bluuebunny/crossref_metadata_2025_split huggingface dataset:
Size-dependent male reproductive success and size-assortative mating in the midwife toad Alytes obstetricans
Authors: Böll S. , Linsenmair K.E. 
Published: April 2008

AbstractIn a field population of the midwife toad, Alytes obstetricans, a temperate zone species with extensive paternal care, size-assortative mating was observed. During the more favourable mating season of 1987, larger males carried bigger single clutches, as expected from assortative matings. Furthermore, larger males experienced higher mating success over the whole season as well as during single egg carrying intervals. However, during the extraordinarily dry breeding period of 1988, no size-related male mating success was found. Males were in both years highly successful caretakers as far as hatching success of the tadpoles was concerned. Brood care was associated with conditional costs for egg-carrying males in 1988, but not in 1987. Neither hatching success nor hatching size of the tadpoles were correlated with male size. Possible causes, leading to the observed mating advantage of larger-sized males in some years, but not in others, are discussed.
Behaviour Components in the Feeding of Wild and Laboratory Rats
Authors: Barnett S.A. 
Published: April 2008

AbstractFeeding behaviour has been studied in rats (Rattus norvegicus Berkenhout) kept in small cages in which a choice of foods was offered. Most of the rats were wild, but some albinos were used for comparison. The main intention of the experiments was to elucidate the component activities which make up feeding behaviour; but some observations on food preferences were made. When offered minced liver, wheat grains, flour and sugar, rats usually ate some of each food; sugar was eaten least, and sometimes little of e i t h e r flour or wheat was taken. When offered the alternative of wheat mixed either with cod liver oil or aniseed oil, as against wheat mixed with arachis oil, consumption was almost confined to the arachis oil mixture. This was true even when, as nestlings, the rats had been given only the distasteful mixture to eat. Both wild and albino rats show very marked exploratory and sampling behaviour during feeding. Evidence is presented that this is a pattern in its own right, and not merely appetitive. Its function is to make possible the rapid learning of topography, and especially the whereabouts of food, water and shelter. Sampling is also important in enabling rats to associate particular physiological actions, whether nutrient or toxic, with different foods. Exploration and sampling occur even when the situation and the foods are familiar, and regardless of age or sex. Continued sampling makes possible regular reinforcement of learned preferences. It also enables rats to change rapidly from a familiar but distasteful food to an unfamiliar but palatable one. Sampling is not stopped by 'satiation', but is released by it. In wild rats, but not albinos, there is highly developed flight and avoidance behaviour. This tends to reduce the dangers of exploratory behaviour. Both wild and tame rats tend to feed in cover when this is practicable. This has indirect social effects, since one rat may rob another in the nest. Social influences on feeding are only incidental. Often they are a product of associative learning. There is no parental guidance of young, nor imitation by young of adults. Displacement grooming was seen when hungry rats were deterred from feeding by the unfamiliarity of the situation; and in other frustrating circumstances. It is concluded that much of the feeding behaviour of wild rats can be interpreted as a resultant of the opposed effects of exploration and sampling on the one hand, and flight and avoidance on the other.
Counting in Jackdaws
Authors: Dawson Betty V. 
Published: April 2008

AbstractA preliminary investigation into 'counting' in Jackdaws using the Discrimination Box as illustrated. Shadrach was trained to the buzzer as a significant cue and Meshach to light flashes. With Shadrach results, significant at the 01 level (X2), were obtained after 300 trials, and with Meshach after 400 trials. Transfer to the other modality gave results, significant at the 01 level, after 100 trials. Transfer from light to buzzer alarmed Meshach and trial sequences became so lengthy that he was discarded. A randomised schedule of 2: 3 buzzes was given to Shadrach, B door being + 3 and - 2, A door being - 3 and +2. Learning was rapid, results being significant at the 01 level after 100 trials. A randomised schedule of 3: 4 buzzes was then given keeping B door + 3 and - 4. Results were significant at the .01 level after 100 trials suggesting that the response was not being made on the basis of 'moreness'. A 2:3:4 discrimination was then given keeping B door still + 3 and -2 and - 4. Experimental breakdown occurred and a 'side response' developed. After a three month rest away from the experimental situation he was unable to relearn the original 2:3 discrimination resorting to a 'side response' which varied from 100-trial sequence to sequence. The results obtained appear to indicate that discrimination between 2 : 3 or 3:4 was based on the discrete properties of the stimulus and not on 'moreness'. Also, that the transfer between modalities is possible where the skill transferred involves discrimination of numbers of stimuli.
Preference for Light of Short Wavelengths in Hatchling Green Sea Turtles, Chelonia Mydas, Tested On Their Natural Nesting Beaches
Authors: Mrosovsky N. , Carr Archie 
Published: April 2008

