The kingfisher just sat there on a wire overlooking a small marsh pond. I assumed it was fishing as it sat with head cocked sideways, looking down. But then I noticed a great blue heron wading in the pond directly below the kingfisher. Was he just watching the heron? Had the heron moved into the kingfisher's fishing hole and now it was just waiting for it to leave?

     I was on the south end of Back Bay in a portion of the MacKay Island National Wildlife Refuge. The United States Fish and Wildlife Service has a neat little nature trail around a marsh slough there. I was exploring it for photo opportunities.

     After a walk around the trail, I noticed that the kingfisher had moved to a spot farther down the road over another pond. As I drove by I was surprised to see that it was again perched over the stalking heron!
What is that kingfisher's fascination with that heron, I wondered? Just about the time my aging brain was making the connection, the heron's beak lashed out at a small school of fish and almost simultaneously, the kingfisher plummeted and plunged into the water and emerged with a wriggling fish himself. The kingfisher had simply been following the heron around, taking advantage of its stalking abilities waiting for it to scare up a school of fish from the murky pond!

     It was a type of if not a true symbiotic relationship. The dictionary defines symbiosis as "the intimate living together of two dissimilar organisms in a mutually beneficial relationship". A bee gets nectar and pollen from flowers and, in turn, pollinates the flowers or plant assuring its future survival. This is probably as good an example as any of a symbiotic relationship. I'm not sure the kingfisher-heron scenario is a true symbiotic relationship, since they are not dissimilar organisms, but their relationship was certainly mutually beneficial!
Another example of "mutually beneficial" feeding habits is provided by the snowy egret. This little white egret with the bright yellow feet are great opportunists when it comes to getting a meal with the help of others.

     In spring and fall, the "snowy" will commonly seek out a group of feeding shovelers, the ducks with the spoon-like bills. At times, shovelers will feed in small groups of eight to a dozen or more birds. They'll form a loose circle where they kick with their feet and spin their bodies, first one way then the other, stirring up the bottom mud. With their unique bills, which are equipped with strainers called lamellae, they can sift out tiny crustaceans and other aquatic life as well as seeds and roots of aquatic plants. The snowy egret is well aware of the potential to get a quick and easy meal due to the stirred up bottom. They will drop down to wade alongside or among the shovelers, dancing and jabbing as tidbits of food become dislodged and suspended by the moving, swirling water. 

     Snowy egrets are cosmopolite about who they dine with too. They frequently team up with glossy ibises. The glossy ibis has a big, down-curved bill, which it uses very actively while feeding. It moves quickly with head down, feeding vigorously, moving its bill back and forth like a scythe through aquatic vegetation, stirring up a lot of aquatic life. The snowy kind of tags along taking advantage of what the ibis scares out.

     Of course, the egret has its own technique, which is often mutually beneficial to whatever bird is feeding near it as well. They reach out with their bright yellow feet, and shuffle them vigorously which also dislodges aquatic insects, worms or frogs, and fish out of hiding. I've even seen snowy egrets shadowing barnyard ducks like the Muscovy, feeding on food stirred up by its movements. In this case, the relationship isn't necessarily mutually beneficial, and there are a number of examples where one species gets the benefit out of the efforts or habits of others.

     Mergansers, gulls, and terns have a relationship of this type at certain times of the year. Mergansers will frequently group up to feed also, feeding either single file or two-by-two, diving for fish. One day on Fishhouse Bay in the Department's Hog Island WMA (Surry), I watched as about 15 or 16 hooded mergansers dove and fed on what must have been a large school of small fish. Just above them a number of ring-billed gulls and common terns hovered. From time to time the water in front of, or to the side of the mergansers would erupt with a spray of small fish. The gulls positioned themselves just over the surface plucking out the panicking fish or just swimming alongside the mergansers and grabbing fish attempting to escape. The terns hovered higher above and dove on the fish in typical tern fashion on the fleeing fish. All of this, not unlike the feeding frenzies offered to gulls, terns, and pelicans when a school of bluefish chases menhaden to the surface on Chesapeake Bay.

     If you look hard enough, you'll find other good examples of one species getting a benefit from another. One of the more interesting examples of this was written up in an article in Virginia Wildlife some years back that related how after a heavy snowfall, wild turkey flocks would associate themselves with a herd of deer. The deer had the ability to dig down with sharp hooves to get at acorns and greens under the snow. The turkeys would actually get down under the deer, tickling their bellies, to get at the holes in the snow which gave them access to the acorns and greens.

     Cowbirds will sit on cows and pick ticks off of them. I've even seen starlings sitting on the backs of Chincoteague ponies either picking off flies or ticks, or maybe just to stay warm on a cold morning. Cattle egrets will feed amid a herd of cattle to catch easy meals of locusts, grasshoppers, and other insects stirred up out of the tall grasses by the cattle.

     The next time you rototill the garden or mow the lawn, watch how robins, mockingbirds, and other birds will drop in almost immediately to take advantage of what you uncovered. Gulls commonly follow the plow to feed on grubs and other insects that are turned up.

     There are even some examples of robbery in nature. The regal bald eagle, which is capable of catching its own meal, commonly pilfers from ospreys by harassing them and forcing them to drop their catch. Widgeon and gadwalls will feed among a flock of coots or canvasbacks, and steal morsels of valesneria (widgeon) grass from them as they surface. Widgeons and gadwalls can't dive, so they resort to grabbing off this special treat from those that can. These are just a few examples of how wildlife and their feeding habits are mutually beneficial, another "wonder of nature."