Ecology - Relationships

The Cattle Egret is often seen in the company of grazing animals.  The grazers stir up insects, which the egret then eats.

• Mutualism
• Commensalism
• Predation
• Parasitism

The oxpecker is a bird that rides around on the backs of cattle and other large animals such as rhinos.  The oxpecker feeds on ectoparasites of the cattle, such as ticks, and warns the animals of approaching predators.

• Mutualism
• Commensalism
• Predation
• Parasitism

Corals and zooxanthellae (zooxanthellae are algae that take up residence in a coral animal. The photosynthetic zooxanthellae provide the coral with sugars in return for nitrogen and other nutrients from the coral.

• Mutualism
• Commensalism
• Predation
• Parasitism

The horsehair worm starts life as an egg laid in a puddle.  The puddle dries out and a grasshopper comes along and eats the egg, which promptly hatches and burrows through the gut of the insect into its body cavity.  Here, the insect grows until it reaches adulthood. At that point it starts producing chemicals which take over the brain of the insect and cause the insect to seek out water, which it jumps into.  The worm then exits the hopper and lives in the puddle, mating and laying more eggs.  The grasshopper, if it doesn't drown, may survive the ordeal. 

• Mutualism
• Commensalism
• Predation
• Parasitism

Herbivores are plant eaters.

• True
• False

Omnivores eat plants and animals.

• True
• False

Producers get their energy from

• food.
• other plants.
• the Sun.

Carrying Capacity is

• the capacity of what one person can carry per day 
• how many animals you have in your daily bag limit at the end of the year
• wildebeest at a watering hole with zebras
• the maximum number of individuals that the environment can support

Biotic or abiotic things that control the size of a population

• Limiting factor
• density- dependent factor
• density- independent factot
• tolerance

One factor that drives population changes is

• the availability of resources.
• predation.
• both a and b.
• none of the above.