bluuebunny/crossref_metadata_2025_split huggingface dataset:
Family Planning in the Kestrel (Falco Tinnunculus): the Ultimate Control of Covariation of Laying Date and Clutch Size
Authors: Daan Serge , Dijkstra Cor , Tinbergen Joost M. 
Published: April 2008

Abstract
The theory that individual birds maximize their fitness by the two major decisions in reproduction concerning date (when to start laying eggs) and clutch size (when to stop laying eggs) is empirically approached in the Kestrel by quantifying Fisher's Reproductive Value for both the clutch (Vc = c. Vo/2) and the parents (Vp). The reproductive value of an egg (Vo) was found to decrease monotonically with laying date (d) due to significant associations with d of the components So (probability for an egg to survive till fledging), S1 (probability to survive from fledging till age 1), S2 (survival age 1 till age 2), and P1 (probability of breeding at age 1). Vp declined negligibly with laying date, although there were significant associations between d (laying date) and N (probability of the nest to produce at least one fledging), Pr (probability of a repeat clutch following nest failure), and La (probability of local survival of the parents following breeding). In experiments where brood size at day 10 after hatching was increased or reduced, Vc increasing experimental brood size, while Vp simultaneously decreased. Total reproductive value (V = Vc + Vp) remained unaffected by the experiments. This result suggests that a rather broad range of clutch sizes maximizes total reproductive value, as far as detectable by the data. While the yield of kestrel hunting, and hence the number of young raisable with constant parental effort (and constant Vp), increased with the spring increase in vole population density, reproductive value of the clutches decreased. For any particular food situation (hunting yield) this leads to a unique combination of clutch size and laying date maximizing V. This could be worked out by calculating fitness contours for all combinations and for different yields (Fig. 12). The optimal solutions are on a declining slope, with smaller clutches associated with later dates. 59.4% of all clutches observed obeyed the maximization criteria. Furthermore, there was a reasonable, unbiased association between predicted laying dates and clutch sizes based on individual male hunting yields and observed dates and clutches as laid by the females. Qualitatively, any method predicts a seasonal decrease in the optimal clutch size when the environment improves while reproductive value declines with progressive date. Preliminary results from an experimental approach to test the assumption of a causal effect of date on Vo, using the release of juvenile kestrels reared in captivity under artificial light schedules, are presented.
Death in the Distance: Mortality Risk as Information for Foraging Ants
Authors: Nonacs Peter 
Published: April 2008

AbstractAnt foragers are known to communicate food presence in distant patches, but do they also communicate information about distant mortality risk? Recruitment to a food source in a laboratory Lasius pallitarsis colony depended upon whether the initial returning foragers had encountered mortality risk (a larger Formica subnuda) and the quality of the food they found. When food quality was high, risk appeared to not affect recruitment; when quality was low, risk inhibited foraging. In a second experiment, L. pallitarsis colonies had access to food of several qualities through a divided trail, which forced foragers to take different routes to and from the food patch. Danger was either entirely absent, present only on the way to the patch, present only on the way from the patch, or along both routes. When food quality was poor colonies recruited to food when risk was absent, but risk anywhere significantly reduced the level of foraging. This included the situation where only returning foragers could encounter danger, which strongly suggests that their behaviour was a critical factor in whether nestmates would continue foraging. When food quality was moderate, only treatments with risk on the way to the food significantly inhibited foraging. When food quality was good, colonies continued to forage at a high rate, irrespective of presence or location or risk. In total, L. pallitarsis foragers appear to communicate and use information about both food and mortality risk in deciding whether to exploit patches.
Long Ultrasonic Calls in Male Rats Following Mating, Defeat and Aversive Stimulation: Frequency Modulation and Bout Structure
Authors: Van Der Poel Augustinus M. , Miczek Klaus A. 
Published: April 2008

