This model is an attempt to mimic the flocking of multiple agent types. The resulting motion also resembles the flocking effect in birds and schools of fish. Agents within each species are homogeneous, i.e. no leader is pre-designated to guide the motion, rather it is the local interaction between the neighbours that sets the motion.
The flocking model was first introduced by Craig Reynolds in 1986 [1]. Three rules typically "separation", "alignment" and "cohesion" is used to make the flocking movement.
The simulation shown here-in is an attempt to extend the flocking model developed by Reynolds. It analyses how the presence of multiple species affects flocking motion.
In this simulation, there are two types of agents: red agents and white agents. Each agent type follows three principle steering behaviours. In addition to it, the heterospecific attraction between the two types of agents govern the interaction between the two agent types.
The model is inspired by mixed species flocking visible in nature. Mixed species flocking is commonly visible in forests where different species of birds are available.
It is hypothesized that mixed species flocking takes place as a means of predator defence. The most popular hypothesis, in fact, is that mixed species flocking improves foraging efficiency. However this is true provided the birds have the same sort of diets and also that the species do not compete over food and in condition where food depletion is not at a risk.
It is envisaged that the model would be of much importance in the area of swarm robotics and agent based systems. Still now, scientists and researchers are using the model of single species flocking in these areas. However we forsee that the model of mixed species flocking would be very valuable as this leads to increasing in flocking efficiency.
created with NetLogo
view/download model file: mixed-species-flocking.nlogo
The rules are the same as that of the Reynolds.
However we have introduced an extra parameter called "heterospecific attraction". Heterospecific attraction is the attraction between two different agent types - in this case the attraction between red-agents and white-agents.
setup - Use this button to setup the initial position of the agents
go - Use this button to run the simulation
scatter - Use this button to randomly scatter the agents
red-agents - Determines the number of red-agents
vision-angle - Determines the angle of vision of red-agents. For example if vision-angle is 60 deg. the red-agent can see 30 deg to its left and 30 deg to its right
vision-depth - Determines the number of patches the red-agents can see
min-separation - The minimum amount of separation allowed
max-align-turn, max-cohere-turn, max-separate-turn - The maximum angle the agents can align, cohere and separate
white-agents - The number of white agents
angle - Determines the angle of vision of white agents
vision - Determines the number of patches the white agents can see
heterospecific-attraction - Determines the amount of inter-agent attraction
Observe how the flocking of the agents vary with the heterospecific-attraction
Flocking model in the Netlogo model Library
[1] Craig Reynolds https://www.red3d.com/cwr/boids/
[2] Flocking model in the netlogo model library