The Spotted Sandpiper is widespread along the shores of lakes, ponds, and rivers. It also has the unusual characteristic of a sexual role reversal. The female is larger, sexually aggressive, and polyandrous — that is, it mates with multiple males, each of which is then left to incubate and brood (what it thinks are) its own chicks.
A year ago, I posted a picture, sandpiper piping, of a spotty that was calling and strutting. I didn’t know what was going on; now, I do. It was a female making an aggressive sexual display towards a nearby male. This last week, I watched this interaction repeatedly.
Having arrived at a dock, a female repeatedly harassed two males. They pretty much ignored her. Here, the female performs her courtship display on tiptoes with wings and tail outstretched.
Such a display is directed towards a particular male and accompanied by a weet-weet call.
“No, no, please don’t leave — weet-weet.”
Finally, the two males flew off. This is the female chasing after them.
Hi Alistair
In the many years we’ve spent gazing into Sky Pond, say from our dining room window, we have watched dozens of spotties alighting and lifting off along the edge of the pond; but never have we seen one hop onto our wharf and dance as this female did! Yours is a charmed eye!
Trevor, this was a tough one to figure out in that many references imply that there is no sexual dimorphism among spotties. But, I had watched something along these lines last year and this time, I saw it in spades. Finally, I found a reference at Cornell (https://www.allaboutbirds.org/guide/Spotted_Sandpiper/lifehistory) under Behavior, that mentioned the “larger females” and said:
My observations now made sense.