Aspects of Aggressive Behaviour in Polecats

• 1 Das Verhalten von Iltissen und Frettchen in einer 16-m²-Arena gegen Artgenossen wird beschrieben.
• 2 Außerhalb der Fortpflanzungszeit werden Fremde belästigt (hier ?ritual aggression” genannt), aber nicht besiegt.
• 3 Während der Fortpflanzungszeit (März bis Juli) kämpfen ♂♂ mit Fremden: sie ergreifen den Eindringling im Nacken, halten ihn fest, versuchen ihn zu schütteln und schleppen ihn umher. Der Gepackte rollt sich über den Boden, bis der andre loslassen muß, und versucht, seinerseits ebenso zuzupacken.
• 4 Ein unterlegener Iltis droht abwehrend mit gekrümmtem Rücken und hochgehaltenem Kopf, öffnet das Maul und weist dem Gegner unter Pfauchen oder Kreischen die Zähne. Der Sieger dreht den Kopf zur Seite und geht breitseits vor.
• 5 ♀♀ sind weniger angriffslustig als ♂♂; sie kämpfen gelegentlich, aber kurz und ohne den Gegner zu unterwerfen. ?Ritual aggression” zeigen sie nur gegen fremde ♀♀.
• 6 Begegnungen zwischen ♂ und ♀♀ in der Paarungszeit sind beschrieben. Ist das ♀ bereit, so kommt es zur Kopula; sonst versucht das ♂ zu kopulieren, das ♀ aber dreht sich auf den Rücken und schnappt sanft nach Genick und Schnauze des ♂. Läßt sich das ♂ nicht abweisen, so kann es zum Kampf kommen: das ♂ schleppt das ♀ am Genick umher und schüttelt es, das ♀ droht, quiekt und schnappt nach dem ♂. Das ♀ wird nicht besiegt. Auch das ♂ kann einen Kampf beginnen, vor allem, wenn es paarungsbereit ist und das ♂ nicht mitmacht. Das ♀ geht dann in Abwehrstellung und droht.
• 7 Im Januar–März werden die Hoden der Iltis-♂♂ größer und diese angriffslustiger: sie beißen öfter einen Partner ins Genick und halten ihn länger fest. Aber auch in heftigen Kämpfen wird der Gegner nicht unterworfen. Es kommt zu Pseudokopulationen mit ihm, wahrscheinlich ausgelöst durch seine Bewegungslosigkeit.
• 8 Im Iltiskampf fehlt das Drohen vor einem Angriff, entsprechend fehlt jedes Vorspiel vor dem Aufreiten und den Kopulationsversuchen.
• 9 Die Beziehungen zwischen Angriffs-, Sexual- und Spielverhalten sind erortert.

     

Thermal Behaviour of Honeybees During Aggressive Interactions

We report here on the interrelationship of aggressive behaviour and thermoregulation in honeybees. Body temperature measurements were carried out without behavioural disturbance by infrared thermography. Guard bees, foragers, drones, and queens involved in aggressive interactions were always endothermic, i.e. had their flight muscles activated. Guards made differential use of their endothermic capacity. Mean thorax temperature was 34.2–35.1°C during examination of bees but higher during fights with wasps (37°C) or attack of humans (38.6°C). They usually cooled down when examining bees whereas examinees often heated up during prolonged interceptions (maximum >47°C). Guards neither adjusted their thorax temperature (and thus flight muscle function and agility) to that of examined workers, nor to that of drones, which were 2–7°C warmer. Guards examined cool bees (<33°C) longer than warmer ones, supporting the hypothesis that heating of examinees facilitates odour identification by guards, probably because of vapour pressure increase of semiochemicals with temperature. Guards in the core of aggressive balls clinged to the attacked insects to fix them and kill them by heat (maximum 46.5°C). Bees in the outer cluster layers resembled normal guards behaviourally and thermally. They served as active core insulators by heating up to 43.9°C. While balled wasps were cooler (maximum 42.5°C) than clinging guards balled bees behaved like examinees with maximum temperatures of 46.6°C, which further supports the hypothesis that the examinees heat up to facilitate odour identification.     

