Question

food web

Sierra Nevada Fresno Water strider bighorn sheep kangaroo rat oak tree Blackberry bush Opalinida Mosquito Bacillus Golden CA tiger salamandar trout Grasshopper CA tree frog Fairy shrimp Fly Tule elk Mushroom Mountain Duckweeed lion Saprolegnia Screech Desert tortoise owl Sun Bumble bee CA gopher snake Grasses Figure 13.2: Central Valley food web. 72 Community Ecology Exercise 13

Answer 1

1. a. Grasshopper

b. CA tiger salamander, screech owl, CA frog

c. Yes, they could feed on bumble bee.

d. Predators are those animals that hunt and kill animals for food. They are carnivores. Preys are those animals which are hunted by carnivores, killed and eaten. An example of predator-prey relationship is that of tigers and deer. Tigers hunt deer for food.

Two examples from the given food web are-

i] CA gropher snake [predator] and CA frog [prey]

ii] Mountain lion [predator] and big horn sheep [prey]

e. Golden trout and fairy shrimp, both feed on duckweed and hence are competitors.

f. Whenever there is any sort of competition for survival, the individuals which are stronger and better adapted to compete, are successful. Competition for food can end up in two ways. First, the stronger population will survive and the other one might end up in extinction. Secondaly, the weaker competing population might adapt in such a way as to survive on meager food resources by reducing its size or any other suitable adaptation, which might occur due to gene mutation.