摘要:

Abstract and SummaryIn Norway rats (Rattus norvegicus) postpartum copulation began later, and was more rapid than mating during a cycling estrus. Faster postpartum mating was a result of shorter intervals between intromissions, rather than fewer intromissions. In addition, postpartum pairs showed a trend towards fewer ejaculatory series. Postpartum female sexual initiation and her attractiveness to the male produced rapid postpartum mating. Preliminary evidence indicates that pups' presence does not determine faster postpartum mating, yet postpartum females did exhibit time‐sharing relationships between their mating and maternal demands. We hypothesize that the rapid pace of postpartum mating is produced by intrinsic neuroendocrine changes characteristic of postpartum estrus and possibly by sexual experienc

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb01374.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract and SummaryThis study is an analysis of the functions of calls used by common crows (Corvus brachyrhynchos) in contexts involving danger. Four types of calls (screams, mixed caws, inflected alarm caws, alert caws) were tape recorded and played back to 7 captive crows. Three types of vocal response (mixed caws, alert caws, long caws) were scored for the 3 most responsive receivers. From the magnitude and temporal course of the responses, and from comparison of the various responses across the different playback types, functional interrelationships among caw types were found. Mixed caw responses showed a single pattern of elicitation only in response to certain playback types, and were inferred to be unifunctional (indicating immediate danger). Alert and long caw responses showed different patterns of suppression and elicitation with respect to playback type, and were inferred to be multifunctional (indicating mild danger; cessation of danger; business as usual; intraspecific aggression). These results are discussed in terms of the information encoded in mobbing and alarm calls, and their functional and adaptive significance.

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb01375.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract and SummaryThe female of the mouthbrooding cichlidPseudocrenilabrus multicolorfrom East Africa takes up her eggs during spawning and carries them continuously in her mouth for approximately 10 days at 27 °C. Then the young — now able to swim — are released from her mouth. A former study showed that the point of release is under the control of an internal timing program in the mother which can be only slightly modified by age‐specific stimuli from the brood. The present investigation is concerned with how brood deprivation influences mouthbrooding in first spawners.If the brood is removed from the mother's mouth for longer periods of time (several days), the internal timing program can be split into two components that control different behavioural parameters:1Brood care motivation, i.e. the readiness to take up brood into the mouth and keep it there but not eat it, is maintained up to 10 to 11 days after spawning (at 27 °C), regardless of the duration of previous brood deprivation.2In contrast, the point of release of brood from the mouth is retarded as a linear function of the duration of previous brood deprivation. Additionally, brood older than 10 days at the point of release is released one day earlier than younger brood.The mechanisms of these different time‐measuring systems are discussed with the aid of a model which assumes internal hour‐glass timers. The adaptive significance of the mechanisms rema

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb01376.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract and SummaryObservations on lapwing foraging on estuarine mudflats showed that:1They detected prey during stationary scanning pauses.2The majority of prey items were taken within three paces of the scanning position; the polychaeteNereis diversicolorwas taken at greater distances than the amphipodCorophium volutator.3Pecks that proved abortive occurred after a greater number of paces than successful pecks, and their proportionate incidence increased with distance from the pause position; it is argued that aborted pecks are due to misidentification of prey cues rather than escape of the prey.4After failing to detect prey from one position, birds gave up and moved to a new scanning position; the median distance moved corresponded to the radius of an area within which 99% of prey items were located.5The total distance moved while taking prey (including steps taken after capture but before the next scanning pause) rarely took birds beyond the boundary of the previously scanned area; birds that chose to remain in the previous scanning position had higher subsequent probabilities of taking prey than those that moved to scan a fresh area.6There was a negative correlation between success rate (proportion of pauses that resulted in prey capture) and rate of movement (steps per min); this was caused by increased distances moved between pauses in low quality foraging areas, and not by handling times interfering with searching, as there was a positive correlation between the number of prey handled per min and searching rate (number of pauses per min).

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb01377.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract and SummaryWhen a mixed pair of one zebra finch (Z) and one Bengalese finch (B) parent raises 2 Z young, the Z parent shows more parental care than the B parent. Three possible hypotheses for this difference are investigated:1— Z parents show more parental care generally, independent of whether the nest contains Z or B young.2— Parents are more stimulated to show parental behaviour by conspecific than by heterospecific young.3— Young have an initial bias to respond preferentially to conspecific parents.The results of an experiment in which mixed pairs raised 1Z + 1B young showed a species‐specific relation in parental behaviour; therefore the first hypothesis can be rejected. Several observations indicate that the species‐specific relation seems to be due to selectivity in the parents of both species and not in the young, making the second hypothesis the most likely one. Literature on other species and functional considerations support this view.Differences were also present in the proportion of allopreening and clumping directed by both parents to the Z and the B young. No direct relation between these differences and the selectivity in parental care

