The Effects of Cryptic Versus Non-Cryptic Eggs on Predation Rate of Ground-Nesting Birds
The Effects of Cryptic versus Non-cryptic Eggs on Predation Rate of Ground-nesting Birds
BSC2011L Title
Determining the effect of cryptic, brown eggs versus non-cryptic, white eggs on the predation rate of ground-nesting bird species.
Abstract
Various interactions occur between organisms. Predation is a crucial interaction in which one species benefits by consuming another. I conducted this experiment to determine if crypsis affected the predation rate of eggs in ground-nesting birds. I hypothesized that cryptic eggs would reduce predation rate, therefore less cryptic eggs should be found. I created a simulation in which eight students randomly “laid” 96 eggs in a predetermined area, and seven predators hunted eight eggs each. The predators did not see the eggs being laid, and were given an egg quota so that all the eggs were not found. Also, they were directed to pick up the first eight eggs they noticed and not look for a particular kind. Half the eggs were white marshmallows representing the non-cryptic eggs, and the other 48 were the cryptic, cocoa covered marshmallows. The resulting values of eggs found were 37 non-cryptic and 18 non-cryptic. However, the expected amount for each type of egg was the total number of eggs to be found divided by two, or 27.5 eggs. I used a Chi-Square test to analyze my results further and found the observed chi-square value, which was 7.453. The p-value was between 0.01 and 0.005. The p-value supported my hypothesis, and with an alpha level of 0.05, I concluded that there was a significant difference between the number of cryptic and non-cryptic eggs found. Then I deduced that this difference was probably because the cryptic eggs were less noticeable to the predators, decreasing the predation rate of them. My results concurred with past experiments and promoted the notion that cryptic eggs may reduce predation rate among ground-nesting birds.
Introduction
Species of organisms can be associated due to biotic or abiotic
BSC2011L Title
Determining the effect of cryptic, brown eggs versus non-cryptic, white eggs on the predation rate of ground-nesting bird species.
Abstract
Various interactions occur between organisms. Predation is a crucial interaction in which one species benefits by consuming another. I conducted this experiment to determine if crypsis affected the predation rate of eggs in ground-nesting birds. I hypothesized that cryptic eggs would reduce predation rate, therefore less cryptic eggs should be found. I created a simulation in which eight students randomly “laid” 96 eggs in a predetermined area, and seven predators hunted eight eggs each. The predators did not see the eggs being laid, and were given an egg quota so that all the eggs were not found. Also, they were directed to pick up the first eight eggs they noticed and not look for a particular kind. Half the eggs were white marshmallows representing the non-cryptic eggs, and the other 48 were the cryptic, cocoa covered marshmallows. The resulting values of eggs found were 37 non-cryptic and 18 non-cryptic. However, the expected amount for each type of egg was the total number of eggs to be found divided by two, or 27.5 eggs. I used a Chi-Square test to analyze my results further and found the observed chi-square value, which was 7.453. The p-value was between 0.01 and 0.005. The p-value supported my hypothesis, and with an alpha level of 0.05, I concluded that there was a significant difference between the number of cryptic and non-cryptic eggs found. Then I deduced that this difference was probably because the cryptic eggs were less noticeable to the predators, decreasing the predation rate of them. My results concurred with past experiments and promoted the notion that cryptic eggs may reduce predation rate among ground-nesting birds.
Introduction
Species of organisms can be associated due to biotic or abiotic