What effect has the release of these animals have on the number of small mammals in the Everglades?

You don't say in your question which animal is being released in the Everglades, but I'm going to guess and say you're talking about snakes - specifically, the Python. These snakes are not indigenous to Florida, they come from other parts of the world. They are caught/captured for various reasons, brought to North America to be nursed back to health, and then released into "the wild" Everglades thinking this would be okay. So far, it has not been okay and these snakes have decimated the area and its native animals.

Explanation:

Pythons are a snake genus that can be found in Africa, Southeast Asia, India and Indonesia. There are seven known species of python that are found in these areas: the Angolan python, the short-tailed python, the Indian python, the ball or royal python, the reticulated python, the African rock python and the Timor python. Of all of these species there are two that are known for being invasive species in North America, particularly in Florida: the Indian python and the African rock python.

Biologists believe that there is currently anywhere from thirty thousand to one hundred thousand snakes that have been released in to the wild in the Florida Everglades. With such incredibly high numbers it is impossible to even know where to begin destroying the pest species. While biologists recognize that they will likely not be able to completely wipe out the foreign species, they do believe that there is a possibility for them to quarantine the damage to the Florida area.

Why Does An Increase in Pythons in the Everglades Matter to You?

Why should you care if pythons are taking over the Florida Everglades? Whether you live in the vicinity of the Florida Everglades or not you should be concerned with the voracity with which these non-native species are taking a hold in the Everglades area. As these extremely large species continue to have a strong hold in the Everglades they have the potential for spreading in to nearby states and threatening other local populations as well. Even if the python populations of the Florida Everglades so not migrate to neighboring states however, these snakes still pose a significant risk to a number of native wildlife species that build up the diverse wildlife that can be found throughout North America.

the correct answer is:

this is an example of the writer telling through description rather than showing through dialogue.

sometimes writers like to explain explicitely what's happening instead of adding dialogues of the situations., which is the case in this passage,

yeah, i think its a good thing what do you think?