Ruby-throated Hummingbirds (Archilochus colubris) nest throughout eastern North America, but in both the first (1988) and second (2008) Atlas of Breeding Birds in New York State, none were found to be breeding in NYC. (As the City Birder, who found this nest, notes: it’s certainly possible that previous nesting was just missed because of the tininess of both the birds and the nests.) That changed last year when one (the males do not stick around) nested in Prospect Park. This year, in a different location, there’s another.
These hummingbirds typically make their nests of thistle and dandelion down held together with spider silk and/or pine resin. (It sounds like a magic spell.) They attach pieces of lichen and/or moss to the exterior, probably as camouflage. A clutch is 1-3 eggs; note how (relatively) tall the nest is, making for a deep, narrow pocket for the eggs. Lightweight spider silk, one of the strongest materials, is also amazingly stretchy: this nest will expand with the newborns as they grow.
Little thrill when I found an empty hummingbird nest in crape myrtle last fall. This year for the 5th year I’ve had chimney swifts in my chimney. I can’t see top of chimney, but I can hear babies chirping while in my den. Drives dog nuts.