Wildlife Observations: Light Migration
I look forward to fall for the chance to watch the southbound migration of warblers leaving the boreal forests of Canada for Central and South America. Certain patterns are evident. The American redstarts and black-and-white warblers are generally the first to come through, often starting in mid-August, and yellow-rumped warblers close out the migration season in late fall.
Warblers ride cold fronts as they move south. They migrate at night, then land to eat in the early morning, settling in for a day of sleep. So early morning either on the day, or the day after, there’s been a drop in temperature is the time to be on the lookout.
But by my anecdotal observation, it’s been slim pickings so far this season. The first notice of a warbler sighting I received was from Julie Ellis of Swarthmore, who observed a male American redstart in her yard on September 10. On September 14, Pete Prown of Rose Valley noted ovenbirds and “lots” of yellow warblers in Rose Valley and the Tyler Arboretum. The “Birdcast” migration tracking tool developed by the Cornell Lab of Ornithology predicted that approximately 53,400 migrating birds would fly over the Philadelphia area on Monday, September 14 (in contrast to only around 3,000 birds the prior evening). So on Tuesday morning, September 15, I sanguinely set out to the Saul Wildlife Sanctuary in Rose Valley – where I observed merely two female common yellowthroats.
As for other taxonomic classifications, a bald eagle flew dramatically low over my Swarthmore backyard on September 5, and Molly Scott observed one in the same location on September 17. In Mid-August, Susan Smythe and I both heard repeated eastern screech owl calls near the intersection of Park, Harvard, and South Princeton avenues at dusk. Pete Prown observed great crested flycatchers, a hairy woodpecker, eastern wood pewees, and Carolina wrens in Rose Valley and the Tyler Arboretum. Ingrid Rosenback submitted a photograph of a Cooper’s hawk perched on a fence at her Bryn Mawr Avenue property. And Susan Smythe submitted a photo of a bobwhite quail on the Swarthmore College campus.
Anthony Addison of Swarthmore submitted a photograph of a small wasp that appeared to be in the process of slaying or consuming a spotted lantern fly! And Julie Ellis submitted a photograph — taken by her husband, Andy Hoffman — of a hornet eating a praying mantis.
Here’s hoping for a more abundant warbler migration over the next few weeks. In the meantime, please visit the Swarthmorean’s website for additional photographs. And please continue to send your observations and photographs below.
You can submit your wildlife sightings below.