Science and learning specialist Gabriel Willow is an urban ecologist and tour guide for NYC Audubon, and leads regular Sunday morning bird walks at Wave Hill. He shares here the walk he led on July 14, 2013.
Today’s walk was nice, if a bit hot and humid. We had nine participants, two of whom had never been to Wave Hill before. (They heard about it from me on an Audubon walk.)
We stuck to the Herbert & Hyonja Abrons Woodland, where it was a bit cooler and shadier. Birds were also laying low in this heat, so not surprisingly the only birds in evidence were:
• Herring Gulls, soaring over the river
• American Robins
• Northern Mockingbirds
• Gray Catbirds
• Song Sparrows
• Common Grackles
• American Goldfinches
If there were relatively few birds to see and hear, there were plenty of cool bugs and flowers to check out. There was a particularly fascinating mini-ecosystem of creatures living on the milkweed plants growing in the meadow of wildflowers below Wave Hill House. Milkweed has milky, poisonous sap, which several clever kinds of insects take advantage of: By consuming them, they become distasteful to birds and other predators. Monarch butterflies are the most famous example of this; we didn’t find any of those, but we did find other toxic, milkweed-eating bugs.
The most noticeable were the bright orange oleander aphids that coated the plants, sucking on the sap and secreting a sweet, sticky “honeydew”. This attracts ants, which eat the sweet secretion and in turn protect the aphids from insect predators such as ladybugs. Nonetheless, there were a number of ladybugs lurking about eyeing the aphids, plus the distinctive stalked eggs of lacewings, which will hatch into predaceous larvae known as “aphid lions.” Flies and wasps were also in evidence, attracted to the aphids’ sticky honeydew coating the leaves.
Among the Joe Pye Weed patches (named for Native American healer Joe Pye), there were numerous Black and Tiger Swallowtail butterflies. In the native woodland, we explored aromatic plants—black birch, sweet shrub and sassafras, which are all used to make root beer and other traditional beverages and tonics.
Despite the quiet bird scene, it was nonetheless a fascinating and enjoyable walk!