-once at their breeding territory in the wet Siberian tundra, the male mates with more than one female; more: ( http://www.nhptv.org/Natureworks/sharptailedsandpiper.htm )

It would be interesting to know if they possess the same endurance as the Bar-tailed Godwit during migration as the travel the same distance?

-this doesn't answer your question but thought that this site was particularly interesting: ( http://www.abc.net.au/wing/community/learningbirdinfo.htm )

-looks like the same people that were involved in the Bar-tailed Godwits, were also looking at the Sharp-tailed Sandpiper; apparently we should be seeing results that would answer your question; ( http://www.lu.se/o.o.i.s?id=15058 )