Hello, welcome to Just Answer. I will do my best to answer your questions. First off, my condolences on the finding of your swallow had perished. I'm not entirely clear on the second bird - it is sitting on the nest currently, correct? Do you know if the eggs have hatched?
i dont believe they have hatchede need a ladder to see in and she has already been scared twice today, once with the male defending the nest and being caught, the second when we went out to look at the nest
sorry, pressed return
Whether the eggs have hatched or not, I would strongly recommend that you minimize any disturbance to the area and nest. Do not encourage her to fly off the nest. This will actually cause her to utilize more energy and reserves. Wild birds have natural instincts of survival and she will sort out how to best care for herself and the nest. I will caution you that if it is overwhelming, she may abandon the nest and leave the chicks/eggs to perish. There is nothing you can do to help with this aspect, except to give her as much privacy and minimize the disturbance around her nest.
..sorry pressed return i don't believe they have hatched - we need a ladder to see in and she has already been scared twice today, once with the male defending the nest and being caught, the second when we went out to look at the nest. we can go and check maybe tomorrow, but my thought is they have not and she is sitting on the eggs. my real concern is whether, if we scare her off the nest every 2-3 days, would she be feeding in her flight (during her short time away from the nest) or given that she is broody and has her eggs in mind, would she bypass the feeding and it provide more harm than good, given that it will be stressful for her. Also might she not return to her eggs if this is done so frequently? i know that other than that and keeping the door locked, that i am powerless to help. My other query is how likely a single swallow is to survive or bring up a family on her own? (and she is tiny as mentioned in 1st email) There are other swallow familes in the grounds and i have seen one since flying above the courtyard feeding as part of its extended loop - i know many were born in the courtyard, but whether they would know she was there, or even if she got to chick feeding & fly stage, would they join in to help her? thank you so much..
These are all great questions, and I really love how much you care for the wildlife and swallow population. Wild birds have a natural instinct to survive. This may result in abandoning the nest in order to live, as in nature, it will always make more sense for the parent to survive in order to reproduce later. Although the bond with the offspring is enormous, when faced with survival, the vast majority of animals will abandon the young in order to survive. If they were to sacrifice themselves for the offspring, then all would perish, whereas if parent survives they can reproduce again.
As for your other question - how likely will a single swallow bring up the family. I do, unfortunately, think it will be exceptionally hard, likely too hard, for a single sparrow to raise the brood. It is quite likely that at some point she will abandon the nest and leave. But, the advantage there is she is more likely to pair up with another mate and start anew.
I hope everything works out for your sparrow population - best of luck with them. If you have any further questions, please feel free to reply.