bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sex‐specific Activity Patterns in Periplaneta americana and their Relation to Mate‐finding
Authors: Seelinger Günter 
Published: August 2010

Abstract and SummarySex‐specific differences in the spatial distribution of American cockroaches (Periplaneta americana) were studied in the laboratory and in a tropical outdoor environment. The study should indicate relevant environmental conditions and distances of male orientation to female sex pheromone. Both sexes are hidden during the day in dark shelters. A male usually leaves his shelter in the evening and moves to a certain exposed site to which he returns night after night. Here he spends most of the night with little locomotory activity. Mated females leave their shelters only for short periods of feeding or oviposition, while older virgin females regularly visit exposed sites and display in a typical calling stance for several hours. Males smelling female sex pheromone usually fly upwind and land on walls or tree‐trunks in the vicinity of the female, from where they continue search by running. Marked males lured away from their usual perch over distances up to 28 m were back at their usual site the following nights.ZusammenfassungGeschlechtsspezifische Unterschiede in der räumlichen Verteilung von Periplaneta americana wurden im Labor und in einem tropischen Gartenareal untersucht. Dadurch sollten Umweltfaktoren und Dimensionen ermittelt werden, die bei der Orientierung der Männchen zum paarungsbereiten Weibchen eine Rolle spielen. Beide Geschlechter leben tagsüber in dunklen Verstecken. Männchen verlassen ihr Versteck am Abend und suchen bestimmte Plätze auf Mauern oder an Baumstämmen auf, an denen sie in verschiedenen Nächten immer wieder anzutreffen sind. Während verpaarte Weibchen ihre Tagesverstecke nur kurzfristig zur Nahrungssuche oder Eiablage verlassen, verbringen unverpaarte Weibchen mit zunehmendem Alter immer längere Phasen außerhalb, wobei sie ein charakteristisches Lockverhalten zeigen. Riecht ein Männchen den weiblichen Lockstoff, so fliegt es in der Regel windauf und landet auf Mauern oder Bäumen in der Nähe des Weibchens. Von dort aus findet es meist schnell zum Weibchen. Markierte Männchen konnten mit Hilfe unverpaarter Weibchen bis zu 28 m weit von ihrem üblichen Aufenthaltsplatz fortgelockt werden, wurden aber in den darauffolgenden Nächten wieder an der alten Stelle beobachtet.
An Ethogram of the Sea Slug, Navanax inermis (Gastropoda, Opisthobranchia)
Authors: Leonard Janet L. , Lukowiak Ken 
Published: August 2010

Abstract and SummaryMany of the assumptions and predictions of classical ethology concern the nature of the physiological mechanisms underlying behavior. Navanax, because of its easily studied nervous system, may be useful in testing the assumptions and predictions of such models. The ethogram of Navanax includes 28 action patterns. Navanax also has 4 distinct “drives”: feeding, reproduction as a male, reproduction as a female and spawning, each activating a specific sequence of action patterns. Competition between simultaneously activated drives appears to be resolved at the motor level, in accordance with the “motor pandemonium model” (Dawkins 1976). The behavioral sequences involved in predation and cannibalism are described. Cannibalism in Navanax occurs in response to chance encounters with conspecifics, rather than as a result of active trail‐following. We conclude that the behavior of Navanax corresponds closely to classical ethological models and that Navanax may prove useful in testing ethological ideas about physiological mechanisms of behavior.ZusammenfassungDas Ethogramm der Nacktschnecke Navanax enthält 28 Erbkoordinationen. Navanax hat vier erkennbare Triebe: Nahrungserwerb, Fortpflanzung als Männchen, Fortpflanzung als Weibchen und Laichen, die je eine Abfolge von Verhaltensweisen in Gang setzen. Mehrere gleichzeitig aktivierte Triebe konkurrieren auf dem motorischen Niveau (“motor pandemonium”, Dawkins 1976). Die Aufeinanderfolgen von Erbkoordinationen beim Beutefang und Kannibalismus werden beschrieben; Kannibalismus kommt bei zufälligen Kontakten mit Artgenossen vor, die nicht eigens gesucht werden. Das Verhalten von Navanax steht in guter Übereinstimmung mit den Modellen der klassischen Verhaltensforschung; das Tier ist gut geeignet für die Überprüfung der Denkmodelle der Verhaltensforschung in bezug auf die physiologischen Mechanismen des Verhaltens, zumal das Nervensystem der Nacktschnecken für nervenphysiologische Untersuchungen sehr günstig ist.
Sexual Selection and the Psychophysics of Female Choice
Authors: Cohen James A. 
Published: August 2010

