Male Territoriality in the Bumblebee Wolf,Philanthus bicinctus (Mickel) (Hymenoptera,Sphecidae): Observations on the Behaviour of Individual ♂♂

Observations were made on the behaviour of male Philanthus bicinctus (Mickel) which defend territories around the nesting burrows of ♀♀. ♂♂ were individually identified with small number tags and focal-animal samples were taken of the behaviour of these ♂♂. Intense interactions were observed between territorial ♂♂ and 1) conspecifics and 2) intruding insects which resembled conspecifics. Evidence is presented which suggests that ♂♂ scent mark their territories.     

Effects of female body size and age and male mating status on male combat in Anastatus disparis (Hymenoptera: Eupelmidae)

1. Aggressive behaviour is widely exhibited by animals to acquire important resources and usually shows a dangerous or nondangerous pattern. Dangerous fighting patterns are usually characterized by fights ending with contestants being severely injured or killed. Resource value is an important nonstrategic factor influencing fighting behaviour. Studies of many species addressing nondangerous fighting behaviour have shown that when resource values change, organisms usually adjust their fighting behaviour accordingly. Only a few species show dangerous fighting patterns. Thus, few relevant studies have addressed how variation in resource value affects aggression with a dangerous fighting pattern. 2. Here, an egg parasitoid wasp, Anastatus disparis, which exhibits a dangerous fighting pattern to acquire mating opportunities, was used as an experimental model to study the adjustment of fighting behaviour resulting from a change in resource value. 3. Our results show that the female properties of body size and age affect their objective resource value and that males increased their fighting intensity for relatively large and young females. However, male mating status in A. disparis may not influence the subjective value of mate resources, and fighting intensity did not significantly differ between mated and virgin males. In addition, the number of times a male had previously mated had no significant effect. These results suggest that mating opportunities are important for both virgin and mated males, resulting in neither of them showing any adjustment in fighting for mating opportunities. 4. Generally, A. disparis males with extreme fighting patterns adjust their fighting behaviour according to the variation in resource value, which avoids the meaningless costs of injury and death.     

Interspecific Communication in Fiddler Crabs: Preliminary Report of a Female Rejection Display Directed toward Courting Heterospecific ♂♂

A newly described display is apparently used by female fiddler crabs (genus Uca) in interspecific communication. The display, termed repetitive-high-rise, is directed primarily toward courting heterospecific ♂♂, which approach or are likely to approach the ♀. We postulate that the display serves to indicate the ♀'s unavailability to these ♂♂ for mating. The ♂♂ respond appropriately by ceasing their approach toward displaying ♀♀. Both reproductively receptive and unreceptive ♀♀ were observed to perform this display. ♀♀ appeared to be able to discriminate, not only between conspecific ♂♂ and heterospecific ♂♂, but also among ♂♂ of heterospecific species. The possible significance for this ability is discussed.     

The evolution of social behaviour in sentinel crabs (Macrophthalmus): implications from molecular phylogeny

Crabs of the genus Macrophthalmus are known to exhibit highly developed and diverse social behaviour, such as allocleaning, fighting and waving display behaviour, the first being observed widely throughout the genus. Fighting behaviour between males has been classified previously into grasping fighting and claw‐extending fighting, and male waving display into four patterns, the vertical non‐forward‐pointing type, vertical forward‐pointing type, lateral non‐forward‐pointing type and lateral forward‐pointing type, on the basis of interspecific behaviour comparisons. To understand the evolutionary pathways of these social behavioural activities, 978‐bp nucleotide sequences from mitochondrial 16S rRNA genes of 21 species, including two outgroup taxa, were analysed and a molecular phylogeny was reconstructed. The resultant tree demonstrated striking inconsistencies with the relationships inferred from morphological features. Species with similar habitat conditions showed similar morphological features, although they were not phylogenetically close relatives. Phylogenetic analysis of allocleaning behaviour suggested that it evolved once in the early history of the lineage. The analysis of fighting behaviour demonstrated that species with claw‐extending fighting, being a more complex behaviour than grasping fighting, are found in the most ancestral part of the phylogeny. The analysis also revealed that claw‐extending fighting has evolved secondarily on two occasions, suggesting that fighting behaviour is not characterized by sufficient phylogenetic components. The superimposition of a waving pattern on to the phylogeny indicated that the lateral non‐forward‐pointing type has evolved from the vertical non‐forward‐pointing type, the lateral forward‐pointing type having evolved from the vertical forward‐pointing type. This scenario also appeared reasonable with respect to the behavioural trends of cheliped movements in waving. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 88 , 45–59.     

