please answer q1-3 This scenario is contrived but matches closely many details o
ID: 151906 • Letter: P
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please answer q1-3 This scenario is contrived but matches closely many details of real parrot populations as well as situations affecting parrot conservation, that is, harvest for the pet trade and loss of vital nest trees due to timber harvest (Figure 1). Consider a hypothetical species of small parrot that matures at age three and then breeds at a modest level (two or three chicks per year) for approximately three years. The parrot is much sought after for sale in the pet trade. Adults can be harvested directly through netting outside the nesting season or nestlings can be removed from nest trees and reared by hand. These parrots only nest in holes in a particular species of palm that is sought after by humans as a source of building material and thatch. Parrot nests are fairly inconspicuous and the harvesting of palms is done without knowledge of where the parrots nest. It also occurs during the dry season, which happens to be the nesting season of the parrots. Thus, some of the palms felled incidentally kill young parrots in nests as well as the attending female Figure 1. Red-bellied macaws (Orthopsittaca manilata) on a dead Buriti palm tree (Mauritia flexuosa). Image: Ltoniolo (own work) via Wikimedia Commons, [CC BY-SA 4.0] We are concerned with a 10,000 km2 community forest. Palm density is 100 per km2, although under the best of conditions at carrying capacity (K) they can be twice asExplanation / Answer
Answer 1: It will be half of carrying capacity. Given K=2 parrots/10 km2, all the parrots above 1 parrot/10 km2 can be removed.
Explanation: maximum sustainable yield (MSY) is the largest yield that can be taken from a species stock over an indefinite period. Fundamental to the notion of sustainable harvest, this concept aims to maintain the population size at the point of maximum growth rate by harvesting the individuals that would normally be added to the population, allowing the population to continue to be productive indefinitely.
In given problem we want to know the maximum number of individuals that can be harvested right now that will allow the population to return to its carrying capacity as quickly as possible, making it ready for another productive harvest. If you look at the logistic growth figure below, you will quickly see that when a population is exactly halfway to its carrying capacity, it is growing at its fastest rate. This means that if we stop harvesting at half its carrying capacity, the population can quickly recover and allow for a successful harvest time after time. The golden question, then, has a golden answer. The maximum sustainable yield (MSY) for a population is exactly equal to half of its carrying capacity. So, there you have it. Problem solved.
Answer 2: It will also be half of carrying capacity. Given K=200 per km2, all the trees above 100 tress per km2 can be removed.
Answer 3: Well the incidental death may affect the sustainability but if the population is checked every year at time of harvest and minimum sustain population is left over, the ecosystem can sustain.
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