Abstract
Ultrasonic calls by rats may represent affective expressions and serve communicative functions. The temporal patterning and frequency modulation of the long, 21-30 kHz ultrasonic calls were studied in 7 male rats. Following ejaculation, defeat and aversive stimulation large samples of consecutive long calls were recorded and analyzed off-line using a spectrum analyzer. The analysis was limited to long calls because other types of calls were relatively rare under the circumstances of this study and the emitter could be determined by a typical breathing pattern with reasonable certainty only for long calls. Log survivor analysis of the intervals between calls revealed that rats emit 95 % of long calls in bouts of less than 6 calls. Except for the higher bout rate after defeat, there were no significant differences between tests in call duration, percent time spent vocalizing, bout duration and intervals between bouts. However, there were significant differences between individuals across tests in call duration, number of calls per bout and bout rate. The pattern and capacity to breathe are likely important limiting factors for several temporal characteristics of rat ultrasounds, in particular maximal call duration and range of interval duration within a bout. Post-ejaculatory calls were often strongly modulated in frequency (i.e. pitch) in the medial and terminal segments. These segments of calls emitted after defeat or aversive stimulation were essentially monotonous. We propose that rats emit at least 2 types of long ultrasonic calls-one monotonous, the other modulated-each reflecting a different affective state of the animal. The modulated type may reflect a state of behavioral inhibition such as initiated by ejaculation whereas the monotonous type may reflect a state of intense fear induced by an actual physical threat in situations where escape is blocked. Both types may serve a "desist-contact" function.
Organization of Fighting in the Polychaete Nereis Virens (Sars) and the Effects of Residency and Orientation
Authors: Miron G. , Desrosiers G. , Retier C. 
Published: April 2008

Abstract
Intraspecific encounters of the polychaete Nereis virens (Sars) were studied within artificial burrows in order to describe behavioural interactions that occur during the defence of the burrow. This work exploited the relationship between variability in contest outcomes and fighting behavioural sequences as a function of different types of encounters. In addition, the effects of resident orientation, duration of resident occupancy (acclimatization) and initial distance of the intruder anterior end from the resident (head or tail) were all included. The eviction frequency was significantly greater in the presence of acclimated individuals. Acclimatization reduced chances of cohabitation between two individuals within the same burrow. However, the importance of the acclimatization was greater in head to head ("H-H") encounters as opposed to head to tail("H-T") encounters. Encounters within a 15 cm distance separating each individuals showed that intruders were expelled in all "H-H" cases (100%) in contrast to 32% in "H-T" encounters. No significant difference was noticed between "H-H" and "H-T" encounters where the initial distance was greater than 15 cm. Fights were settled, on average, in 10 minutes with acclimated individuals in contrast to less than 2 minutes with non-acclimated worms. Behavioural sequences, for agonistic encounters, were more complex in residents than for intruders. Complexity in patterns was also greater for non-acclimated worms.
Information Statistical Analysis and the Frequential Method of Data Collecting: Description and Illustration of a New Model in the Study of Animal Behaviour
Authors: Ellenbroek B.A. , Hoeks B. , Cools A.R. 
Published: April 2008

Abstract
In the past information statistical analyses have been used for the description of the temporal organization of behaviour. In general, these analyses are based upon data collected with the sequential method. This method is known to limit the general applicability of information statistical analyses. In the present report a new model, based upon data collected with the frequential method, is presented. In this model too it is assumed that animals behave according to a MARKOV process. In the present model, however, the assumption of a MARKOV process implies that information (entropy) of a certain behaviour is a function of time, and not a function of "order in time". The key-advantage of this analysis is that it can be assessed to data collected during relatively short lasting observation sessions; using a computerized time recording system with a resolution of 0.1 s, for instance, a 60 min. session provides 36000 sampling points, viz. sufficient data for filling completely a transition matrix. This, in turn, implies that the analysis allows the calculation of the maximum error of the entropy (information) using a purely analytical method. Due to the ideal combination of a high sampling frequency and a relatively short collecting time, this analysis can be used to describe the individual relationships within social group structures in great detail. In the present report the applicability of this analysis is illustrated by assessing it to a single set of data collected in a study o spontaneously occurring changes in a group of 4 Java monkeys (Macaca fascicularis). the analysis deals with data collected in 17 sessions, one hour each, and recorded on separate days. the new analysis provided a detailed and quantitative description of dynamic changes, which could not be detected with the classical frequency analysis. The new analysis also provided a new dimension to the description of dynamic changes which were detected with the frequency analysis.
Effects of Novelty On Taste-Avoidance Learning in Chicks
Authors: Roper T.J. 
Published: April 2008