The Organization of Slave Raids in Dulotic Ants — a Comparative Study (Hymenoptera; Formicidae)

Slavemaking occurs in 8 genera or ants belonging to 2 subfamilies. Their raiding behaviour is described and compared. The basic organisation of a raid comprises scouting, recruitment, fight, and brood transportation. These elements can ordinarily be derived from the behaviour of the independent host species. Certain trends in the evolution of recruitment and fighting behaviour are discussed. “Intraspecific slavery”, which has been described by various authors, probably belongs to territorial behaviour. We doubt whether it represents an evolutionary precursor of true, interspecific slavery.     

Honesty of agonistic signalling and effects of size and motivation asymmetry in contests

Game theoretical models predict that the main function of fighting behaviour is to assess the relative fighting ability of opponents. The sequential assessment game has often been used to investigate contests, while honest signalling theory has received much less attention. With the wolf spider Hygrolycosa rubrofasciata we investigated whether male agonistic signalling can reveal honest information about fighting ability, and how size and motivation asymmetries affect male fighting behaviour. We also determined whether male–male competition affects the courtship behaviour of the males. We found that agonistic drumming activity is an honest indicator of male fighting ability, and that relative size asymmetry and motivation to fight both contribute to the fighting ability. We also found that male–male competition decreases the courtship drumming rate of subdominant males, suggesting that male–male competition limits the opportunities for female choice. We conclude that sequential assessment and honest signalling may both be used in settling contests, and that they may be used simultaneously. Received: 10 December 1998 / Received in revised form: 23 June 1999 / Accepted: 5 July 1999     

Decision Making and Assessment in the Fighting Behaviour of Nannacara anomala (Cichlidae,Pisces)

Predictions from ESS-theory concerning assessment of fighting ability and decision making are tested using a cichlid fish Nannacara anomala. Pairs with a pronounced difference in weight were allowed to interact. Fight duration increased when the difference in weight between the contestants decreased and the probability of an escalation from tail-beating to mouth-wrestling also increased when the weight difference decreased. Despite the fact that weight difference very well predicts the outcome of fights in this species it was found that fishes weighing less than 50 % of the opponent engaged in fighting, which suggests that visual assessment alone provides only limited information about relative fighting ability. The possible functions of various behaviour patterns are discussed in relation to assessment and escalation.     

Ontogenie und Funktion der Rangordnung innerhalb einer Geschwisterschar von Graugänsen (Anser anser L.)

Between the siblings of a family of greylag geese (Anser anser L.) a rank order is established by fighting during the first days after hatching, and also by other, more complex interactions. The position of each goose in the rank order can be defined by three groups of behaviour patterns (aggressive behaviour, “greetings”, escape responses). A clear-cut ranking relation between two individuals is a prerequisite for their close cohesion. The survival function of rank order lies in diminishing the intensity and frequency of agonistic interactions, in diminishing social stress situations and in guaranteeing the close family cohesion.     

Detailed analysis of fighting in polecats (Mustelidae) using ciné film

The phenomenon of fighting was investigated under laboratory conditions using polecats ( Mustela putorius, M. furo and interspecific hybrids). Diadic interactions between male polecats were recorded on 16 mm cine film in an unfamiliar area of 16 m², one individual having been introduced ten minutes before its opponent.
The behaviour patterns involved in fighting are described and their frequencies of occurrence, duration and average bout lengths specified. Biting, which occupied 41% of the animal's time in fighting, and attacking, which made up 27% of the bouts of behaviour, were the most important actions involved in fighting. Polecats most commonly bite their opponent's neck and bites in this region were the longest in duration. Success in gaining a bite was influenced by the opponent's behaviour at the time of the attack.
Polecats fight when one individual bites its opponent and the opponent retaliates by biting; bite was shown to be the commonest response to being bitten. The length of a fight appears to be determined by the levels of motivation to bite of the two opponents, while biting and being bitten operate as a positive feed back mechanism. The fight terminates when the more aggressive opponent ceases to make spontaneous attacks. The reasons why one individual wins a fight are that it consistently spends more time than its opponent in biting, it persists for longer in making spontaneous attacks and its method of attacking is more efficient.     