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb01378.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract and SummaryVaginal marking by female hamsters is more frequent in the presence of a male than when the female is alone; this is so on each of the three dioestrous days of the oestrous cycle. With a male present, marking frequency on Day 4 is about four times greater than on Day 2 or 3 of dioestrus. On Day 4, vaginal marking is correlated with male proximity and is greatest when the male is actively following the female. Vaginal marking is closely associated in time with the female moving away from the male, and particularly with rapid approach‐withdrawal by the female.Discussion centres on the function of vaginal marking. Vaginal secretion has at least two chemical fractions which have different effects on the male. It is likely that the context in which the male samples the vaginal secretion may modify the information that is transferred from the femal

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb01379.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractCommunication of status was demonstrated in females of the paper wasp,Polistes fuscatus. Wasps directed more aggression toward subordinates which were similar in status to themselves than toward dominants or low ranked subordinates. Chemical cues originating from both the head and the ovaries communicate status. The hypothesis that lateral vibrations are used by the queen to communicate her dominance to nestmates was not supported by our findings. No correlation was found between the amount of light body coloration and dominance status. Queens that had been tethered and were thus unable to pursue subordinates aggressively still communicated their status but their dominant rank in the colony was often affected.

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb01380.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract and SummaryThe vocal behavior of the pigeon guillemot (Cepphus columba) was studied for 5 years on Southeast Farallon Island, California in order to determine whether there were, rules common to many of the signals in the repertoire that could relate variation in signal structure to message content. The vocal displays used by pigeon guillemots in social communication are described, and variation in four vocal display classes (Hunch‐whistles, FM notes, Screams, Trills) is quantitatively analysed.Two sets of rules that relate signal structure to message content are proposed to describe variation in pigeon guillemot vocalizations. One set of rules relates continuous variation within each of the four vocal display classes to the signaller's probability of subsequent movement.The second rule set, based on a simple hierarchy, regulates the assemblage of notes into higher‐level units (phrases, displays) which encode progressively more information. Tape playback experiments confirmed an assumption made by this model: lower‐level vocal elements contribute a specific message to each of the higher‐level vocalizations in which they occur. The implications of this model for the perception of sounds and decoding of messages are di

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb01381.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract and SummaryTwo populations of individually marked pikas (Ochotona princeps) were studied on Niwot Ridge, Boulder County, Colorado, U.S.A., to determine if these lagomorphs are able to, and actually do, recognize other individuals through the use of vocal cues contained in the short call. Discriminant function analysis demonstrated that short calls are individually distinct in structure. Furthermore, pikas responded differentially to naturally occurring calls from different individuals and recognition appears to be possible solely through the use of vocal cues contained within the short call.Pikas also discriminated between playbacks of familiar and unfamiliar short calls. The strength of response appears related to the level of competition and the relative amount of threat that a familiar or unfamiliar pika represents to the responding individual.

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb01382.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Abstract and SummaryVariability characterizes the orientation of migratory birds much as it does other aspects of their behavior. Yet, in most orientation experiments measures of central tendency are emphasized, while existing individual variability is seldom addressed other than to make special statistical effort to reduce it. Massing individuals is only useful, however, if there are insignificant differences among them. When the behavior of individual migrants was monitored over several nights and then compared, individual directional preferences were evident. Among‐individual variability in compass orientation was greater than within‐individual variability. The statistical variation that exists around a group mean seems to be a function of differences among individuals showing rather specific preferences. Because the samples may have consisted of individuals representing different breeding localities, the observed differences among individuals may reflect different migratory goals.ZusammenfassungUntersucht wurde an der Grasammer (Passerculus sandwichensis) die Variabilität sowohl innerhalb einer Gruppe als auch am einzelnen Vogel auf dem Frühjahrszug. Mittelwerte für die Gruppe zeigten jahreszeitlich angemessene nördliche Orientierung für jede Versuchsgruppe. Das Verhalten einzelner Zugvögel durch mehrere Nächte ließ individuelle Unterschiede erkennen. Variabilität innerhalb der Gruppe war ausgeprägter als im Verhalten des einzelnen Vogels. Die statistische Abweichung vom Gruppenmittelwert ist allem Anschein nach eine Funktion der Unterschiede zwischen einzelnen Vögeln, die ganz bestimmte Richtungen bevorzugen. Da beide Versuchsgruppen vermutlich aus Vögeln bestanden, die geographisch verschiedenen Populationen mit entsprechend verschiedenen Brutgebieten angehörten, ist es möglich, daß die beobachteten Unterschiede zwischen einzelnen Vögeln auf unterschiedliche

ISSN:0044-3573    

DOI:10.1111/j.1439-0310.1985.tb01383.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY