bluuebunny/crossref_metadata_2025 huggingface dataset:
Orb‐web Orientation and Modification by the Spiders Araneus diadematus and Araneus gemmoides (Araneae: Araneidae) in Response to Wind and Light
Authors: Hieber Craig S.
Published: August 2010

Abstract and Summary

Most orb‐weaving spiders (Araneidae) possess the behavioral capacity to orient and modify their planar webs in response to wind and direct sunlight. These behaviors have generally been interpreted as tactics to avoid thermal loading of the spider or damage to the web. However, previous studies have focused primarily on diurnal araneids that sit at the hubs of their webs in exposed habitats. Here the orientations and modifications of the webs to wind and light for Araneus diadematus and Araneus gemmoides, two spiders which use retreats in less exposed habitats, are examined.

Light had no effect on the web structure of A. diadematus or on its web orientation. Araneus gemmoides, however, demonstrated a significant perpendicular orientation of the plane of the web to light; a response which is probably to increase prey interception rather than control isolation.

In response to wind, A. diadematus demonstrated a significant reduction in the surface area of the web, while A. gemmoides demonstrated a significant parallel orientation of the web to wind with no change in web structure. The responses of both spiders to wind resemble behaviors shown by other orb‐weavers, and probably function to avoid web damage. These responses to wind and light are related to the use of a retreat, and to differences in web building behavior and habitat.

Die Orientierung und der Bau der Fangnetze zweier Araneus‐Arten unter Wind‐ und Lichteinfluß wurden im Windkanal untersucht.

Licht hatte auf Struktur und Orientierung der Netze von A. diadematus keinen Effekt. A. gemmoides zeigte jedoch im Licht eine deutliche Vertikal‐Orientierung der Netzebene. Diese Spinne scheint ihr Netz nach dem Licht auszurichten; vielleicht steigert das die Beutemenge.

Als Reaktion auf Wind nahm bei A. diadematus die Netzfläche deutlich ab. A. gemmoides hingegen orientierte das Netz parallel zum Wind, verkleinerte es aber nicht. Beide Reaktionen ähneln dem Verhalten anderer Radnetzspinnen und dienen wahrscheinlich dazu, Netzschäden zu vermeiden.
Distress Calling by Woodland Birds: Seasonal Patterns, Individual Consistency and the Presence of Conspecifics
Authors: Greig‐Smith P. W.
Published: August 2010

Abstract and Summary

Woodland birds of 20 species were captured in mist‐nets in winter (September to February) and summer (April—August) and scored for whether or not they made distress calls while being handled. Birds of only two species showed significant tendencies to be consistent in calling or failing to call when recaptured, but most species had weak trends in. the same direction. Some species changed seasonally in the tendency to call, but there was no general pattern. In winter, but not summer, the incidence of calling was correlated across species with an index of the number of conspecifics likely to hear the call, but there was no comparable correlation with variations within species. In the long‐tailed tit, calling was associated with struggling, and with eyelid colour, which reflects a bird's mood. This implies that calling may be directed at a captor as well as at flock companions.
Social Dispersion and Genetic Variation in Two Species of Emballonurid Bats
Authors: McCracken Gary F.
Published: August 2010

Abstract and Summary

Saccopteryx leptura and S. bilineata are closely related, sympacric species of neotropical bats that exhibit marked differences in social organization and dispersion patterns. S. leptura is monogamous and roosts in small groups of 1 to 5 (Y = 2.6) individuals that are finely dispersed. S. bilineata is harem‐polygamous and roosts in larger groups of 1 to 42 (Y = 8.1) individuals that are more coarsely dispersed. Allozyme genetic studies of individuals from Trinidad, W I. demonstrate that both species carry similar, high levels of polymorphism and heterozygosity. Although significant genetic heterogeneity was observed among geographical populations of S. leptura, there is no evidence for either species that social structuring leads to inbreeding and the loss of heterozygosity, or that it promotes the development of genetic heterogeneity among social units that could accelerate the evolutionary diversification of these taxa. These results do not support a recently proposed hypothesis that social structuring in mammals has these effects.

Observed intercolony genetic heterogeneity among adult males resident in multimale groups of S. bilineata is greater than intercolony heterogeneity of adult females. This is an apparent result of female dispersal and the recruitment of males into their parental groups. These results suggest that the adult males within large colonies may be kin‐related.
Antennal Drumming Behavior in Polistes Wasps (Hymenoptera: Vespidae)
Authors: Pratte Michel , Jeanne Robert L.
Published: August 2010

Abstract and Summary

Antennal drumming, in which Polistes queens rapidly beat the antennae on the rims of nest cells, is described in detail for P. fuscatus and shown to be performed in the context of feeding prey to the larvae. Following the distribution of solid food to the larvae, the queen goes from cell to cell on the nest, drumming her antennae on the cell rims, producing an audible sound. After several min of this, each drum on a cell is followed by contact with a larva, usually the one in the drummed cell, during which the queen regurgitates prey juice to the larva. The average burst of drumming lasts just under one s. The two antennal flagella strike the cell rim together at an average frequency of 29 strokes per s. Similar behavior is documented in 10 other Polistes species. We hypothesize that antennal drumming communicates to the larva that it is about to receive liquid food from the adult and should withhold the release of salivary secretion. This predicts that a larva that has received the drumming signal will exude less secretion than if it has not been recently signaled. An experimental test of this hypothesis yielded the predicted result, and we therefore conclude that our hypothesis is supported.
Acoustic Behaviour of Birds and Mammals in the Predator Context; I. Factors Affecting the Structure of Alarm Signals. II. The Functional Significance and Evolution of Alarm Signals
Authors: Klump G. M. , Shalter M. D.
Published: August 2010

Abstract and Summary

I. 7 vocalizations emitted in the predator context are defined in terms of their function. The physical and physiological constraints on the evolution of the physical structure of alarm calls with respect to detectability and localizability are discussed. Detection of various calls depends on signal amplitude, environmental attenuation, signal‐to‐noise ratio, discrimination of the receiver against background noise, and absolute auditory sensitivity of the receiver. The combined effect of these factors is discussed for an exemplary predator‐prey system, in which the hearing of both, predator and prey is known.

Localizability of an alarm call is determined by its frequency, bandwidth, and possibly its amplitude relative to the auditory threshold of the receiver. Crude differentiation between localizable and non‐localizable signals is not possible, and localizability of particular sounds varies between species. In some cases the question of detectability may render the problem of localizability unimportant. Besides detectability and localizability, other factors such as the acoustic background formed by the alarm calls of sympatric species and by the species' own repertoire of calls are discussed.

II. Requisite conditions and available evidence for the evolution of alarm calls through individual selection and kin selection are described.

Five types of alarm calls are discussed individually:

The occurrence of mobbing calls indicates that a major function of these calls is predator deterrence (“move on”), although the calls also alert other prey and promote cultural transmission of the predator's characteristics.

Alarm calls associated with evasive actions of the prey cause the predator to give up the hunt or diminish its hunting success by warning other prey, which only in some cases are closely related to the caller.

Distress calls of a seized prey either attract other prey which then mob the predator, or attract other predators, which presumably attack the first predator. In both cases the chances to escape are enhanced because the predator's attention is diverted.

Defence calls are used to threaten a predator. These calls often mimic sounds of other predators.

Distraction calls may enhance the effect of distraction display.

Although the different functions of various alarm calls are treated individually, certain of the calls may have more than one function and may be employed in nonpredator contexts as well.
Influence of Winter on Endocrine State and Behavior in European Blackbirds (Turdus merula)
Authors: Schwabl H. , Wingfield J. C. , Farner D. S.
Published: August 2010

Abstract and Summary

Plasma levels of luteinizing hormone (LH), testosterone, 5α–dihydrotestosteronc (5α–DHT) and corticosterone in wintering European blackbirds (Turdus merula) were analysed according to sex and age, and under two environmental conditions that reflect availability and the degree of competition for food.

Circulating levels of LH, basal in all groups, appeared to be unaffected by more intense competition. However, levels of testosterone increased in males, whereas females had higher levels of 5α–DHT than of testosterone. This suggests a function of these hormones in aggressive behavior for procurement of food.

Plasma concentrations of corticosterone were positively correlated with time elapsed between capture and procurement of blood sample. They were significantly elevated in first–year birds and females but not in adult males during times of reduced availability of food. This could reflect greater stress in first–year birds and females than in adult males, indicating higher costs of wintering in the breeding area for low–ranking individuals. This differential effect of severe winter conditions according to age and sex could be among the ultimate factors in selection for partial migration in the population.

Wir analysierten die Plasmakonzentrationen von luteinisierendem Hormon (LH), Testosteron, 5α–Dihydrotestosteron (5α–DHT) und Corticosteron im Brutgebiet überwinternder Amseln nach Alter und Geschlecht sowie zwei Umwelttemperaturen, die das Nahrungsangebot und das Ausmaß aggressiver Auseinandersetzungen widerspiegeln. Die Plasmaspiegel von LH waren im Vergleich zu den Konzentrationen während der Brutzeit bei alien Gruppen sehr niedrig und wurden von den beiden Umweltsituationen nicht beeinflußt. Im Gegensatz dazu waren bei Männchen die Plasmaspiegel von Testosteron bei Nahrungsknappheit erhoht. Die Testosteronspiegel der Weibchen waren sehr niedrig, und es deutete sich kein Einfluß der jeweiligen Umweltsituation an. Jedoch waren bei Weibchen die Konzentrationen von 5α–DHT höher als die von Testosteron. Höhere Androgenspiegel während Zeiten mit gesteigerten aggressiven Auseinandersetzungen könnten auf eine Funktion dieser Hormone in der Steuerung aggressiven Verhaltens außerhalb der Brutzeit hindeuten. Die Plasmakonzentrationen von Corticosteron waren mit der Dauer des Fangstresses positiv korreliert. Bei erstjährigen Individuen und Weibchen, nicht aber bei adulten Männchen, waren sie bei Futterknappheit deutlich erhöht. Dieses Ergebnis könnte damit erklärt werden, daß niedrigrangige Jungvögel und Weibchen bei Kälteeinbrüchen größeren Belastungen unterworfen sind als adulte Männchen. Dies könnte einer der Selektionsfaktoren sein, die zur Evolution von Teilzugverhalten in der untersuchten Amselpopulation führten.
Relatedness of Workers to Brood in the Social Wasp, Polistes exclamans (Hymenoptera: Vespidae)
Authors: Strassmann Joan E.
Published: August 2010

Abstract and Summary

In the social wasp, Polistes exclamans, relatedness of workers to the brood they rear is quite low. In a 4 year study relatedness of workers to brood was determined on 338 nests by marking all females including the queen and censusing the nests throughout the season. Workers were rearing siblings on 26% of all nests and nieces and nephews on 50% of all nests. Siblings and nieces and nephews were reared together on 10% of nests, and nieces and nephews that were the progeny of two different sisters were reared on 14% of nests. Multiple mating by the egg‐layer would reduce relatedness of workers to brood still further. Workers rear siblings on so few nests that high levels of relatedness between workers and brood may not be a critical factor for the maintenance of group living. Differences in the probability that a female can successfully nest alone between early spring and mid summer may be the reason workers usually rear distant relatives on the nest they emerged from rather than beginning their own nest where they could rear progeny.

Vier Jahre lang wurden in 338 Nestern der sozialen Wespe Polistes exclamans alle Arbeiterinnen und die Königinnen markiert und über den Sommer die Individuen gezählt. Der Verwandtschaftsgrad zwischen den Arbeiterinnen und ihren Pfleglingen ist gering: In 26% aller Nester ziehen die Arbeiterinnen Geschwister auf, in 50% aller Nester Nichten und Neffen, in 10% aller Nester beides, und in 14% aller Nester Nichten und Neffen, die von zwei Schwestern stammten. Wären die Königinnen mehrfach von verschiedenen Männchen begattet, dann wären die Verwandtschaftsgrade noch geringer anzusetzen. Besonders enge Verwandtschaft zwischen Arbeiterinnen und Brut kann kaum die Ursache für die Staatenbildung sein. Eher ist entscheidend, daß ein Weibchen in der Zeit zwischen Frühling und Sommermitte kaum allein ein Nest betreuen kann.
Song Sharing in the Brown‐headed cowbird (Molothrus ater)
Authors: Dufty Alfred M.
Published: August 2010

Abstract and Summary

Songs were recorded from two separate populations of brown‐headed cowbirds (Molothrus ater). High levels of song sharing were found in each and, in one population, paired males shared more song types than did the remainder of the population. Song learning, in conjunction with low dispersal, is thought to contribute heavily to song sharing in this species.

Männliche Kuhstärlinge (Molothrus ater) teilen viele ihrer Gesangstypen mit Nachbarn. Zwei weit voneinander entfernte Populationen haben völlig verschiedene Gesangstypen. Wiederfänge beringter Individuen belegen, daß die Jungen wie die Erwachsenen heimattreu sind. Das und die Tendenz, die Gesänge früh im Leben zu lernen, scheint sich auf den Grad der Gesangsübereinstimmung auszuwirken. Die Folgen der Gesangsübereinstimmung in dieser Art sind unbekannt.
Repeat and Serial Singing Modes in American Redstarts (Setophaga ruticilla): A Test of Functional Hypotheses
Authors: MacNally R. C. , Lemon R. E.
Published: August 2010

Abstract and Summary

Male American redstarts (Setophaga ruticilla) exhibit two modes of singing: repeat mode, characteristic of the early stages of breeding prior to arrival of females and before nesting; and serial mode, which prevails later when nesting has commenced and thereafter. Repeat mode consists of the repetition of a single song type, usually a song that has an “accented” ending such that the terminal phone is not repeated. The remainder of a male's repertoire is sung serially without much immediate repetition, and these songs usually do not have unrepeated endings (“unaccented”). Two examples of each mode were presented to territorial adult ( 2 years old) males, both early in the season when most often they were singing repeat mode, and later in the breeding cycle, when males more often sang serial mode. Earlier studies hypothesized different functions for these modes and one study claimed a difference in response during playback. In the present study, there were no distinguishable differences in responses by males to either singing mode, nor between the two modes at either time during the breeding season. We discuss the results relative to the earlier claims and to alternative functional hypotheses.

Männliche Schnäpperwaldsänger (Setophaga ruticilla) haben zwei Singformen: Wiederholungsgesang (WG), in dem Wiederholung vorherrscht und der einen markanten Schluß hat, sowie der Reihengesang (RG), der ohne auffällige Wiederholungen Themen aneinanderreiht. WG ist typisch für die Zeit vor der Ankunft der Weibchen, RG für die Zeit ab dem Nestbau. Revierbesitzenden Männchen (über 2 Jahre alt) wurden beide Singformen vorgespielt, sowohl wenn sie selbst WG wie wenn sie RG sangen. Entgegen den Erwartungen fanden sich keine Unterschiede in den Reaktionen auf die jeweils vorgespielten Gesänge.
The Influence of Castration and Testosterone Replacement on the Song Architecture of Canaries (Serinus canaria)
Authors: Heid Petra , Güttinger Hans R. , Pröve Ekkehard
Published: August 2010

Abstract and Summary

The influence of testosterone on the general architecture of the song of castrated canaries was studied. Testosterone was applied to juvenile and adult castrated birds by silastic implants of testosteronepropionate. Song parameters such as frequency distribution of pauses between vocalizations, length of tours and stability of elements within a tour were measured.

1. An adult castrated male is able to sing spontaneously; these songs coincide in frequency distribution of pauses, length of tours and stability of elements within a tour with the characteristics of autumnal song. These parameters reach values typical for fullsong after one week of hormone treatment. 30–40 days after the first implantation an obvious elongation of tours occurs.

2. Young castrated birds do not sing when adults without hormone replacement. The pause frequency distribution typical for fullsong is established after one week of testosterone treatment. These animals showed the same elongation of tours after a longer hormone therapy (30–40 days).

The stability of elements within a tour needed 30–40 days to reach fullsong values. The influences of testosterone on specific levels of hierarchical song organization were discussed: there is an increase of motivation; the syntax of fullsong is activated by the hormone treatment; a differentiation of motor capabilities is induced in young castrated birds.

Kastration und Hormonsubstitution (Silasticimplantate mit Testosteron‐propionat) bei männlichen Kanarienvögeln ergaben folgende Auswirkungen auf das Gesangsverhalten der Tiere:

1. Ein adult kastriertes Tier singt spontan; dieser Gesang entspricht in seiner Pausenverteilung, seiner Tourenlänge und der Stabilität der Elemente innerhalb der Tour dem Herbstgesang.

Nach einer Woche Hormonbehandlung werden für diese Gesangsparameter die für den Vollgesang üblichen Werte erreicht. 30–40 Tage nach der ersten Implantation kommt es zu einer auffälligen Tourenverlängerung.

2. Jung kastrierte Tiere singen adult ohne Hormonsubstitution nicht.

Die Pausenverteilung des Vollgesangs tritt schon nach einer Woche Testosteronbehandlung auf. Auch bei diesen Versuchstieren kam es nach längerer Testosterongabe zu einer deutlichen Tourenverlängerung.

Die Stabilität der Elemente innerhalb der Tour erreichte erst nach 30 bis 40 Tagen Werte des Vollgesangs.

3. Diskutiert wird der unterschiedliche Einfluß von Testosteron auf die verschiedenen Merkmalsebenen der Verhaltensorganisation: es steigert die Gesangsmotivation der Tiere; die Syntax des Vollgesangs wird durch die Hormongabe aktiviert; jung kastrierte Tiere, deren Gesangsontogenese durch die Kastration unterbrochen wurde, sind nicht sofort in der Lage, einen Gesang mit stabilen Elementen zu äußern. Testosteron löst die Differenzierung der gesangsrelevanten Hirnstrukturen (HVc, RA) aus, die erst nach einiger Zeit abgeschlossen ist.
Sex Differences in Social Play of Scimitar‐horned Oryx Calves (Oryx dammah)
Authors: Pfeifer Sharon
Published: August 2010

Abstract and Summary

Sexual differences in play have been reported for a variety of mammalian species, the majority of which arc polygynous and sexually dimorphic in size. These observed sex diflerences in play have been interpreted by the physical training hypothesis as having evolved to train young differentially for adult roles. This study examined sex differences in play behaviour of a polygynous, but isomorphic, ungulate — the scimitar‐horned oryx (Oryx dammah).

8 calves were studied in captivity at the National Zoological Park's Conservation and Research Center. Mate calves initiated more bouts of social play and used more components of contact and dominance during play than did ♀♀. Age was an important factor in play partner choice, but sex and genetic relatedness were not. Mixed sex play was common, and the duration of play between ♂♂ and ♀♀ was longer than that between ♀♀. The results supported the physical training hypothesis, but suggested that size dimorphism between the sexes was also important in the ontogeny of sex differences in play.

Von verschiedenen Tieren werden geschlechtsspezifische Spiele beschrieben. Die meisten dieser Tiere sind polygyn und sexuell dimorph. Das führte zu der Hypothese, diese Spiele dienten dam, die Jungen auf ihre verschiedenen Erwachsenen‐Rollen vorzubereiten. Hier werden Spiele einer polygynen aber monomorphen Antilope, Oryx dammah, auf geschlechtsspezifische Unterschiede untersucht.

8 Junge (4 ♂♂, 4 ♀♀) wurden in Gefangenschaft beobachtet. Männliche Kälber begannen signifikant mehr Spiele und verwendeten mehr Kontakt– und Dominanzelemente als weibliche. Spielpartner wurden nach dem Alter ausgewählt, aber nicht nach Geschlecht oder Verwandtschaft. Gemischtes Spielen war üblich und dauerte länger als Spielen allein zwischen weiblichen Kälbern.

Größendimorphismus der Geschlechter scheint wichtig für die Entwick‐lung geschlechtsspezifischer Unterschiede beim Spielen.
Nest‐associated Vocalizations of Female Red‐winged Blackbirds, Agelaius phoeniceus
Authors: Beletsky L. David , Orians Gordon H.
Published: August 2010

Abstract and Summary

Female red‐winged blackbirds (Agelaius phoeniceus) often vocalize near their nests and so risk divulging nest locations. In a field study conducted during the 1983 breeding season in south‐central Washington, USA, females vocalized upon departing and arriving at their nests during their pre‐incubation, incubation and nestling‐feeding phases. Females tended to utter Type 1 songs in these situations, a type thought to be used for pair‐bond maintenance. One hypothesis to explain these vocalizations, that they are directed at mates to signal them of female movements, was rejected because the vocalizations were given regardless of male presence on territory. Another hypothesis, that the vocalizations are directed at other females to coordinate group departures, was rejected because most females departed singly and females did not leave their nests in response to playback of Type 1 song. We present an alternative hypothesis, that Type 1 song given in nest‐associated contexts functions in intra‐pair communication and particularly in individual and reproductivestatus identification of females. Males would benefit from such a system by being able to differentiate polygynous mates from each other and from other females, while females would benefit by constantly reinforcing pair‐bonds and obtaining sexual non‐interference during incubation and nestling phases.

Weibliche Rotschulterstärlinge (Agelaius phoeniceus) singen häufig nahe am Nest und riskieren dadurch, dessen Lage zu verraten. Das wurde in der Brutsaison 1983 in Südwashington, USA, näher untersudit. Die Weibchen äußerten „Gesangsmuster 1”, das dem Partnerzusammenhalt dienen soil. Sie taten es vor und während der Brutzeit und in der Nestlingszeit, und zwar wenn sie zum Nest kamen oder es verließen. Sie taten es auch, wenn ihre Mannchen abwesend waren; das Singen zeigt also wohl nicht dem Partner die An– und Abflüge des Weibchens an. Ebensowenig synchronisieren Weibchen dadurch ihre Abflüge. Vermutlich dient dieses Singen dazu, dem Partner die Individualität und den sexuellen Zustand des Weibchens anzuzeigen. Männchen könnten daran ihre verschiedenen Weibchen erkennen und von fremden unterscheiden, die Weibchen selbst könnten sich vor sexuellen Anträgen während der Brüt– und Fütterphasen schützen.
Social Relationship as a Variable Affecting Responses to Mobbing and Alarm Calls of Common Crows (Corvus brachyrhynchos)
Authors: Brown Eleanor D.
Published: August 2010

Abstract and Summary

This study is an examination of the effect of social familiarity between sender and receiver on responses to mobbing and alarm calls in common crows (Corvus brachyrhynchos). Four types of calls (screams, mixed caws, inflected alarm caws, alert caws) were tape recorded from each of six different senders and played back to three sibling receivers. Three types of vocal responses (mixed caws, alert caws, long caws) were scored. The senders were either siblings of, familiar to (heard and seen only from a distance), or unknown to the receivers. The receivers did not respond more to the voices of senders from one social category than another. These results do not support the hypothesis that kin selection shaped mobbing behavior in crows.

