Animals make social decisions to avoid or lessen the social transmission…
Animals make social decisions to avoid or lessen the social transmission of pathogens
Mechanisms of Social Avoidance are used as defenses to prevent pathogen transmission
Art of Pathogen Handling or Immunolocial Defenses
Social Avoidance (Most Important Factor)
Engage in fewer social interactions as part of a sickness response
Examples: Caribbean Spiny Lobsters avoid dens of infected individuals, immune challenged mice reduce their own rates of social contact by avoiding group members, Mandrills avoid grooming contaminated body regions (Romano et al, 2020)
Response: Animal species have a natural understanding of how to minimize the spread of a pathogen. They are able to sense and isolate themselves or the infected individual(s) by different layers of defenses to prevent transmission.
Changes in an individual status (informed and/or infected) influence social interactions. Those changes in social relationships lead to structural changes in the network that affects social transmission (Romano et al, 2020)
Infected individuals will have weak or no social relationships within the group. This is where social avoidance come into play. They are avoided by others or they reduce interaction rates on their own to limit the pathogen transmission.
Informed individuals will have the strong social relationships. Within the social groups, they are seen as valuable interacting partners, favoring information transmission.
Information and pathogen flow suggest social connectivity, with emergent patterns of social behavior and is a trade-off through a survival indicator (Romano,et al, 2020).
Increased information gain + decreased pathogen exposure = increased survival rate (Romano et al, 2020)
Decreased information gain + increased pathogen exposure = decreased survival rate (Romano et al, 2020)
Response: Social relationships and interactions are heavily influenced by the individuals status. Informed individuals are going to band together and form their own network vs infected individuals who will be isolated. A good example is of the self quarantining during the Covid epidemic. Individuals who are exposed or infected will be avoided and no interactions will occur. And informed individuals or family networks will use their defenses and will group together to stay healthy and reduce the risk of exposure.
Contact rates change between infected and non-infected individuals when a pathogen is introduced into a system and is detected. The network structure then changes, like more subgroups, which affects the efficiency or pathogen spread (Romano et al, 2020).
Primates and Parasites: an infection is detected (e.g. odor), contact decreases by use of aggresive behavior to keep infected individuals away, and the network structure changes to decrease the spread (Romano et al, 2020)
Communication systems in species can also change in relation to the contact rates from a targeted and local contact-based modality to a global or broader modality
Humans and Viruses: the infection is detected, information is spread by use of online info on a large scale, and those infected are isolated (Romano et al, 2020)
Ants and Fungus: the fungus is detected (e.g. chemical signals), the information is spread through pheromones, locally and globally to decrease contact, and the and the network is restructured (Romano et al, 2020)
Romano V, MacIntosh A, Sueur C. 2020. Stemming the Flow: Information, Infection, and Social Evolution. Trends in Ecology and Evolution.