On the evening of September 4, Mark Vass found one American Golden-Plover at the main pond at Bald Knob.  It was too late in the day for anyone else to expect to get there in time, so I showed up at first light on the morning of September 5 and was happy to find that it was still there.  This marks the sixth or seventh record for American Golden-Plover for this location since 1993.

 

A little after 9 AM, the bird flew from the pond, seemingly unprovoked, and landed on the abundant bare earth near the highway construction site.  I walked up Bald Knob Road a short way to see if I could refind it, and was delighted to find the reason that it had flown from the pond - it had discovered ANOTHER golden-plover!  I watched them flying together a few times, calling, and ultimately splitting up, with the original bird returning to the pond and the second bird appearing to head south along the highway bed.  However, about 45 minutes after that, the second plover returned to the pond and stayed for about five minutes, before being harassed and ultimately chased off by the first plover.  The second plover probably returned to the construction site and was probably still in the area when I left although I could not find it.  I was able to photograph both birds together to document the existence of both, see the second picture below.  This was my second record for this species in Allegheny County.