bluuebunny/crossref_metadata_2025 huggingface dataset:
Pairs and Harems in a Cichlid Fish, Lamprologus brichardi1
Authors: Limberger Dominique
Published: August 2010

Abstract and Summary

L. brichardi is a substrate brooding cichlid with facultative polygamy. The social organization was studied in the field for a 6‐week period. The mating structure was examined in detail in the laboratory. Two types of social groupings are described:

Aggregations of sexually mature but nonterritorial fish, also frequently visited by territory holders in the vicinity.

Reproductive units (families) mainly consisting of the reproducing pair members and offspring from several broods. All family members defend a common territory around the shelter site. Occasionally a male has access to two females each with a separate territory (harem).

The factors influencing mating structure were investigated in the laboratory:

Females select breeding sites rather than partners.

Without competitors for breeding sites, and with an equal or nearly equal sex ratio, harems were established nearly as often as pairs.

Young males are physically able to mate and form a harem; but they are usually prevented from doing so by more competitive (larger) males.

Competition for breeding sites is not a prime influence on harem formation, although it is of great importance in determining the composition and size of the breeding population.

Just as many pairs as harems were formed with and without predators, even though, with predators, no young survived.

In L. brichardi the formation of harems is not predominantly determined by the distribution of suitable spawning sites. The monopolization of females is only slightly influenced by the distance between their territories.

In L. brichardi it is not necessary for harem formation that the male is bigger than the female.

Behavioural protocols and data on growth rates, as well as spawning intervals, did reveal any consistent difference between pairs and harmes.

Of the variables tested, male competition for females was therefore the sole determinant of who should mate.
Pineal Body and Magnetic Sensitivity: Homing in Pinealectomized Pigeons under Overcast Skies
Authors: Maffei Lamberto , Meschini Enrico , Papi Floriano
Published: August 2010

Abstract and Summary

Since birds use the earth's magnetic field for compass orientation when astronomical cues are lacking and it has recently been suggested that the pineal body is part of their magnetic compass, test releases have been performed in overcast conditions with pigeons deprived of the pineal body. On the whole, both experimental and control birds were capable of homeward orientation, though the bearings of experimental were rather more scattered. No differences in homing speed or success were recorded. Thus, the pineal body does not appear to play an important role in the homing of pigeons.
The Feeding Behaviour of Starlings (Sturnus vulgaris) in the Presence of ‘Eyes’
Authors: Inglis I. R. , Huson L. W. , Marshall M. B. , Neville P. A.
Published: August 2010

Abstract and Summary

Previous studies that have looked at the aversive properties of simple, predator‐related, eye‐like patterns presented in an artificial context, have yielded conflicting results. The aim of the present series of experiments was to investigate whether such stimuli had potential for use as bird scarers. The starling (Sturnus vulgaris) was the subject species. The experimental procedure was designed to provide a relevant and objective, interval scale of aversiveness based upon the ability of eye patterns to deter hungry birds from a feeding area.

Each subject was deprived of food for 5 h and then tested in an apparatus which exposed an eye pattern over a food trough immediately after the bird alighted on that trough. 10 measures of the starlings' feeding behaviour were monitored over a 1‐h trial. It was predicted that five of these variables would be positively and five negatively correlated with an increase in the fear evoking properties of the stimulus. The 10 measures were analysed using principal component analysis and the first component in every experiment had the signs of the latent vectors of the variables exactly in the predicted pattern and therefore appeared to be an ‘aversiveness index’. The scores from this first component were then used in a Latin square ANOVA to distinguish subject, test order and stimulus effects.