Sexual Differences in Aggressive Behaviour of the Apennine Chamois

The aggressive behaviour of female and male Apennine chamois has been compared quantitatively. As opposed to what males did, females significantly attacked each other less often; preferred to gore body regions with a low risk of lethal injury, made a greater use of direct forms of aggression; seldom interacted with the opponent before attacking and gored it more often. Front clashing and fighting were very rare in both sexes. Females live in resident kin-groups, while young males disperse and adults are solitary. To a large extent habitat separation occurs between the sexes. Sexual differences in patterns of aggressive behaviour may be related to the different gregariousness of females and males, probably influenced by resource availability in the habitats they use. Chamois sexes are nearly monomorphic, females bearing slightly less hooked horns than males. This species may have evolved strongly hooked weapons as a first step to advanced wrestling or butting type horns from the ancestral stiletto shape, as goats and sheep, as well as deer, have done.     

Ontogeny of Aggressive Behaviour in Schools of Yellowtail, Seriola Quinqueradiata

We studied ontogenetic changes in social interactions, especially in aggressive behaviour of the migratory marine yellowtail, Seriola quinqueradiata (Carangidae), and compared these to morphological and physiological changes. No agonistic interactions were observed during the larva period until 10 mm in total length (TL), at approximately 20 days after hatching. Typical shivering behaviour with J-posture was observed during metamorphosis, when fin rays and calcification of vertebra were completed and there was an increase of tissue thyroid hormone. The onset of aggressive behaviour was just after metamorphosis to the juvenile period, and coincided with a significant increase in tissue cortisol levels. The onset of schooling behaviour was at 12 mm TL, slightly after the onset of aggressive behaviour. From observations of individual aggressive behaviour within juvenile schools, we found three categories of social rank: dominants (10-20%), intermediates (10-20%), and subordinates (60-80%). There was an inverse relationship between social rank and cortisol concentration. Otoliths of dominant fish in 8 experimental groups were labeled and the fish were returned to their groups. Six labeled dominants appeared after 1 day and three after 1 week rearing, respectively, indicating that social rank was maintained for at least 1 week (binomial distribution, p < 0.05). Dominants were larger than subordinates after 1 day rearing, whereas dominants were smaller after 1 week rearing. From long-term rearing experiments using individual otolith marking, larvae that showed the J-posture more frequently tended to become dominants after metamorphosis, indicating a positive correlation between the J-posture and aggressive behaviour. Synthesizing all results from behavioural experiments, we generated a behavioural model for the triggering mechanism of aggressive behaviour and size selection of school members.     

Indirect Genetic Effects and Housing Conditions in Relation to Aggressive Behaviour in Pigs

Indirect Genetic Effects (IGEs), also known as associative effects, are the heritable effects that an individual has on the phenotype of its social partners. Selection for IGEs has been proposed as a method to reduce harmful behaviours, in particular aggression, in livestock and aquaculture. The mechanisms behind IGEs, however, have rarely been studied. The objective was therefore to assess aggression in pigs which were divergently selected for IGEs on growth (IGEg). In a one generation selection experiment, we studied 480 offspring of pigs (Sus scrofa) that were selected for relatively high or low IGEg and housed in homogeneous IGEg groups in either barren or enriched environments. Skin lesion scores, a proxy measure of aggression, and aggressive behaviours were recorded. The two distinct IGEg groups did not differ in number of skin lesions, or in amount of reciprocal fighting, both under stable social conditions and in confrontation with unfamiliar pigs in a 24 h regrouping test. Pigs selected for a positive effect on the growth of their group members, however, performed less non-reciprocal biting and showed considerably less aggression at reunion with familiar group members after they had been separated during a 24 h regrouping test. The enriched environment was associated with more skin lesions but less non-reciprocal biting under stable social conditions. Changes in aggression between pigs selected for IGEg were not influenced by G×E interactions with regard to the level of environmental enrichment. It is likely that selection on IGEg targets a behavioural strategy, rather than a single behavioural trait such as aggressiveness.     

