Characteristics of Populaions

What is a population? Population - groups of individuals of the same species living in a particular place at the same time Population density – the number of individuals living in a particular area

Distribution Patterns Random –In random distribution, organisms occur in no particular order. The appearance of the organism is random throughout the area without an overall pattern. Uniform –Organisms that are distributed in a uniform manner are spread evenly over an area. No one plant has more or less of the organisms than any other place. Clumped –Clumped organisms are concentrated at points throughout an area. Clusters may offer the population protection from enemies, wind, or cold.

Communication within populations Visual displays Sound Use of chemicals Physical contact

Visual displays A male peacock uses his large fan as a display to attract a mate. When not used for display, the fan feathers trail behind the bird. In this position, the fan feathers are called a train, like the trailing fabric on a bride’s gown. Female peafowl do not have fans.

Sound The males courtship and territorial call is a series of Mournful cooing notes with the second note having a little more emphasis. It sounds like coah cooo cooo coo. The call is often mistaken for that of an owl. A shorter call is used by both adults near the nest. There is also a whistling twitter. This is usually heard when they take off.

Use of chemicals A pheromone is a chemical that triggers a natural behavioral response in another member of the same species. There are alarm pheromones, food trail pheromones, sex pheromones, and many others that affect behavior or physiology. Their use among insects has been particularly well documented, although many vertebrates and plants also communicate using pheromones.chemical insectsvertebratesplants

Physical contact Touch plays an important part in the lives of a pod of dolphins. On one hand, many different types of touching can be seen – from the gentle touch of a mother to her calf, to the stroking all over the body between two dolphins for the purpose of courtship, including rubbing each other's bodies, mainly the sex organs. And, on the other hand – relating to the status of the dolphin within the pod, aggressive contact can be seen, including: tail slaps, butting and even biting. An example of communication by touch: when a mother and her calf swim together, there is often contact between the base of the mother's tail and the calf's body; giving the calf a feeling of security and protection, while providing the mother with information on the location of her calf.