The main findings from the eight experiments are as follows. Simple eye‐like patterns can indeed deter hungry starlings from feeding in their vicinity. The presence of a pair of eyes painted on a white card caused an 88% reduction in time spent on the nearby food trough and a 65% reduction in actual feeding time. The presence of ‘pupils’ in the patterns is essential for simple circles alone are not significantly more aversive than the control card. Once a pattern has the ‘pupil/iris’ distinction then a circular outline becomes important although the shape of the ‘pupil’ appears relatively unimportant. Eyes with coloured irises are more effective than black and white patterns but the degree of contrast between the ‘pupil’ and ‘iris’ appears irrelevant. Increasing the number of simultaneously presented eyes from one to three is correlated with an increasing trend in aversiveness which is destroyed if the same stimuli are presented within the context of a simple head outline. Changing the orientation of a pair of eyes from horizontal to vertical only slightly reduces their aversiveness. The size of the patterns appears to be unimportant within the range tested. The aversive properties of eyespots and of broadcast starling distress calls are positively additive. The effectiveness of a stimulus combining all the important features mentioned is as aversive as is a realistic model of the head of an owl.
The Social Structure of Inachus phalangium, a Spider Crab Associated with the Sea Anemone
Authors: Wirtz Peter , Diesel Rudolf
Published: August 2010

Abstract and Summary

The behaviour of the spider crab Inachus phalangium (Fabricius, 1775), which lives in association with the sea anemone Anemonia sulcata (Pennant), was studied in the field.

The crab was found in the littoral zone of the Mediterranean Sea near Banyuls sur Mer, France, in the whole depth range studied (0.5–25 m). The crabs had a long‐lasting association with individual Anemonia sulcata, occasionally with Aiptasia mutabilis. Most crabs were found in association with the same anemone for several days, some crabs were found in association with the same anemone for longer than one month.

In the areas studied, on average 65 Inachus phalangium were found on 100 anemones.

Crabs released in the vicinity of anemones moved towards them and entered them. Inachus phalangium could walk between the tentacles of Anemonia sulcata and Aiptasia mutabilis without eliciting feeding reactions of the anemone. The crabs left the anemones for moulting. After moulting masking material was removed from the exuvia and used again. The animals returned into an anemone while still soft. Material used for masking, usually algae, could be picked off the body and eaten. Masking material may be a food reservoir in addition to providing camouflage.

Anemones were left only during night‐time. The crabs left their anemone to moult, to feed in the vicinity, fleeing from larger conspecifics, and to migrate to a different anemone.

Outside the anemone's protection Inachus was eaten by several species of fish.

Individuals appeared to avoid each other. 57% of all animals were found alone on an anemone. Large males and females were more frequently found alone than were small males and females. Fights were observed between members of the same and of the opposite sex. During fights, legs and claws could be torn off.

Adult males migrated more often between anemones and moved over larger distances when migrating than did adult females. Adult males probably migrated in search of sexually mature females. Such a roving strategy is evolutionarily stable only when the higher costs (in terms of energy expenditure and mortality) are compensated for by a higher number of offspring than produced in the alternative, pair‐bonding strategy.
A Study of the Behaviour of the Australian Field Cricket Teleogryllus commodus (Walker) (Orthoptera: Gryllidae) in the Field and in Habitat Simulations
Authors: EVANS A. R.
Published: August 2010

Abstract and Summary

The behaviour ofT. commodus(Walker) in the field and in simulated natural habitats is described. Regular predictable sequences of behaviour are represented by an ethogram.

Most behaviour was centred around burrows or sheltered sites. Burrows appeared to be a limiting resource and there may be behavioural dimorphism in ♂ ♂ (burrower and non‐burrower strategies).

Individuals were found to form gregarious clusters and appeared to be attracted to areas already occupied by crickets. Territorial spacing and other social interactions occurred within these clusters.

♂ ♂ and ♀ ♀ were found to be mobile, and moved continually between sites. The movement of ♂ ♂ and ♀ ♀ between burrows (calling sites) was measured. Adult ♂ ♂ never remained at a burrow for longer than two days. In simulated natural habitats ♂ ♂ moved in response to two factors: first, and most common, as a result of eviction by other ♂ ♂ second, as a response to the absence of ♀ ♀. When cricket density was increased in habitat simulations crickets clustered at calling sites.

