Ten cygnets are in the process of being born on Hampstead Heath.
Five of the fluffy fledglings made their entrance near the Hampstead No 1 pond on Friday (May 6).
Papa swan is "frantically building a nest" as Mama gives birth to her brood.
Louisa Green, a volunteer for the Swan Sanctuary said: "The eggs are hatching. This morning five had hatched and there are 10 eggs so she's not done yet.
"Mamma's doing really well, I don't know how she does it but she copes really well with the public watching her.
"They are all on the nest at the moment.
"She won't take them on the water until they are all hatched.
"Soon they'll be swimming and we'll have them walking between the ponds - that's when I'll get really anxious."
She said Papa swan was well and "getting ready for all ten".
"He's frantically breaking down reeds to build up the nest. He's staying by her side. He does this every year; when there's action he doesn't stray very far.
"It's very exciting."
Coriander Stuttard watched some cygnets being born to Mamma and Papa swan on Friday saying it was "very special".
"I walk and run every day but there have been a few people who have been regularly checking and there was talk of when it might be so we've been expecting it.
"I knew something was happening the day before because the female's behaviour really changed - she seemed quite agitated, standing up and turning a quarter turn on her nest quite regularly and she also appeared to be 'chatting' to the eggs."
"The male who has been mostly seen in the middle of the pond came much closer to her."
She added: "It was quite difficult to see how many of them there were. She was keeping them under her wing still sitting on her eggs.
"It was really quite dramatic to see when they emerged. It's very special, it's amazing and awe-inspiring to see nature doing its work."
In 2020 a brood of 10 cygnets hatched.
Coriander said regular locals were telling a tame resident heron to go away fearful its got his eye on the young swans.
She also urged dog owners to keep their pets on a lead around the area.
She added: "Don't go too close to the swans either now or as they get older - the male swan's job for his family is to defend...."
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