Port Mahon, Delaware The shorebirds come mid to late May every year to feed on Horseshoe crab eggs left behind. This is the final stop for Red Knots, Ruddy Turnstones, Dunlin, Sanderlings, Least and Semi-palmated Sandpipers and Short-billed Dowitchers. The 2016 season has been unseasonably cold and wet causing the waters to be cooler than usual. Horseshoe crabs need a steady 60 degrees water temperature to encourage them to come enmass onto the beaches of Delaware and New Jersey on the Delaware shore. To date (5/20/2016) the horseshoe crabs have yet to come in, causing the birds to forage on what they can find.