The adaptive significance ofT. commodusbehaviour is discussed.
Effects of Prey Movement and Prey Odor on Feeding in Garter Snakes
Authors: BURGHARDT GORDON M. , DENNY DALLAS
Published: August 2010

Abstract and Summary

The role of prey movement in feeding behavior was investigated in 10 garter snakes (Thamnophis sirtalis) repeatedly presented with paired stationary and continuously rotating sections of earthworm (Lumbricus terrestris). Additionally, prey odor intensity and source were varied and the performance of a tongueless snake was compared to normal animals.

Experiment 1 showed that garter snakes will selectively attack rotating over nonmoving sections of earthworm across a wide range of speeds (1–2048 rpm) with an optimum between 16 and 256 rpm. However, blocking the odor from the sections and presentation of speeds greater than 500 rpm decreased response to moving sections. Experiment 2 showed that at 22–32 rpm moving sections were selected over stationary sections when odor from both was blocked.

Experiment 3 assessed the effects of varying ambient odor conditions upon selection of artificial moving and stationary prey. Ambient earthworm odor resulted in a sustained high rate of tongue‐flicking while, with no odor present, snakes showed a gradually increasing rate of tongue‐flicking that declined within a few minutes.

Experiments 4 and 5 studied the effects of tongue removal upon the selection of moving and nonmoving prey. Gross changes in the feeding sequence were noted. A long‐term tongue‐less adult fed by opening her mouth and thrashing about her cage when presented with earthworm odor and only preferred moving prey at 32 rpm; a control showed the normal stalk‐and‐strike sequence. The tongueless snake was less attracted to the moving earthworm at a distance than were normal snakes and the use of vision seemed less integrated rather than compensably improved.

The results are discussed in reference to the critical flicker‐fusion frequency, klepto‐parasitism, and escape tactics of prey.
Social Stress in the Fieldvole: Differential Causes of Death in Relation to Behaviour and Social Structure
Authors: Rasa O. Anne E. , van den Höövel H.
Published: August 2010

Abstract and Summary

The fieldvole (Microtus arvalis) undergoes population density fluctuations associated with mass deaths at high densities. The causes of these mass deaths have not yet been fully explained although hypoglycaemic shock can account for a proportion of them. The study investigates another social stress induced disease, uraemia, and its relationship with social status, sex and behaviour in this species. Behavioural parameters together with blood sugar and blood nitrogen levels were measured in 8 captive groups of 8 animals each over an 8‐day period and the dominance status and sex of animals that died were recorded. In ♀♀ there was a strong negative correlation between attacks received, the frequency of fleeing and blood sugar levels. In ♂♂, attacks received and flight were correlated with elevated blood nitrogen and decreased weight despite increased feeding. Females died showing symptoms typical of hypoglycaemic shock while, in ♂♂, the symptoms were typical for uraemia. The differential causes of death are probably related to the sex‐based differences found in social behaviour and social structure.

Die Todesursachen von Feldmäusen unter hoher Populationsdichte sind noch nicht völlig erklärt. Bei einigen kann hypoglykämischer Schock die Todesursache sein, aber nicht bei alien. Hier wird untersucht, ob auch Urämie, eine andere durch sozialen Streß ausgelöste Krankheit, eine Rolle spielen könnte.

An Gruppen von 8 Feldmäusen, je 3 ♂♂ und 5 ♀♀, in einem großen Käfig unter halbnatürlichen Bedingungen gehalten, wurde das Verhalten beobachtet und Gewicht, Blutzucker und Blutharnstoffgehalt über 8 Tage hinweg gemessen. Die Gruppen stabilisierten sich innerhalb von 24 h; das größte ♂ und alle ♀♀ taten sich zusammen und schlossen die beiden kleineren ♂ ♂ aus. Mehr als 50% der kleinen ♂ ♂ starben, ebenso 25% der kleinen ♀♀. Die ♀♀ starben innerhalb von 4 Tagen, die ♂ ♂ zwischen dem 4. und 8. Tag. Erduldete Angriffe und Flucht korrelierten hoch negativ mit dem Blutzuckerspiegel der ♀♀. Bei den ♂ ♂ korrelierten erduldete Angriffe und Flucht mit einem erhöhten Harnstoff‐ und Zuckergehalt des Blutes und mit — trotz erhöhtem Fressen —abnehmendem Gewicht.

