bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temporal Organisation in the Behaviour of Newborn Infants in Active Sleep
Authors: Briem Valdimar 
Published: April 2008

AbstractThe human neonate normally spends nearly 2/3 of its time asleep, and of this time ca 2/3 are spent in active sleep (AS). The present study was designed to investigate the temporal organisation and behavioural composition of this state. The hypothesis was put forward that the amount of facial behaviour that could be observed at any point in time during AS was representative of the neonate's general state of activation, and that the degree of activation varied with cyclic regularity. To test this, the facial behaviour of 8 normal neonates was filmed, and the films observed repeatedly. All activity occurring in three facial regions was registered and the resultant behavioural sequences analysed. It was found that facial behaviour tended to occur in bursts, and the median activity-quiescence cycle length was about 9 seconds. The amount of facial behaviour tended to wax and wane in a compound rhythm, and the lengths of the activity cycles involved could be predicted from a geometric function model. The results were compared with the evidence for cyclic behavioural activity found by previous investigators, and several explanatory models were examined. It is proposed that the activity cycles observed here are related to the rhythmicity observed in other behavioural states of the human infant.
Comment Le Chant Du Troglodyte (Troglodytes Troglodytes) Émerge Du Bruit
Authors: Brémond Jean-Claude , Kreutzer Michel 
Published: April 2008

AbstractThe information theory tells us which strategies can be used to compensate for alterations introduced by the channel. By encoding, the wren constructs his song in such a way that it can take advantage of most of these strategies. By decoding, it does not use all the strategies which encoding has made available. The choise and number of those which are used is a function of difficulties which the bird will encounter in recognizing the song of its own species. For instance, the duration or even the existence of silences between the notes are not taken into account. The bird uses them only to remove a difficulty about elements recognition. In this manner it is possible to explain the effectiveness and reliability of song as a means of communication.
Aggressive Behaviour Between Territorial Cichlids (Astatotilapia Burtoni) in Relation To Rank and Territorial Stability
Authors: Fernö Anders 
Published: April 2008

AbstractTerritorial mosaics of A. burtoni were studied in the laboratory. A difference in rank between neighbouring territorial fish was usually found, with the male with higher rank exhibiting more offensive behaviour and the opponent resisting more passively. A role asymmetry in boundary disputes was found in both high- and low-intensity aggression. Linear rank orders were formed. High rank was associated with a high aggressive and sexual activity towards non-territorial fish and a high mating succes". Territorial size was larger in superior males. A superior did not, however, generally expand his territory towards an inferior. This could be due to the involvement of escalated aggression with the reduction of territory. Most males of low rank did, however, eventually lose their territories. Establishing and losing territories were correlated with a low level of low-intensity aggression. Escalated fighting seldom occurred in spite of a strong competition for females, and aggression was usually limited to Frontal display and low-intensity aggression. Frontal display also played a key role for de-escalation of physical aggression. A. burtoni seems to follow the strategy "Honest", using a honestly graded display with few escalations.
Extra-Pair Copulations and Mate Guarding in the Polyterritorial Pied Flycatcher, Ficedula Hypoleuca
Authors: Lundberg Arne , Gottlander Karin , Alatalo Rauno V. 
Published: April 2008

Abstract1. Seven out of 24 observed copulations (= 29% ) in the pied flycatcher were extra-pair copulations (EPCs). There was no significant difference between EPCs and pair copulations (PCs) with respect to timing and duration, possibly indicating that both are equally successful. Thus, proportion of copulations may reflect share of paternity. 2. Females usually do not solicit EPCs and often try to avoid them. We cannot find that females have much to gain from EPCs, while attempts to resist forced copulations may impose some costs. The fact that EPCs still are rather frequent suggests that it might be cheaper for a female to accept an EPC than to resist it. 3. Males spend much of their time mate guarding but the distance between pair members is longer for polyterritorial males than for monoterritorial males. Still, we cannot find any significant differences in risks or possibilities of EPCs between males of different mating status. However, the relaxed mate guarding by polyterritorial males suggests that these males might take higher risks, and they also suffer more territory intrusions. 4. It is most likely that male reproductive strategies are not maintained as a frequency-dependent mixed ESS with equal pay-offs for all paired males. Instead, male strategies are conditional on phenotype and breeding circumstances.
The Effects of Parent and Offspring Gender On Food Allocation in Budgerigars
Authors: Stamps Judy , Clark Anne , Kus Barbara , Arrowood Pat 
Published: April 2008

