Ear-tipping alerts other volunteers that the cat is sterilized and can be spared the stress of being trapped and anesthetized for a surgical procedure that has already been performed.

Q: A new friend invited me to her home, and I was surprised that one of her cats was missing an ear tip. What was left of the ear looked normal, except that it had been cut in a straight line. I&#8… ...

When I step out my front door, the first thing I usually see is a feral cat soaking up the sun. Some may view community cats as a nuisance, but these… Animal Life: The Benefits Of Ear-Tipped ...

The practice, called "ear tipping," is a common method of distinguishing between sterile and fertile cats in order to keep stray populations down. Christopher Furlong/Getty Images ...

These cats have been ‘ear-tipped’ or ‘notched’. This is a surgical alteration showing that a free-living, feral cat has been spayed or neutered and returned to the streets.

According to Tamara, Snowball's "house servant" (Tamara's words), the 10-year-old cat has a problem with her left ear. The problem started with some crusting/ scabbing on the ear's tip.

Ever seen feral cats with a distinct cut on the tip of their ears? This isn’t from their tough life on the streets or from fighting, but rather a way to identify that they have been sterilised ...