Abstract
Hatchling green sea turtles, Chelonia mydas, preferred blue and green stimuli to red when tested in a two choice situation on their natural nesting beaches. These stimuli when used singly were also more effective than the red in distracting turtles on their way to the sea. The preference for blues and greens over red was not simply dependent on overall intensity differences between the stimuli. There were in fact two components in the reactions of the turtles to light. There was a tendency to go to lights the more intense they were. Combined with this there was a tendency to go to lights of shorter wavelengths. Since turtles, if left unrestricted in these experimental situations, would rapidly reach the sea, the experiments were likely to have been testing some aspect of sea finding ability. HOOKER'S (1911) views on the importance of photic behaviour in sea finding are therefore generally confirmed, but whether the turtle prefers lights of short wavelengths because of their colour or because they appear brighter cannot yet be said. The relevance of these behavioural results to visual mechanisms in turtles is discussed, in particular the possibility of some shift in spectral sensitivity at a peripheral level in scotopic conditions.
An Experiment On Spacing-Out as a Defence Against Predation
Authors: Tinbergen N. , Impekoven M. , Franck D. 
Published: April 2008

Abstract
The paper is concerned with the tracing of a selection pressure which would account for the fact (believed to be sufficiently well established) that individuals of many well-camouflaged species live further away from other individuals of their species than the distance from which even bird predators are able to detect them. Artificially camouflaged hens' eggs were laid out in plots of different densities. Wild Carrion Crows were attracted to each plot by a standard "sample egg" which, while painted in the same way as the other eggs on the uppermost half, was laid out in a more conspicuous way. In spite of the fact that the Crows spent more time searching in the "scattered" than in the "crowded" plots, the crowded eggs suffered a much higher mortality. It is concluded that even for individuals of a well-camouflaged species it must be of advantage to live further away from others than the Direct Detection Distance of their predators. However, the experiments do not show that a crowded population as a whole suffers higher predation than a scattered population; experiments to test this and other aspects of the problem are in progress. It is argued that the absolute values of the density dependent mortality scores of the experiments cannot be applied to natural populations, because their density will in most cases be determined by other ultimate factors as well.
The Feeding Behaviour of Domestic Chicks as a Function of Rate of Pecking By a Surrogate Companion
Authors: Tolman C.W. 
Published: April 2008

AbstractThe feeding behaviour of chicks was observed in the presence of a model hen that was made to peck at rates of 30, 60, 120, and 240 per min. under two conditions of presentation: with the beak striking the floor to make a tapping sound and with the beak failing to strike the floor for silent pecking. Tapping sounds were also presented at the four rates while the model remained notionless. Under the silent pecking conditions, the number of food pecks emitted by the subjects was found to increase with the rate of pecking by the model. The addition of the tapping sound enhanced this effect, particularly at the two higher rates. The tapping sounds alone had no apparent effect upon the feeding behaviour of the chicks. It was concluded that the pecking movements of companions can be important in controlling the feeding behaviour of chicks. The tapping sound was tentatively interpreted as a general motivator.
The Lutong of Kuala Selangor
Authors: Bernstein Irwin S. 
Published: April 2008

AbstractA field study of the Lutong, (Presbytis cristatus) was conducted in Malaya. Lutong troops were observed for more than 1000 hours and were found to be markedly territorial. Only one control male lives in each troop and he actively defends the territory against incursions by other lutong males. Each troop moves slowly through its territory feeding and resting and comes into frequent visual contact with adjacent troops. Each troop is a well organized social unit but only the control males show consistent hostility to one another when troops meet. Grooming, play, sexual responses, maternal behavior and agonistic episodes are described as well as travel, feeding and diurnal patterns. These patterns appear similar to those reported in other Presbytis species, but contrast markedly with macaque and baboon reports. Differences in behavior between species of Presbytis do not exceed differences reported in the same species by different observers in different areas.
Reproductive Behavior in the Passifloraceae and Some of Its Pollinators in Central America
Authors: Janzen Daniel H. 
Published: April 2008

AbstractThe movements of the styles (and consequently stigmas) of flowers of Central American Passifloraceae is described. The timing of this behavior is closely associated with the timing of flower visitors and pollinators; the result is that the first pollinators to arrive visit many flowers and can contact only anthers. Later, the styles bend over and these same insects place a mixture of pollen from many flowers on the stigmas, rather than a coat of pollen from the same flower as would have been the case had the styles been bent over from the time of flower opening. The flowers pollinated by hummingbirds (flying all day) are much slower to turn down their stigmas than are the species pollinated by early morning bees with a short flight period. It is postulated that the selective forces that have led to the timing and movements of the styles and stigmas are those positive advantages generally associated with out-crossing in plants.
Maternal Behavior in the Rat: an Investigation and Quantification of Nest Building
Authors: Denenberg Victor H. , Taylor Rhoda E. , Zarrow M.X. 
Published: April 2008

