I contacted via E-mail -the rehabilitator from the
The Wild Bird Fund, Inc.
565 Columbus Avenue
NY, NY
10024
[between 87th and 88th Streets]

Their website says
"The Wild Bird Fund’s mission is to provide medical care and rehabilitation to injured, ill, and orphaned wildlife of New York City and to release them back to the wild. We are a non-profit 501(c)(3) and the only wildlife rehabilitation facility in New York City."

I got a call back from a very nice person there who said they would take the cygnet if I can get it to them, but they themselves do not rescue the animals. She suggested I contact a pigeon rescue group on Yahoo group. I will E-mail them. But the cygnet is quite large-- almost adult size. Would it be dangerous to grab it?
Lately I haven't even seen it on the land.
Do you have any suggestions on how to grab it?
I have attached a photo of the family- taken May 27, 2013, when the cygnets were small. The white cygnet is next to one of the parents.