At 6.15 pm, April 25, 2021, Gordon & Michael Biro observed the Yellow-browed Warbler (or Hume’s Leaf-warbler), feeding at eye-level, in modestly dense creek-side shrubbery, in Shalebank Hollow Park, on the west bank of Mullet Creek, 200 m east of Shalebank cul de sac & 600 m east of the formal pathway near Hwy 403, the last location we were reliably told that the bird had been seen the previous day. The bird was in a loose feeding flock of 10 Ruby-crowned Kinglets, 4 Golden-crowned Kinglets & one Red-breasted Nuthatch. Two Brown Creepers were immediately nearby. We viewed the Warbler for 30 seconds, at a distance of 5 m, then, at 6.20 pm, we spotted it again 50 m further east & watched it for one minute, as close as 4 m away, from just above ground level to 3 m up. We never left the edge of the creek bed & the pathway is fragile to non-existent most of the way. It would be ill-advised for any more than 3 birders at a time to be on this route & this is an advisory that the rocky & slippery footing poses a risk to non Mountain Goats.
Other birds of interest on site, as of 5.30 pm, were Merlin, Hermit Thrush & Northern Waterthrush + a dozen more abundant species. A flock of a half dozen Black-capped Chickadees, seen at 5.30 pm, was no longer present when the Warbler & its entourage were found foraging.
(Ref. Dropped pin) Shalebank Hollow Park is off Folkway Drive, Mississauga.