Optimal Foraging (Ants Behavior)

Ecologically, ants are known to display various foraging behaviors. These are adaptations to the environment aimed at overall survival. According to the optimal foraging theory, ants are predicted to attempt to maximize the amount of gained energy while reducing the amount of expended energy in obtaining food (White and Foster 617).This lab investigated foraging preferences of ants.

Literature review

When ants work in groups and find food, their foraging behavior is determined by the type of food and its location. There has been illustrations that in case while foraging the ants stumble upon huge amounts of food, some ants are sent back to the colony to recruit more ants instead of all the ants going back. This is probably in a bid to reduce energy needs. The experiment was set through the various sugar concentrations in order to determine their influence on the social behavior of ants. The outcome could be relied upon to confirm previous studies on animal social behavior as well as pheromones contributions on insects’ behavior (Sauteret al., 435).

Methodology

1% sugar solution was made by dissolving 1 gram of sugar in 100ml of water. 20% sugar solution was made by dissolving 20 grams of sugar in 100 ml of water. At least two of the smallest plastic foraging trays that were in the laboratory were obtained. An active ant colony was located. In experiment 1, one of the smallest plastic trays was placed approximately 10cm from the colony and was filled with the 1% sugar solution. The number of ants in contact with the feeding tray was recorded at one minute interval for 20 minutes. In experiment 2, experiment 1 was repeated; however, this time the trays were filled with 20% sugar solution and the trays placed slightly in a different location than where experiment 1 was performed. Again, the number of ants in contact with the tray was recorded in 1 minute intervals over the 20 minutes observation period. In experiment 3, the two trays were filled with 20% sugar solution, then one tray was placed 10 cm away from the colony entrance while the other was placed on the opposite side of the colony at 20cm. The number of foragers at each tray was recorded in 1 minute intervals over the 20 minute observation period.

Results

Discussion

Through the outcome, the enumerated ants were presented graphically as shown in the graph below for experiments 1, 2, and 3. The third experiment used two sets of food trays to investigate the food seeking behavior in relation to the position of the food.  The ants went to the food in the opposite direction because it was placed closer to them. The colony, therefore, chose the shortest distance to the food source.

The graph shows more attraction to the food source by the ants because of the concentration and short distance from the colony. Ants have the ability to quantify the food sources and determine whether to involve additional ants to be able to secure as much food as possible. Given the organised mode of securing food, the ants take the shortest time possible to acquire any available food (Tarniello210).

In experiment 1, the population of ants visiting the tray remained minimal for the first 11 minutes despite the small distance of the tray from the colony. This is due to the fact that the food provides less energy, and upon realising the small amount of food source, some ants resorted to explore further in a bid to acquire more food as some were left on the only available food source. Given the low concentration of sugar in this solution, the ants would spend more energy for a lowered amount of sugar or food acquired, hence non economical (Panaitm 35).

In experiment 2, despite the same distance, there were more ants visiting this tray given the higher concentration of sugar. The amount of ants visiting the trays increased consistently in all experiments as time increased. However, there was a drop in numbers being observed after the 15th minutes probably because the food resource is exhausted. In experiment 3, the numbers still rose as opposed to experiment 2; in experiment 3 there was the highest number of ants visiting the trays for up to over 50 ants in a minute at approximately 52nd minute.

Conclusion

From the experiment, collective foraging helps significantly in improving the food finding behavior of ants. Minimising the distance to a food source reduces the time and energy spent in foraging (Holldobler and Wilson 23). The result obtained from this study conforms to the optimal foraging theory that ants maximize the amount of gained energy by choosing food that has high energy levels while reducing the amount of expended energy in obtaining food by using the shortest distance possible to the food source. Food is a critical part of efficient foraging in the animals’ kingdom and, and acquisition could help explain the overall behavior of animals in an ecosystem (Montana 222).

Works cited

Holldobler, Belle, and Wilson, Edmund. The Ants.Harvard University Press. 1990

Montana, Danhof. Strongly typed genetic programming.Evolutionary Computation,3 (1995): 199-230.

Panaitm, Leah. Ant foraging revisited. Submitted to the Ninth International Conference on the Simulation and Synthesis of Living Systems,2004.

Sauter, John, Matthews Parunakand, Sander Brueckner. Evolving adaptive pheromone path planning mechanisms.In proceedings of first International Joint Conference on Autonomous Agents and Multi-Agent Systems,(2002): 434-440.

Tarniello, John. Ecology, evolution and division of labour in social insects.Animal Behaviour, 53 (1997): 209-213.

White, Pagurek, and Oppacher Foster. Improving the ant system by integration with genetic algoritms.Proceedings of the Third Annual Conference,(1996): 610-617.