Ok so as many of us know the prices for lower color pets are this side of pathetic.
Natural - 10 tu
Sepia - 100 tu
Cream - 100 tu
Black - 9,000 tu
Ginger - 28,000 tu
These are the lowest prices for each color in shops, I just looked them up. Yes the release hatch has discouraged adding more unwanted pets to sell back into the system. However there is no effective system on rescreatu to remove so many unwanted lower color pets from the system. Kir only wants high color pets most of the time. If the pets are abandoned into the forest they are still in circulation. Other users can still get them they have not been removed from the game like Kir does with pets.
My suggestion
Make a quest (probably a Kir like quest) that asks for no colors above ginger, with the lower colors being most common. Seasonals may be asked for, but is much rarer than with common pets. Yes it is a kir format but the kir format works quite well for taking down pet numbers.
Possible story line: Hello I run the pets for the poor foundation. We send pets all over the four planets to those who need a companion. These people can't really afford to buy said pets (don't worry we make sure they can feed them) , however our organization would love pet owners like yourself to help with our cause. Sorry I can't afford to pay you any tu for your help, but our resident pets here find many interesting items, maybe after you've helped the organization enough we can give you some.
Possible mechanics
You are asked for pets ranging from natural - ginger (natural being the most common)
You have a limit of say 10 pets per user per day, it would keep people from gaining points too quickly. (They could always say "Sorry we're over capacity, could you wait until we've shipped out some of the pets already here to their new homes?)
Reward System Ideas
A) You are given a point or credit for how many of each kind of pet you bring in (The Kir system.) Say you bring in a natural, after she/he has asked you for ten more naturals you will get a point. That or just have a part of a point awarded at that time.
10 Naturals = 1 point
5 Sepias = 1 point
2 Creams = 1 point
Black = 1 point
Ginger = 2 points
Have seasonals worth a very good number of points.
(I'd say not include but we have black and ginger seasonals priced at 1 mill in the shops.)
(Just possible point number ideas to give an idea of what I was thinking.)
or
B) After you give in so many pets you'll get a randomly selected item from their available prize shop.
I'm not saying that the prizes should be pets by any means. They'd have to be something that would keep being useful to users.
Possibilities:
Ingredients for Stat boosting potions. (useful for when the battle system is back up and running.)
Possibly high point/ very rare items to make dye kits (as I said either very expensive for the number of points or rarely given depending on the reward system liked better.
Books
Squishies
Stat boosters and dye kit pieces would keep people coming back because you don't just get enough for a book or squishy and stop.
If she/ he gave you random items it would also make it more like the springs where it may take a long time to get the desired items, which would encourage people to keep bringing in the pets.
It's by no means a perfect idea, and it'll probably get blown full of holes. I was just putting something forward for a possible solution to the huge amount of low colored pets. If you like the idea or have a possible modification that may make it better please suggest away. I don't care how it's done but I want /something/ done about the low color pet numbers. Trying to make money with your rancher shop is pretty terrible these days.