Shared Fantasies and Elite Politics: The Sri Lankan ‘Insurrection’ of 1971

The conventional view that the 1971 Sri Lankan insurrection was a highly organized and centrally directed attempt by a Marxist conspiratorial party (Janata Vimukti Peramuna) to seize State power is both partial and incomplete. Partial, because it incorporates the urban bias inherent in Political Science and thus ignores significant aspects of the insurrection, such as the purely rural locus of the fighting. Incomplete, because it requires ad hoc explanations to account for the supposed success of the JVP in attracting rural supporters. An alternative interpretation, based on fieldwork at the time, is that the insurrection was the product of post-war processes of rural class formation.     

Nest defence in a stingless bee: What causes fighting swarms in Trigona carbonaria (Hymenoptera, Meliponini)?

The Australian stingless bee Trigona carbonaria sometimes displays a striking collective behaviour, known as a ‘fighting swarm’ in which thousands of workers fight and die. Molecular analysis of eight naturally-occurring fights showed they almost always comprise just two colonies, one of which is located within 2 m of the fight. Fighting swarms were experimentally triggered by manipulating colonies so that they received non-nestmate workers. Combined, our investigations suggest that T. carbonaria fighting swarms arise as a collective defence of the nest from conspecific invasion (e.g. robbery or nest usurpation) Received 16 November 2007; revised 31 March 2008; accepted 1 July 2008.     

Theaflavin‐3,3´‐digallate increases the antibacterial activity of β‐lactam antibiotics by inhibiting metallo‐β‐lactamase activity

Metallo‐β‐lactamases (MBLs) are some of the best known β‐lactamases produced by common Gram‐positive and Gram‐negative pathogens and are crucial factors in the rise of bacterial resistance against β‐lactam antibiotics. Although many types of β‐lactamase inhibitors have been successfully developed and used in clinical settings, no MBL inhibitors have been identified to date. Nitrocefin, checkerboard and time‐kill assays were used to examine the enzyme behaviour in vitro. Molecular docking calculation, molecular dynamics simulation, calculation of the binding free energy and ligand‐residue interaction decomposition were used for mechanistic research. The behaviour of the enzymes in vivo was investigated by a mouse infection experiment. We showed that theaflavin‐3,3´‐digallate (TFDG), a natural compound lacking antibacterial activities, can inhibit the hydrolysis of MBLs. In the checkerboard and time‐kill assays, we observed a synergistic effect of TFDG with β‐lactam antibiotics against methicillin‐resistant Staphylococcus aureus BAA1717. Molecular dynamics simulations were used to identify the mechanism of the inhibition of MBLs by TFDG, and we observed that the hydrolysis activity of the MBLs was restricted by the binding of TFDG to Gln242 and Ser369. Furthermore, the combination of TFDG with β‐lactam antibiotics showed effective protection in a mouse Staphylococcus aureus pneumonia model. These findings suggest that TFDG can effectively inhibit the hydrolysis activity of MBLs and enhance the antibacterial activity of β‐lactam antibiotics against pathogens in vitro and in vivo.     