AbstractParental feeding rates in relation to the sex of parents and offspring were studied in domesticated budgerigars in large flight cages at Davis, California. While neither the male nor the female parent preferentially fed offspring of either sex, paternal feeding rates were strongly related to the sex ratio of the brood. Fathers fed female-biased broods much more frequently than male-biased broods throughout the nest cycle, and male feeding rates were highly correlated with the sex ratios of the broods. Mothers exhibited a similar but much weaker tendency to feed female-biased broods more often, and only at the end of the nest cycle was there a barely significant relationship between sex bias and maternal feeding rate. As a result of the extra parental care, female-biased broods obtained nearly three times more regurgitations in the final pre-fledge period than male-biased broods. Brood sex ratios were unrelated to fledge weights, and male and female nestlings fledged at comparable weights. However, for all but the smallest broods, there was a strong negative relationship between the percent of females within the brood and the average age of fledging. Fledge age, in turn, was related to post-fledge activity rates. Females fledging at younger ages initiated more flights than those fledging at older ages. Conversely, in males, fledge age was either unrelated, or positively related to the rate of flights. There were also significant negative relationships between female fledge age and reproductive success (e.g. number of young fledged in the first breeding season), but no significant relationships between male fledge age and reproductive success. Hence, male parents may provide extra care to broods biased toward the offspring sex which most benefits from this extra care.
Selection for Larval Vagility in Drosophila Melanogaster
Authors: Katz Mary , Levine Louis , Rockwell Robert F. 
Published: April 2008

AbstractSix lines of the Drosophila melanogaster Oregon-R stock were established and each line was selected for either slow or fast larval movement through a system that consisted of single, double, or triple rings. Selection was successful in all three "slow lines" but not in any of the "fast lines". A test for movement of the adults from each of the six lines failed to reveal any correlated response. It is concluded that larval vagility in this stock is close to the maximum possible, and that there is no common genetic control over the tested types of movement in the two active stages of the organism's life cycle.
Patch Use and Patch Depletion By the Spider and Howling Monkeys of Santa Rosa National Park, Costa Rica
Authors: Chapman Colin 
Published: April 2008

AbstractPatch depletion is an assumption that underlies many behavioural ecological models, yet it has rarely been examined. The evidence presented here suggests that the spider and howling monkeys of Santa Rosa National Park, Costa Rica use food resources that occur in patches and generally deplete the patches they use. However, some types of patches (e.g. large fruiting trees for spider monkeys, and trees used as sources of leaves for howlers) are not depleted by the feeding activity of primates. An examination of which types of patches are depleted and the manner in which depletion likely occurs, allows an assessment of possible factors underlying the different types of social organizations in these species.
Influences On the Choice Between Territorial and Satellite Behaviour in Male Libellula Quadrimaculata Linn. (Odonata: Libellulidae)
Authors: Convey Peter 
Published: April 2008