Die ♀♀ starben mit Symptomen, die typisch sind für einen hypoglykämi‐schen Schock; die ♂ ♂ zeigten typische Symptome einer Urämie. Beobachtungen des Sozialverhaltens zeigten, daß kleine ♀♀ während der ersten 4 Tage kurz‐zeitigem Streß durch häufige Attacken der großen ♀♀ ausgesetzt waren und dann von den Gruppen aufgenommen wurden. Untergeordnete ♂ ♂ wurden in gleichbleibend hohem Maße von dem dominierenden ♂ angegriffen und niemals in die Gruppe aufgenommen — ein Langzeitstreß‐Syndrom. Die unter‐schiedlichen Todesursachen der kleinen ♂ ♂ und ♀♀ sind wahrscheinlich auf geschlechtsspezifische Unterschiede im Sozialverhalten und in der Sozialstruktur zurückzuführen.
Vigilance Behaviour and Alarm Calls in a Captive Group of Meerkats, Suricata suricatta
Authors: Moran Greg
Published: August 2010

Abstract and Summary

At least one member of captive groups of meerkats (Suricata suricatta) typically is situated in a prominent, elevated location. This study provides an initial description of this pattern of behaviour and evidence to suggest that it serves a vigilance function. While on the ledges, animals behaved in an alert and watchful fashion and emitted two particular classes of vocalization in response to potential dangers to the colony. Other group members responded to these alarm vocalizations with a range of alerting and retreating patterns. The vigilance behaviour system provides a useful model for the investigation of several sociobiological hypotheses and of a sophisticated alarm vocalization network.

In jeder gefangen gehaltenen Gruppe von Erdmännchen (Suricata suricatta) gab es mindestens ein Tier, das sich gewöhnlich auf eine erhöhte Stelle mit guter Aussicht setzte.

In jeweils halbstündigen Beobachtungen, die in drei Serien von je 20mal über 3 Jahre verteilt waren, saß im Mittel in über 95 % der Zeit mindestens ein Tier auf solchem Posten. Ausnahmen betrafen Zeiten nach dem Tod eines Koloniemitglieds.

Alle Tiere saßen häufig auf solchen Posten, aber in den letzten beiden Beobachtungsperioden vor allem das erwachsene Männchen. Es verharrte in den beiden letzten Jahren auch jeweils für längere Zeit auf diesem Posten als die anderen Tiere.

Die auf dem Aussichtsposten befindlichen Tiere verbrachten mehr Zeit aufgerichtet und die Umgebung musternd als die Tiere, die sich anderswo aufhielten.

Die meisten Alarmrufe kamen von Tieren auf dem Aussichtsposten. Sowohl die Alarmrufe der Individuen wie die Reaktionen der anderen darauf sind verschieden. Auf Tonbandrufe reagieren die Tiere zunächst mit Deckungsuche, doch verliert sich die Reaktion mit häufigerer Wiederholung.

Das Sitzen an erhöhter Stelle scheint ein wichtiger Bestandteil der Sozialstruktur zu sein und als Wächter‐Amt zu dienen. Wachesitzen ist unverträglich mit Fressen und anderem Selbsterhaltungs‐Verhalten. Das Wächter‐Amt der Surikaten weist auf einen hohen Verwandtschaftsgrad innerhalb der Gruppen hin.
The Effect of Early Experience on the Development of “Aggressive” Behaviour in Formica lugubris Zett. (Hymenoptera: Formicidae)1
Authors: Moli Francesco Le , Mori Alessandra
Published: August 2010

Abstract and Summary

The possible rôle of early experience in the development of aggression in Formica lugubris Zett. was examined by setting up artificial colonies containing young workers hatched on the same day. Group 1 consisted of young workers hatched in the presence of homospecific adults, and so having “normal” experience. Group 2 young workers were reared from hatching with Formica rufa L. adults, and so had “altered” experience. Group 3 had young workers drawn from cocoons and reared in isolation from adults. Intra‐ and interspecific aggressive behaviour of the young workers in the three categories were analysed and quantified 16 and 30 days after hatching, after staging fights with F. lugubris and F. rufa.

