Many animal rescue groups are made up of only foster homes. This means they don't have a shelter, and every time they rescue an animal, they have to find a place for it to stay until it is adopted. The group I volunteer with, All Paws Rescue, currently has around 30 active foster homes for dogs. This means that we constantly have dogs coming into our rescue, being fostered, being adopted out, and then new ones coming in. Coordinating all of the dogs coming in and going out can be a lot of work, but everyone cooperates to make it go smoothly. A couple of years ago I volunteered to be the Dog Intake Coordinator (there is also a Cat Intake Coordinator who handles all of the cat intakes and cat foster homes). Like everything else in our rescue, this is a volunteer position - no one in our group gets paid! We just do this because we love to help animals. So the way I help as the dog intake coordinator is to make sure our dog foster homes have what they need in the form of paperwork, supplies, and dogs. When a volunteer tells me they are ready to take on a foster dog, I try to match one to them that is a good fit. Some of our foster homes can only take in hypoallergenic dogs, or small dogs, or female dogs, or other special requirements, so whenever possible I try to match up a dog in need with the available foster home to make sure it works out for everyone. However often the dogs that need rescue don't come with information like if they are house-trained, or if they get along with small dogs, or if they like cats. That is why many foster animals come to my house or another experienced volunteer's house for a short time for an evaluation. Then when another foster home opens up that is a good fit for that dog, the dog goes to that home and that opens up a space for us to take in another dog to evaluate. The down side is I end up having to give most of the "easy" dogs to other foster homes, and the only ones that stay with me are those with issues. But the up side is I get to foster a lot of awesome dogs.
For example, tonight after work I am picking up this dog: