There is one sure place to find Ruby-throated hummingbirds during fall migration – a jewelweed patch. But the yellow flowered Pale jewelweed Impatiens pallida won’t do, only the bright orange blooms of Spotted jewelweed I.capensis. It’s an ancient relationship, finely tuned over time to suit each partner’s needs.
Though Spotted jewelweed is also attractive to bumblebees, there’s no doubt its flowers have evolved in tandem with hummingbirds. It’s the only North American species of Impatiens that is bird pollinated, but the genus is widely diversified in Africa with a quarter of the 109 species adapted to bat and bird pollination.
The orientation of Spotted jewelweed’s nectar spurs, and its copious production of high sugar nectar make the flowers uniquely attractive to hummers. Most of North America’s bird pollinated flowers – Bee balm, Cardinal flower, Penstemons – bloom during the summer and are not available for fall migration. But the late summer timing of Jewelweed blooms coincides nicely with the movements of a Ruby-throat population much swelled by juveniles.
Fortunately, this little forest with its springs and low ground is great habitat for Spotted jewelweed. Many decades ago I recall much of the bottomlands covered with this weedy annual. But then came deer, whose appetite for the tender foliage reduced many jewelweed patches to ragged, flowerless stubs. So I began to push back with the creation of “deer-free zones” – large natural brush fences often composed of the huge invasive honeysuckle shrubs we’d been cutting down.
One of the largest deer-free jewelweed patches now spans both sides of a long bridge over a wet swale, and has been full of hummingbirds all fall. I stand quietly on the bridge watching them nectar, the feeding activity interspersed by high speed chases, minor skirmishes, and just hanging out on low branches.
They’re moving so fast from flower to flower that it’s hard to get a good picture.
But one young male stayed on a perch preening for several minutes, an activity I have never been privileged to observe before.
As fall migration winds down and the ruby-throats are fewer, I hope that the many who passed through this forest were well replenished for the rest of their long journey.