Framed by the sweeping curve of the Bay Bridge’s western end, the Chesapeake’s blue-black waters stretched before us like a velvet display cloth. Twenty yards off shore, the ducks looked like living jewels on this brilliantly sunny afternoon.

As we watched, the small flock of tiny ducks kept disappearing into the cold, black waters, only to reappear several seconds later, like corks bobbing to the surface. Each duck stayed on the surface for a few more seconds before it would take a small forward leap and dive again in search of food.

The males were a striking pattern of black and white. The body was pure white. The folded wings appeared as a dark line above the body. In the sharp, clear air, the head was an iridescent blend of royal purple and deep forest green. The entire back of the head was a huge white patch that matched its body. Through the binoculars, we could see the duck’s stubby blue-gray bill.

These were buffleheads (Bucephela albeola), the smallest ducks in North America. Just a little more than a foot long from bill to tail, these energetic ducks typically weigh about 12–13 ounces. Mallards, in comparison, are just less than 2 feet long and weigh about 2.5 pounds.

The males in their breeding plumage had captured our eyes, but there were an equal number of females in the flock. With her gray-brown body and dark wings, each female was a drab companion. The head was dark and the white patch on her head was limited to a modest oval patch behind and below her eye.

Buffleheads are diving ducks. As we witnessed, they squeeze the air out from between their feathers before making a leaping dive in search of food. They eat small aquatic invertebrates, including crustaceans like crabs and mollusks like clams. The feeding behavior we were watching was typical.

They stay on the surface for about 10–15 seconds and then dive for an equal period, repeating the process as long as food is plentiful.

Judging by their constant dives, they had clearly found a great feeding location.

Male buffleheads are in breeding plumage from October through May. Unlike other ducks, buffleheads form monogamous pair bonds. They can live for more than 15 years, so the pairs we witnessed on the Bay may have been together for years.

Breeding grounds for buffleheads are forested areas with nearby ponds or lakes from Ontario to Alaska.

The birds build nests in tree cavities — almost always in abandoned northern flicker nests. Birders have begun to supplement these natural sites with bird boxes similar to the ones used with great success for wood ducks.

Because the natural nesting sites started out as flicker nests, bufflehead breeding distribution is an exact subset of flicker breeding territory.

During the late fall, buffleheads head south and spread out across the United States. They can be found on bays and lakes in small flocks. The birds skip the Central Plains and Appalachia, but can be found anywhere else where appropriate habitat exists.

They prefer coastal bays, and the Chesapeake is among their favorite wintering territories. Buffleheads’ winter range extends into Mexico and Cuba.

Our viewing pleasure was finally interrupted by a power boat heading down the Bay. The flock took off as the boat approached, running a few frantic steps on the surface of the water before becoming airborne. The beating wings were a blur as the birds rocked back-and-forth in a frenzied flight, just above the surface. The males have a big white panel on their extended wings, but the patch was impossible to distinguish clearly with the ducks in rapid retreat.

With a little luck, we will have more chances to see these tiny ducks in action. Their migration to wintering waters ends in December. They would be here in the Chesapeake for a few more months before they headed back to Canada as part of their timeless breeding ritual.

Few birds are as reliant as buffleheads on the health of another avian species, in this case, the northern flicker. But this is a dependency that seems to be working. Buffleheads are relatively abundant and their population appears to be growing.

As I considered this avian oddity, I thought about how some people believe they succeed solely because of their native talents and hard work. I know that’s an illusion. Somewhere there is a northern flicker in everyone’s life, perhaps not immediately seen, but there nonetheless.

I sat on the dock, my surgically repaired legs stretched in front of me. I couldn’t get up on my own. My dependency was as profound as that of the bufflehead’s reliance on flicker nesting holes.

I looked up at the extended hands of my wife. As she helped me to my feet, I found such reliance not only necessary but also infinitely more satisfying than illusions of independence.