Fostering is a term used whereby a pair of birds will care and rear young birds that are from a different pair of species. These birds will accept the young and care for them until they are fully fledged.
Fostering is normally used when young are abandoned, lost or scared away from their natural parents or due to the unfortunate loss of one or both parents.
What bird does this? Well, the most commonly used bird species for fostering is the
Bengalese Finch – Lachura Domestica. (Society Finch)
How to get the Foster Pair of Individual to accept the eggs? It can be a rather easy process. Normally the foster pair will be comfortable and nesting but this does require you have a pair of foster finches/societies setup and nesting. If this is the case then you will need to place the eggs into the nest. if all goes well the foster parents will accept the new arrivals and begin caring for them. It can be a rather nerve racking experience but certainly try to stay clear and give the birds some space during the inspection phase. The last thing you want to do is scare them off with constant nest inspections.
I have been in a situation recently where a pair of my Painted Firetails had a beautiful clutch consisting of 5 eggs. Somehow my Hen got free from the aviary and I was not able to catch her and return her to the nest. Unfortunately she was nowhere to be found which meant that I had a real problem on my hands. The male of course will not sit on the eggs entirely during this phase and his role is to later be the main source for feeds.
At the time I did not own a foster pair and was almost certain my eggs were bound for the bin.
I knew of fostering pairs but did not have the space or time to get them nor did I have the opportunity to wait for them to get associated with their environment and nest.
Like many, I began scouring the web for an answer. Unfortunately not much was mentioned with regards to the situation besides the obvious answer of possessing a foster pair. It later dawned on me that maybe my other painteds in the aviary would accept these eggs if placed in their nest. It was risky and I did not know much about it but I decided to give it a shot.
I have 3 pairs of painteds in my aviary including the lost hen pair so options were available. I looked around the nests and found a young hen that was sitting. I inspected the 5 eggs for damage and perhaps infertile ones and decided to add 4 eggs in total to the now foster pair of painteds nest.
The initial response from the hen after carefully placing them into the centre of the nest represented some confusion. The Cock even popped his head in to inspect and they seemed to hover over the eggs for a while. I decided to leave them be and returned only later the next day. The results were positive as both hen and cock had accepted the eggs and were happily sharing responsibilities.
To cut the story short, the pair successfully raised all 4 youngsters.
Although this situation worked for me with my Painted Firetails you must also appreciate that the painted are not too fussy about nest inspections. If you are caught in a similar situation try and avoid too much interference with you other pairs and their breeding. This will especially not work if their eggs have already hatched and you are just placing unhatched eggs in the nest.
Some finch varieties share similar breeding seasons so this may get you through the troubles. You may have similar success and I wish you best of luck.