Abstract and SummaryEvolutionary theories of female mate‐choice tacitly assume a considerable ability of females to discriminate among potential mates on the basis of male epigamic differences. The general validity of this assumption is evaluated here through the application of comparative psychophysics. It is shown that perceptual or behavioral responses are typically logarithmic, rather than linear, functions of the stimulus intensity (the Weber‐Fechner relationship). In general, then, ever‐greater increments in absolute stimulus strength are required in order to elicit successive levels of discrimination. Through female choice, the mean value of a male epigamic trait increases in a population over evolutionary time. As this baseline increases, ever‐greater absolute increments in the magnitude of the trait will be required in order for females to make successive discriminations among males. Thus, while male costs of producing stronger signals continue to rise, the corresponding benefits follow a diminishing returns function. This provides an inherent physiological check on the “runaway” selection process envisioned by Fisher (1930). Psychophysical theory also predicts that there should be a positive correlation between the mean value of a male epigamic trait in a species (or population) and the discriminatory acuity of females along the relevant stimulus intensity dimension. This prediction is testable via the comparative method. Sensory discrimination ability is here viewed not only as a product of natural selection but also as having important feedback influences upon the evolutionary process itself.Zusammenfassung

Es wird angenommen, daß Partnerwahl durch das Weibchen eine Form sexueller Selektion ist, die zu extravaganten sekundären Geschlechtsmerkmalen bei Männchen führt.
Die Hypothese erfordert, daß Weibchen unter den verfügbaren Männchen auf der Basis dieser Merkmale wählen und daß ihre Präferenz gerichtet ist.
Zu Beginn der Evolution eines solchen männlichen Merkmals ist diese Unterscheidung relativ einfach. Je stärker das Merkmal ausgebildet ist, desto schwieriger wird die Unterscheidung, und zwar wegen psychophysikalischer Beschränkungen des Unterscheidungsprozesses. Infolgedessen nimmt die Wirksamkeit der Partnerwahl durch die Weibchen allmählich ab.
Die den Sinnessystemen von Tieren zugrundeliegende Physiologie besitzt damit eine bisher nicht erkannte Kontrollfunktion für das von Fisher (1930) postulierte “Davonlaufen” (run‐away) der sexuellen Selektion.
Adoption, Parent‐Chick Recognition and Maladaptation in the Herring Gull Larus argentatus
Authors: Holley A. J. F. 
Published: August 2010

Abstract and Summary1. Tinbergen (1953) concluded that herring gulls can recognize their own young by the time they are 5 days old.2. Berens von Rautenfeld (1978) demonstrated that cliff nesting herring gulls would accept alien chicks older than 5 days old but supported Tinbergen's findings concerning ground nesting herring gulls.3. In three separate recent studies involving 119 pairs nesting on diverse flat terrains there was a total of 16 naturally arising adoptions by pairs whose own young varied between 6 and 35 days of age.4. All adoptions were by both members of the pair and all adoptees were of comparable age to the adopters' brood.5. Some of the adoptions were by argentatus of fuscus.6. It is concluded that herring gulls are unable to recognize their own young until they are about 35 days old and that at present nesting densities on flat terrain this inability is maladaptive.Zusammenfassung

Tinbergen (1953) schloß, daß Silbermöwen ihre eigenen Küken erkennen, nachdem sie 5 Tage alt sind.
Berens von Rautenfeld (1978) hat bewiesen, daß Silbermöwen in Hangkolonien fremde Küken akzeptieren, die älter als 5 Tage sind; er unter‐stützte aber Tinbergens Folgerung hinsichtlich der Silbermöwen in Bodenkolonien.
In drei verschiedenen, neu durchgeführten Untersuchungen mit 119 brütenden Paaren in verschiedenen flachen Kolonien gab es insgesamt 16 natürliche Adoptionen bei Paaren, deren eigene Küken zwischen 6 und 35 Tage alt waren.
Stets adoptierten beide Elternvögel, und alle Adoptierten waren im Alter den eigenen Küken vergleichbar.
In einigen Fällen wurde fuscus von argentatus adoptiert.
Es ist zu schließen, daß die Silbermöwen ihre eigenen Küken erst erkennen können, wenn sie etwa 35 Tage alt sind, und bei den gegenwärtigen Nestdichten auf flachem Gelände ist dies nicht sehr angepaßt.
Parent‐Offspring Association in Mute Swans (Cygnus olor)
Authors: Scott D. K. 
Published: August 2010