AbstractTerritorial behaviour of male Libellula quadrimaculata Linn. was investigated at Wicken Fen, Cambridgeshire, in 1986. Males were intensely territorial, expelling any other males that flew into their territory. Territories were defended for the mating opportunities that they provided. As local population density increased a number of males adopted satellite behaviour, although most continued to behave territorially. Wingspan and hindwing length were significantly larger in satellites than in territorial males. The likelihood of satellite behaviour was not related to male age. There was also no difference in age between satellite-host pairs in which both individuals were of known age. Satellite males were not observed to mate successfully, though they did not suffer the costs associated with territorial defence. A series of removal experiments demonstrated that the satellites could take over a territory and behave aggressively to other males. Scaling factors may have an important function in forcing larger males to adopt the less successful satellite role. Notably, flight muscle content was lower than expected in larger individuals, which should result in lower power output per unit body weight, and thus lower maximum acceleration and manoeuverability.
Assessments and Decisions During Mate Choice in Gammarus Pulex (Amphipoda)
Authors: Dick Jaimie T.A. , Elwood Robert W. 
Published: April 2008

Abstract
Male Gammarus pulex preferentially enter precopulatory mate guarding with large females close to moulting. The interactions of males and females were observed in an attempt to elucidate the process by which males assess females and, further, to determine how such information gathering influences mating decisions. Males which encountered single females, which had recently been experimentally separated from other males, grabbed and held those females in a perpendicular hold prior to establishing the precopulatory hold. The higher the reproductive quality of the female the more rapid was the male decision to move into the perpendicular hold but this was followed by an increased level of abdomen flexing and antennae touching. Once precopula was established, higher quality females received more stroking with the free gnathopods. When two females were encountered, some males simply took the first contacted and this resulted in random pairing. Other males, however, demonstrated the ability to sequentially sample as well as simultaneously compare females and, if this occurred, they almost invariably took the higher quality female. Discrimination between two females was more rapid as the difference in their qualities increased whereas males engaged in more grabbing and holding when females were of similar moult stages. The data show that assessment of female size and moult stage occurs early in the interaction, whereas subsequent activities such as flexing and stroking are probably involved in courtship, possibly serving to pacify females.
Ontogeny of Ultrasonic Vocalizations in the Woodmouse (Apodemus Sylvaticus L.). I: Temporal Organization
Authors: Pontet André , Gyger Marcel , Schenk Francoise 
Published: April 2008

Abstract
We have studied the ontogeny of ultrasonic vocalizations in the woodmouse, Apodemus sylvaticus, a high vocalizing palearctic murid species. Vocalization and behaviour were recorded as the pups were daily isolated for three minutes at ambiant temperature in two different experimental conditions: a plus-maze and a cup. The temporal organization of the vocalizations was analysed using log survivor functions of the intervals between the calls. These functions provided a reliable bout criterion indicating that ultrasound production by the youngest pups was clustered in bouts. Ontogenetic changes in the ultrasound production appeared different when measured in calls or in bouts per time unit. The call rate decreases from PND 11 onwards, whereas the bout rate remains elevated up to PND 15. Ultrasound production and locomotor activity arc associated from PND 11 onwards. The high ultrasound production by two-week old pups in the plus-maze is related to a very high locomotor activity in this experimental condition. We have identified four different steps in the ontogeny of ultrasonic vocalisations in the woodmouse: 1) Just after birth, the pups emit very few ultrasounds. 2) Around PND 3, there is a tremendous vocal output: the pups vocalize in a tonic mode, almost continuously. 3) The tonic mode goes gradually into a phasic mode in which ultrasounds are clustered in bouts; the total production decreases as the pups grow up. From PND 11 onward, most of the calls are produced during locomotion. 4) Around PND 15 there are mainly single calls, like in the adults. The very intense and frequent calls emitted during the second step are known to be distress calls. Since their production is accompanied by a high muscular activity, that might also delay cooling of the pups. The calls emitted by two-week old pups might serve as contact calls increasing the cohesion between the pups at the time of the first excursions out of the nest. In this way, these calls might diminish the predation risk and would facilitate a possible protection or retrieval by the mother.
Dangerous Lions and Nonchalant Buffalo
Authors: Prins H.H.T. , Iason G.R. 
Published: April 2008

