂ in an apparent sampling of potential copulating partners. Differences in mating success among the polygynous ♂♂ were compared with male behavior and territory resources, and criteria were developed to test the importance of intrasexual male competition and female mate choice in explaining the mating system of the populations. Song behavior best explained differences in mating success of ♂♂ with lesser effects of neighboring ♂♂ and the defensible resources around the call-sites. The social organization of song populations resembles that of a dispersed lek with ♀♀ visiting many ♂♂ but mating with few ♂♂. We discuss the observations on indigobirds in relation to behavioral selection, sexual selection, and mating systems. Mating systems of certain populations and species are compared using statistics of individual mating success.  相似文献   

11.
Observations of 8 groups each containing three adult spiny mice (Acomys cahirinus) revealed that instances of chasing and physical displacement were quite common, while fighting and biting were rarely observed. The relationships between the most frequent behavioral categories were presented in a correlation matrix. In a second, study, ♀♀ tested in their home cages were dominant over ♂♂ In the ♂♂ home cages, however, no differences in the frequency of ♀ vs. ♂ aggression were observed. More instances of aggression were observed in the cages of the ♀♀ than in the cages of the ♂♂.  相似文献   

12.
Während zweier Monate (1965) wurden im Banff National Park (Kanada) qualitative und quantitative Daten über das Brunftverhalten des amerikanischen Wapiti (Cervus canadensis) gesammelt. Einige Verhaltensweisen sind erstmals genauer beschneben. Die ♀♀-Gruppen sowie die Zahl der mit ihnen lebenden Spießer und 21/2- und 31/2 jähngen ♂♂ wurden zu Beginn der Brunft kleiner, an ihrem Ende wieder größer. Das Zahlenverhältnis von ♀♀ und Kälbern blieb dabei gleich. Spießer blieben länger als ältere ♂♂ in den ♀♀-Gruppen und schlossen sich ihnen früher wieder an. Bei Brunftbeginn traten die über 31/2Jährigen ♂♂ zu den ♀♀-Gruppen, spalteten sie und vertrieben jüngere ♂♂. Sonogramme erläutern genauere Angaben über das Röhren und den Alarmruf, der bei ♂♂ höher ist als bei ♀♀. Durch Röhren, Geweihschlagen am Gesträuch, Graben und Suhlen scheinen andere ♂♂ aufmerksam und angelockt zu werden. Das führt zu Zweikämpfen und fördert die geschlechtliche Auslese. ♂♂ ab 31/2 Jahren können ejakulieren beim Röhren, Geweihschlagen, Graben, Stehen in der Suhle, nach dem Zusammentreiben von ♀♀ und beim Alarmrufen. Heftige Kämpfe waren selten, nur einmal kam es zu Schlägen auf den Körper. Kampfwunden scheinen unwesentlich als Todesursache. ♂♂ kämpfen bevorzugt mit Altersgenossen, ältere kämpfen mehr als junge, alle zu bestimmten Tages- und Jahreszeiten mehr als sonst. Reviere scheint es nicht zu geben. Harem-♂♂ treiben zu bestimmten Tages- und Jahreszeiten besonders häufig ♂♀ mit Kälbern zusammen. Mehr als 31/2 Jahre alte ♂♂ bestritten 94 % der heterosexuellen Kontakte, die ebenfalls tages- und jahreszeitlich verschieden häufig waren. Harem-♂♂ vertrieben am häufigsten über 31/2jährige ♂♂, selten Spießer, am seltensten 21/2jährige ♂♂. Wenn es beim Drohen blieb, war immer der Angreifer gleich alt oder älter als sein Gegner; die Häufigkeit solcher nicht zur Berührung führenden aggressiven Begegnungen änderte sich mit der Tageszeit. ♀♀-Gruppen werden offenbar von adulten ♀♀, nicht von jungen ♂♂ ?geführt”. Über 31/2jährige ♂♂ verbrauchen wohl in der Brunft Energiereserven, denn sie fressen weniger lange und sind mehr mit Laufen und anderen Bewegungen beschäftigt als jüngere ♂♂.  相似文献   

