Since fallow deer are polygynous species that congregate once every year, males must fight to obtain access to estrous females.
The relationship between antler size and body condition can be treated as indicators to reflect body condition within a given year.
These secondary sexual characteristics can have dual functions, which include the attractiveness of males which females can ultimately choose and fighting ability of the male.
It was found that males with larger antlers had higher mating success, where males with asymmetrical antlers did not.
When males develop their antlers, there are always trade-offs between reproduction and survival, which can shape the decision in an individual's choice.
Genetic variations exist within fallow deer populations with variable antler growth, males that exhibited faster-growing antlers early in life are able to grow longer antlers without any significant cost; this shows that there is, in fact, phenotypic variation among fallow deer populations.

Aggressive behaviour is often observed when individuals are seeking out mates, scarce resources, and even territories.
Species that compete using their weapons usually engage when there is a mutual agreement, but if there are any noticeable asymmetries such as a broken or lost weapon this may alter the behaviour of an individual to engage in a fight.
 Likelihood and severity of antler damage were looked at in fallow deer, to test whether antler damage was associated with contest tactics and duration, and if there was an association with the tendency for individuals to engage in fighting.
Individuals with undamaged antlers were more likely to attack, using high-risk tactics which included jumping, clashing, or backward-pushing behaviour, this was exhibited by both contestants; dominant males were more likely to have damaged antlers.
Dominance ranks exist within fallow deer populations, which can be linked to aggression level and body size; when competing for a male, however, how ranks are obtained is not studied extensively.
Since fallow deer are polygynous species that congregate once every year, males must fight to obtain access to estrous females. The relationship between antler size and body condition can be treated as indicators to reflect body condition within a given year. These secondary sexual characteristics can have dual functions, which include the attractiveness of males which females can ultimately choose and fighting ability of the male. It was found that males with larger antlers had higher mating success, where males with asymmetrical antlers did not. When males develop their antlers, there are always trade-offs between reproduction and survival, which can shape the decision in an individual's choice. Genetic variations exist within fallow deer populations with variable antler growth, males that exhibited faster-growing antlers early in life are able to grow longer antlers without any significant cost; this shows that there is, in fact, phenotypic variation among fallow deer populations.
Aggressive behaviour is often observed when individuals are seeking out mates, scarce resources, and even territories. Species that compete using their weapons usually engage when there is a mutual agreement, but if there are any noticeable asymmetries such as a broken or lost weapon this may alter the behaviour of an individual to engage in a fight.  Likelihood and severity of antler damage were looked at in fallow deer, to test whether antler damage was associated with contest tactics and duration, and if there was an association with the tendency for individuals to engage in fighting. Individuals with undamaged antlers were more likely to attack, using high-risk tactics which included jumping, clashing, or backward-pushing behaviour, this was exhibited by both contestants; dominant males were more likely to have damaged antlers. Dominance ranks exist within fallow deer populations, which can be linked to aggression level and body size; when competing for a male, however, how ranks are obtained is not studied extensively.
Fallow deer