Question

carrying capacity
case study #3
hurricanes can have a huge impact on the ecosystems they affect. animals may be killed or have their habitats destroyed by floods, winds and rainfall. in 1998, hurricane mitch reduced the endangered puerto - rican parrot population to half its size.

1. what was the limiting factor in this scenario?
2. will this likely be a constant factor for the parrot population?
3. what are other ways species might be limited by weather?

different kinds of limiting factors
some limiting factors depend on the size of the population in question. for example, in the first case study, the number of fish is only a limiting factor when the bear population reaches a certain size. therefore, the amount of fish can be considered a density - dependent limiting factor. other factors will have an effect on populations no matter what their current size is. for example, the hurricane in the third case study would have affected the parrot population whether it was large or small. therefore, weather is often considered a density - independent limiting factor.
for each of the following limiting factors, determine if they are density dependent or independent.

1. food: with a limited amount of food available, a population will be forced to stop growing.

dependent or independent? why?

1. altitude: many species cannot live at high altitudes due to the lack of oxygen and extreme cold.

dependent or independent? why?

Explanation:

1. The limiting factor in the scenario is the hurricane as it reduced the endangered Puerto - Rican Parrot population to half its size.
2. It is not likely to be a constant factor as hurricanes are not a continuous occurrence. They are sporadic natural events.
3. Species might be limited by weather through flooding that destroys habitats, extreme cold that causes hypothermia and death, or extreme heat that leads to dehydration and heat - stress.
4. Food is a density - dependent limiting factor because the impact of food availability on a population depends on the population size. A larger population will face more competition for limited food resources.
5. Altitude is a density - independent limiting factor because it affects species regardless of their population size. High altitude conditions like lack of oxygen and extreme cold are environmental factors that do not change based on the density of the population.

Answer:

1. Hurricane
2. No
3. Flooding, extreme cold, extreme heat
4. Dependent; Impact depends on population size
5. Independent; Affects regardless of population size