UK Nature and Environment

From my limited understanding the removal of an apex predator can cause role effects through a good chain. First their primary preys will tend to over populate. Then the food sources for this pretty well get devastated by the extra consumption. Then any animal or plant that relies upon whatever food sources can collapse as well.

The example that was explained to me, and please give me some grace as this is me remembering this from a zoology course in college a decade ago, I a burn in Yellowstone national Park.

Birders had noticed that a population of a small songbird had collapsed. When wolves were reintroduced to the park they started to bounce back. Turns out the birds only beard in a particular your of shrub. That shrub was getting over eaten by the elk population despite it not being a prefered food since. The elk were heavily overpopulated and devouring less preferred food in much higher volumes because there were no wolves to keep the population in check. So when wolves can't back everything started to balance back out.

This is a pretty straightforward example of how interconnected the average food web in an ecosystem in. These kind of role effects can spread well past the immediate area where a key species is removed. But hopefully it can help show how one species can be so critical for an ecosystem. I don't know about the animals in this case, but I suspect it would be something like this.