Rapscallion and Reindeer Moss

Somebody her along Cape Cod Bay in Eastham owns a little putt-putt of a boat called the Rapscallion.  It's moored a short sandy walk from the cottage I'm renting for the month of September.  At low tide--my favorite time, because I can walk out forever on the tidal flats, watching the birds and being squirted by clams--Rapscallion lolls on the flats like this:

Today, though, when I took my morning walk with the dogs, the tide was just past high, and for the first time I saw Rapscallion riding the water, bobbing and turning on its mooring:

Having thus illustrated the power of the tide, I feel obligated to say something profound about it.  Unfortunately, I can't think of anything that isn't a cliche. Maybe my imagination is on vacation.  So I'll let this little house, perched over the beach where Rapscallion floats at high tide, make that statement for me:

Along the way to the beach, as the dogs snuffled along under the pitch pines and oaks, I saw lots of this kind of moss:

This is reindeer moss, and I understand from a website called Cape Cod Coastal Ecology that it "prefers open areas near pine woodlands. It often grows in large colonies, though single clumps can also be found. This lichen is a major part of open, sandy areas surrounded by pitch pines. It is often one of the first colonizers in forest succession and can absorb the needed water and nutrients from the air. It is known for its longevity and can survive for many decades...." and that it "is an environmental indicator for air quality. Their presence suggests low concentrations of atmospheric pollutants such as sulfur dioxide."

http://capecodcoastalecology.net/home.html

I'm glad that the dogs and I are breathing good air here.  As if there could be any doubt. 

While heading back to the house after my beach walk, I picked up this egg shell from the grass and moss beside the road:

It's about an inch long--on the big side, for a bird's egg.  What kind is it?  The birds whose calls I hear most often around here are chickadees and crows.  This egg is far too big to have been laid by a tiny chickadee, so I would guess it's a crow's egg...  except that Wikipedia tells me that the egg of the common crow, corvus brachyrhynchos, is about an inch and a half long, and looks like this:

So, wrong color and wrong size for a crow...but what is it?  Another mystery to solve.