单胺氧化酶B基因单核苷酸多态性与藏獒对陌生人攻击行为的关联分析

采用行为测试的方法,测定藏獒和拉布拉多犬在陌生人接近时的攻击行为差异,应用PCR-RFLP技术检测单胺氧化酶B(MAOB)基因第3外显子单核苷酸多态性,分析其在藏獒(陌生人接近时进行攻击)和拉布拉多犬(陌生人接近时无攻击行为)两个品种间基因型频率与基因频率分布差异.结果 表明:MAOB基因型频率与基因频率在两个品种中分布差异不显著(P＞0.05).x2适合性检验显示,藏獒处于Hardy-Weinberg极不平衡状态(P＜0.01),拉布拉多犬处于Hardy-Weinberg平衡状态(P＞0.05).藏獒和拉布拉多犬品种间,在陌生人接近时的攻击行为差异与MAOB基因T119C多态性可能无直接关系.     

The Effect of Submissive Experiences on Dominance and Aggressive Behaviour of Xiphophorus (Pisces,Poeciliidae)

• 1 Aus einer Gruppe junger Xiphophorus-Hybriden (X. helleri × X. maculatus) wurden 20 Fischpaare an aufeinanderfolgenden Tagen ausgewählt, so daß jedes Paar während eines Tages untersucht werden konnte. Die zwei Fische jeden Paares wurden zuerst für 45 Min. zusammengesetzt, um den dominierenden α-Fisch und den untergeordneten Ω-Fisch zu bestimmen. Nur in 15 Paaren entschied sich die Dominanz innerhalb dieses Zeitraums, bei sieben innerhalb 30 Min., wenn sie gefüttert wurden. Alle bildeten stabile Dominanzverhältnisse ohne Umkehrungen, außer in einem ziemlich zweifelhaften Falle.
• 2 Darauf wurden die α-Fische aus 8 Paaren (experimentellen Paaren) je zu einem größeren Fisch gesetzt, von dem sie einen ganzen Tag lang beherrscht wurden; die α-Tiere der 7 anderen Paare kamen (Kontrollpaare) zu einem kleineren, der ihnen niemals überlegen war. (Täglich entschied das Los, ob ein Paar eine experimentelle (E) oder eine Kontroll-(C) Behandlung bekommen sollte, so daß die 8 E- und 7 C-Paare statistisch äquivalent waren.) Die 5 übrigen Paare wurden nicht weiter für das Experiment gebraucht. Nach einem Tag wurden die α-Fische wieder ins selbe Aquarium gesetzt wie zuerst, zusammen mit ihren α-Partnern, die inzwischen in einem anderen Aquarium isoliert gewesen waren. Der einzige statistisch gesicherte Effekt war, daß die früheren Ω-Fische nach einer schweren E-Behandlung ihrer α-Partner in signifikant mehr Fällen anzugreifen begannen als nach einer C-Behandlung der α-Partner.
• 3 Andere Experimente über den Einfluß von Subordinationserfahrungen auf die Dominanz werden besprochen. Die Ergebnisse werden nach einer Hypothese interpretiert, die wechselseitige positive Einflüsse zwischen dem Flucht- und dem Angriffsverhalten annimmt und die den meisten Dominanzverhältnissen in Tiergruppen zugrunde liegen kann.

     

Sexual and Aggressive Behaviour in Species Hybrids of Poecilia mexicana and Poecilia velifera (Pisces,Poeciliidae)

The inheritance of sexual behaviour patterns was studied in species hybrids of Poecilia mexicana and Poecilia velifera. In addition, the aggressive behaviour and some morphological characters have been investigated and checked for a possible correlation between and within these three different traits studied. All the characters are inherited polygenically. The minimum genetic factors could be estimated only for some characters.     

Hiding Behaviour of Long-tailed Macaques (Macaca fascicularis): II. Use of Hiding Places during Aggressive Interactions

In an observational study on captive long-tailed macaques ( Macaca fascicularis ), the ability to hide was investigated in the social context of aggression. The use of five different types of hiding place during highly aggressive interactions was recorded and the choices of six different rank-sex classes were compared using an index of attractiveness of the different types of hiding place during highly aggressive interactions. There was no significant difference between the rank-sex classes in selection of the hiding places that could be connected with visibility: no specific location or type was preferred, either by the group as a whole or by any specific rank-sex class. Thus long-tailed macaques do not seem to hide shortly after aggressive interactions.     

