Often the percent of an animal species in the wild that survive to breed again is lower following a successful breeding season. This is part of nature‘s self- regulation, tending to keep population stable. A study of merlins (small falcons) in northern Sweden observed the number of breeding pairs in an isolated area and the percent of makes (banded for identification) who returned the next breeding season. Here are the data for nine year.
Breeding pairs
28 29 29 29 30 32 33 38 38
Percent Returns
82 83 70 61 69 58 43 50 47
1.Is there a clear explanatory variable and response variable in this setting? If so, tell which is which, If not, explain why not.
2. How would you describe the form of the relationship?
3.do you expect the correlation to be positive or negative? Near + or not? Explain.
1. In this setting, the number of breeding pairs is the explanatory variable, which is the variable that is believed to have an influence on another variable. The percent of males who returned the next breeding season is the response variable, which is the variable being studied and is expected to change in response to the explanatory variable.
2. The form of the relationship between the number of breeding pairs and the percent of males who returned can be described as a negative relationship. As the number of breeding pairs increases, the percent of males who return tends to decrease.
3. The correlation between the number of breeding pairs and the percent of males who returned is expected to be negative. As mentioned earlier, as the number of breeding pairs increases, the percent of males who returned tends to decrease. Therefore, the correlation is expected to be negative, indicating an inverse relationship between these two variables.
In this setting, the explanatory variable is the number of breeding pairs, and the response variable is the percent of males who return the following breeding season.
The form of the relationship between the number of breeding pairs and the percent of males who return can be described as a decreasing trend. As the number of breeding pairs increases, the percent of males who return tends to decrease.
Based on the description of nature's self-regulation and the purpose of keeping population stable, we would expect the correlation between the number of breeding pairs and the percent of males who return to be negative. This is because as the population size increases and more breeding pairs are successful, there may be limited resources or competition for territories, leading to a lower survival rate for returning males. The correlation is expected to be near to -1, indicating a strong negative relationship.