Question

what do you conclude about inter-specific competition between these species?

wildt do you Conciue duuucci spec LUME species? ...... Wolf spider — Grass spider --- Orb weaver spider Proportion of population Proportion of population Height of webs Prey Size The wolf spiders have the largest carrying capacity (K) Competitive exclusion will cause the orb weaver spiders go extinct Niche partitioning based on prey size should allow the three spider species to coexist Niche partitioning based on web height should allow the three spider species to coexist

Answer 1

The wolf spider, orb-weaver spider, and grass weaver spider are three distinct spider species that are present in the same habitat or niche.

As can be seen from the first graph on the left, the three species exhibit a distinct height of webs with almost little overlap. Hence they would not face competition based on habitat and all these can co-exist in the given niche.

The figure on the right exhibits the prey size of these spiders. The grass and orb-weaver spiders have a huge difference in their prey size with very little overlap. However, the wolf spider does exhibit a significant overlap in prey size with both the grass and the orb-weaver spiders. Thus, it will be facing huge competition in terms of food from both the species.

From the given data, we cannot talk about the carrying capacity of these spiders. Hence the first option is irrelevant to the question.

Clearly the orb spiders are not facing competitive exclusion, rather competitive exclusion is faced by the wolf spider.

And as argued earlier, the partitioning in habitat/niche is good which will promote the co-existence of these species.