Chronic wasting disease (CWD) is a. caused by an infectious fungus which causes bats to wake up in the middle of the winter, wasting energy, and eventually killing them b. caused by a non-infectious heavy metal toxin that bioaccumulates in bird stomachs until the bird is no longer able to digest food, causing it to waste away c. caused by an infectious misfiled protein, or prion, that creates vacuoles in a deers brain and alters their behavior to the point that they slowly die from starvation d. a form of mange that causes bears to lose all of their fur, thus chasing their appearance to look much skinner than normal Starvation is not considered a disease as it is not infectious and thus can not be "transmitted" from one animal to another a. true b. false Brown tree snakes in Guam are an example of a. an introduced commensal which is affecting bird species by improving the resilience of other reptiles to chytrid fungus b. an introduced ecosystem engineer that is changing bird habitat by dispersing tree seeds and altering canopy cover c. an introduced competitor which is affecting birds on guam by eating the same spider species that they birds rely on d. an introduced predator species that is affecting populations of birds directly through predation Zebra mussels were carried into the great lakes in the ballast water of tanker ships. They were brought frequently, arrived in good health and in large numbers. This is a high ______ ______ meaning they are more likely to be a successful invasive species fill in the blank propagule pressure Starlings were introduced to the US by Shakespeare enthusiasts. The birds have since spread across the US and are out-competing native birds (like the blue bird) a. true b. false