AbstractFive experiments were conducted to investigate the effect of novelty on visually-mediated taste-avoidance learning in domestic chicks. In experiments l a and b, chicks were reared with either uncoloured or blue fluid in their home cages, and then required to discriminate between blue and uncoloured fluids that were either palatable or unpalatable (quinine-adulterated). For some chicks the distasteful fluid was novel in appearance, for others it was familiar. In both experiments chicks readily discriminated between a novel unpalatable fluid and a familiar palatable one, but failed to discriminate between a familiar unpalatable fluid and a novel palatable one. This failure to discriminate resulted from avoidance of the palatable fluid. In neither experiment did novelty enhance the rate of avoidance learning. Experiment 2 tested more directly the effect of novelty on speed of avoidance learning. Chicks were reared on either red or blue palatable fluid, then tested with either red or blue distasteful fluid. Avoidance learning was more rapid when the distasteful fluid was novel in colour, in both red-reared and blue-reared chicks. Experiment 3 investigated the inability of chicks to discriminate between a familiar unpalatable fluid and a novel palatable one, demonstrated in experiment 1. Chicks were required to discriminate between different-coloured palatable and unpalatable fluids when both were familiar in appearance (experiment 3a) or when both were novel (experiment 3b). Discrimination occurred in the first case but not in the second. In addition, avoidance learning was slower when both unpalatable fluids were familiar. I conclude that (a) novelty faciliates visually-mediated taste-avoidance learning in chicks and (b) the failure of chicks to discriminate a novel palatable fluid from a familiar unpalatable one depends on the relative novelty of the palatable fluid and not on the relative familiarity of the unpalatable one. The results are discussed in the context of warning coloration and are explained in terms of an interaction between unlearned and learned avoidance tendencies.
Thermoregulatory Behaviour of Rock Lizards in Response To Tail Loss
Authors: Martin José , Salvador Alfredo 
Published: April 2008

Abstract
The consequences of tail loss on the thermal biology of high-altitude rock lizards (Lacerta monticola) were studied by comparing field body temperatures, selected body temperatures in a gradient, and behavioural patterns of thermoregulation of tailed and tailless lizards in the field. Neither field nor selected body temperatures differed significantly between these groups. Time spent basking, mean duration of basking, and basking frequency did not differ between tailed and tailless lizards. Tailless lizards seemingly adjusted for running impairment by using rocks to a greater extent than did tailed lizards, and low morning body temperatures by increasing maximal duration of basking periods and keeping shorter distances to the nearest refuge. Tailless lizards modify thermoregulatory behaviour, but obtain the same thermoregulatory precision as tailed lizards, possibly allowing maximization of physiological processes linked to tail regeneration.
Short Duration Time Constant Associated With Chewing in the Guinea Pig
Authors: Gerstner Geoffrey E. , Goldberg Louis J. 
Published: April 2008