Abstract
A technique has been developed to quantify nest building in rats. Small wooden dowels are provided as nest material. Rats shred the dowels, and the degree of nest building is determined by the amount shredded daily. Pregnant females show a marked increase in dowel shredding at or just prior to the time of parturition; shredding falls precipitously after parturition. Males and nonpregnant females show no such pattern over an equivalent period of time; their dowel shredding, in fact, decreases over time. A series of experiments were carried out involving hormone manipulations of pregnant and nonpregnant females. The only significant finding was that progesterone reduced the percentage of females which shredded dowels and also delayed the time of onset of this behavior. When nonpregnant females and males were exposed to cool ambient temperatures, dowel shredding increased markedly. On the other hand, exposing females to a warm temperature blocked dowel shredding behavior. Some similarities and differences between these findings and findings for the rabbit and mouse are discussed.
Measures of the Aggression of Parental Male Three-Spined Sticklebacks
Authors: Wootton R.J. 
Published: April 2008

AbstractThis study compared three methods used to measure aggression in the male three-spined stickleback by using them to measure changes in behaviour over the twelve days following the fertilization of eggs. These methods have been used in various studies without the certainty that they measure the same behavioural phenomena. In addition a number of different, possible measures of aggression were taken in the hope that this would show whether a unitary drive concept of aggression was realistic. The methods consisted of recording the behaviour of experimental males in one of three situations: (i) a tube containing another male was visible for five minutes, (ii) another male was visible through a glass partition at all times, (iii) a fish-shaped wax model was visible for two minutes. Each method showed that in the twelve days after the fertilization of eggs, there was a U-shaped trend in the frequency of biting, frequency of charging and in the rate of biting per minute of time spent oriented towards the test stimulus. In Method (i), the total oriented time took up about 70% of a test period, was not correlated with frequency of biting and did not show a U-shaped trend. In Method (ii) and (iii) the total oriented time formed an average less than 50% of a test period, was correlated with frequency of biting and did follow a U-shaped trend over the 12 days. In both Method (iii) and especially Method (ii) fanning was an important component of the test period, notably in the middle of the 12 day period. There were no comparable trends in either spine-raising or threatening. The agreement between Methods (i) and (ii) was very close for the frequency and rate measures but not for the duration measures. Only one model, that painted red ventrally and silver dorsally, showed a significant degree of agreement with Methods (i) and (ii). The measure rate of biting per minute of oriented time, which is independent of both the length of the test period and the total oriented time, showed a very high level of agreement in comparisons between the three methods. Allowing for the differences inherent in the methods it was concluded that there probably was a common causal factor for the changes in aggression seen over the parental period and measured in the three different test methods. The literature and personal observations suggest that these changes are paralleled by changes in territorial size over the parental period. Behaviour such as spine-raising and threatening did not show similar changes and so may not be affected by the same factor or factors.
Reproductive Behavior and Its Relation To Territoriality in Cal Op Ter Yx Ma Cula Ta (Beauvois) (Odonata: Calopterygidae)
Authors: Waage Jonathan K. 
Published: April 2008

AbstractPair-forming, courtship, mating, and post-copulatory behaviors are described for populations of Calopteryx maculata in the central and northeastern United States. Two pair forming displays were noted: (1) a display of the male's wings and abdomen (the cross display) at an oviposition site in his territory to an approaching female; and (2) a hovering courtship flight before a perching female. Similar displays are performed by C. aequabilis, C. splendens, and C. virgo, although intra- and interspecific variations occur in the cross display and its position in the pair-forming sequence. Both displays present the species and sex-specific color patterns of the male's wings and abdomen to the female early in pair formation. Pair formation differs in the three types of male-female encounters observed: (1) female flies into the male's territory; (2) male discovers an ovipositing female; and (3) male discovers a female on shore. The first type involves only territorial males and is the only one in which the cross display is performed. The other encounters involve both territorial and nonterritorial males. Courtship flight is present in the pair-forming sequences of all three encounter types. The cross display identifies a particular male with an oviposition site in his territory. This makes it possible for females to choose among males on the basis of the suitability of these oviposition sites. Females mating with territorial males benefit from reduced interference from other males during oviposition. The selective advantages of territoriality for a Calopteryx male are: (1) an increase in his mating frequency by the exclusive occupation of an oviposition area attractive to females ; and (2) an increase in the number of eggs he fertilizes by protecting mated females during their oviposition. It is likely that territorial behavior in Calopteryx functions primarily in obtaining and selecting mates and secondarily in reducing interference with pair formation and oviposition. Sexual selection among males for attracting mates and lessening sperm competition may have been an important factor in the evolution of territorial behavior in Calopteryx.
Thermoregulatory Behavior of Eared Seals
Authors: Gentry Roger L. 
Published: April 2008

