I would not recommend that Bleeding hearts be first on any list of doves to acquire if you have not had a few years of experience with other types. (domestic pigeons in my opinion don't qualify as other types) I mean other types of exotic doves or pigeons.

Bleeding hearts require:

* sizable walk in aviary or flights they are not suitable for an individual cage or small cages. They spend lots of time walking the floor of their aviary and are never suited for wire floor cages.

* good seed diet, supplemented with some rich high protein treats like diced boiled egg, diced cheese (for calcium and protein), and or mealworms (I no longer use mealworms but I did for many years and they love them) I rely on egg and cheese and it works very well.

* no disturbance from other large birds (i.e. they should have a cage to themselves) though then can be kept with smaller birds like diamonds and even finches.

* mild temperatures, they cannot tolerate intense color and should not be exposed to freezing conditions for any length of time.

* lastly, lots of patience from their keeper is of utmost importance for success.

Bleeding hearts mature in about one year of age but generally do not become active or pursue breeding until 18 -24 months, and as they age they get better. They are very long lived and breed for many years. My oldest birds died at age 27 and was a superb breeder for most of those years. I have other pairs that are in their teens and do well. 

They certainly take time to settle down under new ownership and adjust to their new care and surroundings. That will slow their progress and breeding interest some until they adjust. the cage and surroundings are very important, because regardless of age, if the birds are not content and settled they will never breed.

I have bred them since 1973 and find that most people who fail with Bleeding hearts were simply to impatient, expecting the birds to nest within 6 months or so. One needs to wait 2 years minimum to give Bleeding hearts a fair chance. I often heard comments, like I kept them a year (*or less) and nothing happened so I sold them. :) those are the birds I try to buy cause I know the people never gave them a fair chance. 

As parents they may require a few nesting failures to get the hang of it, some do some don't, but eventually it seems if they fail once or twice, they learn quickly and succeed the next time. Once they begin breeding they are very productive and its not unusual for a pair to produce clutch after clutch of young, often two per clutch but sometimes only ones makes it. I have often had breeding pairs to produced 8 to 10 young in a years time sometimes more sometimes less. Typically 6,7 to 8 young per year from an active pair is common. A few years ago with 3 breeding pairs all producing, they collectively raised 27 young in a 12 month period. 

Prime breeding age for Luzons is 3-10 years of age. from 10 - 15 they still breed but perhaps not as often, beyond 15, they are slow and may nest only once or twice a season. Some very old pairs simply stop they appear fine and look superb but don't breed any longer. guess thats not unusual.