Search results for "Agonistic behaviour"

Testosterone-Mediated Effects on Fitness-Related Phenotypic Traits and Fitness

2009

International audience; The physiological and behavioral mechanisms underlying life-history trade-offs are a continued source of debate. Testosterone (T) is one physiological factor proposed to mediate the trade-off between reproduction and survival. We use phenotypic engineering and multiple laboratory and field fitness-related phenotypic traits to test the effects of elevated T between two bank vole Myodes glareolus groups: dominant and subordinate males. Males with naturally high T levels showed higher social status (laboratory dominance) and mobility (distance between capture sites) than low-T males, and the effect of T on immune response was also T group specific, suggesting that behav…

The role of male coloration in the outcome of staged contests in the European common wall lizard (Podarcis muralis)

2016

Colour signals play a key role in regulating the intensity and outcome of animal contests. Males of the common wall lizard (Podarcis muralis) show conspicuous ventrolateral ultraviolet (UV)-blue and black patches. In addition, some populations express a striking ventral colour polymorphism (i.e., discrete orange, white and yellow morphs). In this study, we set out to evaluate the potential signalling function of these colour patches by staging pairwise combats between 60 size-matched adult lizards (20 per morph). Combats were held in a neutral arena, with each lizard facing rivals from the three morphs in a tournament with a balanced design. We then calculated a fighting ability ranking usi…

Effects of acute administration of nicotine and lobeline on agonistic encounters in male mice

2000

The effects of acute administration of two nicotinic ligands, (-)-nicotine and (-)-lobeline were examined on isolation-induced aggression in mice. Individually housed male mice confronted anosmic “standard opponents” in a neutral arena 10 min after drug administration. Encounters were videotaped and evaluated using an ethologically based analysis facilitating estimation of time allocated to 11 broad behavioral categories. Nicotine did not have significant effects on threat or attack but significantly diminished time allocated to digging. The lowest dose of lobeline significantly diminished attack and induced a slight increase of immobility without significantly diminishing other behaviors w…

Female-female aggression and male polyterritoriality in the pied flycatcher

1994

Physiological and agonistic behavioural response of Procambarus clarkii to an acoustic stimulus

2012

Summary This study examined the effects of an acoustic stimulus on the haemolymph and agonistic behaviour of the red swamp crayfish Procambarus clarkii. The experiment was conducted in a tank equipped with a video recording system using 6 groups (3 control and 3 test groups) of five adult crayfish (30 specimens in total). After one hour of habituation, the behaviour of the crayfish was monitored for two hours. During the second hour, the animals in the test groups were exposed to a linear sweep (frequency range 0.1-25 kHz; peak amplitude 148 dBrms re 1 µPa at 12 kHz) acoustic stimulus for 30 minutes. Exposure to the noise produced significant variations in haemato-immunological parameters a…

Do Pied Flycatcher Females Defend an Extra Nest Hole Against Conspecific Females?

1999

AbstractIn birds, females are often aggressive against conspecific females during the breeding. There are many explanations for this intrasexual aggression by females: e.g., nest site or food resource defence, prevention of intraspecific brood parasitism or infanticide, and monopolization of paternal care. A pair might also benefit by defending an alternative nest site in addition to the current nest site. Here, I study by experimentation whether pied flycatcher (Ficedula hypoleuca) females defend an extra nest box as an alternative nesting site. Further, I examine whether females behave differently when their mate is present vs not present. I measured the reactions by resident females to a…

AGONISTIC INTERACTIONS IN A LIOLAEMUS LIZARD: STRUCTURE OF HEAD BOB DISPLAYS

2007

Males from different iguanian lizard species engage in frequent visual signaling during agonistic interactions, mainly by displaying head bobs. We conducted a detailed study of the structure of head bob displays mediating male agonistic interactions in Liolaemus lemniscatus lizards. We staged pair-wise encounters where one male, the intruder, was placed in the terrarium of a conspecific male, the resident. During these interactions, males exhibited only one type of head bob display made up of three distinct units: a low amplitude bob (unit 1), a brief pause (unit 2), and two consecutive high-amplitude bobs (unit 3). Head bob displays occurred singly or as a part of a bout, with a mean numbe…

Effects of several degrees of chronic social defeat stress on emotional and spatial memory in CD1 mice

2015

In the present study, the effects of several degrees of CSDS (Chronic Social Defeat Stress) on emotional and spatial memory in mice were evaluated in separate experiments. Male CD1 mice were randomly assigned to four experimental groups (n=10-12) for each experiment: NS (non-stressed), S5, S10 and S20 (5, 10 and 20 sessions of CSDS, respectively). The S groups underwent the corresponding number of agonistic encounters (10min each) over a 20-day period. 24h after the last session of CSDS, mice performed the inhibitory avoidance (Experiment 1) or the Morris water maze test (Experiment 2). In both experiments, animals were also evaluated in the elevated plus maze for 5min to obtain complementa…

Effects of acute social stress on the conditioned place preference induced by MDMA in adolescent and adult mice

2014

Exposure to social defeat stress increases the rewarding effects of psychostimulants in animal models, but its effect on 3,4-methylenedioxymethylamphetamine (MDMA) reward has received little attention. In the present study, we evaluated the influence of social defeat on the rewarding effects of MDMA in adolescent [postnatal day (PND) 29-40] and adult (PND 50-61) male mice using the conditioned place preference paradigm. Experimental mice were exposed to social defeat in an agonistic encounter before each session of conditioning with 1.25 or 10 mg/kg of MDMA. The effects of social defeat on corticosterone levels and the motor or the anxiogenic effects of MDMA were also evaluated. Mice expose…

Inhibitory avoidance learning in CD1 mice: Effects of chronic social defeat stress

2015

Chronic social defeat stress (CSDS) is an animal model widely used to determine the neurobiological mechanisms of stress and its associated pathologies. In this study, the effects of CSDS on inhibitory avoidance (IA) were evaluated in post-pubertal and adult male CD1 mice, instead of the C57BL/6J strain used in the CSDS standard protocol. CSDS consisted of daily 5-min (experiments 1 and 2) or 10-min (experiment 3) agonistic encounters on 21 consecutive days. Twenty four hours after the last session of CSDS, all the mice were tested for IA. They were also evaluated in an elevated plus-maze, obtaining complementary measures of locomotor activity and emotionality. In experiments 1 and 2, IA le…