Abstract1. Thermoregulatory behavior was studied in the Steller sea lion and in the South Australian fur seal during their respective reproductive seasons. Data were gathered using a temperature-sampling technique. 2. The rest postures used by animals of both species were closely correlated with solar radiation (as indicated by rock temperatures). At low temperatures both species used postures that concealed the flippers, thus exposing a minimum of surface area to the air. In addition, sea lions huddled against one another at low temperatures, but fur seals did not. 3. No quantitative species differences existed in behavioral responses to low (10°C) rock temperatures. At intermediate temperatures both species progressively exposed their flippers to the air. At high temperatures (30°C and above) both species resorted to the water for cooling. Female sea lions became wet at temperatures 5°C lower than did fur seals. 4. Fur seal males without direct access to water temporarily abandoned their territories and went to sea at a mean rock temperature of 33°C (approximate solar radiation level between 0.666 and 1.073 cal./cm2/min.). 5. Mass movements of females from dry areas across the rookery to the water were temperature-dependent in both species. 6. The behavior of sea lion pups showed less of a direct correlation with temperatures than for their mothers. 7. The social consequences of thermoregulatory behavior were, 1) increased frequency and intensity of sexual investigation by males toward females, 2) an increase by 11% to 15% in aggression among males, and 3) a reduction (by one half) in copulation frequency for males that abandoned their territories to gain access to water for cooling.
Physiological and Biochemical Correlates of Individual Differences in Behavior of Wolf Cubs
Authors: Fox M.W. , Andrews R.V. 
Published: April 2008

Abstract
In two litters of wolf cubs, individual differences in exploratory behavior, prey killing ability and social dominance were demonstrated, test scores showing a high degree of correlation as shown in an earlier study (Fox, 1972). Subjects with high, intermediate and low scores were selected for heart rate determinations monitored biotelemetrically under a test sequence designed to evaluate emotional reactivity. After these temperament and emotional-autonomic reactions had been determined, cubs were subjected to confinement and handling stress, blood samples being taken serially for plasma cortisol estimations. This treatment was repeated after ACTH injection. These findings demonstrate a marked difference in sympathetic tone and adrenal responsiveness to stress between high and low ranking cubs. High ranking cubs showed a greater sympathetic tone (higher resting EKG) and the adrenal-pituitary response to stress and ACTH treatment was of greater magnitude than in subordinates. Subjects of middle rank and with intermediate behavioral scores had a higher sympathetic tone than subordinates and under stress had a shorter latency and greater magnitude of cortisol secretion than either their higher or lower ranking peers.
Triadic Differentiation: an Inhibitory Process Protecting Pair Bonds in Baboons
Authors: Kummer H. , Götz W. , Angst W. 
Published: April 2008

AbstractField observation and pilot field experiments suggested the hypothesis that a social inhibition prevents male hamadryas baboons from encroaching on each other's females. The hypothesis was tested in a set of enclosure experiments which led to the following results : 1. When two males were simultaneously confronted with an unfamiliar female, one would become her "owner", either by defeating his rival or by the latter's withdrawal. 2. No fights occurred, however, when one male was allowed to watch a troop mate interact with a new female before he was admitted to them. He then respected the pair bond even if he was dominant over the owner. This agreed with the inhibition hypothesis. The alternative dominance hypothesis was rejected at the 0.01 level. 3. When males from different troops were used, some rivals attacked the owners and took their females. Most attacks were directed by powerful rivals against the particularly inferior males of one troop, suggesting that dominance factors can, in extreme cases, override the rival's inhibition. 4. The inhibition appeared to be restricted to the context of owning females in that it did not significantly affect the male's performance in food dominance tests. 5. A few casual interactions between the pair sufficed to inhibit the rival. The owner's overt demonstrations of possession had no additional effect in these experiments. 6. The stabilizing functions of the inhibition in the hamadryas society are discussed. 7. The inhibited rivals performed a number of redirected and conflict activities. An analysis shows that the inhibition suppresses friendly as well as aggressive approaches in the rival, thus keeping him away from the pair. 8. The owner's interactions with the rival were also inhibited, but much less than the rival's interactions with the pair. In contrast, interactions between the pair were increased and intensified by the rival's presence. 9. In one exceptional test, the female appeared in the role of the excluded rival. The formation of triads thus seems to reduce two of the component dyadic relationships while furthering the third. The possible mechanisms of such "triadic differentiation" are mentioned and its probable function in the formation of groups and subgroups is outlined.