Abstract
Previous investigations have reported a time constant on the order of a few seconds associated with temporal perception in humans, and with movement patterns in humans and other mammalian species. It has been suggested that the time constant represents the operation of a physiological oscillatory mechanism that is common among many mammalian species. However, the time constant has not yet been observed in laboratory animals; therefore, there is no laboratory-based behavior paradigm upon which studies into the physiological nature of this time constant can be based. Because of our familiarity with guinea pig feeding, the current study was undertaken in order to find evidence of the time constant in feeding-associated activities of guinea pigs. Eleven guinea pigs were starved for a 24 hr period, then placed individually into a rich behavioral arena for 30 min, during which time they were videotaped continuously while they roamed freely. The animals inevitably ate during these videotape sessions, and a detailed analysis of chewing parameters was done. It was found that chewing typically occurs in bursts, and that the median burst duration was 1.03 - 3.46 s for individual animals. Chewing burst durations were similar to the durations of many movement patterns in other species including humans. This provides further support for the hypothesis that there is a highly conserved time constant associated with movement patterns in mammals. It is believed that guinea pig chewing bursts provide a convenient laboratory based model for elucidating the neuro-physiologic mechanisms of this time constant.
Sequential Assessment and Decision-Making in Humans
Authors: Sullivan Matthew S. , Burnham Dawn , Stevens-Wood Barry , Sheldon Ben C. 
Published: April 2008

Abstract
In two experiments inspired by theories of sequential information-gathering tasks such as sequential mate assessment, human subjects were asked to view sequences of pictures of mythical birds, each of which varied in value according to one of three stimuli, namely tail length, band width or intensity of black and carried an associated score. The subjects chose one picture from the sequence so as to maximise their points scored. Only one picture could be seen at a time, if a picture was rejected it could not be revisited and there was a small constant devaluation of each successive picture. In the first experiment two random sequences of each of the three stimuli were viewed and subjects were given no prior information on the population of pictures, nor was the devaluation specified. In the second experiment, which used only pictures which varied in tail length, subjects cach saw a different random sequence and then the same fixed sequence. In addition, they were told there was either a 5%, 10% or 20% devaluation of succesive birds, and half the subjects were given prior information on the population to be viewed. Thus in this experiment scores could be corrected for position in the sequence. To summarise the major results: 1. Choice was made at an early stage in the sequence, usually the 3rd, 4th or 5th picture, and this was consistent in both experiments. 2. In Experiment 2, subjects given prior information or smaller devaluation functions chose later in the sequence. 3. In Experiment 2 there were no differences in the corrected scores achieved by subjects in our treatments of prior information or devaluation, but subjects achieved higher absolute scores as the devaluation decreased. 4. In both experiments the value of the chosen picture was positively correlated with the mean value of the prior sequence seen when absolute scores are used, but in Experiment 2 this effect disappears when corrected scores are used. 5. A large positive jump was a cue to stop in both the random and fixed sequences. Identification of relevant variables and patterns of decision making may further enlarge our understanding of sequential assessment in humans and other animal species.
Mirror Image Pattern Matching By Bumble Bees
Authors: Korneluk Y.G. , Plowright C.M.S. 
Published: April 2008

Abstract
Bumble bees (Bombus impatiens) were trained to discriminate between a rewarding and non-rewarding artificial flower that differed only in their configuration of four identical petals. On choice tests between 2 empty flowers, the bees chose the flower with the configuration of the rewarding flower over the mirror image, but the mirror image over a novel flower. This behaviour is the same as has been observed with honey bees and functional interpretations are considered. The problem of distinguishing between left-right pattern reversals and true mirror image transformations is discussed.
Experiments On Embryo Survivorship, Habitat Selection, and Competitive Ability of a Stickleback Fish (Gasterosteus) Which Nests in the Rocky Intertidal Zone
Authors: Macdonald J.F. , Macisaac S.M. , Bekkers J. , Blouw D.M. 
Published: April 2008

