Every year at my gym, I see a bunch of dead birds under the tree.....for about a week.
They spray the trees to rid of them bugs.
At least a few times a year, the ponds around here are floating with dead fish.
They sprayed the ponds for algae, weed, bugs.
I remember foxes, panthers, herons, storks used to nest behind my moms house.....they're all gone. I saw them dead in the streets and killed off by poisoning from the contractors (it's done all the time to rid the area of animals)...turtles, alligators, even otters on the roads....saw alot of lost foxes running everwhere. Time to build the houses.
There are many reasons why animals disappear. A few homeless cats are not the reason.
I guess your anecdotal reports of a few observations outweigh all the studies done by universities and conservation programs.
What a great idea. We could replace every study in federal and state budgets just by using personal observations of random people. That's very scientific.