This dense mess of short twigs is some kind of witch's broom. Something has caused the tree to wig out. Iowa State's cyclonic extension service explains:
"A number of stresses, both biological and environmental, can lead to the formation of brooms. Organisms such as fungi, phytoplasmas (bacterial-like organisms), mites, aphids, and mistletoe plants can cause abnormal growth when they attack a host tree. Environmental stresses that injure the growing points of branches can also trigger the formation of brooms. Some brooms appear to be caused by genetic mutations in the buds of the branches. Unlike brooms caused by living organisms, there is usually just one broom per tree when the cause is a genetic mutation."
There were two in this tree, which is out at Jamaica Bay.