Hängt bei nordamerikanischen Krähen (Corvus brachyrhynchos) der Effekt von Haß‐ und Warnrufen vom sozialen Vertrautheitsgrad von Sender und Empfänger ab? Von sechs verschiedenen Individuen, den Sendern, wurden vier verschiedene Ruf‐Typen (Kreischen, gemischte Kräh‐Laute, modulierte Alarm‐Kräh‐Laute, Aufmerk‐Kräh‐Laute) auf Magnetband aufgenommen und drei Geschwistern als Empfängern vorgespielt. Für diese Empfänger waren die Sender entweder Geschwister, außerhalb der Käfige lebende Bekannte (früher aus einer gewissen Entfernung gehört oder gesehen), oder Unbekannte. Als Antworten wurden drei verschiedene Ruf‐Typen (gemischte Kräh‐Laute, Aufmerk‐Kräh‐Laute, lange Kräh‐Laute) beobachtet. Die Reaktionen der Empfänger auf die Stimmen von Individuen verschiedenen Bekanntheitsgrades waren nicht unterschiedlich. Dieses Ergebnis stützt nicht die Hypothese, daß das Haß‐ und Warn‐Verhalten der Krähen durch Verwandten‐Selektion geformt wird.
Decisions in Multiple Goal Contexts: Habitat Selection of the Spider, Agelenopsis aperta (Gertsch)
Authors: Riechert Susan E.
Published: August 2010

Abstract and Summary

Enclosure experiments were used to examine the habitat selection process exhibited by the desert spider, Agelenopsis aperta (Gertsch). Habitat structure was controlled while spider responses to temperature and prey availability were assessed. Individual spiders were tested both in trials where only one parameter was varied (single goal) and in trials where both parameters were varied (multiple goal). Naive individuals (lab reared) representing two populations that exist under different thermal regimes were tested as well as crossbred individuals (one parent from each population).

Individuals from different populations performed similarly in the experiments. Agelenopsis chose sites affording prey and a narrow “preferred” temperature range in the respective single goal experiments, while it failed to select sites affording both prey and preferred temperatures in the multiple goal experiments. Here individual spiders went either to sites affording preferred temperatures only or to those providing prey but less favorable temperatures. Several alternative explanations for these findings are considered. Shade may cue selection of favorable temperatures by Agelenopsis while both olfactory and vibratory cues apparently are used in locating prey.

Gefangenschaftsexperimente an der Wüstenspinne Agelenopsis aperta (Gertsch) dienten der Untersuchung der Habitatwahl. Die Habitatstruktur war in diesen Experimenten kontrolliert, die Reaktionen der Spinnen auf die Parameter Temperatur und Verfügbarkeit der Beute wurden gemessen. Getestet wurden einzelne Spinnen sowohl unter Bedingungen mit nur einem variierten Parameter (Einzelziel), als auch unter Variation beider Parameter (Mehrfachziel). Versuchstiere waren unerfahrene Individuen (Laboraufzucht) aus zwei hinsichtlich der thermischen Umweltbedingungen unterschiedlichen Populationen. Bastarde aus je einem Elter aus jeder Population wurden ebenfalls untersucht.

Alle Klassen von Individuen verhielten sich in den Experimenten ähnlich. Agelenopsis wählte in den jeweiligen Einzelziel‐Experimenten jene Standorte aus, die Beute gewährten, bzw. deren Temperatur in einem engen “Bevorzugungsrahmen” lag. Andererseits gelang es der Spinne in den Mehrfachziel‐Experimenten nicht, Standorte auszuwählen, die sowohl in bezug auf die Beute als auch in ihren thermischen Eigenschaften von hervorragender Qualität waren. Hier bevorzugten die einzelnen Tiere Plätze, die entweder nur nach der Temperatur oder nach der Beute eine besondere Eignung aufwiesen. Verschiedene alternative Erklärungen für diese Befunde werden in Betracht gezogen. Es scheint, daß Agelenopsis sich bei der Auswahl günstiger Temperaturen an Schattenplätzen orientiert, während sowohl olfaktorische als auch vibratorische Reize beim Orten von Beute eine Rolle spielen.
Nestmate Recognition in the Bald‐faced Hornet, Dolichovespula maculata (Hymenoptera: Vespidae)
Authors: Ryan Ruth E. , Cornell Thomas J. , Gamboa George J.
Published: August 2010

Abstract and Summary

Laboratory studies of nestmate recognition (114 h of blind, behavioral observations) were conducted on gynes (potential queens) of the bald‐faced hornet, Dolichovespula maculata. Gynes isolated from their natal nest and nestmates, gynes exposed only to their nestmate gynes, and gynes exposed to both their natal nest and nestmates, later were more tolerant of their nestmates than they were of unrelated gynes. Thus, gynes of D. maculate have the ability to recognize their nestmate gynes apart from the context of the natal nest utilizing individually borne recognition cues.

