I don't have to tell you what kind of bird this is. Adult Bald Eagles are massive raptors with wing spans between 6 and 7 feet. In flight, their brown bodies can appear almost black, but their head and tail feathers are a clean white. What you may not know, is that Bald Eagles don't start out looking like this. According to various sources, it takes at least 4 years for Bald Eagles to obtain full adult plumage.
Immature birds have variably mottled wings and lack the distinctive white head and tail of adults. 1st-year birds (like above) have dark bellies with obvious white wing pits. 2nd-year birds (below) have lighter bellies and dark heads. 3rd-year birds (not pictured) are similar, but typically show more white in the head.
The 4th-year bird below shows limited white wings spots, and a mostly white tail framed with brown.
Feather color aside, immature Bald Eagles are similar in structure and size to their parents and show the same orange legs and large, hooked bills.
Note: The ages of the above birds are my best guesses -- if you have a different opinion of any of these birds, I'd love to hear it. The birds were photographed in mid-February in Bath, Maine.
Here in southern Maine, I frequently encounter stands of Scotch Pine (Pinus sylvestris). This conifer is native to northern Europe but has been planted throughout New England. Scotch Pine has two short (~2") needles per bundle. Look closely, and you'll notice the needles twist along their length. Red Pine also has two needles per bundle, but they are longer (~5") and straight. Below are some photos of Scotch Pine. For more info, including photos of the tree's distinctive bark, visit the Pinus sylvestris profile at GoBotany.
Common Slipper Shells (Crepidula fornicata) can be found along much of the Atlantic coast of the US, and, though small (typically under 2" long), they are recognized easily by the light plate that covers roughly half of the shell's underside. I've read that children (and playful adults) will float these gastropod shells like little boats in tide pools.
The same local spot where I've been observing Tinder Conk and Birch Polypore is also home to several Snowshoe Hares (Lepus americanus). I've yet to see a hare here in the flesh, but I've seen plenty of evidence of their passing. From their round pebble poops, to nipped twigs and well-worn pathways, these camouflaged lagomorphs leave their marks on a snowy landscape.
When moving through open areas, Snowshoe Hares bound, with their two front feet registering staggered behind their larger side-by-side hind feet. The photos above show the pattern in soft snow. On packed snow, individual toe and palm pads may be visible (see below). The trail widths I measured were between 7 and 8 inches. Eastern Cottontails leave similar track patterns, but their hind feet and trail widths (<5") are not as wide.