Abstract
1. Aspects of the influence of predation on the African buffalo Syncerus caffer were studied in Lake Manyara National Park, northern Tanzania, from 1981 to 1985. 2. During the study period, predation by lions was the most important cause of death in buffalo but occasionally major epidemics, such as rinderpest, can be by far the most important cause of death. 3. A comparison of Manyara with four other areas in Africa shows that the Manyara buffalo ran the same level of risk as those in these other areas, and that in periods in which epidemics or drought conditions are absent it was normal that ultimately some 90% of the large herbivores fell victim to predation. 4. Juvenile mortality in females was higher than in males but adult mortality in females was lower than in males. Adult bulls ran a much higher risk to be killed by lions (12.9% p.a.) than herd-living buffalo (4.4% p.a.); the latter category comprised cows and sub-adult bulls. 5. Risk of predation was highest near the ecotone between grasslands and structurally closed vegetations. Grasslands were as dangerous as woodlands and thickets, and only the mudflats were really safe. The chance to be killed fell steeply away from (potential) cover for lions. 6. Buffalo were more vigilant at night than during the day, peripheral animals more so than central ones. Adult bulls were more vigilant than other categories of buffalo. It is concluded that vigilance in buffalo was not restricted to predator detection. 7. The choice of feeding areas in buffalo was not dictated by predation risk alone.
Adaptive Superparasitism and Patch Time Allocation in Solitary Parasitoids: the Influence of the Number of Parasitoids Depleting a Patch
Authors: Visser Marcel E. , VAN ALPHEN Jacques J.M. , Nell Henk W. 
Published: April 2008

AbstractAn ESS model that predicts more superparasitism and longer patch times with an increasing number of searching parasitoids in a patch, was tested in experiments with Leptopilina heterotoma, a solitary larval parasitoid of Drosophila. The observed egg distributions and patch times were in quantitative agreement with the predictions of the model; oviposition and patch time decisions are clearly influenced by the number of conspecifics in the patch. Both in the model and in the experiment patch quality was kept constant (the number of hosts and the patch area per parasitoid were kept constant). The model predicted and the experiments showed that parasitoids gain less offspring per unit of time when searching a patch together: superparasitism leads to mutual interference. No self-superparasitism should have occurred when parasitoids searched alone. This prediction was only met with females that had been kept in isolation in the days before the experiment; when stored in groups of four, self-superparasitism did occur. This indicates an ability of the parasitoids to assess the probability of future superparasitism by conspecifics.
Variation in the Mating System and Associated Parental Behaviour of Captive and Free-Living Cichlasoma Nigrofasciatum (Pisces, Cichlidae)
Authors: Keenleyside Miles H.A. , Bailey Robert C. , Young Vicki H. 
Published: April 2008

Abstract
C. nigrofasciatum typically breed in monogamous pairs with biparental care of the young for up to 6 weeks. In experimental ponds in southern Canada and streams in north-western Costa Rica two variations on this system were studied: male desertion followed by maternal care, and simultaneous bigamy by males. In the ponds, with a female-biased sex ratio, males deserted or became bigamous when their broods were at all stages from eggs to advanced, free-swimming fry. These departures from monogamy did not consistently influence brood survival, except that broods deserted by their father shortly after spawning did not survive, whereas those deserted when they were at least one week into the fry stage survived to independence with only their mother as guardian. Both in the ponds and at the field sites females with monogamous partners spent more time away from their broods than did deserted females, but only in the ponds did this correspond with reduced feeding by the deserted females. In nature all parental females foraged less often than did non-parental females, and this reduction was not strongly influenced by mate desertion. Brood defense behaviour by adults in monogamous pairs provided some evidence of division of parental labour. In the ponds guarding females attacked sub-adult juveniles more than males did, whereas in the field guarding females attacked non-cichlid fishes (mainly characins and poeciliids) and conspecific females and juveniles more than males did. Both in the ponds and the field guarding males attacked conspecific adult males more than females did. Most deserted, brood-guarding females seen in Costa Rican streams had young that were relatively large, mobile fry, approaching independence. This may reflect the need for both parents to guard their young during the first few days of free-swimming. They are probably highly vulnerable to predators at this stage and paternal desertion may be more costly than later, when they are stronger swimmers and better able to escape from predators.
Evolutionary Dissipation of an Antisnake System: Differential Behavior By California and Arctic Ground Squirrels in Above- and Below-Ground Contexts
Authors: Goldthwaite Ronald O. , Coss Richard G. , Owings Donald H. 
Published: April 2008

