Wild or Domestic?
Do you know how to tell the difference between our native Western Cottontail rabbits and a domesticated rabbit? All wild rabbits are a mix of brown and black fur, which is called agouti color. Domestic rabbits can also be agouti colored but their shape is different. Wild rabbits don't get more than a couple of pounds in weight and have slender faces and long slender legs. If you see a rabbit in any other color, like white or black or tan or gray, it is definitely a domestic rabbit.
Baby rabbits are more difficult to tell the difference. In most cases, when you find a nest of baby rabbits, you should do nothing at all! The mom is probably close by. She only goes to the nest to feed and otherwise stays away so that she does not attract predators to her babies. Sometimes mama makes a nest in places that seem odd but if you can possibly leave the area alone for just a few weeks, the babies will be weaned and leave the nest at 3 weeks old. They will quickly learn to run and hide and be very wary of everything. If they are not afraid of people, they are probably domestic rabbits. This website has excellent photos and info of baby cottontails at different ages.
If you find an injured rabbit, take it to a wildlife rehabilitator as soon as possible. Dehydration can quickly lead to organ failure in babies. Cat bites are lethal if not treated right away. If you are near Orange County, CA and you have found an injured rabbit or have a nest of babies that you absolutely cannot leave alone or put back, call (949)201-5009 or contact us and we will do our best to get you in touch with someone who can help.
Further reading:
https://rabbit.org/faq-orphaned-baby-bunnies/
https://owl-online.org/animal-guide/cottontail/
http://www.bio.miami.edu/hare/wildbabies.pdf