Search results for "Dominance hierarchy"

The chemistry of competition: exploitation of heterospecific cues depends on the dominance rank in the community

2014

Interspecific competition is an important ecological mechanism shaping the traits of the interacting species and structuring their communities. Less competitive species benefit from evading direct encounters with aggressive dominants, whereas dominant species could use cues left by subordinates to steal their resources or to chase them off. Here, we studied competitive interactions among five common and syntopic ant species in Central Europe (Formica polyctena, Formica rufibarbis, Lasius niger, Myrmica rubra and Tetramorium caespitum) and investigated their ability to react to heterospecific chemical cues. Using aggression assays, we established a clear dominance hierarchy of these species,…

Social defeat and subordination as models of social stress in laboratory rodents: A review

1998

This paper is a review of the main research topics currently investigated in laboratory rodents using the stress of defeat or subordination as ethologically relevant models of social stress. First, the main characteristics of the resident/intruder paradigm and the colony models are given. Second, a general description of the behavioral, neuroendocrinological, physiological, neurochemical, neurological, and immunological responses found with these models, and their temporal dynamics, are discussed. Finally, the studies carried out that compare the response induced by social stress with that observed with more conventional models are also reviewed. It is concluded that these animal models of …

Improved growth performance in rainbow trout Oncorhynchus mykiss reared at high densities is linked to increased energy retention

2015

Abstract Behaviour has been suggested as an underlying factor influencing how rearing density affects growth performance in Salmonid fishes. At low densities there is an elevated intensity of aggressive interactions and the formation of dominance hierarchies. As density increases, it is commonly assumed that aggression decreases, as the cost and effort required to establish and maintain dominance hierarchies increase. The increased energy expenditure associated with aggressive interactions has been identified as one mechanism causing a reduced efficiency in feed utilisation and therefore decreased growth performance. Manipulating aggressive behaviour through density may have advantages from…

Beyond ‘nasty neighbours’ and ‘dear enemies’? Individual recognition by scent marks in a lizard (Podarcis hispanica)

2008

True individual recognition (TIR), the ability to recognize conspecific individuals on the basis of identity cues, is required for the evolution of several social traits (e.g. the maintenance of dominance hierarchies). However, knowledge about the distribution and functional significance of TIR is scant in some vertebrate groups, such as reptiles. In this study we used a functional modification of a habituation-dishabituation paradigm to investigate the existence and adaptive significance of TIR in a territorial lizard (Podarcis hispanica, Lacertidae). Males discriminated between individual rivals of similar characteristics (e.g. size, weight, familiarity) solely on the basis of their scent…

Egalitarian mixed-species bird groups enhance winter survival of subordinate group members but only in high-quality forests

2020

AbstractOnly dominant individuals have unrestricted access to contested resources in group-living animals. In birds, subordinates with restricted access to resources may respond to intragroup contests by acquiring extra body reserves to avoid periods of food shortage. In turn, higher body mass reduces agility and increases predation and mortality risk to subordinates. Birds often live in hierarchically organized mixed-species groups, in which heterospecific individuals are considered to substitute for conspecifics as protection against predators at a significantly reduced competition cost. Crested tits (Lophophanes cristatus) and willow tits (Poecile montanus) form mixed-species groups duri…

Attacks of songbirds in mixed‐species flocks by Eurasian Sparrowhawks: strategies of predators and potential prey

2020

Neuronal and neuroendocrine mechanisms of social rank and stress coping in teleost fish

2015

Fights for social dominance are stressful and results in an activation of the brain serotonergic system. Subordinate animals in an established dominance hierarchy are characterized by a chronic elevation of brain serotonergic activity, an effect that seems to mediate the behavioural inhibition observed in these animals. By contrast, social dominance has been associated with elevated dopaminergic activity, and dopamine (DA) has behavioural effects to some extent opposing those of serotonin (5HT). In addition to effects of the social environment, brain monoaminergic functions are controlled by genetic factors. For instance, zebrafish (Danio rerio) classified as bold, showing a propensity for …

Black Grouse leks on ice: Female mate sampling by incitation of male competition?

1995

Male-male competition is assumed to limit female choice of mates, but it may also help females to choose the most vigorous males. We studied the mate sampling behaviour of female black grouse (Tetrao tetrix) at spatially unstable leks on ice-covered lakes. In the absence of territories and site-dependence in outcomes of fights, the male dominance hierarchy is very evident on ice. When being courted by dominant males, females frequently tried to approach other males. This was frequently prevented because (1) the courting male and the approached male were involved in physical fight, or (2) the dominant male followed the female and the approached male escaped and avoided contact with him. Thes…

The genetic basis of balanced polymorphism in Philaenus (Homoptera)

2009

In Philaenus spumarius (Homoptera), colour polymorphism is mainly determined by a series of allelic genes. The dominance and co-dominance relationships of the following seven alleles were analysed: T (trilineatus), M (marginellus), F (flavicollis-F), L (lateralis), C (flavicollis-C, gibbus and leucocephalus), O (quadrimaculatus, albomaculatus and leucophthalmus) and t (typicus). The colour phenotypes are indicated in brackets. On the basis of partly direct and partly indirect evidence, T was found to be the top dominant and t the bottom recessive allele in the female sex. In the males, T is also the top dominant, but t comes second in the hierarchy. Conclusive evidence of the dominance of T…