Quiz 5: Primate Behavioral Ecology


In an effort to scientifically investigate hypotheses, the scientific method addresses the need to define the hypotheses, quantify and translate it into units of data, and finally, to develop tools to record the data. To gather data, a methodology must be in place and serve as a set of means used for data collection. • In quantitative methods, data is recorded in a standardized format such that the individual data can be compared across time and space. • In qualitative methods, data is not collected or recorded in a standardized format. Instead, qualitative data is utilized to enlighten the observer about the subject of their study. The difference between quantitative and qualitative methods is that quantitative data is the most effective type of data as it can be analyzed statistically to answer questions about hypotheses. Although qualitative data cannot be readily used statistically, they do fill in the gaps that may exist in quantitative data by adding context and additional insight about the subject. The differences between the two methods are important because both components, quantitative and qualitative, are essential and complement one another when understanding behavior.   For example, from the quantitative method, the data can provide information on how many times throughout the day, week or month, a group of Chimpanzees gather at a watering hole. However, the qualitative data may suggest that the gathering may be more for social benefits as opposed to simply hydration purposes.

Behavioral ecology is the study of behavior from both ecological and evolutionary viewpoints. In other words, behavior ecology examines how organisms deal with ecological pressures from behavioral and morphological perspectives. In the study of behavioral ecology, the amount of lifetime reproductive output is not the measure of importance, as this measure is more applicable when referring to the fitness of organisms. What is measured is the amount of energy that an organism uses in any given behavior, whether it got back what it expended (neutral behavior), lost energy in the behavior (cost to the organism) or gained energy in the behavior (benefit to the organism). Therefore, it is the assumption of behavioral ecology that an organism will attempt to maximize their net energy gains and minimize their costs. With respect to the cost-benefit assumption of behavioral ecology, not everything "costs" energy. A behavior can in of itself, not have a function and thus, not "cost" energy. Behavior is broadly defined as all the actions and inactions of an organism, where in addition to engaging in an active state (such as running, fighting and eating), an organism engaging in an inactive state (such as not-running, not-fighting and not-eating) is as equally as important because all are considered forms of behavior. Behaviors that do not have a cost or benefit arise when it contributes to the overall survival of an organism. For example, when an organism such as a chameleon is in its environment, it remains still when a predator is nearby. By staying still and allowing its camouflage to hide it from the predator, the chameleon does not expend any energy, thus there is no cost in energy for its behavior. At the same time, as it lies still, it does not gain energy in its behavior either and therefore, does not benefit from this behavior. However, it survives detection from the predator and its camouflaging traits (along with the behaviors associated with having the traits) are passed to its offspring.

Altruism is when an organism behaves in a way that has a net loss of energy to the actor but a net gain of energy in the receiver. The concept of altruism behavior is counter-intuitive to natural selection as altruism serves to minimize an organism's fitness, as giving itself a net loss of energy decreases its chances of reproductive success. However, altruism is still compatible with natural selection via kin selection, which is the idea that although an organism can act in an altruistic manner, the individual receiving the benefit from the behavior is a close genetic relative. Therefore, a certain percentage of that individual's genotype is still benefitting and able to be passed onto offspring, a concept that is in-line with natural selection.   For example, an organism may expend energy to protect its young from a predator. While this behavior minimizes the organism's chance for reproductive success in the future (as it may be injured or die from interacting with the predator), via kin selection, its genotype in the protected offspring may still have a chance for reproductive success. In reciprocal altruism, an individual behaves in a way that benefits another at a cost to itself, and the other individual in turn, benefits the original actor, either immediately or in the future. For example, there are birds that detect predators and give warning calls to signal other birds. This behavior does not benefit the bird (or the original actor) giving the warning call, as it will provide the predator its own location and thus, placing itself in danger. The benefit is placed upon the other birds that have been warned. However, in future circumstances, other birds will reciprocate and provide warning calls as well, thereby providing benefit back to the original bird (or the original actor). It may not be feasible to measure all reciprocal altruism, as there are so many relationships between individuals in a population, a community, even between different species. As human beings, not all cultural kin are biological kin, in that close friendships within tight-knit social circles can serve as quasi-families. In such relationships, humans may opt to apply kin selection behaviors towards individuals who are not biological kin. The resulting impact of such application of kin behaviors could be that genotypes of these individuals will not be carried forward into future generations.