Describe the ecological niche of humans. Do you think our realized niche has changed during the past 100 years? Why or why not?

A particular species of butterfly is capable of surviving and reproducing both in open grasslands and in forested habitats. However, in the forested habitats this butterfly  is heavily predated (eaten) by a forest bird species, so the beetle species avoids these areas and is generally found only in grasslands. Which of the following statements are true? Answer choices: A. The butterfly's realized niche includes both grasslands and forested habitats. B. The butterfly's fundamental niche includes only grasslands. C. The butterfly's realized niche includes only grasslands. D. The butterfly's fundamental niche includes both grasslands and forested habitats E. The butterfly and the forest bird species are in competition.

Which of the following statements about the concept of ecological niche is correct? A species' realized niche, may or may not be the same as its fundamental niche   The fundamental niche of a species includes biotic and abiotic factors while the realized niche only includes biotic factors   A species' fundamental niche is always smaller than its realized niche   A niche is the same as a habitat

1. Examine the food webs for Lake Victoria, East Africa (fig 31.2 a,b) before and after the introduction of the Nile perch (Leveque 1995). Calculate the mean food chain length, percent of trophic groups at various levels, and connectance for each food web. Oreochromis Insectivorous Fish Chironomids Chaoborous Man Piscivorous Fish Zooplanktivorous Haplochromines Rastrineobola Zooplankton Detritus/Phytoplankton Lake Victoria in the 1970s Detritivorous Phytoplanktivorous Haplochromines Figure 31.2. (a) Food web structure of Lake Victoria before introduction of the Nile Perch. [continued on next page) Molluscivorous Fish Molluscs