Aggressive Behaviour Between Gymnocharacinus Bergi (Pisces, Characidae) And Other Neotropical Fishes From A Thermal Stream In Patagonia

Gymnocharacinus bergi is a stenothermal endangered fish only found in the headwaters of a thermal stream within the temperate Somuncurá Plateau (Patagonia, Argentina). In spite of the presence of other fish species in the Valcheta Stream basin, none of these has been found at the headwaters. Temperature and salinity cannot account for the absence of extremely eurytopic Cnesterodon and Jenynsia. In addition, there is no evidence of diet overlapping or territory defence between these species and G. bergi. Therefore, we hypothesise that agonistic behaviour might be related to G. bergi's isolation. Experiments were performed in order to analyse interspecific interaction between G. bergi and individuals of the other two species. Cnesterodon decemmaculatus showed a submissive behaviour while Jenynsia multidentata was clearly aggressive. G. bergi decreased its aggressive behaviour towards C. decemmaculatus throughout the experiment. However, when placed with J. multidentata, its aggressive behaviour did not diminish. We suggest that the characteristics of the agonistic behaviour displayed by J. multidentata, opposite from those displayed by C. decemmaculatus, might account for the absence of J. multidentata in G. bergi's present habitat. With respect to C. decemmaculatus, other factors such as its low counter current swimming ability might play a major role in this phenomenon.     

Structural and Functional Alterations in Right Dorsomedial Prefrontal and Left Insular Cortex Co-Localize in Adolescents with Aggressive Behaviour: An ALE Meta-Analysis

Recent neuroimaging work has suggested that aggressive behaviour (AB) is associated with structural and functional brain abnormalities in processes subserving emotion processing and regulation. However, most neuroimaging studies on AB to date only contain relatively small sample sizes. To objectively investigate the consistency of previous structural and functional research in adolescent AB, we performed a systematic literature review and two coordinate-based activation likelihood estimation meta-analyses on eight VBM and nine functional neuroimaging studies in a total of 783 participants (408 [224AB/184 controls] and 375 [215 AB/160 controls] for structural and functional analysis respectively). We found 19 structural and eight functional foci of significant alterations in adolescents with AB, mainly located within the emotion processing and regulation network (including orbitofrontal, dorsomedial prefrontal and limbic cortex). A subsequent conjunction analysis revealed that functional and structural alterations co-localize in right dorsomedial prefrontal cortex and left insula. Our results are in line with meta-analytic work as well as structural, functional and connectivity findings to date, all of which make a strong point for the involvement of a network of brain areas responsible for emotion processing and regulation, which is disrupted in AB. Increased knowledge about the behavioural and neuronal underpinnings of AB is crucial for the development of novel and implementation of existing treatment strategies. Longitudinal research studies will have to show whether the observed alterations are a result or primary cause of the phenotypic characteristics in AB.     

Aggressive howling in wolves

During two studies that investigated the responses of wolf packs to either human simulations or pre-recorded playbacks of wolf, Canis lupus, howling, single adult wolves from five different packs approached my location and howled on a total of six occasions. The howls uttered by these close-approaching wolves were significnatly deeper in pitch than comparable samples of howls recorded from animals that did not approach. In addition, howls of two of the five animals differed in structure from most of the other howls recorded during both studies. These close-approach howls were characterized by the presence of harmonically unrelated frequency sidebands near the end of the howl. This feature was rate in howls recorded during occasions when wolves kept their distance. These results indicate that the structure of wolf howling during aggressive interactions with strange wolves follows Morton's (1977) motivation-structural rules, which state that natural selection will favour the use of low-frequency, harsh sounds by hostile animals. This relationship follows from the physical constraints of vocal production: animals of larger size can produce sounds of lower pitch and harsher tonal quality. As body size is a primary determinant in the outcome of aggressive interactions, vocalizations signalling size (i.e.low-pitched, harsh sounds) will be of selective value for individuals engaged in aggressive interactions.     

Epigenetics of Aggressive Behavior

Russian Journal of Genetics - Multiple studies demonstrating the association of aggressive behavior with allelic variants of neurotransmitter system genes appear to be controversial, while...