Question

case study #3
hurricanes can have a huge impact on the environment. they affect animals may be killed or have their habitat destroyed by intense winds and rainfall. in 1999, hurricane hugo reduced the puerto rican parrots population to half its size.

1. what was the limiting factor in this scenario?
2. will this likely be 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 was the hurricane as it destroyed the habitat and killed animals, reducing the Puerto Rican Parrot's population.
2. It is unlikely to be a constant factor as hurricanes are not a continuous occurrence; they are sporadic natural - disasters.
3. Species might be limited by weather through factors like extreme cold killing individuals, heavy rains flooding habitats, or droughts reducing water sources.
4. Food is a density - dependent limiting factor because as the population size increases, the competition for the limited food supply intensifies.
5. Altitude is a density - independent limiting factor because it affects species regardless of their population size; the lack of oxygen and extreme cold at high altitudes are environmental conditions that impact all individuals in the area.

Answer:

1. Hurricane
2. No
3. Extreme cold, heavy rains, droughts
4. Dependent; As population grows, competition for food increases.
5. Independent; Affects species regardless of population size.