Abstract and SummaryIn the Oxford area, mute swan cygnets usually remained with their parents for some time after fledging and then left to join nearby flocks while their parents remained on the territory. When they were with their parents before leaving, cygnets were infrequently displaced by other individuals during feeding. After leaving their parents and joining flocks, cygnets suffered frequent displacement by unrelated flock members and spent significantly less time feeding. However, although some cygnets stayed with their parents on territory throughout the winter, others left in autumn soon after they could fly. Cygnets stayed longer on good quality territories than on poor quality territories. In addition, small cygnets (which are less successful in aggressive encounters) stayed longer than larger cygnets. There was no evidence of a sex difference in the duration of stay.ZusammenfassungDie Bedeutung des verlängerten Zusammenhaltens zwischen Eltern und Jungen bei Vögeln, die weder gemeinschaftlich brüten noch danach ihre Jungen füttern, ist nicht völlig geklärt. Die Arbeit prüft die Hypothese, wonach Jungvögel territorialer Arten gegen innerartliche Konkurrenz dadurch besser geschützt sind, daß sie länger im Revier ihrer Eltern verweilen. Solange junge Höckerschwäne dies tun, werden sie weniger oft durch andere Schwäne vertrieben als in der Zeit danach, wenn sie sich Trupps angeschlossen haben. Zudem ist ihre Freßintensität in der Zeit vor dem Verlassen der Eltern höher als danach. Jungschwäne scheinen in dem elterlichen Revier so lange zu verweilen, wie es für sie nützlich ist, und verlassen es aus eigenem Antrieb. In ergiebigen Revieren bleiben Jungvögel länger als in suboptimalen, und kleinere Junge (die weniger erfolgreich streiten) verweilen länger als größere.
Is Social Grooming Altruistic?
Authors: Dunbar R. I. M. , Sharman M. 
Published: August 2010

Abstract and SummaryWe evaluate the claim that social grooming is altruistic because it occupies time that could otherwise be spent feeding. Time spent feeding is shown (1) to be correlated negatively with time spent resting and (2) not to be correlated with social time for two genera of Old World monkeys. Social time thus tends to be conserved in the face of increasing demand for feeding time at the expense of resting time. This suggests either that the altruistic costs of grooming are trivial or that grooming is more valuable to the groomer in terms of benefits to be derived from, for example, the formation and maintenance of alliances.ZusammenfassungWir prüfen die These, daß soziale Körperpflege altruistisch sei, weil sie Zeit erfordert, die zur Nahrungsuche verwendet werden könnte. An zwei Gattungen von Altweltaffen wird gezeigt, daß 1. die Zeit für Nahrungsuche negativ korreliert ist mit der Ruhezeit und 2. nicht korreliert ist mit der “Sozialzeit”. Muß mehr Zeit für die Nahrungsuche verwandt werden, so bleibt die Sozialzeit erhalten, während die Ruhezeit verkürzt wird. Das läßt vermuten, daß soziale Körperpflege kaum etwas kostet oder daß sie beim Anknüpfen und Aufrechterhalten sozialer Beziehungen nützlich ist.
The Time and Energy Costs of Play Behaviour in the Cat
Authors: Martin Paul 
Published: August 2010

Abstract and SummaryThe time and energy costs of play behaviour were assessed empirically for 10‐ to 12‐week‐old kittens (Felis catus), using a variety of methods. Play was found, on average, to occupy 9% of total time. The net daily energy expenditure (in excess of resting metabolism) due to play was found to account for approximately 4% (and at most 9%) of total daily energy expenditure, excluding growth. These results cast some doubt on the assertion, commonly found in the behavioural literature, that play is very “costly” and must, therefore, have important beneficial effects. An alternative suggestion is that play may have only minor benefits, which nonetheless outweigh its minor costs.ZusammenfassungMit verschiedenen Methoden wurden Zeit‐ und Energieverbrauch des Spielverhaltens von 10‐ bis 12wöchigen Kätzchen (Felis catus) bestimmt. Spielen beansprucht im Durchschnitt 9% der Gesamtzeit und netto (abzüglich Grundumsatz) ungefähr 4% (bis höchstens 9%) des gesamten täglichen Energieverbrauchs ausschließlich Wachstum. Diese Resultate lassen Zweifel aufkommen über die oft in der Verhaltensforschung geäußerte Behauptung, Spiel koste viel Energie und müsse deshalb wichtige günstige Wirkungen haben. Wir schlagen eine andere Erklärung vor, nämlich daß Spiel nur geringe günstige Wirkungen hat, daß diese Wirkungen jedoch die geringen Energiekosten überwiegen.
Hormonal Determination of Song Capacity in Females of the Zebra Finch: Critical Phase of Treatment1
Authors: Pohl‐Apel Gunvor , Sossinka Roland 
Published: August 2010