The isolation of a D. maculate gyne from its natal nest at emergence affects its development of recognition ability but, unlike Polistes, does not prevent it from later recognizing nestmates. This apparent difference in the ontogeny of nestmate recognition ability between the primitively eusocial Polistinae and the highly eusocial Vespinae may be at least partly attributable to behavioral differences between emerging gynes of the two subfamilies.

Laborstudien zum Sippenerkennen (114 h ohne Kenntnis der Verwandtschaft) wurden an Weibchen der Wespe Dolichovespula maculata durchgeführt. Es gab drei Gruppen von Weibchen: 1. solche, die vom Geburtsnest und seinen Bewohnern abgesondert wurden (Isolierte); 2. solche, die nur mit ihren Nest‐bewohnern Kontakt hatten (Nestkollegen); 3. solche, die mit ihrem Geburtsnest und den Nestbewohnern Kontakt hatten (Kontrollgruppe). Alle waren den Nestkollegen gegenüber toleranter als gegenüber unverwandten Weibchen. Weibchen von D. maculata können also ihre Nestkollegen auch außerhalb des Nestes erkennen, sie tragen Erkennungszeichen mit sich.

Isolierung eines Weibchens vom Heimatnest nach dem Schlüpfen beeinträchtigt zwar die Entwicklung der Erkennungsfähigkeit, verhindert aber — im Gegensatz zu Polistes‐Wespen‐ nicht das spätere Erkennen von Nest‐geschwistern. Dieser Unterschied in der Ontogenese des Sippenerkennens zwischen den primitiven Polistinae und den hochentwickelten eusozialen Vespinae mag zum Teil auf Verhaltensunterschiede zwischen den jungen Weibchen der zwei Subfamilien zurückgehen.
Snapping by Foals ofEquus caballus
Authors: Crowell‐Davis S. L. , Houpt K. A. , Burnham J. S.
Published: August 2010

Abstract and Summary

Foals were observed to snap to juvenile and adult ponies and, rarely, to other foals in a wide variety of circumstances. There was no difference in the rate of snapping by colts and fillies. Colts snapped to a stallion more often than would be expected if they were snapping randomly to any adult; fillies snapped randomly to either sex. In (mean ± SE) 21 ± 5% of the cases the foal approached the pony to which it snapped. In 24 ± 3% of the cases the foal was approached by the pony to which it snapped, while in 54 ± 6% of the cases the two were in immediate proximity prior to the snapping. No aggression was directed toward the foal in 62 ± 5 % of the cases. Aggression was directed toward the foal before snapping in 31 ± 5% of the cases and after initiation of snapping in 7 ± 1% of the cases. Adults and foals also nosed each other before and after snapping. Mares sometimes responded to snapping by their own foal, usually by exhibiting aggression toward the pony to which the foal had snapped. It was concluded that snapping may have multiple signal functions, depending on context and that it may be a displacement activity of foals and young horses derived from nursing behavior.

Unter verschiedenen Umständen schnappten Fohlen (männliche und weibliche gleich häufig) nach jungen und ausgewachsenen Ponies, selten jedoch nach anderen Fohlen. Männliche Fohlen schnappten öfter als erwartet nach einem Hengst, weibliche schnappten ohne Unterschied nach beiden Geschlechtern. In 62 ± 5% der Fälle war kein aggressives Verhalten gegen das Fohlen gerichtet. Es gab gegenseitiges Nasenreiben zwischen Fohlen und ausgewachsenen Tieren vor und nach dem Schnappen. Wenn das eigene Fohlen nach einem Pony schnappte, zeigten Stuten gelegentlich aggressives Verhalten gegen das Pony. Es scheint, daß Schnappen verschiedene Funktionen haben kann, je nach Zusammenhang, und daß es sich dabei um eine Übersprungbewegung von Fohlen und jungen Pferden handelt, die vom Säugeverhalten herstammt.
The Gaping Reaction and the Development of Fear in Young Zebra Finches (Taeniopygia guttata castanotis)
Authors: Bischof Hans‐Joachim , Lassek Reinhard
Published: August 2010

Abstract and Summary

Responses of young zebra finches towards different stimuli were tested between hatching and 20 days of age. The stimuli applied were: tactile stimulation with a stick, acoustic stimulation from a loudspeaker playing begging calls of other nestlings, and stuffed dummies of zebra finches and Bengalese finches as visual stimuli. Tactile and acoustic stimuli resulted in gaping responses from the first day of life. Visual stimuli elicited gaping from about day 10 or 11, 4 days after the opening of the eyes. At day 13, gaping responses towards stimuli decreased and were replaced by fear responses from day 16. The implications of the results for sensory development and imprinting are discussed. The development of fear in the young zebra finches is compared with results from filial imprinting.

Antworten junger Zebrafinken auf verschiedene Außenreize wurden täglich vom Schlupf bis zum Alter von 20 Tagen registriert. Die verwendeten Stimuli waren: taktile Reize, die mit Hilfe eines Stöckchens gesetzt wurden, akustische Reize (Bettelrufe anderer Junger, die über einen Lautsprecher eingespielt wurden), und optische Reize in Form von ausgestopften Zebrafinken bzw. Japanischen Mövchen.

