Social behavior is defined as “interactions among individuals, normally within the same species, that are usually beneficial to one or more of the individuals”. This type of behavior is found in invertebrates and vertebrates and not just in animals with well-developed brain and nervous systems. The great evolution scientist Charles Darwin introduced the idea of thinking about social behaviors within animals species. He noted that “It is the best competitors within a species, the “fittest” individuals, that survive and reproduce.” It is often misconceived that social behavior always results in a mutually beneficial end, but scientists believe it is also apart of natural selection and can lead to competition, which corresponds to Darwin’s perspective on social behavior.
Social behavior can be categorized from altruistic and breeding/parental behavior to more specific behaviors like grooming and play. Although this behavior can be seen in many different species, animals in aggregations (group of individuals) have increased opportunities to interact.
Types Of Social Behaviors
Altruism is when an individual performs an action which is at a cost to themselves, but benefits, either directly or indirectly, without the expectation of reciprocity or compensation for that action. Altruism is considered a social behavior because it involves an interaction between 2 or more individuals.
In addition to benefiting others, altruism also lowers the helpers reproductive success, while increases the reproductive success of the individual being helped. You would think that being an altruistic individual would lower one’s fitness, because their reproductive success is lowered. You have to look at altruism at a group level, and without altruism species would go extinct. Having a large group of altruistic individuals will give them an advantage and enhance their reproductive success.
Examples of Altruism in Animals:
- Within the Australian Songbird species, only territory owners breed, and the rest help find food, take care of other offspring, etc. They are giving up their opportunity to reproduce and limit their fitness for the better of the group
- The Belding’s ground squirrel shows altruistic behavior by alarming the others when there is a predator around. This makes this individuals extremely susceptible to being caught by the predator, but gives the others a chance to get away
- Vampire bats show reciprocal altruism, in which blood meals from successful foraging bats will be regurgitated and shared with the unsuccessful individuals. The successful bats expect when they are unable to get food, another will share with them.
Breeding/ Parental Behavior
Breeding behaviors differ between different types of animal populations, but for every population there are specific behaviors and actions that the individuals preform. Breeding behavior can happen between male and female, male and male (to determine dominant male), and female and female. In some species, the females will get together during breeding season and form a social group among one another. In these groups they show parental behaviors such as looking after another individual’s young while the other searches for food. They can also use their group as defense, and protect the young from males who want to kill them in order to mate again. Regarding male species, they can form a group to chase the dominant male away, to increase mating success. Courtship is also shown as being a social behavior in regards to breeding. For example, Frigate birds get together and present their giant red throat sacs for around 20 Minutes. If the male has attracted a female, the female will fly and land next to the male.
Division of Labor
In many different species of animals certain jobs and tasks are taken on by certain individuals. These jobs could be reproducing, foraging, building and protecting. This social behavior is seen very frequently in insect colonies like bees and ants. Bee colonies consist of three different types of bees: workers, drones, and the queen. The worker bees are the majority of the colony and are sterile females, meaning they are unable to reproduce. These bees carry out a number off tasks in the hive such as care for the queen and offspring, clean the cells, build beeswax combs, and handle incoming nectar. The drones are the male bees in the colony and only are present during the spring and summer. Their role is to fertilize the queen during her mating flight, and die immediately upon fertilization. The queen bee is the only sexually developed female in the colony and her main function is reproduction. The queen can lay up to 1,500 eggs per day, and 250,000 per year. These three different tasks within the colony are essential to keeping the population alive. Other species like ants function similarly, building little societies to keep the population thriving.
Grooming and Playing
Grooming is a social behavior found among many different animals. This behavior consists of washing, picking, and smoothing of another individuals fur or skin with the intent of cleaning one another. The most common example is when chimps groom one another and is universal throughout the chimp population. Although the intent is cleanliness, there is relaxation and bonding involved with grooming.
Playing is a behavior that is sometimes hard to distinguish between aggressive behavior. Typically playing behavior in animals consists of interactions that involve locomotion such as climbing, running, and chasing. These individuals are not fighting, but it could lead to competitive behavior.
Scientists and researchers are so intrigued with observing the social interactions animals have with one another and try and understand the underlying reasons of why different behaviors happen. Social behaviors are observed in many different ways using continuous sampling (watching one animal or subgroup and recording all of their activities for a pre-determined amount of time) and instantaneous sampling (watching one animals or a group and recording what the animals is doing at pre-set intervals). Its hard to determine what exactly these behaviors mean, but by making hypothesis and predictions we can formulate answers.