Related Experiment Video
Updated: Jun 20, 2026
06:24
Individual Culturing of Tigriopus Copepods and Quantitative Analysis of Their Mate-guarding Behavior
Published on: September 26, 2018
Aggressive behavior and performance in the Tegu lizard Tupinambis merianae
Anthony Herrel1, Denis V Andrade, José Eduardo de Carvalho
1Département d'Ecologie et de Gestion de la Biodiversité, 57 rue Cuvier, Case postale 55, 75231, Paris Cedex 5, France. anthony.herrel@mnhn.fr
Physiological and Biochemical Zoology : PBZ
|September 18, 2009
Summary
Larger lizards with stronger bite forces are more aggressive, showing a trade-off between fighting and fleeing. This physical performance in lizards may influence resource competition and predator defense.
Area of Science:
- Animal behavior
- Evolutionary biology
- Physiology
Background:
- Aggression is vital for resource competition in animals.
- Hormonal and neurological factors influencing aggression are well-studied.
- The link between physical performance and aggression is less understood.
Purpose of the Study:
- To investigate the relationship between physical performance (bite force) and aggression in a sexually dimorphic teiid lizard.
- To determine if higher bite force correlates with increased aggressive behavior towards perceived threats.
Main Methods:
- Utilized a large, sexually dimorphic teiid lizard species for the study.
- Measured bite force as an indicator of physical performance.
- Assessed aggressive responses towards an approaching human threat.
Main Results:
- Larger body size and higher bite force were positively correlated with increased aggression, irrespective of sex.
- Individuals with greater bite force exhibited reduced escape responses and slower movement.
- A trade-off between "fight" (aggression) and "flight" (escape) abilities was observed.
Conclusions:
- Physical performance, specifically bite force, is a significant predictor of aggression in this lizard species.
- Enhanced "fight" capabilities may be linked to reduced "flight" responses, suggesting an adaptive strategy.
- Large body size and strong bite force may lower the threshold for engaging in aggressive encounters, aiding resource acquisition and predator defense while minimizing injury risk.
Related Concept Videos
02:39Predator-Prey Interactions
Predators consume prey for energy. Predators that acquire prey and prey that avoid predation both increase their chances of survival and reproduction (i.e., fitness). Routine predator-prey interactions elicit mutual adaptations that improve predator offenses, such as claws, teeth, and speed, as well as prey defenses, including crypsis, aposematism, and mimicry. Thus, predator-prey interactions resemble an evolutionary arms race.Although predation is commonly associated with carnivory, for...
01:20Mate Choice
Mate choice—the decision about whom to mate with—is a type of natural selection, since animals must reproduce to pass down their genes. Mate choice is also called intersexual selection because the behavior occurs between the sexes.
01:06Fixed Action Patterns
A fixed action pattern (FAP) is a specific, hard-wired sequence of behaviors that occurs in response to an external stimulus, called a sign stimulus. The behavior is “fixed” because it is essentially unchangeable—proceeding similarly across individuals of a species every time it occurs.
01:47Aggression
Humans engage in aggression when they seek to cause harm or pain to another person. Aggression takes two forms depending on one’s motives: hostile or instrumental. Hostile aggression is motivated by feelings of anger with intent to cause pain; a fight in a bar with a stranger is an example of hostile aggression. In contrast, instrumental aggression is motivated by achieving a goal and does not necessarily involve intent to cause pain (Berkowitz, 1993); a contract killer who murders for hire...
01:46Types of Selection
Natural selection influences the frequencies of particular alleles and phenotypes within populations in several different ways. Primarily, natural selection can be directional, stabilizing, or disruptive. Directional selection favors one extreme trait and shifts the population towards that phenotype while selecting against individuals displaying alternate traits. Stabilizing selection favors an intermediate trait with a narrow range of variation. Deviation from the optimal phenotype towards an...