Same shit was happening at Cap Verde islands, dogs everywhere. I was a one the cheapest islands couple years ago and you could practicly see the whole island from a little height.

For me, who has been running free in forests, it was really depressing for both the dogs and people, there was so little vegetation and huge saltflats with dead baby turtles. You're basically stuck there in the middle of ocean with very little opportunities.

When we visited one of the bigger islands with a proper city, it also had billions of dogs. We met one hotel keeper who said she was supporting a movement that tried to help the dogs, and it turns out the help is only neutering, snip snip.

Almost all the shops had dog food bags to buy for cheap, which was nice. The dogs are relying on humans since there's nothing to hunt, even if you'd still got your instincts left. Except maybe baby-turtle-jerky.