Indeed wading birds are vulnerable directly from this cold but by having their foraging areas frozen over for a significant amount of time. Dabbling ducks-- ditto. And shorebirds-- well, they have been challenged for several days now.
Any insectivores will have a rough time for the next several days unless they were well fattened up by the end of 2017 or now have access to a feeding station with suet, mealworms. etc. Yes, hummingbirds will be very interested in sugar water-- and fortunately they can exist on only nectar for a few days at least-- if they are healthy and have good instincts. Even seed and fruit eaters may be in trouble if they do not have ready access to food and heavy cover.
Frank Hamilton's example is a good one in terms of how to provide extra food for our birds--- as was Ann Maddock's hummer feeder heater set up. And, by the way, there is now a commercial sugar water heater available (go to our NC Hummingbird FB page for details from Dwayne Martin who has been testing it out this week). This was actually developed during the last couple years in the Northwest-- for overwintering Anna's Hummingbirds. But clearly there is a market in the Southeastern US this year as well!
**Also-- by the way-- I have had both coastal as well as inland hummer (2 in Raliegh) hosts JUST attracting a hummingbird to their nectar in the last couple days! So IF you can keep your feeder thawed, be sure to have an eye out: you may get a late season customer!! And let me know right way, of course!
Here on the farm, I just made a fresh batch of suet that I will be crumbling as well as fitting into my cage-wthin-a-cage feeder. I have millet, safflower and sunflower out and just added water to my (simple and inexpensive) heated dog dish-- with a big shell in the middle for easy, safe access. Guess the snow is falling now but not quite making it to the ground in the Sandhills--so far.
Stay warm and safe everyone-- and enjoy the birds!