Here is an interesting bit of information about this species that I found on Wikipedia:
"Spotted Sandpipers nest on the ground. During each summer breeding season, females may mate with, and lay clutches for, more than one male, leaving incubation to them. This is called polyandry. Male parents of first clutches may father chicks in later male's clutchs, probably due to sperm storage within female reproductive tracts, which is common in birds. Females that fail to find additional mates usually help incubate and rear chicks. "Prior to incubation, blood plasma concentrations of testosterone and dihydrotestosterone are substantially higher in males than in females" and these levels plummet 25-fold in males as incubation proceeds. Additionally, mated females have testosterone concentrations that are 7 times higher than those of unmated females."
There is always something new to learn about our world and the creatures that occupy it.