Abstract
Arctic ground squirrels (Spermophilus parryii ablusus) have been free from snake predation for about 3 million years. To evaluate the effects of this prolonged relaxation of natural selection, lab-born Arctic ground squirrels were compared to snake-inexperienced California ground squirrels (Spermophilus beecheyi fisheri) from a habitat where rattlesnake and gopher snake predation is intense. Their behavior was video taped during 10-min encounters with a Pacific gopher snake (Pituophis melanoleucus catenifer) in a seminatural above-ground setting and in an artificial burrow. In separate trials, a domesticated Norway rat was used as a control for the effects of encountering a novel animate object; this rat was enclosed in a slowly moving opaque nylon bag above ground but was allowed to move freely below ground. No evidence was found that, after prolonged relaxed selection from snakes, Arctic ground squirrels retained the specialized behavioral antisnake defenses evident in California ground squirrels. Although we originally hypothesized that the more constrained burrow context might limit the evolutionary dissipation of behavioral antisnake defenses, we found no evidence of a more intact system in Arctic squirrels below than above ground. Arctic squirrels used many of the same general kinds of motor patterns as California squirrels, but in ways that failed to differentiate the gopher snake from the rat in either above- or below-ground contexts. In contrast, the California squirrels tail flagged only in the presence of the snake above ground and differentially applied substrate-throwing at the snake and rat burrow intruders, harassing the snake more than twice as much as the rat. Above ground, California ground squirrels were more conservative toward both adversaries than Arctic ground squirrels were, keeping their distance and therefore experiencing fewer noxious consequences, such as snake strikes. However, this result was context dependent. Below ground, California ground squirrels were more willing than Arctic ground squirrels to approach and harass both burrow intruders. Although repeated striking evoked occasional snake-directed substrate throwing above ground, Arctic ground squirrels never threw substrate at the snake in the burrow. In comparison with California ground squirrels, Arctic ground squirrels appear to enter their first gopher snake encounter with both a much lower assessment of the risk involved and less clearly defined knowledge about how to deal with these risks. We conclude that 3 million years of genetic drift has altered the cognitive system structuring the meaning of snakes to Arctic ground squirrels in various settings.
Effect of Genotype and Litter Size On Discrimination of Mothers By Their Twelve-Hour-Old Lambs
Authors: Nowak R. , Lindsay D.R. 
Published: April 2008

AbstractThe ability of 12-h-old Border Leicester x Merino (BL x M) and pure Merino (M) lambs to seek a ewe and to discriminate their mothers from alien dams was tested in a two choice situation. When released in a triangular enclosure at 6 m from two penned ewes placed next to each other, most lambs reached a ewe before the end of the 5-min test. BL x M lambs were more attracted to the ewes than M lambs and could better discriminate their own mothers from alien dams. Although BL x M lambs were heavier than M lambs, the differences observed were mainly related to an effect of breed rather than to birth weight. There were no significant differences due to litter size or sex within each breed. On the other hand the differences between breeds were more marked in multiple than in single born lambs. This suggests the existence of an interaction between breed and litter size in the behavioural performances of very young lambs. It is concluded that young lambs can take an active part very early in life in the normal development of selective mother-young relationships. Also, 12 hours after birth, single and multiple BLxM lambs can discriminate between their own and alien mothers better than M lambs.