Going to the Wall?

The Wall lizard has flourished on the Spanish island of Ibiza (along with clubbers). Twenty years ago, Ibiza had no snakes. At this time, however, importing Olive trees became suddenly trendy (https://www.theguardian.com/environment/2022/may/27/snakes-or-lizards-stark-game-of-survival-ibiza-aoe). Some of the imported Olive trees had snakes secreted away in their branches. Horseshoe whipsnakes and Ladder snakes, now found on Ibiza, eat Wall lizards. The Ibiza population of Wall lizards has crashed QED.