Abstract
Like other 'white' sticklebacks, those ncsting intertidally at Spry Bay, Nova Scotia, Canada, remove fertilized eggs from the nest, disperse them over the surrounding area, and provide no subsequent parental care. However the breeding substrate at Spry Bay is devoid of the filamentous algae which are the normal breeding substrate of the white stickleback and which elsewhere facilitate survival of abandoned embryos. Experiments show that embryos dispersed in the intertidal zone at Spry Bay survive surprisingly well despite the complete absence of parental care and the periodic absence of water. Intertidal embryos generally develop faster than embryos in the adjacent subtidal zone, but there are exceptions to this pattern. Intertidal males show site fidelity to their nests despite interrupted access to territory, and they show consistent preference for nesting in the intertidal zone in the field. In the laboratory, and in the absence of tidal flux and competition, males taken from the rocky intertidal zone generally prefer to breed on bare rock substrate even when filamentous algae are freely available. When white stickleback males from an adjacent population which breeds subtidally in filamentous algae are introduced into the experimental aquaria as competitors, they exclude the males that breed on bare rock. The surprisingly high survivorship of embryos in the rocky intertidal zone, the habitat selection of males for bare substrate, and their exclusion by males that breed subtidally on algae, all suggest that the highly unusual breeding behaviours of intertidal white males form an effective alternative breeding repertoire. Because breeding habitat selection has implications for mate selection, the possibility exists that sticklebacks with different breeding repertoires at Spry Bay may mate assortatively.
Individual Differences in Vocalisations of Young Barbary Macaques (Macaca Sylvanus): a Multi-Parametric Analysis To Identify Critical Cues in Acoustic Signalling
Authors: Hammerschmidt Kurt , Todt Dietmar 
Published: April 2008

AbstractIt had been shown that Barbary macaque (Macaca sylvanus) mothers are able to individually recognise their offspring by its vocal signals, but it remained unclear which acoustical cues may account for such an ability. In order to address this issue from a basic perspective, about 1800 calls of infants and yearlings (N = 10) were investigated. The investigation applied a method of signal analysis which allowed to determine a large number of parameters (N = 84) for each vocal signal. The application of discriminant and cluster analyses provided the following results: (1) Animals differed in almost all call parameters. However, individuals were best identified by specific parameters which formed an individually characteristic parameter set. (2) Those parameters that facilitated the assignment of vocal patterns to a given individual usually were different among individuals. (3) Infants and yearlings achieved the same maximum value of correct assignment. However, infants achieved a reasonable assignment at a much smaller number of call parameters. (4) Cluster analysis of vocalisations revealed that Barbary macaques uttered individual versions of common call types. (5) When the discriminant analysis was rerun on the call clusters, the correct assignment could be improved from 81 % to 94% for infants and from 80.5% to 96% for yearlings. Our findings suggest that Barbary macaque mothers can recognise their offspring by more than one signal cue, and such a strategy may improve the recognition system's robustness against possible distortions caused by the environment. The pronounced differences in vocal patterns of young Barbary macaques may help mothers or other group members to readily learn and recognise the individually specific signal features. The methodological procedures described in this paper provide a powerful tool for an assessment of signal parameters also in other areas of vocal interactions.
Individual Differences in Egg Cannibalism in Female Dark Chub (Pisces: Cyprinidae)
Authors: Katano Osamu , Maekawa Koji 
Published: April 2008

Abstract
Nine of 41 identifiable females of dark chub, Zacco temmincki, in a river cannibalized eggs of other females. There was no significant difference in body size, condition factor or the location of home range between cannibals and noncannibals. In laboratory experiments, one male and two females were introduced into an aquarium to observe the behaviour of individual females while a pair spawned. The response of 16 females to spawning was observed and 15 of 16 females exhibited egg cannibalism. The percentages of egg-eating behaviour for individual females varied from 11.1 to 81.8%, and did not change significantly over the course of the experiment. Dark chub were multiple spawners. In a river the number of spawning sequences for cannibals was significantly higher than that for noncannibals. The number of eggs laid by cannibals was estimated to be 1.55 times as many as that by noncannibals.