Stages in Formation of Social Relationships — An Experimental Investigation in Kangaroos (Macropodoidea: Mammalia)

A stage concept for the development of social relationships between unfamiliar individuals has been proposed by Kummer. This concept, originally derived from studies of Old World Primates, describes changes in developing relationships by types of interactive behaviour (fighting, presenting, mounting and grooming) that regularly occur in this sequence during the formation of dyads and triads. Kummer also formulated a set of rules predicting stage sequence, velocity, final stage, triadic and polyadic influences depending on individual status. The present investigation describes stages in the formation of relationships of macropodoids as well. Typical behaviour patterns for the sequence are avoidance, social exploration, aggression, one-sided amicable behaviour, mutual amicable behaviour and in some species social play. Transition to new, especially nonaggressive stages, was found to be initiated by higher status animals. Duration, number of skipped stages, inversions (rare events!) and highest stage reached per dyad depend on the participants' status and triadic/polyadic influences, as predictable by Kummer's proposed rules. A comparison of 3 species demonstrates the influence of socio-ecological factors that seem to be species-characteristic. The stages can thus be used to describe not only different qualities of individual relationships but also ‘social dispositions’ sensu Mason.     

Role of the olfactory pathway in agonistic behavior of crayfish, <Emphasis Type="Italic">Procambarus clarkii</Emphasis>

Crayfish establish social dominance hierarchies through agonistic interactions, and these hierarchies are maintained through assessment of social status. Chemical signals influence several aspects of fighting behavior, but the specific chemosensory sensilla involved in detecting these signals in crayfish are unknown. The goal of our study was to examine the importance of aesthetasc sensilla—olfactory sensors on the antennules of decapod crustaceans—in regulating changes in fighting behavior in crayfish, Procambarus clarkii, over the course of repeated pairings. We selectively ablated aesthetascs from pairs of crayfish after the first day of trials and compared the behavior of these ablated animals to that of pairs of intact controls. Results show that unablated crayfish significantly decreased the number and duration of fights over repeated pairings, whereas crayfish lacking aesthetascs continued to engage in similar amounts of fighting across all three trial days. This difference shows that aesthetascs regulate fighting behavior in P. clarkii.     

The coevolution of juvenile play–fighting and adult competition

Although play–fighting is widespread among juvenile mammals, its adaptive significance remains unclear. It has been proposed that play is beneficial for developing skills to improve success in adult contests (motor‐training hypothesis), but the links between juvenile play–fighting and adult aggression are complex and not well understood. In this theoretical study, we investigate the coevolution between juvenile play–fighting and adult aggression using evolutionary computer simulations. We consider a simple life history with two sequential stages: a juvenile phase in which individuals play–fight with other juveniles to develop their fighting skills; and an adult phase in which individuals engage in potentially aggressive contests over access to resources and ultimately mating opportunities, leading to reproductive success. The simulations track genetic evolution in key traits affecting adult contests, such as the level of aggression, as well as juvenile investment in play–fighting, capturing the coevolutionary feedbacks between juvenile and adult decisions. We find that coevolution leads to one of two outcomes: a high‐play, high‐aggression situation with highly aggressive adult contests preceded by a prolonged period of juvenile play–fighting to improve fighting ability, or a low‐play, low‐aggression situation in which adult contests are resolved without fighting and there is minimal investment in play–fighting before individuals mature. Which of these outcomes is favoured depends on the mortality costs and on the type of societal structure: societies with strong reproductive skew, favouring monopolization of resources, show high levels of adult aggression and high investment in juvenile play–fighting, whereas societies with low reproductive skew have both low adult aggression and low levels of play–fighting. A review of empirical evidence, particularly in the primate genus Macaca, highlights some limitations of our model and suggests that other, complementary functional explanations are needed to account for the full range of competitive and cooperative forms of play–fighting. Our study illustrates the power of evolutionary simulations to shed light on the long‐standing puzzle of animal play.     

The β3‐integrin endothelial adhesome regulates microtubule‐dependent cell migration

Integrin β3 is seen as a key anti‐angiogenic target for cancer treatment due to its expression on neovasculature, but the role it plays in the process is complex; whether it is pro‐ or anti‐angiogenic depends on the context in which it is expressed. To understand precisely β3's role in regulating integrin adhesion complexes in endothelial cells, we characterised, by mass spectrometry, the β3‐dependent adhesome. We show that depletion of β3‐integrin in this cell type leads to changes in microtubule behaviour that control cell migration. β3‐integrin regulates microtubule stability in endothelial cells through Rcc2/Anxa2‐driven control of active Rac1 localisation. Our findings reveal that angiogenic processes, both in vitro and in vivo, are more sensitive to microtubule targeting agents when β3‐integrin levels are reduced.     

