Mystery of the Grackles' roost trees

For the last week I've continued to monitor the huge numbers of grackles roosting for the night in the trees surrounding the Pulitzer Fountain -- the fountain in front of the Plaza Hotel.

As the days get shorter, the grackles arrive earlier. On Monday they were already flying in at 5:30 pm . By 5:45 they were streaming in in groups of twenty or fifty. A cloud of about 300 starlings flew in around 5:50. By 6:15pm I'd say there were easily 1000 birds in the 10 Linden trees that form a half-circle around the fountain.trees.

Early this morning Donna Browne, erstwhile chronicler of the Trump-Parc hawk family, checked out the Grackle roost to see when they fly out. She reports that the birds began to leave at 6:37 a.m.

The mystery I refer to in the headline above is hidden in a poem about the Pulitzer Fountain that was sent to me by Mary Birchard, a Central Park birder. But it will not make sense unless I mention another detail about the Pulitzer Fountain that had not seemed particularly relevant earlier: the fountain is topped by a bronze statue of a nude woman. She is leaning over in a posture reminiscent of the popular painting entitled September Morn. Here's E.B. White's poem:

THE LADY IS COLD
(Intimations at Fifty-eight Street)

The fountain is dry at the Plaza,
The sycamore trees go bare;
The ivy is sere and it has a
Resigned and immutable air.

The lady is cold at the fountain,
The sitter is cold on the ledge,
The Plaza is gaunt as a mountain,
The air is a knife with as edge.

But what is this sniff and this twitter,
And what is the pluck at my vest ?
What gleam in the eye of the sitter,
What lamb of a cloud in the west ?

The earth is but held in solution,
And March will release before long
The lady in brazen ablution,
The trees and the fountain in song !

Here is the mystery: E.B. White describes the trees as Sycamores. Yet the ten trees now surrounding the fountain are Lindens. Could the famous writer, a resident of a farm in rural Maine and the author of a book filled with natural science details [Charlotte's Web] have mistaken a Linden for a sycamore? Impossible.

What happened to the sycamores E.B.White mentions in his poem? I'm determined to find out, and I'll let you know what I discover.
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