Abstract and SummaryFemale nestlings of the zebra finch were treated with physiological doses of estradiol at varying ages and for different durations. Most of the females produced song after adult testosterone‐treatment: Estradiol‐treatment from day 2 posthatch until day 18 produced a male‐like song quality in females. Treatment from day 2 or 4 until day 11 produced poor song in females, comparable to the early juvenile song of males. Treatment started after day 4 and continuing for no more than 6 days produced no singing in females. Thus, both timing and duration of estradiol‐treatment influence song capacity.Females, shamtreated as nestlings, do not display vocalizations which resemble male song. In a few control females however, after adult testosterone‐treatment a new type of vocalization was observed which by context is homologous to the courtship song of males, but the vocalizations do not show any acoustic parameters typical for the song of the males.ZusammenfassungWeibliche Nestlinge des Zebrafinken wurden mit physiologischen Dosen Östradiol behandelt, wobei Beginn und Dauer der Behandlung variiert wurden. Ein Teil der Versuchstiere sang nach Adult‐Testosteronbehandlung: Eine Östrogenbehandlung vom 2. bis zum 18. Lebenstag bewirkt eine Gesangsqualität, die in fast alien Parametern dem Gesang adulter männlicher Zebrafinken entspricht. Bei Behandlung vom 2. oder 4. Lebenstag bis zum 11. Lebenstag produzieren die Weibchen einen einfachen Gesang, der dem frühen Jugendgesang der Männchen vergleichbar ist. Setzt die Frühbehandlung erst nach dem 4. Lebenstag ein und dauert nicht länger als 6 Tage, läßt sich bei den adulten Tieren kein Gesang induzieren. Somit ist die Qualität des von den Weibchen produzierten Gesanges abhängig von Beginn und Dauer der Östrogen‐Früh‐behandlung.Weibchen, die als Nestling nur Placebo‐behandelt wurden, singen in der Regel nach Adult‐Testosteronbehandlung nicht. Einige wenige produzierten jedoch neue Lautäußerungen, die vom Kontext her als Balzgesang zu deuten sind, aber in den akustischen Parametern nicht dem Gesang der Männchen ähneln.
A Quantitative Analysis of Facial Expression in the Plains Zebra
Authors: Schilder Matthijs B. H. , van Hooff Jan A. R. A. M. , van Geer‐Plesman Ciska J. , Wensing Joep B. 
Published: August 2010

Abstract and SummaryThis study on the facial expressions of the plains zebra is concerned with those facial expressions about which the literature is not consistent as far as the description and functional naming are concerned. In order to establish which facial expressions occur a vector analysis approach was adopted in which a quantitative inventory was made of combinations of the main facial expression components. 20 combinations (facial expressions) were found to occur frequently. We then grouped these facial expressions on the basis of similarities in the contexts in which they occur, using calculations of (dis)similarity measures, followed by several types of cluster analysis. In this way we found 7 groups of facial expressions which, with the help of the contextual parameters used in the analysis, could be further reduced to 6 groups and could be interpreted and labeled as: submission (bared teeth with ears forward, sideward or backward, chewing movements and occasionally head lowering); play face (biting intentions with ears forward or sideward); threat (ears backward, often together with the head pointing towards the opponent); herding threat (a head‐low posture with ears backward); greeting (ears forward, repeated mouth openings without showing teeth); and another submissive expression (head low, ears backward). Methods, results and interpretations are discussed in the light of the existing literature and hopefully some of the confusion about zebra facial expression is removed. However, some reserve remains justified with respect to the extent to which the proposed model can be generalized, because it is founded on data from only one zebra herd with a particular composition.
The Ontogeny of Behavior of Free‐living Beavers (Castor canadensis)
Authors: Patenaude Françoise 
Published: August 2010

Abstract and SummaryWe followed the behavioral development of 8 young American beavers (Castor canadensis) in their natural environment. The behavioral development of wild beaver kits living in a familial unit with one adult pair and yearlings can be divided in three distinct phases. 1. The first 4–5 weeks during which the neonates were confined to the lodge were characterized by physical maturation and a very rapid development of locomotion, alimentation, care of the fur, and social behaviors. 2. The next phase extended from first emergence from the lodge to the next spring. Development of ability to stay submerged, exploration of the aquatic part of the home range of the family and refinement of skills characterized this period. No new behavior patterns appeared during this phase. 3. The last period extended from about 10 months to the dispersal of the animals when they were around 2 years old, and was marked by the development of building behaviors and of food gathering. Comparisons with the development of captive beavers suggested that in general, the environmental conditions did not significantly alter the developmental pattern of young beavers. Comparisons with other accounts on the development of some other rodents indicate that beavers are most similar to some precocial hystricomorphs that exhibit a slow rate of development.
Habitat Selection in Birds and the Role of Early Experience
Authors: Glück Erich 
Published: August 2010