13.
The current study aims at documenting the psychometric properties of the Subjective Distress Associated with Adult ADHD-Self-Report (SDAAA-SR), a newly developed instrument for the assessment of psychological suffering in ADHD adults. The SDAAA-SR was administered to 247 students and 142 ADHD adults. Factor structure, internal consistency, test–retest reliability, convergent validity and discriminant validity were assessed. Sensitivity to change was examined in a subsample of 25 ADHD patients who participated in a 1-year therapy. The initial pool of 62 items was reduced to 33 items distributed in a three-component structure. Internal consistency was excellent for the “distress due to inattention/disorganization” subscale and good for the “distress due to hyperactivity/impulsivity” and “distress due to self-esteem deficit” subscales. Test–retest reliability in a subsample of 98 students was substantial for all three subscales. ADHD patients scored significantly higher than students on distress due to “inattention/disorganization” and “hyperactivity/impulsivity,” but no difference was observed for “self-esteem deficit.” The components “inattention/disorganization” and “hyperactivity/impulsivity” displayed moderate to large correlations with the corresponding dimensions of the Adult Self-Report Scale for ADHD (ASRS-V1.1). Distress due to “inattention/disorganization” and “self-esteem deficit” was significantly associated with lower satisfaction with social behaviors (QFS, social functioning questionnaire) and quality of life (WHOQOL-BREF). Distress due to “inattention/disorganization” and “self-esteem deficit” significantly decreased after a 1-year therapy. The SDAAA-SR represents a reliable and valid measure of adult ADHD-associated distress, an important but often undocumented parameter in the clinical setting. Its use as an outcome variable in psychological interventions deserves further investigation.  相似文献   

14.
Accounts of primate social dominance hierarchies often imply that the achievement of superior status is a “goal”, akin to a valued resource or commodity, and that hierarchies emerge in multimale groups from prolonged competitive conflicts over social status. This possibility is not consistent with our observations of five newly formed triads of adult male squirrel monkeys (Saimiri sciureus). Stable linear hierarchies based on clear asymmetries in the direction of intermale agonism and genital displays were established quickly, with virtually no reciprocal fighting, and in the absence of rank-related differences in plasma cortisol or testosterone. Although affiliative social overtures were initiated more often by high-ranking and middle-ranking males, affiliative overtures were directed equally often toward all members of each group. From the outset of the study all males, regardless of rank, spent an average of 33% of their time huddling in affiliative contact with male cagemates. These results suggest that in newly formed groups of adult male squirrel monkeys, social hierarchies reflect an expedient convention that reduces conflict and facilitates the formation of small cohesive groups. © 1994 Wiley-Liss, Inc.  相似文献   

15.
Larvae of Urechis caupo Fisher & MacGinitie, reared in the laboratory, were exposed to potential settlement stimuli, including natural sediment from adult burrows, and “scent” obtained from the skin of adult animals. Competent larvae settled rapidly and specifically in response to adult burrow sediment when compared with their responses to other natural and abiotic sediments. Larvae also responded specifically to chemical “scent” from adult animals when the “scent” of another echiuran worm, Listriolobus pelodes Fisher served as a control. Larval responses to chemical “scent” were as great as their responses to natural burrow sediment. Hence, it is likely that larvae settle gregariously in nature in response to “scent” on sediment grains of adult burrows. The chemical “scent” had a molecular weight between ≈3500 and 14000 daltons, as determined by dialysis. It quickly lost its effectiveness in promoting settlement after it was heated to 80 °C, but was relatively stable at ambient ocean temperatures, retaining its effectiveness for several days. It was soluble in sea water. However, larvae did not respond to the chemical “scent”, unless it was adsorbed onto a surface. Purely tactile stimuli, such as the shape, texture, and size-distribution of particles, were not important settlement cues during these experiments.  相似文献   

16.
A. Béjin 《Andrologie》1997,7(3):336-342
We provide data on several aspects of sexual behaviour: masturbation, age at first intercourse, sexual practices during first intercourse, homosexuality and heterosexuality, sexual practices over a lifetime, sexual activity in the past twelve months, frequency of sexual intercourse, last sexual intercourse, achieving orgasm (through vaginal penetration, masturbation by partners, fellatio and cunnilingus), sexual dysfunctions. Data come from recent national sex surveys in: Great Britain (1990–91; n=18.876), Finland (1991–92; n=2250), the United States (1992; n="3432) and especially from the ACSF survey (n=20.055), the French national telephone survey on sexual behaviour conducted between September 1991 and February 1992. Some results about the prevalence of sexual dysfunctions in sexually active men 18 to 69 years old, in France (in %):
  • - “You do not have an erection (impotence)”
  • - “often”: 7%, “sometimes”: 12%
  • -“You ejaculate too early, even before entering you partner” “often”: 5%; “sometimes”: 16%
  • - “You ejaculate too soon, upon or shortly after entering your partner” “often”: 10%; “sometimes”: 27%
  • - “It takes you too long to ejaculate once you have entered your partner” “often”: 4%; “sometimes”: 16%
  • - “You fail to ejaculate at all” “often”: 2%; “sometimes”: 5%
  • - “You don't have an orgasm” “often”: 7%; “sometimes”: 7%
  • - “You feel no or insufficient sexual desire” “often”: 3%; “sometimes”: 16%.
  •   相似文献   