Bei taktilen und akustischen Reizen antworteten die Jungen vom 1. Tag an mit Sperreaktionen; visuelle Reize wurden vom 10. bis 11. Tag an beantwortet, 5 Tage nach dem ersten Öffnen der Augen. Mit 13 Tagen nahm die Sperreaktion auf Reize ab und wurde vom 16. Tag an vollständig durch Furchtreaktionen ersetzt. Die Implikationen der Ergebnisse in bezug auf die sensorische Entwicklung der Tiere und auf sexuelle Prägung werden diskutiert.
Functional Interrelationships Among the Mobbing and Alarm Caws of Common Crows (Corvus brachyrhynchos)
Authors: Brown Eleanor D.
Published: August 2010

Abstract and Summary

This study is an analysis of the functions of calls used by common crows (Corvus brachyrhynchos) in contexts involving danger. Four types of calls (screams, mixed caws, inflected alarm caws, alert caws) were tape recorded and played back to 7 captive crows. Three types of vocal response (mixed caws, alert caws, long caws) were scored for the 3 most responsive receivers. From the magnitude and temporal course of the responses, and from comparison of the various responses across the different playback types, functional interrelationships among caw types were found. Mixed caw responses showed a single pattern of elicitation only in response to certain playback types, and were inferred to be unifunctional (indicating immediate danger). Alert and long caw responses showed different patterns of suppression and elicitation with respect to playback type, and were inferred to be multifunctional (indicating mild danger; cessation of danger; business as usual; intraspecific aggression). These results are discussed in terms of the information encoded in mobbing and alarm calls, and their functional and adaptive significance.
The Syntactic and Semantic Organization of Pigeon Guillemot (Ceppbus columba) Vocal Behavior
Authors: Nelson Douglas A.
Published: August 2010

Abstract and Summary

The vocal behavior of the pigeon guillemot (Cepphus columba) was studied for 5 years on Southeast Farallon Island, California in order to determine whether there were, rules common to many of the signals in the repertoire that could relate variation in signal structure to message content. The vocal displays used by pigeon guillemots in social communication are described, and variation in four vocal display classes (Hunch‐whistles, FM notes, Screams, Trills) is quantitatively analysed.

Two sets of rules that relate signal structure to message content are proposed to describe variation in pigeon guillemot vocalizations. One set of rules relates continuous variation within each of the four vocal display classes to the signaller's probability of subsequent movement.

The second rule set, based on a simple hierarchy, regulates the assemblage of notes into higher‐level units (phrases, displays) which encode progressively more information. Tape playback experiments confirmed an assumption made by this model: lower‐level vocal elements contribute a specific message to each of the higher‐level vocalizations in which they occur. The implications of this model for the perception of sounds and decoding of messages are discussed.
Behavioural Interactions between Avian Predators and their Avian Prey: Play Behaviour or Mobbing?
Authors: Verbeek N. A. M.
Published: August 2010

Abstract and Summary

In this paper I review reports in the literature in which hawks (mainly species ofAccipiter) pursued avian prey without apparently trying to capture them (Table 1). In some reports the hawks were in turn chased by the prey as well (Table 2). The species that were pursued in “playful” fashion were either belted kingfishers (Megaceryle alcyon), woodpeckers or corvids. The pursuits have been interpreted in the literature as play behaviour.

A search of the literature showed that many species of woodpeckers and corvids are eaten by accipiters (Table 3). However, the species that are pursued in “playful” fashion are generally those woodpeckers and corvids that are larger than the male or female accipiter pursuing them (Table 4). It is not surprising that the smallest of the accipiters (A. striatus) was involved in most of the pursuits that have been recorded (Tables 1 and 2).

I argue that the hawks were inexperienced, hungry individuals which pursued inappropriately large prey. The prey's behaviour is interpreted as mobbing. They are safe because they can escape by diving into the water (kingfisher), they are larger than the hawk or they outnumber it.
Pineal Body and Bird Navigation: New Experiments on Pinealectomized Pigeons
Authors: Papi Floriano , Maffei Lamberto , Giongo Francesca
Published: August 2010

Abstract and Summary

Three series of experiments were performed with pinealectomized homing pigeons released under sun. In the first series, birds were not subjected to further treatments; their homing behaviour turned out to be scarcely or not at all impaired.

In the second series, birds were kept in an oscillating magnetic field before release. The same deflecting effect of the treatment was observed in both control and operated birds; this shows that the pineal is not involved in this magnetic effect and adds to the evidence contrary to a role of the pineal in processing magnetic information for navigational purposes.

In the third series, birds were kept in continuous dim light (DD) or in artificial light dark cycles (LD) for three or five days before the test. In intact birds in DD, free running of the circadian rhythm which controls the sun compass was observed. The rhythm of pinealectomized birds turned out to be entrainable to light‐dark cycles, as birds in LD were capable of homeward orientation. Operated birds in DD, on the contrary, performed poorly in orientation; also their homing success was impaired. Therefore, the pineal body turns out to act as a pacemaker for the circadian rhythm controlling the sun‐compass orientation.
Eosinophilic fasciitis as a paraneoplastic phenomenon associated with metastatic colorectal carcinoma
Authors: Philpott Hamish , Hissaria Pravin , Warrren Lachlan , Singhal Nimit , Brown Michael , Proudman Susanna , Cleland Les , Gillis David
Published: August 2010

A 72‐year‐old man presented with erythema and induration of his calves and forearms. He had a past history of stage 1 colorectal carcinoma, treated with resection and primary anastamosis 4 years earlier. A diagnosis of eosinophilic fasciitis was made based on the characteristic clinical appearance, peripheral blood eosinophilia and a skin biopsy. There was no improvement in the condition following treatment with prednisolone or methotrexate. One year later, abnormal liver function studies were noted, and an abdominal computed tomography scan and subsequent needle biopsy of the liver confirmed a neoplastic lesion in the liver consistent with a metastatic colorectal carcinoma. Systemic chemotherapy with oxaliplatin, 5‐fluorouracil and capecitabine was commenced, and resulted in partial remission of the colorectal carcinoma. Simultaneously, the indurations of the forearms and calves also improved, suggesting that the eosinophilic fasciitis was a paraneoplastic phenomenon.
A possible new cause of spa bath folliculitis: Aeromonas hydrophila
Authors: Mulholland Adrian , Yong‐Gee Simon
Published: August 2010