Abstract and SummaryThe role of early experience in habitat selection in linnets (Acanthis cannabina) was tested in automatic habitat cages. Young linnets were kept in groups under three different habitat conditions: spruce‐, foliage‐ and plastic‐perches. In a choice test the members of the spruce‐ and the foliage‐group preferred their familiar habitat whereas the “plastic”‐group showed this preference only on the first experimental day and then behaved at random on the following days. In a further aviary experiment the females of the spruce‐group constructed nests in small spruce trees, whereas the females of the foliage‐group constructed nests in small foliage bushes. The early habitat experience seems strongly to influence later habitat and nest‐site selection in the linnets.
Androgen and Corticoid Levels in Blood and Body Extracts of High‐ and Low‐ranking Swordtail Males (Xiphophorus helleri) before and after Social Isolation
Authors: Hannes Ralph‐P. 
Published: August 2010

Abstract and SummaryThe two highest‐ and the two lowest‐ranking swordtail males were determined by the criterion of number of attacks directed at and received from every other male in their breeding tanks. The events were recorded until 50 bites were given (high‐ranking males) or received (low‐ranking males). 40 high‐ and 40 low‐ranking males were bled either after being socially isolates for 4 weeks or after reaching the target number. Androgen and corticoid concentrations both in their blood and their body extracts were measured by means of radioimmunoassay.Although the agonistic behaviour patterns and social experience of high‐ and low‐ranking males were totally different, the baseline hormonal states of the animals were indistinguishable both in body extracts and blood. Isolation led to decreased blood androgen and corticoid levels in high‐ and low‐ranking males. In the body extracts, only the corticoids were reduced. A significant correlation between blood and tissue concentrations was found only in the case of corticoids.I would suggest that the contradictory findings in the literature dealing with the relationship between hormones and dominance result from differences in experimental procedure.
Discrimination and Avoidance Reactions towards Predatory and Nonpredatory Fish by Blacknose Dace, Rhinichthys atratulus (Pisces: Cyprinidae)
Authors: Fraser Douglas F. , Mottolese Thomas N. 
Published: August 2010

Abstract and SummaryThe hypothesis that blacknose dace Rhinichthys atratulus discriminate between piscivorous creek chub Semotilus atromaculatus and nonpiscivorous common suckers Catostomus commersoni was tested in a seminatural, artificial stream. Dace avoided the nonpredatory suckers less than they did the predatory chub, which they avoided during both day and night. However, dace significantly avoided the nonpredator at night. Further, experienced and inexperienced dace avoided the nonpredator similarly, suggesting that they had not learned to discriminate predator from nonpredator in their natural habitat. These results are consistent with two hypotheses (1) that individuals varied in ability to discriminate predatory from nonpredatory fishes, and (2) that the predator was more active than the nonpredator, thereby “frightening” the dace more. At temperatures of < 6°C the nonpredator was inactive and dace no longer avoided it at night, but continued to avoid the active chub, suggesting that movement constituted part of the avoidance‐releasing stimulus. Because dace avoided nonpredators, they may waste time in natural streams avoiding harmless fish. It is suggested that the dace cannot afford the risk of a mistaken identity, which may be high in the stream environment, and selection favors those that avoid all large, moving fish.
Egg Trading in the Chalk Bass, Serranus tortugarum, a Simultaneous Hermaphrodite
Authors: Fischer Eric A. 
Published: August 2010

Abstract and SummaryThe simultaneously hermaphroditic fish, Hypoplectrus nigricans, engages in a form of reciprocal spawning called “egg trading”, where one partner gives up eggs for fertilization in exchange for the opportunity to fertilize those of the partner. Since egg trading appears to be important in the evolutionary maintenance of hermaphroditism in H. nigricans, an attempt was made to determine if another species, Serranus tortugarum, behaved in a similar fashion. S. tortugarum do trade eggs, and the phenomenon seems to be widespread in simultaneously hermaphroditic serranids. However, the cues for spawning are much subtler than in H. nigricans and other simultaneously hermaphroditic serranids. This trait appears to be an evolutionary response to the occurrence of heavy sperm competition in the form of streaking.