I’m currently volunteering at a wildlife rehab centre in Scotland. Yesterday some of the staff went on a rescue of a family of swans - mum and half a dozen newly hatched cygnets. Included in the rescue was one egg that had internally pipped but not yet starred.

On arrival at the centre one staff member decided that the egg needed to be assisted to hatch. Can you please answer or confirm the following questions:

1- How long does it normally take for a cygnet to hatch? I’ve worked with penguin eggs and know that it can take up to 48 hours.

2- At what point should you intervene - again, with the penguin eggs we did not interfere until after 48 hours, when if the chick was having trouble we assisted by carefully removing a small portion of the outer hard shell only, being cautious not to disturb the inner membrane and damage any blood vessels

The egg is currently in a brooder and we’re trying to keep the humidity up so that the chick doesn't dehydrate - however knowing the exact degree of humidity is difficult without a hygrometer. In my view staff interfered with the hatch process way too early, since there was no sign of external pipping.

Any information or assistance most gratefully received.

Sincerely,
Fran