    17.
    Oren M. Becker 《Proteins》1997,27(2):213-226
    Clustering molecular conformations into “families” is a common procedure in conformational analysis of molecular systems. An implicit assumption which often underlies this clustering approach is that the resulting geometric families reflect the energetic structure of the system's potential energy surface. In a broader context we address the question whether structural similarity is correlated with energy basins, i.e., whether conformations that belong to the same energy basin are also geometrically similar. “Topological mapping” and principal coordinate projections are used here to address this question and to assess the quality of the “family clustering” procedure. Applying the analysis to a small tetrapeptide it was found that the general correlation that exists between energy basins and structural similarity is not absolute. Clusters generated by the geometric “family clustering” procedure do not always reflect the underlying energy basins. In particular it was found that the “family tree” that is generated by the “family clustering” procedure is completely inconsistent with its real topological counterpart, the “disconnectivity” graph of this system. It is also demonstrated that principal coordinate analysis is a powerful visualization technique which, at least for this system, works better when distances are measured in dihedral angle space rather than in cartesian space. © 1997 Wiley-Liss, Inc.  相似文献   

    18.
    Obligate neotenic salamanders die if forced to metamorphose. We suggest that this can be explained by assuming: 1) their “excess” DNA is “junk” DNA; 2) the “adult” specifying portion of the DNA becomes junk DNA and is available for repeated duplication. This suggests a “new” junk DNA molecular clock. We obtain remarkable agreement in “predicting” the amount of DNA per nucleus in present day non-obligate neotene salamanders from this molecular clock. These observatons are consistent with the idea that the development of these animals is describable in terms of differentiation trees whose branches (gene cascades) corresponding to adult somatic tissues accumulate deleterious mutations over evolutionary time. We show that the amount of DNA per nucleus increases linearly with the phylogenetic age of salamander families. The lack of constraints by natural selection, on unused adult branches, may account for the large amount of so-called “junk DNA” in obligate neotenic salamanders. The effects of this excess DNA, via increased cell size, suggest a positive feedback, ecophysiological explanation for such junk DNA: adaptation to cool water environments is enhanced by the lower metabolism associated with more DNA, larger cells and slower developmental time.  相似文献   

    19.
    20.
    The pesticide efficacy of locally available seven botanicals “Gime” (Chenopodium ambrosioides), “Ayderke” (Jatropha curcas), Neem (Azadirachta indica), Melia (Melia azadirach), “Chobe” (Cisus rotonifolia), “Kelewa” (Maesa lanceolata) and “Antharfa” at a rate of 4% weight by weight was evaluated for the control of cowpea bruchid using 200?g cowpea seeds in 500?cm3 volume jar in 2010 and 2011 under laboratory condition at Sirinka Agricultural Research Centre. The combined analysis showed that “Gime” (both leaf and seed) had high speed of pesticide effect as it showed significantly higher per cent of parent adult mortality (84 and 71%, respectively) as to the standard check Malathion 5% dust (100%) in the first day of adult mortality count. “Antharfa” and “Ayderke” also have shown significantly higher per cent of parent adult mortality as to Malathion in the third and fifth day of adult mortality count, respectively. In the seventh day, all botanicals showed significantly higher per cent of adult mortality as compared to untreated check. “Gime” leaf and seed powder, “Ayderke” seed, Neem seed and “Antharfa” leaf powders significantly reduced the number of progeny emergence per day as compared to all other treatments. Moreover, these botanicals were effective in reducing per cent seed damage (0.00, 0.00, 0.57, 5.86 and 10.86%, respectively) and storage loss (0.00, 0.00, 0.073, 1.02 and 2.27%, respectively). Gime (both leaf and seed powder), “Ayderke” seed and Neem seed are locally available, simple for preparation and environmentally friendly. Therefore, these three botanicals can be recommended to satisfy the demand for organic food and save the seed damage and yield loss of cowpea caused by Callosobruchus maculates and bean bruchid (Zabrotes subfasciatus) which has similar biology with Callosobruchus maculatus.  相似文献   

    设为首页 | 免责声明 | 关于勤云 | 加入收藏

    Copyright©北京勤云科技发展有限公司  京ICP备09084417号