GOOD JOB!!! You are much more responsible than most people, and you should be very proud of yourself!!!
I'm glad to see that most of the US is starting to take Animal Abuse/Neglect very seriously. I hate to say it, but most people who have no care about the welfare of animals will only stop unless they are threatened with criminal charges, and most states and local law enforcement have learned this and started to take it very seriously. Both the ASPCA and the Human Society in all states now have the ability to go to a local judge and ask for a warrant to both take temporary-custody of any animals in a household or farm and serve their owners with a summons that has a court date on it, with a charge of Animal Abuse on it. Then they take the animals from the property and put them into temporary custody, get them any vet care that they might need, and then the owners of the animals either show-up to the court date and the judge decides whether or not they get the animals back. In all cases the owners are required to pay for any and all vet bills that were accumulated, along with the daily cost for the animal's care (food, shelter, and man-power to care for them per day), even if the animals are legally taken away from the owners...99% of the time, in my personal experience, the judge will compromise with the Human Society/ASPCA agent and they will tell the owners "If you voluntarily give-up ownership of the animal(s) to the agency, then no criminal charges will be filed against you, and all you will need to do is pay the total bill accrued by the animal over the course of it's stay since it was seized from your home/farm"...And if the owner refuses to sign-over their ownership of the animal(s) voluntarily, then the agent will ask the judge to file Animal Abuse charges against them, and another court date will be set...And probably 90%+ percent of the time, the judge finds them guilty of Animal Abuse, they have a permanent misdemeanor charge put on their criminal record, they are never legally allowed to own another animal ever again, not even a goldfish, and then they have to not only pay for the total cost of the animal's stay at the agency up until that trial date happens, which is usually in the thousands by that time, but they also have to pay a fine for the Animal Cruelty misdemeanor conviction (each one, depending on how many animals they had seized, each animal is another count and another misdemeanor charge/conviction on their criminal record), and the most expensive part is they have to pay the court-costs for both the original hearing and the trial, which is typically thousands of dollars by the end of the whole thing...So most people are advised by their lawyers to simply sign-over ownership of the animal(s) to the agency at the first hearing so they aren't charged with any criminal charges, and then just pay the bill they owe the agency for the care of the animal(s) up until the hearing...Sometimes the judge will still file a legal-injunction stating that they are not allowed to own any other animals for a certain amount of time, usually they do this and it's typically a 5-year period they are not allowed to own any other animals (every single hearing I've had to go to as a witness of Animal Abuse or Neglect has resulted in the person signing over their ownership of their animal(s) except for 2, and they've all been legally prohibited from owning any other animals for 5-years)...
Most people at these hearing start crying about how much they love their animals and how they didn't mean to hurt them...I've heard people say that "They just simply forgot" to feed their pets, or they "forgot that the animal was being kept outside for months and months in the winter", yet they absolutely love their pets and they "are like their own children". (Keep in-mind in the case of me being a witness it's always been either a bird/parrot or a reptile/amphibian that was left outside in the Pennsylvania winters)...I've probably been to around 40-50 of these hearings and 2 one-day trials where the owners refused to sign-over ownership over the last 8+ years I've been with the Avian/Reptile Rescue, and because I'm the Medial-Liaison I always have to go to the courthouse and give the judge detailed-description of the condition of the bird or reptile that was brought in to the Rescue, either by their owners for surrender, or by someone else who either found them outside and brought them in, or by someone who knew the people or were their neighbors and who simply took the animals and brought them in (I don't advise doing that, always call local law enforcement because animals are considered "personal property" in all states in the US, which means you're actually commiting a theft of property by just taking the animals and you can be charged with burglary, larceny, etc. and civilly sued by the owners for theft/burglary, trespassing, and a host of other laws that you break if you just come onto their property and take an animal, even an animal who is dying of starvation, dehydration, exposure, etc., doesn't matter, as long as animals are considered as being "personal property" in all of the US states, you will never be able to actually just go and save their lives by taking them off of someone's property, it's legally considered the same as stealing a car, a lawnmower, or anything else that you come onto their property and just take; it's messed-up and the laws need to change...)
I'm so glad you stepped-up and not only provided a loving, caring home for this Budgie, but you also did the right thing and turned those people in...They most-likely were not charged with any criminal charges in exchange for them voluntarily surrendering all of their pets, and they will probably also have to go to court and officially sign-over ownership of the Rabbit and the Dog, and hopefully the judge will legally ban them from owning any other pets for a long time...So you saved not only these 3 animals, but probably many, many more to come in the next few years...