In group 1 no conspecific aggression was evident, but attacks were almost always recorded in heterospecific encounters. In group 2 there was no tolerance of homospecifics, initial contact frequently being followed by immediate over attack with all elements of aggressive behaviour. The reverse applied for F. lugubris with “altered” learning and F. rufa workers, there was mutual recognition and acceptance, as they were ants of the same colony. The young workers reared in isolation (group 3) fought in 60 % of homospecific encounters on the 16th and 40% on the 30th day; disturbance of conspecific recognition was clear. Nevertheless combat occurred in almost all heterospecific encounters.

This work demonstrates that differences in early experience may influence the amount and direction of aggression in F. lugubris ant‐workers at 16 and 30 days of age. This may explain the existence of slave‐workers in natural dulotic societies.

Der Einfluß früher Erfahrungen auf die Entwicklung der Aggression bei der Ameise Formica lugubris wurde in künstlichen Kolonien an Arbeiterinnen geprüft, die am jeweiligen Tag geschlüpft waren, und zwar in Gruppe 1 unter Artgenossen, in Gruppe 2 unter Erwachsenen von Formica rufa; Arbeiterinnen der Gruppe 3 waren aus Kokons geholt und handaufgezogen. Inner‐ und zwischenartliches Angriffsverhalten wurden am 16. und 30. Tag nach dem Schlupf analysiert. In Gruppe 1 gab es keine deutliche Aggression zwischen Artgenossen, wohl aber beim Zusammentreffen mit F. rufa. — In Gruppe 2 gab es bei den ersten Kontakten mit Artgenossen häufig sofort Angriffe und alle Elemente aggressiven Verhaltens; hingegen waren die aus derselben Kolonie stammenden F. lugubris und F. rufa friedlich miteinander. — Isoliert aufgezogene Arbeiterinnen kämpften am 16. Tag in 60%, am 30. Tag in 40% der Begegnungen mit Artgenossen, aber auch in fast allen Begegnungen mit Artfremden.

Frühe Erfahrung hat also einen Einfluß auf das spätere Aggressions‐verhalten. Das dürfte bei Sklavenhalter‐Ameisen eine Rolle spielen.
The Breeding System of the Acorn Woodpecker in Central Coastal California
Authors: Koenig Walter D. , Mumme Ronald L. , Pitelka Frank A.
Published: August 2010

Abstract and Summary

The breeding system of the acorn woodpecker in California is detailed, and evidence supporting the occurrence of both cooperative polygamy (polygynandry) and nonbreeding by group offspring still living in their natal territory (helping) is presented. Both these phenomena occur independently and often simultaneously within the population. Although groups almost invariably consist of close relatives, incest is avoided, apparently by the recognition of close relatives. However, 10 cases of known or probable inbreeding have been recorded, resulting both from philopatry and from breakdowns in the usual pattern of incest avoidance. The latter appears to occur when the cost of attracting an unrelated mate is unusually high; the overall extent and significance of inbreeding in the acorn woodpecker remain to be determined.

Eichelspechte leben in Gruppen, die aus einem “Brüterzentrum” (bis zu 4 Männchen und 2 Weibchen) bestehen und den nichtbrütenden Helfern; das sind bis zu 10 Nachkommen beiderlei Geschlechts aus mehreren Vorjahresbruten der Gruppe. Brutgruppen entstehen, indem sich eine Gruppe von Schwestern und eine Gruppe ihnen verwandtschaftlich nicht nahestehender Brüder zusammenschließen. Hinzu kommen dann Zuwanderer und die eigenen Nachkommen. Diese brüten in der Familie nicht, es sei denn ein andersgeschlechtiger Elter stirbt und wird durch einen Fremden ersetzt. In diesem Falle können Nachkommen brüten, obwohl ihr gleichgeschlechtiger Elter noch in der Gruppe ist. Sterben alle Brüter eines Geschlechts, wandern andere Individuen dieses Geschlechts ein; Zuwanderer gibt es aber auch zusätzlich.

Zuwanderer sind 1. Geschwister von Brütern, 2. Gruppennachkommen, die nach einem erfolglosen Brutversuch außerhalb wieder daheim Heifer werden, 3. Gruppennachkommen, die kein Auswandererglück hatten und im heimatlichen Revier brüten, nachdem ihr andersgeschlechtiger Elter starb. Als Folge dieser Brüt‐Ordnung wird Inzest weitgehend vermieden, offenbar zum Teil durch Verwandtschaftserkennen. Dennoch sind 10 Fälle von Inzucht beschrieben; 5 davon nach einem Zusammenbruch des Verwandtschaftserkennens, 5 aus Ortstreue. Inzucht scheint aufzutreten, wenn die Kosten für das Anwerben eines unverwandten Partners ungewöhnlich hoch sind. Wie häufig das vorkommt und welche Folgen es für das Sozialverhalten hat, bleibt zu untersuchen.
Sex‐specific Activity Patterns in Periplaneta americana and their Relation to Mate‐finding
Authors: Seelinger Günter
Published: August 2010

Abstract and Summary

Sex‐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.

Geschlechtsspezifische 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 Summary

Many 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.

Das 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 Summary

Evolutionary 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.

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 Summary

1. 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.

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 Summary

In 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.

Die 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 Summary

We 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.

Wir 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 Summary

The 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.

Mit 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 Summary

Female 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.

Weibliche 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 Summary

This 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 Summary

We 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 Summary

The 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 Summary

The 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 Summary

The 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 Summary

The 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.
Alarm Calling in Richardson's Ground Squirrels (Spermophilus richardsonii)
Authors: Davis Lloyd S.
Published: August 2010

Abstract and Summary

A three‐year field‐study of Richardson's ground squirrels was conducted to assess whether alarm calling functions to warn close relatives (“kin selection” hypothesis) or manipulate conspecifics (a “selfish” hypothesis).S. richardsoniihad distinct calls for terrestrial and aerial predators, and the responses of squirrels varied appropriately according to the context of calls, implying that calling conveyed correct information concerning the nature of the danger. Alarm calling elicited by naturally occurring encounters with potential predators during 454 h of observation, and by a thrown frisbee in 70 experimental trials, was not equally probable for all age/sex classes. Squirrels were most likely to call when they had offspring or siblings nearby, which is supportive of the hypothesis that alarm calling is maintained by kin selection. Adult males, residing in the vicinity of either their probable progeny or their nonlittermate half‐siblings, were the most likely age/sex class to call during the lactation period when young were below ground and were most vulnerable. I conclude that alarm calling by Richardson's ground squirrels is nepotistic rather than manipulative.
Structure and Use of Song in the Yellow‐headed Blackbird (Xanthocephalus xanthocephalus)
Authors: Cosens Susan E. , Falls J. Bruce
Published: August 2010

Abstract and Summary

Analysis of yellow‐headed blackbird songs indicated that accenting and buzzing songs differed in note structure, energy distribution, and loudness. Buzzing songs showed a shift in energy distribution as a result of propagation through marsh habitat whereas accenting songs did not. Results suggest that accenting songs should propagate further in marsh habitat than buzzing songs. Two experiments, done to test whether song types differed in functional distance, showed that the presence of a male song of either type, or a male or female model on their territories increased use of buzzing songs by males. In the absence of auditory or visual stimulation, males used mainly accenting songs. Results supported the hypothesis that buzzing songs are used primarily for short‐range interactions whereas accenting songs are used primarily for long‐range general advertising.