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In the animal kingdom, life can sometimes be more like game of Thrones that Charlotte’s Web. Bloody conflicts over territory, mates, and more are common in social animals, and several species have their own anticipatory behaviors to prepare when a fight seems imminent. They remain quiet, monitor their surroundings, go on raids, and even bond with their allies through play and grooming.
According to a study published today in the journal Trends in ecology and evolutionEnvironmental cues and memories may indicate that it is time to prepare for war. These behaviors are so important that these preparations can affect the evolution of a species, population dynamics and even the structure of communities.
“Intergroup conflict is widespread throughout the natural world and is found in social species from ants to primates,” study co-author Andrew Radford, a behavioral biologist at the University of Bristol in the United Kingdom, said in a statement. “Studying other species experimentally and under natural conditions can not only expand our understanding of a pervasive aspect of sociality, but can also help provide insight into our own troubled ancestry.”
Battle Preparation is an Evolutionary Force
Conflict over resources needed by all animals exerts a powerful evolutionary force on a large number of social species, including several primates, meerkats (meerkat meerkat), several species of birds and, most obviously, humans. According to the team, this force potentially affects fitness and survival.
Humans prepare for war with increased vigilance, climbing to higher ground to gather information, conducting ambushes and raids, and silently spying on enemy territory to avoid detection. Groups of chimpanzees (Troglodyte bread) They tend to rest on hilltops in places where competitions between groups occur, rather than foraging, traveling, or other noisier activities. Experiments have also shown that dwarf mongooses (Helogale parvula) will move more slowly and adopt vigilance behaviors when they hear a rival’s vocal cues or pick up their scent to more easily monitor their surroundings.
“What is becoming very clear is that preventative behavior is widespread whenever intergroup conflict is encountered,” added study co-author and behavioral ecologist at the University of Bristol, Josh Arbon. “There is growing evidence that the amount of anticipatory behavior displayed depends on the current threat level. It is seen more when rivals are more likely to be encountered, are larger, less familiar, or more likely to attack.”
Territory, raids and gameplay.
A threat of intergroup conflict can also influence how animals use space. Dwarf mongooses deposit more territorial scent marks when they detect a rival nearby, while meerkats tend to mark by sniffing near burrows that intruders have explored. Black howler monkeys (alouatta caraya) will even return to locations from past contests, potentially as a way to signal their presence to neighbors. In contrast, Japanese macaques (macaca fuscata), chacma baboons (papio ursino), and long-tailed tits (Aegithalos caudatus) tend to avoid areas inhabited by rivals.
A more extreme conflict preparation behavior is to attack or actively seek out rivals in their own territory. Male chimpanzees silently invade neighboring territories in single file. They then move toward the vocalizations of other groups, potentially preparing to attack their rivals. Ringed mongooses engage in deadly gang attacks and even conduct raids to kill the offspring of their rivals.
When an external threat increases, various mammal species will respond by staying together. The chimpanzees groom and play with each other later in the collective defense of territory. These types of behaviors are likely to facilitate better communication, reduce anxiety, improve bonding, and promote stronger fighting strength.
“There is increasing evidence that non-human animals adjust various behaviors to enhance information gathering, incentivize participation in contests, reduce anxiety, and minimize collective and individual risk in anticipation of encounters with rival groups,” Arbon said. “What is notable is that these behaviors occur in a wide range of social species.”
Driving evolution
According to the team, future studies could evaluate how animals detect threat levels and adjust their preventive behavior. It’s also unclear how much brain power is associated with these preventive strategies.
“Intergroup conflict could be an important social driver of cognitive evolution,” says Radford. “But this remains a difficult idea to test, and disentangling the relative importance of memory cues and signals is challenging.”
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