Final answer:
The capture-recapture A) method is a feasible technique for estimating the population of grasshoppers in a backyard. It involves marking a sample of the population, releasing them, and then using the proportion of marked individuals in a subsequent sample to estimate total numbers, but alternative methods might offer more precision.
Step-by-step explanation:
It is indeed feasible to employ the capture-recapture method to estimate the population of grasshoppers in your backyard, but its effectiveness can vary based on several factors. The capture-recapture method is a technique commonly used for mobile organisms, such as mammals, birds, or fish, and it involves marking a sample of captured animals before releasing them back into the environment. Over time, these marked individuals mix with the unmarked population. A second capture then allows scientists to estimate the total population based on the proportion of marked to unmarked individuals. In our example, if 80 grasshoppers are captured, marked, and released, and then a second sample of 100 grasshoppers includes 20 marked individuals, the estimated population size (N) would be 400 (80 x 100 / 20). However, this method has limitations. Marked animals may learn to avoid capture or preferentially be recaptured, and the marking technique might harm some species. Alternative techniques for estimating population size include electronic tracking, camera traps, and DNA analysis. These methods can sometimes provide more precise and detailed estimates, especially in areas with many species or large study spaces.