Rive said:
effectiveness of bell collars
This article mentions the points you raised and possible solutions.
https://scienceinsights.org/why-do-people-put-bells-on-cats-and-should-you/
"Bells aren’t the only option, and for bird protection specifically, they’re not even the most effective one. A few alternatives have been studied:
Bright collar covers: The Birdsbesafe collar cover is a brightly colored fabric sleeve that fits over a cat’s collar. Because birds have excellent color vision, the vivid colors act as a visual warning. Studies found cats wearing these covers brought home 61% fewer birds, outperforming bells. The tradeoff is that they don’t help with mammals, which rely more on hearing and smell than color vision.
Neoprene bibs: The CatBib is a small flap that hangs from the collar and physically interferes with a cat’s ability to use its paws during a pounce. Studies found it prevented 81% of successful bird catches and 45% of mammal catches, making it one of the most effective options tested.
Electronic sound devices: Some collars emit a beep at regular intervals rather than relying on movement to trigger a sound. These performed similarly to bells in studies, reducing hunting success at roughly the same rate.
Combining methods, like using a bell alongside a bright collar cover, can address both bird and mammal prey more comprehensively than any single approach.”
Also this but I only have the abstract. A bit of a mixed bag.
https://www.researchgate.net/public...mestic_Cats_in_a_Continental_European_Setting
"Our results are in line with previous findings from Australia, the United States, and the United Kingdom and highlight the great potential of visual and acoustic cues in reducing hunting success in domestic cats also in Continental Europe. On the other hand, our result show that the number of prey brought home by cats overestimates their hunting bag, if scavenging is not considered."