A 34‐year‐old man presented with a pubic eruption of 4 weeks duration, affecting both himself and his partner. He had been treated unsuccessfully with intravenous and oral dicloxacillin. The eruption was a severely inflammatory folliculitis, with haemo‐serous exudate and marked oedema. A clinical diagnosis of herpes simplex virus folliculitis was disproved when routine bacteriology isolated Aeromonas hydrophila and multiple viral polymerase chain reaction studies were negative. Histology demonstrated a chronic folliculitis with no organisms present. Both he and his partner were treated with oral ciprofloxacin 500 mg bd for 6 weeks with clinical clearance of infection, but both developed a scarring alopecia. Infection was attributed to possible contamination of a poorly maintained home spa bath with A. hydrophila.
Multiple neonatal haemangiomatosis with liver haemangiomas and anaemia
Authors: Mendiratta Vibhu , Anand Rama , Chander Ram , Harjai Bhawana , Gupta Tanvi
Published: August 2010

A 5‐month‐old girl presented with six cutaneous haemangiomas that appeared over a 1‐month period. Investigations revealed anaemia and multiple liver haemangiomas. After 3 months follow up, there has been some further enlargement of the cutaneous lesions but no increase in number, while the liver lesions have remained stable, without any other systemic complications.
Exploration of the occupations of people with schizophrenia
Authors: Urlic Karen , Lentin Primrose
Published: August 2010

Background:  Participation in occupations is a powerful determinant of wellbeing. This study focusses on obtaining a greater understanding of the occupational experiences of people with schizophrenia and the factors that facilitate or hinder occupational engagement.

Sample:  Six participants with schizophrenia living in an Australian urban community who were clients of an assertive outreach team formed the sample.

Methods:  Data gathered via semi‐structured interviews and observation were thematically analysed.

Results:  The findings are reported in three main themes: struggling to survive in the present, enabling and constraining factors in the living environment and the importance and value of work.

Conclusions:  These findings provide further evidence for occupational therapists working with consumers of mental health services to adopt practices that enable self‐determination of participation in occupations, increase supports and resources within the community environment and expand opportunities for work.
Endorectal ultrasound in the staging of rectal tumour: A local experience
Authors: Chung Chi‐Chiu , Kwok Shek‐Yuen , Tsang Wilson Wen‐Chieng , Chan Eva Sze‐Wah , Li Michael Ka‐Wah
Published: August 2010

Objective: Endorectal ultrasound (ERUS) has been shown to be the most accurate modality available for the local staging of rectal tumours. Local reports on ERUS are, however, still scanty. The present paper aims to report the initial experience with ERUS in our local institution.

Method: From July 1998 to November 1999, patients suffering from mid‐ or low‐rectal tumours were studied. Endorectal ultrasound was performed using a 10.0‐MHz self‐rotating transducer. The ultrasound staging results were then compared with the subsequent pathological staging after surgery.

Results: Five patients had stenosing growths precluding ERUS. Twenty‐eight patients had ERUS successfully performed. Of these, two patients did not receive surgery. The ultrasound staging and the pathological staging in the remaining 26 patients were compared. Endorectal ultrasound had an accuracy of 88% in T‐staging, with understaging in two cases and overstaging in two cases. The accuracy of N‐staging was 81%, with two patients understaged and one patient overstaged.

Conclusion: Endorectal ultrasound is highly reliable in the loco‐regional staging of rectal tumours. Local surgeons, especially those with a colorectal interest, are encouraged to perform this focused ultrasound examination of their own territory.
LAPAROSCOPIC WEDGE RESECTION OF GASTRIC STROMAL TUMORS
Authors: Leung F. , Siu W.T. , Tang C.N. , Chau C.H. , Li M.K.W.
Published: August 2010

Background: Large gastric stromal tumors that are not suitable for endoscopic polypectomy usually necessitate open surgical resection. Laparoscopic wedge resection of gastric stromal tumors has been demonstrated to be a feasible approach by small series case reports.

Patients and method: Patients with gastric stromal tumours were diagnosed by upper endoscopy and CT scan were performed. Hemostatic procedure was performed for bleeding lesions when applicable. All patients underwent diagnostic laparoscopy and laparoscopic ultrasound examination to assess the lesions and rule out metastatic disease. Extragastric closed technique was employed for stromal tumors located at the body of stomach, where they are mobile and surrounded by ample amount of redundant normal gastric wall. Transgastric approach via anterior gastrototomy was employed for lesions near the gastro‐oesophageal junction, fundus and close to the greater and lesser omentum, where there were not adequate surrounding stomach wall. Operative time, resumption of full diet, analgesic requirement, post‐operative stay, morbidity and mortality were analysed prospectively.

Results: From June 1995 to February 2000, 31 patients with gastric stromal tumors underwent laparoscopic wedge resection in our unit. There were 16 male and 15 female patients, aged 40 to 84 (mean = 64). Average operative time was 82 (45–180) minutes. Extragastric closed techniques were employed for 7 patients and the remaining lesions were extirpated via gastrotomy. Two patients with fundal lesions required conversion to open procedure because of adhesions to the posterior abdominal wall. Patients required 2 doses of post‐operative intramuscular pethidine for pain control and 6 days (median) to resume full diet. The median post‐operative stay was 6 days. One patients developed stroke on post‐operative day 3. Another patient developed diffuse peritoneal metastasis 30 months after the initial procedure. In all cases, clear resection margins were confirmed on histology.

In conclusion: Laparoscopic wedge resection of gastric stromal tumors is safe and feasible approach with low perioperative morbidity.