Chaos theory, or unforeseeable consequences

Can you believe this? This is what the crows are doing to lawns in Vancouver. This is next door to my parent's house. This lady has always kept her lawn immaculate, even though her husband died many, many years ago after complications from a stroke.

If you've not heard, crows are a huge problem in Vancouver. My parents' house is right in their daily migration path, and around dusk the sky is black as they make their way to the area where they roost/nest for the night. If you inadvertently come too close to a nest of theirs, they will swoop, dive and peck you on the head. One theory being posited for what the crows are doing to lawns like this all over Vancouver is that recently the city switched to small garbage-bins for all private residences, sort of a dumpster-in-mini-form for every house. These dumpsters the crows cannot get into. So, perhaps they are hungry now. They used to eat a lot of garbage, strewing the weekly trash all over back allies and around people's front lawns. Now, this. Who would have thought that a well intentioned plan of cleaning up the garbage would have caused this. My parents have not yet been hit. I suppose it's only a matter of time, though.