The winner and loser effect: integrating multiple experiences

An important question in state-dependent behaviour is how multiple influences on state are integrated to determine current behaviour. Aggressive behaviour is known to be affected by a prior contest experience. Nevertheless, whether and how multiple prior fighting experiences are integrated into a fighting decision remain unexplored. In this study, individuals of Rivulus marmoratus (Cyprinodontidae), a hermaphroditic fish, were given different combinations of two prior fighting experiences to investigate: (1) the effect of penultimate experiences on the probability of winning a subsequent contest; (2) the relative effect of a recent win and loss; and (3) whether the effect of a winning experience was as short lived as observed in other species. Penultimate and recent fighting experiences were given to the test fish approximately 48 and 24 h prior to the dyadic contests, respectively. From the results of the five types of contests staged, we conclude that: (1) penultimate fighting experiences had a significant effect on the probability of winning a subsequent contest; (2) a more recent experience had a more pronounced effect than an earlier experience, which suggested that the effect of a fighting experience would decay and/or the effect of a recent experience would interfere with the effect of an earlier experience; (3) no asymmetric effect between a winning experience and a losing experience was detected; and (4) the effect of both a winning and a losing experience lasted for at least 48 h in R. marmoratus which was the maximum time tested in these experiments. The possible reasons for the differences in results among studies of experience effects on contest outcomes are discussed. Copyright 1999 The Association for the Study of Animal Behaviour.     

Sensorimotor gating and spatial learning in α7‐nicotinic receptor knockout mice

The role of acetylcholine and specific nicotinic receptors in sensorimotor gating and higher cognitive function has been controversial. Here, we used a commercially available mouse with a null mutation in the Chrna7^tm1Bay gene [α7‐nicotinic acetylcholine receptor (nAChR) knockout (KO) mouse] in order to assess the role of the α7‐nAChR in sensorimotor gating and spatial learning. We examined prepulse inhibition (PPI) of startle and nicotine‐induced enhancement of PPI. We also tested short‐ and long‐term habituation of the startle response as well as of locomotor behaviour in order to differentiate the role of this receptor in the habituation of evoked behaviour (startle) vs. motivated behaviour (locomotion). To address higher cognition, mice were also tested in a spatial learning task. Our results showed a mild but consistent PPI deficit in α7‐nAChR KO mice. Furthermore, they did not show nicotine‐induced enhancement of startle or PPI. Short‐ and long‐term habituation was normal in KO mice for both types of behaviours, evoked or motivated, and they also showed normal learning and memory in the Barnes maze. Thorough analysis of the behavioural data indicated a slightly higher degree of anxiety in α7‐nAChR KO mice; however, this could only be partially confirmed in an elevated plus maze test. In summary, our data suggest that α7‐nAChRs play a minor role in PPI, but seem to mediate nicotine‐induced PPI enhancement. We found no evidence to suggest that they are important for habituation or spatial learning .     

Demonstration of Strength and Concealment of Weakness in Escalating Fights of Male Swordtails (Xiphophorus helleri)

In the green swordtail (Xiphophorus helleri) confrontations between strange males regularly escalate to high levels of mutual Bites and Fin Grips, even between males differing greatly in size. The original expectation of early game theory models that the behaviours of the ultimate winners and losers are indistinguishable until shortly before the end of the fight could not be confirmed. A significant characteristic of loser behaviour is that the Biting rates are higher before and after escalation. Conversely, Fin Grips are more frequent in the ultimate winners than the losers. However, such behavioural differences are very poor predictors of the outcome of the fight from the viewpoint of a single fighting individual during the contest. Correct forecasts did not exceed 67%. The escalating fights of swordtails are considered as trials of strength in which the stronger male tries to demonstrate strength by the most costly behaviour pattern available, namely Fin Grips, and the weaker male conceals weakness quite successfully by countering with the same tactic and suppressing signs of weakness such as Avoidance behaviour.